Blasta/blasta.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""

TODO

* Delete cookie if session does not match

* Delete entry/tag/jid combination row upon removal of a tag.

"""

import asyncio
from asyncio import Lock
from datetime import datetime
from fastapi import Cookie, FastAPI, File, Form, HTTPException, Request, Response, UploadFile
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse, HTMLResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
import hashlib
import json
import logging
from os import mkdir
from os.path import getsize, exists
import random
import slixmpp
from slixmpp import ClientXMPP
from slixmpp.exceptions import IqError, IqTimeout
import slixmpp.plugins.xep_0060.stanza.pubsub as pubsub
import slixmpp.plugins.xep_0059.rsm as rsm
from sqlite3 import connect, Error, IntegrityError
from starlette.responses import RedirectResponse
import sys
import time
import tomli_w
from typing import Optional
import urllib.parse
import uvicorn
import webbrowser
import xml.etree.ElementTree as ET


try:
    import tomllib
except:
    import tomli as tomllib

DBLOCK = Lock()

class Data:

    def cache_items_and_tags(entries, jid, tag=None):
        """Create a cache file of node items and tags."""
        item_ids = []
        tags = {}
        for entry in entries:
            entry_tags = entry['tags']
            entry_url_hash = entry['url_hash']
            tags_to_include = []
            if tag:
                if tag in entry_tags:
                    item_ids.append(entry_url_hash)
                    tags_to_include += entry_tags
                    for tag_to_include in tags_to_include:
                        tags[tag_to_include] = tags[tag_to_include]+1 if tag_to_include in tags else 1
            else:
                item_ids.append(entry_url_hash)
                tags_to_include += entry_tags
                for tag_to_include in tags_to_include:
                    tags[tag_to_include] = tags[tag_to_include]+1 if tag_to_include in tags else 1
        if tags:
            tags = dict(sorted(tags.items(), key=lambda item: (-item[1], item[0])))
            tags = dict(list(tags.items())[:30])
            if tag: del tags[tag]
        if item_ids:
            directory = 'data/{}/'.format(jid)
            if not exists(directory):
                mkdir(directory)
            if tag:
                filename = 'data/{}/{}.toml'.format(jid, tag)
            # Add support for search query
            #if tag:
            #    filename = 'data/{}/query:{}.toml'.format(jid, query)
            #if tag:
            #    filename = 'data/{}/tag:{}.toml'.format(jid, tag)
            else:
                filename = 'data/{}.toml'.format(jid)
            data = {
                'item_ids' : item_ids,
                'tags' : tags}
            Data.save_to_toml(filename, data)

    def extract_iq_items(iq, jabber_id):
        iq_items = iq['pubsub']['items']
        entries = []
        name = jabber_id.split('@')[0]
        for iq_item in iq_items:
            item_payload = iq_item['payload']
            entry = Syndication.extract_items(item_payload)
            entries.append(entry)
        # TODO Handle this with XEP-0059 (reverse: bool), instead of reversing it.
        entries.reverse()
        return entries

    def extract_iq_items_extra(iq, jabber_id, limit=None):
        iq_items = iq['pubsub']['items']
        entries = []
        name = jabber_id.split('@')[0]
        for iq_item in iq_items:
            item_payload = iq_item['payload']
            entry = Syndication.extract_items(item_payload, limit)
            url_hash = Utilities.hash_url_to_md5(entry['link'])
            iq_item_id = iq_item['id']
            if iq_item_id != url_hash:
                logging.error('Item ID does not match MD5. id: {} hash: {}'.format(iq_item_id, url_hash))
                logging.warn('Item ID does not match MD5. id: {} hash: {}'.format(iq_item_id, url_hash))
            db_file = 'main.sqlite'
            instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
            if entry:
                entry['instances'] = instances or 0
                entry['jid'] = jabber_id
                entry['name'] = name
                entry['url_hash'] = url_hash
                entries.append(entry)
        # TODO Handle this with XEP-0059 (reverse: bool), instead of reversing it.
        entries.reverse()
        result = entries
        return result

    def open_file_toml(filename: str) -> dict:
        with open(filename, mode="rb") as fn:
            data = tomllib.load(fn)
            return data

    def organize_tags(tags):
        tags_organized = []
        tags = tags.split(',')
        #tags = sorted(set(tags))
        for tag in tags:
            if tag:
                tag = tag.lower().strip()
                if tag not in tags_organized:
                    tags_organized.append(tag)
        return sorted(tags_organized)

    def remove_item_from_cache(jabber_id, node, url_hash):
        filename_items = 'items/' + jabber_id + '.toml'
        entries_cache = Data.open_file_toml(filename_items)
        if node in entries_cache:
            entries_cache_node = entries_cache[node]
            for entry_cache in entries_cache_node:
                if entry_cache['url_hash'] == url_hash:
                    entry_cache_index = entries_cache_node.index(entry_cache)
                    del entries_cache_node[entry_cache_index]
                    break
            data_items = entries_cache
            Data.save_to_toml(filename_items, data_items)

    def save_to_json(filename: str, data) -> None:
        with open(filename, 'w') as f:
            json.dump(data, f)

    def save_to_toml(filename: str, data: dict) -> None:
        with open(filename, 'w') as fn:
            data_as_string = tomli_w.dumps(data)
            fn.write(data_as_string)

    async def update_cache_and_database(xmpp_instance, jabber_id: str, node_type: str, node_id: str):
        # Download identifiers of node items.
        iq = await XmppPubsub.get_node_item_ids(xmpp_instance, jabber_id, node_id)
        if isinstance(iq, slixmpp.stanza.iq.Iq):
            iq_items_remote = iq['disco_items']

            # Cache a list of identifiers of node items to a file.
            iq_items_remote_name = []
            for iq_item_remote in iq_items_remote:
                iq_item_remote_name = iq_item_remote['name']
                iq_items_remote_name.append(iq_item_remote_name)

            #data_item_ids = {'iq_items' : iq_items_remote_name}
            #filename_item_ids = 'item_ids/' + jabber_id + '.toml'
            #Data.save_to_toml(filename_item_ids, data_item_ids)

            filename_items = 'items/' + jabber_id + '.toml'
            if not exists(filename_items) or getsize(filename_items) == 13:
                iq = await XmppPubsub.get_node_items(xmpp_instance, jabber_id, node_id)
                if isinstance(iq, slixmpp.stanza.iq.Iq):
                    entries_cache_node = Data.extract_iq_items_extra(iq, jabber_id)
                    data_items = {node_type : entries_cache_node}
                    Data.save_to_toml(filename_items, data_items)
                else:
                    print('iq problem')
                    breakpoint()
                    print('iq problem')
            else:
                entries_cache = Data.open_file_toml(filename_items)
                if not node_type in entries_cache: return ['error', 'Directory "{}" is empty'. format(node_type)]
                entries_cache_node = entries_cache[node_type]
                db_file = 'main.sqlite'

                # Check whether items still exist on node
                for entry in entries_cache_node:
                    iq_item_remote_exist = False
                    url_hash = None
                    for url_hash in iq_items_remote_name:
                        if url_hash == entry['url_hash']:
                            iq_item_remote_exist = True
                            break
                    if url_hash and not iq_item_remote_exist:
                        await SQLite.delete_combination_row_by_jid_and_url_hash(
                            db_file, url_hash, jabber_id)
                        entry_index = entries_cache_node.index(entry)
                        del entries_cache_node[entry_index]

                # Check for new items on node
                entries_cache_node_new = []
                for url_hash in iq_items_remote_name:
                    iq_item_local_exist = False
                    for entry in entries_cache_node:
                        if url_hash == entry['url_hash']:
                            iq_item_local_exist = True
                            break
                    if not iq_item_local_exist:
                        iq = await XmppPubsub.get_node_item(
                            xmpp_instance, jabber_id, node_id, url_hash)
                        if isinstance(iq, slixmpp.stanza.iq.Iq):
                            entries_iq = Data.extract_iq_items_extra(iq, jabber_id)
                            entries_cache_node_new += entries_iq
                        else:
                            print('iq problem')
                            breakpoint()
                            print('iq problem')

                entries_cache_node += entries_cache_node_new

                if node_type == 'public':
                    # Fast (low I/O)
                    if not SQLite.get_jid_id_by_jid(db_file, jabber_id):
                        await SQLite.set_jid(db_file, jabber_id)
                        #await SQLite.add_new_entries(db_file, entries)
                    await SQLite.add_tags(db_file, entries_cache_node)
                    # Slow (high I/O)
                    for entry in entries_cache_node:
                        url_hash = entry['url_hash']
                        if not SQLite.get_entry_id_by_url_hash(db_file, url_hash):
                            await SQLite.add_new_entries(db_file, entries_cache_node)
                            await SQLite.associate_entries_tags_jids(db_file, entry)
                        #elif not SQLite.is_jid_associated_with_url_hash(db_file, jabber_id, url_hash):
                        #    await SQLite.associate_entries_tags_jids(db_file, entry)
                        else:
                            await SQLite.associate_entries_tags_jids(db_file, entry)

                data_items = entries_cache
                Data.save_to_toml(filename_items, data_items)
                return ['fine', iq] # TODO Remove this line
        else:
            return ['error', iq]

class HttpInstance:
    def __init__(self, accounts, sessions):

        self.app = FastAPI()
        templates = Jinja2Templates(directory='template')

        self.app.mount('/data', StaticFiles(directory='data'), name='data')
        self.app.mount('/export', StaticFiles(directory='export'), name='export')
        self.app.mount('/graphic', StaticFiles(directory='graphic'), name='graphic')
        self.app.mount('/script', StaticFiles(directory='script'), name='script')
        self.app.mount('/stylesheet', StaticFiles(directory='stylesheet'), name='stylesheet')

        filename_configuration = 'configuration.toml'
        data = Data.open_file_toml(filename_configuration)

        contacts = data['contacts']
        contact_email = contacts['email']
        contact_irc_channel = contacts['irc_channel']
        contact_irc_server = contacts['irc_server']
        contact_mix = contacts['mix']
        contact_muc = contacts['muc']
        contact_xmpp = contacts['xmpp']

        settings = data['settings']

        jabber_id_pubsub = settings['pubsub']
        journal = settings['journal']

        node_id_public = settings['node_id']
        node_title_public = settings['node_title']
        node_subtitle_public = settings['node_subtitle']

        node_id_private = settings['node_id_private']
        node_title_private = settings['node_title_private']
        node_subtitle_private = settings['node_subtitle_private']

        node_id_read = settings['node_id_read']
        node_title_read = settings['node_title_read']
        node_subtitle_read = settings['node_subtitle_read']

        nodes = {
            'public' : {
                'name' : node_id_public,
                'title' : node_title_public,
                'subtitle' : node_subtitle_public,
                'access_model' : 'presence'},
            'private' : {
                'name' : node_id_private,
                'title' : node_title_private,
                'subtitle' : node_subtitle_private,
                'access_model' : 'whitelist'},
            'read' : {
                'name' : node_id_read,
                'title' : node_title_read,
                'subtitle' : node_subtitle_read,
                'access_model' : 'whitelist'}
                }

        origins = [
            "http://localhost",
            "http://localhost:8080",
            "http://127.0.0.1",
            "http://127.0.0.1:8080",
        ]

        self.app.add_middleware(
            CORSMiddleware,
            allow_origins=origins,
            allow_credentials=True,
            allow_methods=["*"],
            allow_headers=["*"],
        )

        # This is workaround for setting a "cookie" issue
        # It appears that there is a problem to set or send a "cookie" when a template is returned.
        @self.app.middleware('http')
        async def middleware_handler(request: Request, call_next):

            # Handle URL query
            if request.url.path != '/save':
                param_url = request.query_params.get('url', '') or None
                param_hash = request.query_params.get('hash', '') or None
                if param_hash:
                    return RedirectResponse(url='/url/' + param_hash)
                if param_url:
                    url_hash = Utilities.hash_url_to_md5(param_url)
                    return RedirectResponse(url='/url/' + url_hash)

            response = await call_next(request)
            jabber_id = session_key = None

            infoo = {
                'accounts' : accounts,
                'sessions' : sessions
            }
            print(infoo)

            # Handle credentials (i.e. so called "cookies")
            if request.url.path == '/disconnect':
                jid = request.cookies.get('jabber_id')
                if jid in accounts: del accounts[jid]
                if jid in sessions: del sessions[jid]
                response.delete_cookie('session_key')
                response.delete_cookie('jabber_id')
            else:
                try:
                    # Access the variable from the request state
                    jabber_id = request.app.state.jabber_id
                except Exception as e:
                    print(request.cookies.get('jabber_id'))
                    print(e)
                    pass
                try:
                    # Access the variable from the request state
                    session_key = request.app.state.session_key
                except Exception as e:
                    print(request.cookies.get('session_key'))
                    print(e)
                    pass
                if jabber_id and session_key:
                    print(['Establishing a sessiong for:', jabber_id, session_key])
                    response.set_cookie(key='jabber_id', value=jabber_id)
                    response.set_cookie(key='session_key', value=session_key)
#                    del request.app.state.jabber_id
#                    del request.app.state.session_key
                    request.app.state.jabber_id = request.app.state.session_key = None
            return response

#                response.set_cookie(key='session', value=str(jid) + '/' + str(session_key))
#                response.set_cookie(key='session',
#                                    value=jid + '/' + session_key,
#                                    expires=datetime.now().replace(tzinfo=timezone.utc) + timedelta(days=30),
#                                    max_age=3600,
#                                    domain='localhost',
#                                    path='/',
#                                    secure=True,
#                                    httponly=False, # True
#                                    samesite='lax')

        @self.app.exception_handler(404)
        def not_found_exception_handler(request: Request, exc: HTTPException):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            message = 'Blasta system message » Not Found.'
            description = 'Not found (404)'
            path = 'error'
            return result_post(request, jabber_id, description, message, path)

        @self.app.exception_handler(405)
        def not_allowed_exception_handler(request: Request, exc: HTTPException):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            message = 'Blasta system message » Method Not Allowed.'
            description = 'Not allowed (405)'
            path = 'error'
            return result_post(request, jabber_id, description, message, path)

        @self.app.exception_handler(500)
        def internal_error__exception_handler(request: Request, exc: HTTPException):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            message = 'Blasta system message » Internal Server Error.'
            description = 'Internal error (500)'
            path = 'error'
            return result_post(request, jabber_id, description, message, path)

        @self.app.get('/connect')
        def connect_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                response = RedirectResponse(url='/jid/' + jabber_id)
            else:
                template_file = 'connect.xhtml'
                template_dict = {
                    'request' : request,
                    'journal' : journal}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/contact')
        def contact_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'contact.xhtml'
            template_dict = {
                'contact_email' : contact_email,
                'contact_irc_channel' : contact_irc_channel,
                'contact_irc_server' : contact_irc_server,
                'contact_mix' : contact_mix,
                'contact_muc' : contact_muc,
                'contact_xmpp' : contact_xmpp,
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/disconnect')
        def disconnect_get(request: Request,
                           response: Response,
                           jabber_id: str = Cookie(None),
                           session_key: str = Cookie(None)):
#            response.set_cookie(max_age=0, value='', key='jabber_id')
#            response.set_cookie(max_age=0, value='', key='session_key')
            response = RedirectResponse(url='/')
            response.delete_cookie('session_key')
            response.delete_cookie('jabber_id')
            return response

        @self.app.get('/favicon.ico', include_in_schema=False)
        def favicon_get():
            return FileResponse('graphic/blasta.ico')

        @self.app.get('/help')
        def help_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'help.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about')
        def help_about_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'about.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/folksonomy')
        def help_about_folksonomies_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'folksonomy.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/ideas')
        def help_about_ideas_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            protocol = request.url.scheme
            hostname = request.url.hostname + ':' + str(request.url.port)
            origin = protocol + '://' + hostname
            template_file = 'ideas.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'origin' : origin}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/philosophy')
        def help_about_philosophy_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'philosophy.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/projects')
        def help_about_projects_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'projects.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/software')
        def help_about_software_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'software.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/thanks')
        def help_about_thanks_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'thanks.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/xmpp')
        def help_about_xmpp_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'xmpp.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/xmpp/atomsub')
        def help_about_xmpp_atomsub_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'atomsub.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/xmpp/libervia')
        def help_about_xmpp_libervia_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'libervia.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/xmpp/movim')
        def help_about_xmpp_movim_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'movim.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/about/xmpp/pubsub')
        def help_about_xmpp_pubsub_get(request: Request):
            date_now_iso = datetime.now().isoformat()
            date_now_readable = Utilities.convert_iso8601_to_readable(date_now_iso)
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'pubsub.xhtml'
            template_dict = {
                'request' : request,
                'date_now_iso' : date_now_iso,
                'date_now_readable' : date_now_readable,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/feeds')
        def help_about_feeds_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'feeds.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/questions')
        def help_questions_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'questions.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/syndication')
        def help_syndication_get(request: Request):
            hostname = request.url.hostname + ':' + str(request.url.port)
            protocol = request.url.scheme
            origin = protocol + '://' + hostname
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'syndication.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'origin' : origin,
                'pubsub_jid' : jabber_id_pubsub}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/help/utilities')
        def help_utilities_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            hostname = request.url.hostname
            protocol = request.url.scheme
            hostname = request.url.netloc
            origin = protocol + '://' + hostname
            bookmarklet = 'location.href=`' + origin + '/save?url=${encodeURIComponent(window.location.href)}&title=${encodeURIComponent(document.title)}`;'
            template_file = 'utilities.xhtml'
            template_dict = {
                'request' : request,
                'bookmarklet' : bookmarklet,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/jid', response_class=HTMLResponse)
        @self.app.post('/jid')
        async def jid_get(request: Request, response : Response):
            node_type = 'public'
            path = 'jid'
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                node_id = nodes[node_type]['name']
                result, reason = await Data.update_cache_and_database(xmpp_instance, jabber_id, node_type, node_id)
                if result == 'error':
                    message = 'XMPP system message » {}.'.format(reason)
                    description = 'IQ Error'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                else:
                    response = await jid_main_get(request, node_type, path, jid=jabber_id)
                    return response
            else:
                description = 'An XMPP account is required'
                message = 'Blasta system message » Please connect with your XMPP account to view this directory.'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        @self.app.get('/jid/{jid}')
        @self.app.post('/jid/{jid}')
        async def jid_jid_get(request: Request, response : Response, jid):
            response = await jid_main_get(request, node_type='public', path='jid', jid=jid)
            return response

        async def jid_main_get(request: Request, node_type=None, path=None, jid=None):
            ask = invite = name = origin = start = ''
#           pubsub_jid = syndicate = jid
#           message = 'Find and share bookmarks with family and friends!'
#           description = 'Bookmarks of {}'.format(jid)
            max_count = 10
            entries = None
            related_tags = None
            tags_dict = None
            param_filetype = request.query_params.get('filetype', '') or None
            param_mode = request.query_params.get('mode', '') or None
            param_page = request.query_params.get('page', '') or None
            param_protocol = request.query_params.get('protocol', '') or None
            param_query = request.query_params.get('q', '') or None
            if param_query: param_query = param_query.strip()
            param_tags = request.query_params.get('tags', '') or None
            param_tld = request.query_params.get('tld', '') or None
            if param_page and param_mode != 'feed':
                try:
                    page = int(param_page)
                    page_next = page + 1
                    page_prev = page - 1
                except:
                    page = 1
                    page_next = 2
            else:
                page = 1
                page_next = 2
            page_prev = page - 1
            index_first = (page - 1)*10
            index_last = index_first+10
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id == jid or node_type in ('private', 'read'):
                xmpp_instance = accounts[jabber_id]
                # NOTE You need something other than an iterator (XEP-0059).
                #      You need a PubSub key that would hold tags.
                filename_items = 'items/' + jabber_id + '.toml'
                # NOTE Does it work?
                #      It does not seem to actually filter tags.
                # NOTE Yes. It does work.
                #      See function "cache_items_and_tags".

                # TODO Search by query
                #if param_query:

                if param_tags or param_tld or param_filetype or param_protocol:
                    tags_list = param_tags.split('+')
                    if len(tags_list) == 1:
                        tag = param_tags
                        entries_cache = Data.open_file_toml(filename_items)
                        entries_cache_node = entries_cache[node_type]
                        filename_cache = 'data/{}/{}.toml'.format(jid, tag)
                        Data.cache_items_and_tags(entries_cache_node, jid, tag)
                        if exists(filename_cache) or getsize(filename_cache):
                            data = Data.open_file_toml(filename_cache)
                            item_ids_all = data['item_ids']
                            related_tags = data['tags']
                            if len(item_ids_all) <= index_last:
                                index_last = len(item_ids_all)
                                page_next = None
                            item_ids_selection = []
                            for item_id in item_ids_all[index_first:index_last]:
                                item_ids_selection.append(item_id)
                            entries = []
                            for entry in entries_cache_node:
                                for item_id in item_ids_selection:
                                    if entry['url_hash'] == item_id:
                                        entries.append(entry)
                            for entry in entries:
                                entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                                entry['tags'] = entry['tags'][:5]
                            description = 'Your {} bookmarks tagged with "{}"'.format(node_type, tag)
                            message = 'Listing {} bookmarks {} - {} out of {}.'.format(node_type, index_first+1, index_last, len(item_ids_all))
                            #item_id_next = entries[len(entries)-1]
                        else:
                            description = 'No {} bookmarks tagged with "{}" were found for {}'.format(node_type, tag, jid)
                            message = 'Blasta system message » No entries.'
                            page_next = None
                            page_prev = None
                    elif len(tag_list) > 1:
                        pass #TODO  Support multiple tags
#               if not param_tags and not param_tld and not param_filetype and not param_protocol and not param_url and not param_hash:
                else:
                    name = jabber_id.split('@')[0]
                    entries_cache = Data.open_file_toml(filename_items)
                    entries_cache_node = entries_cache[node_type]
                    filename_cache = 'data/{}.toml'.format(jid)
                    #if len(entries_cache_node) and not exists(filename_cache):
                    Data.cache_items_and_tags(entries_cache_node, jid)
                    if exists(filename_cache) or getsize(filename_cache):
                        data = Data.open_file_toml(filename_cache)
                        item_ids_all = data['item_ids']
                        related_tags = data['tags']
                        if len(item_ids_all) <= index_last:
                            index_last = len(item_ids_all)
                            page_next = None
                        item_ids_selection = []
                        for item_id in item_ids_all[index_first:index_last]:
                            item_ids_selection.append(item_id)
                        entries = []
                        for entry in entries_cache_node:
                            for item_id in item_ids_selection:
                                if entry['url_hash'] == item_id:
                                    entries.append(entry)
                        for entry in entries:
                            entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                            entry['tags'] = entry['tags'][:5]
                        description = 'Your {} bookmarks'.format(node_type)
                        message = 'Listing {} bookmarks {} - {} out of {}.'.format(node_type, index_first+1, index_last, len(item_ids_all))
                        #item_id_next = entries[len(entries)-1]
                    else:
                        description = 'Your bookmarks directory appears to be empty'
                        message = 'Blasta system message » Zero count.'
                        start = True
            elif jabber_id in accounts:
                # NOTE Keep this IQ function call as an exception.
                #      If one wants to see contents of someone else, an
                #      authorization is required.
                # NOTE It might be wiser to use cached items or item identifiers
                #      provided that the viewer is authorized to view items.
                xmpp_instance = accounts[jabber_id]
                db_file = 'main.sqlite'
                tags_dict = {}
                if param_query:
                    description = 'Bookmarks from {} with "{}"'.format(jid, param_query)
                    entries_database = SQLite.get_entries_by_jid_and_query(db_file, jid, param_query, index_first)
                    entries_count = SQLite.get_entries_count_by_jid_and_query(db_file, jid, param_query)
                    for tag, instances in SQLite.get_30_tags_by_jid_and_query(db_file, jid, param_query, index_first):
                        tags_dict[tag] = instances
                elif param_tags:
                    description = 'Bookmarks from {} tagged with "{}"'.format(jid, param_tags)
                    entries_database = SQLite.get_entries_by_jid_and_tag(db_file, jid, param_tags, index_first)
                    entries_count = SQLite.get_entries_count_by_jid_and_tag(db_file, jid, param_tags)
                    for tag, instances in SQLite.get_30_tags_by_jid_and_tag(db_file, jid, param_tags, index_first):
                        tags_dict[tag] = instances
                else:
                    description = 'Bookmarks from {}'.format(jid)
                    entries_database = SQLite.get_entries_by_jid(db_file, jid, index_first)
                    entries_count = SQLite.get_entries_count_by_jid(db_file, jid)
                    for tag, instances in SQLite.get_30_tags_by_jid(db_file, jid, index_first):
                        tags_dict[tag] = instances
                if not entries_database:
                    message = 'Blasta system message » Error: No entries were found.'
                    description = 'No results'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                if entries_count:
                    entries = []
                    for entry in entries_database:
                        tags_sorted = []
                        for tag in SQLite.get_tags_by_entry_id(db_file, entry[0]):
                            tags_sorted.append(tag[0])
                        entry_jid = SQLite.get_jid_by_jid_id(db_file, entry[5])
                        url_hash = Utilities.hash_url_to_md5(entry[2])
                        instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                        entries.append(
                            {'title' : entry[3],
                             'link' : entry[2],
                             'summary' : entry[4],
                             'published' : entry[6],
                             'updated' : entry[7],
                             'tags' : tags_sorted,
                             'url_hash' : url_hash,
                             'jid' : entry_jid,
                             'name' : entry_jid, # jid.split('@')[0] if '@' in jid else jid,
                             'instances' : instances})
                    for entry in entries:
                        try:
                            date_iso = entry['published']
                            date_wrt = Utilities.convert_iso8601_to_readable(date_iso)
                            entry['published_mod'] = date_wrt
                        except:
                            print('ERROR: Probably due to an attempt to convert a non ISO 8601.')
                            print(entry['published'])
                            print(entry['published_mod'])
                            print(entry)
                    index_last = index_first+len(entries_database)
                    if entries_count <= index_last:
                        index_last = entries_count
                        page_next = None
                    message = 'Listing bookmarks {} - {} out of {}.'.format(index_first+1, index_last, entries_count)
                else:
                    # TODO Check permission, so there is no unintended continuing to cached data which is not authorized for.
                    iq = await XmppPubsub.get_node_item_ids(xmpp_instance, jid, node_id_public)
                    if isinstance(iq, slixmpp.stanza.iq.Iq):
                        iq_items_remote = iq['disco_items']
    
                        # Cache a list of identifiers of node items to a file.
                        iq_items_remote_name = []
                        for iq_item_remote in iq_items_remote:
                            iq_item_remote_name = iq_item_remote['name']
                            iq_items_remote_name.append(iq_item_remote_name)
    
                        #data_item_ids = {'iq_items' : iq_items_remote_name}
                        #filename_item_ids = 'item_ids/' + jid + '.toml'
                        #Data.save_to_toml(filename_item_ids, data_item_ids)

                        item_ids_all = iq_items_remote_name
                        #item_ids_all = data['item_ids']
                        #related_tags = data['tags']
                        if len(item_ids_all) <= index_last:
                            page_next = None
                            index_last = len(item_ids_all)
                        item_ids_selection = []
                        for item_id in item_ids_all[index_first:index_last]:
                            item_ids_selection.append(item_id)
    
                        iq = await XmppPubsub.get_node_items(xmpp_instance, jid, node_id_public, item_ids_selection)
                        entries = Data.extract_iq_items_extra(iq, jid)
                        if entries:
                            for entry in entries:
                                entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                                message = 'Listing bookmarks {} - {} out of {}.'.format(index_first+1, index_last, len(item_ids_all))
                                description = 'Bookmarks from {}'.format(jid)
                        else:
                            message = 'Blasta system message » Zero count.'
                            description = 'Bookmarks directory appears to be empty'
                            invite = True
                    else:
                        message = 'XMPP system message » {}.'.format(iq)
                        name = jid.split('@')[0]
                        path = 'error'
                        if not iq:
                            message = 'XMPP system message » Empty.'
                            description = 'An unknown error has occurred'
                            invite = True
                        elif iq == 'Item not found':
                            description = 'Bookmarks directory appears to be empty'
                            invite = True
                        elif iq == 'forbidden':
                            description = 'Access forbidden'
                        elif iq == 'item-not-found':
                            description = 'Jabber ID does not appear to be exist'
                        elif iq == 'not-authorized':
                            description = 'You have no authorization to view ' + name + '\'s bookmarks.'
                            
                            ask = True
                        elif iq == 'Node not found':
                            description = name + '\'s bookmarks directory appears to be empty.'
                            invite = True
                        elif 'DNS lookup failed' in iq:
                            domain = jid.split('@')[1] if '@' in jid else jid
                            description = 'Blasta could not connect to server {}'.format(domain)
                        elif iq == 'Connection failed: connection refused':
                            description = 'Connection with ' + name + ' has been refused'
                        elif 'Timeout' in iq or 'timeout' in iq:
                            description = 'Connection with ' + name + ' has been timed out'
                        else:
                            breakpoint()
                            description = 'An unknown error has occurred'
                        if invite:
                            hostname = request.url.hostname + ':' + str(request.url.port)
                            protocol = request.url.scheme
                            origin = protocol + '://' + hostname
                        template_file = 'ask.xhtml'
                        template_dict = {
                            'request': request,
                            'ask' : ask,
                            'alias' : jabber_id.split('@')[0],
                            'description': description,
                            'invite' : invite,
                            'jabber_id': jabber_id,
                            'jid': jid,
                            'journal': journal,
                            'message': message,
                            'name': name,
                            'origin': origin,
                            'path': path}
                        response = templates.TemplateResponse(template_file, template_dict)
                        response.headers["Content-Type"] = "application/xhtml+xml"
                        return response
            else:
                description = 'An XMPP account is required'
                message = 'Blasta system message » Please connect with your XMPP account to view this directory.'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            template_dict = {
                'request': request,
                'description': description,
                'entries': entries,
                'jabber_id': jabber_id,
                'jid': jid,
                'journal': journal,
                'message': message,
                'node_type': node_type,
                'page_next': page_next,
                'page_prev': page_prev,
                'pager' : True,
                'param_query' : param_query,
                'param_tags': param_tags,
                'path': path,
                'pubsub_jid': jid,
                'node_id': nodes[node_type]['name'],
                'start': start,
                'syndicate': jid,
                'tags' : tags_dict or related_tags or ''}
            if param_mode == 'feed':
                template_file = 'browse.atom'
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xml"
            else:
                template_file = 'browse.xhtml'
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/blasta.svg')
        def logo_get():
            return FileResponse('graphic/blasta.svg')

        @self.app.get('/', response_class=HTMLResponse)
        @self.app.get('/new', response_class=HTMLResponse)
        async def root_get_new(request: Request, response : Response):
            response = await root_main_get(request, response, page_type='new')
            return response

        @self.app.get('/popular', response_class=HTMLResponse)
        async def root_get_popular(request: Request, response : Response):
            response = await root_main_get(request, response, page_type='popular')
            return response

        @self.app.get('/query', response_class=HTMLResponse)
        async def root_get_query(request: Request, response : Response):
            response = await root_main_get(request, response, page_type='query')
            return response

        @self.app.get('/recent', response_class=HTMLResponse)
        async def root_get_recent(request: Request, response : Response):
            response = await root_main_get(request, response, page_type='recent')
            return response

        async def root_main_get(request: Request, response : Response, page_type=None):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            node_id = path = syndicate = page_type
            param_filetype = request.query_params.get('filetype', '') or None
            param_mode = request.query_params.get('mode', '') or None
            param_page = request.query_params.get('page', '') or None
            param_protocol = request.query_params.get('protocol', '') or None
            param_query = request.query_params.get('q', '') or None
            if param_query: param_query = param_query.strip()
            param_tags = request.query_params.get('tags', '') or None
            param_tld = request.query_params.get('tld', '') or None
            if param_page and param_mode != 'feed':
                try:
                    page = int(param_page)
                    page_next = page + 1
                    page_prev = page - 1
                except:
                    page = 1
                    page_next = 2
            else:
                page = 1
                page_next = 2
            page_prev = page - 1
            index_first = (page - 1)*10
            db_file = 'main.sqlite'
            if param_tags or param_tld or param_filetype or param_protocol:
                entries_count = SQLite.get_entries_count_by_tag(db_file, param_tags)
                match page_type:
                    case 'new':
                        description = 'New bookmarks tagged with "{}"'.format(param_tags)
                        entries_database = SQLite.get_entries_new_by_tag(db_file, param_tags, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_new_by_tag(db_file, param_tags, index_first)
                    case 'popular':
                        description = 'Popular bookmarks tagged with "{}"'.format(param_tags) # 'Most popular'
                        entries_database = SQLite.get_entries_popular_by_tag(db_file, param_tags, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_popular_by_tag(db_file, param_tags, index_first)
                    case 'recent':
                        description = 'Recent bookmarks tagged with "{}"'.format(param_tags)
                        entries_database = SQLite.get_entries_recent_by_tag(db_file, param_tags, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_recent_by_tag(db_file, param_tags, index_first)
                    # TODO case 'query':
            else:
                match page_type:
                    case 'new':
                        description = 'New bookmarks'
                        entries_database = SQLite.get_entries_new(db_file, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_new(db_file, index_first)
                        entries_count = SQLite.get_entries_count(db_file)
                    case 'popular':
                        description = 'Popular bookmarks' # 'Most popular'
                        entries_database = SQLite.get_entries_popular(db_file, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_popular(db_file, index_first)
                        entries_count = SQLite.get_entries_count(db_file)
                    case 'query':
                        node_id = syndicate = 'new'
                        description = 'Posted bookmarks with "{}"'.format(param_query)
                        entries_database = SQLite.get_entries_by_query(db_file, param_query, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_by_query_recent(db_file, param_query, index_first)
                        entries_count = SQLite.get_entries_count_by_query(db_file, param_query)
                    case 'recent':
                        description = 'Recent bookmarks'
                        entries_database = SQLite.get_entries_recent(db_file, index_first)
                        tags_of_entries = SQLite.get_30_tags_by_entries_recent(db_file, index_first)
                        entries_count = SQLite.get_entries_count(db_file)
            if not entries_database:
                message = 'Blasta system message » Error: No entries were found.'
                description = 'No results'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            tags_dict = {}
            #for tag, instances in SQLite.get_tags_30(db_file):
            for tag, instances in tags_of_entries:
                tags_dict[tag] = instances
            entries = []
            for entry in entries_database:
                tags_sorted = []
                for tag in SQLite.get_tags_by_entry_id(db_file, entry[0]):
                    tags_sorted.append(tag[0])
                jid = SQLite.get_jid_by_jid_id(db_file, entry[5])
                url_hash = Utilities.hash_url_to_md5(entry[2])
                instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                entries.append(
                        {'title' : entry[3],
                         'link' : entry[2],
                         'summary' : entry[4],
                         'published' : entry[6],
                         'updated' : entry[7],
                         'tags' : tags_sorted,
                         'url_hash' : url_hash, #entry[1]
                         'jid' : jid,
                         'name' : jid, # jid.split('@')[0] if '@' in jid else jid,
                         'instances' : instances})
            for entry in entries:
                try:
                    date_iso = entry['published']
                    date_wrt = Utilities.convert_iso8601_to_readable(date_iso)
                    entry['published_mod'] = date_wrt
                except:
                    print('ERROR: Probably due to an attempt to convert a non ISO 8601.')
                    print(entry['published'])
                    print(entry['published_mod'])
                    print(entry)
            index_last = index_first+len(entries_database)
            if entries_count <= index_last:
                # NOTE Did you forget to modify index_last?
                # NOTE No. It appears that it probably not needed index_last = entries_count
                page_next = None
            #if page_type != 'new' or page_prev or param_tags or param_tld or param_filetype or param_protocol:
            if request.url.path != '/' or request.url.query:
                message = 'Listing bookmarks {} - {} out of {}.'.format(index_first+1, index_last, entries_count)
                message_link = None
            else:
                message = ('Welcome to Blasta, an XMPP PubSub oriented social '
                           'bookmarks manager for organizing online content.')
                message_link = {'href' : '/help/about', 'text' : 'Learn more'}
            template_dict = {
                'request' : request,
                'description' : description,
                'entries' : entries,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'message' : message,
                'message_link' : message_link,
                'node_id' : node_id,
                'page_next' : page_next,
                'page_prev' : page_prev,
                'page_type' : page_type,
                'pager' : True,
                'param_query' : param_query,
                'param_tags' : param_tags,
                'path' : path,
                'pubsub_jid' : jabber_id_pubsub,
                'syndicate' : syndicate,
                'tags' : tags_dict}
            if param_mode == 'feed':
                # NOTE Consider scheme "feed" in order to prompt news
                # reader 'feed://' + request.url.netloc + request.url.path
                template_file = 'browse.atom'
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xml"
            else:
                template_file = 'browse.xhtml'
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        """
        # TODO Return to code /tag and / (root) once SQLite database is ready.
        @self.app.get('/tag/{tag}')
        async def tag_tag_get(request: Request, tag):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            node_id = 'tag:{}'.format(tag)
            syndicate = '?tag={}'.format(tag)
            path = 'tag'
            # NOTE Perhaps it would be beneficial to retrieve "published" and
            #      tags ("category") of viewer to override the tags of Blasta
            # TODO If URL exist in visitor's bookmarks, display its properties
            #      (summary, tags title etc.) before data of others.
#           if Utilities.is_jid_matches_to_session(accounts, sessions, request):
            page = request.query_params.get('page', '') or None
            if page:
                try:
                    page = int(page)
                    page_next = page + 1
                    page_prev = page - 1
                except:
                    page = 1
                    page_next = 2
            else:
                page = 1
                page_next = 2
            page_prev = page - 1
            index_first = (page - 1)*10
            index_last = index_first+10
            tags_dict = {}
            for entry in entries_database:
                for entry_tag in entry['tags']:
                    if entry_tag in tags_dict:
                        tags_dict[entry_tag] = tags_dict[entry_tag]+1
                    else:
                        tags_dict[entry_tag] = 1
            tags_dict = dict(sorted(tags_dict.items(), key=lambda item: (-item[1], item[0])))
            tags_dict = dict(list(tags_dict.items())[:30])
            #tags_dict = dict(sorted(tags_dict.items(), key=lambda item: (-item[1], item[0]))[:30])
            print(tags_dict)
            entries = []
            for entry in entries_database:
                if tag in entry['tags']:
                    entries.append(entry)
            for entry in entries:
            # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
        """

        @self.app.post('/', response_class=HTMLResponse)
        async def root_post(request: Request,
                            response: Response,
                            jabber_id: str = Form(...),
                            password: str = Form(...)):
            if not Utilities.is_jid_matches_to_session(accounts, sessions, request):
                # Store a variable in the request's state
                request.app.state.jabber_id = jabber_id
                session_key = str(random.random())
                request.app.state.session_key = session_key
                accounts[jabber_id] = XmppInstance(jabber_id + '/blasta', password)
                # accounts[jabber_id].authenticated
                # dir(accounts[jabber_id])
                # accounts[jabber_id].failed_auth
                # accounts[jabber_id].event_when_connected
                sessions[jabber_id] = session_key
                # Check if the user and password are present and valid
                # If not valid, return "Could not connect to JID"
            
            # FIXME Instead of an arbitrary number (i.e. 5 seconds), write a
            # while loop with a timeout of 10 seconds.

            # Check whether an account is connected.
            # Wait for 5 seconds to connect.
            await asyncio.sleep(5)
            #if jabber_id in accounts and accounts[jabber_id].connection_accepted:

            if jabber_id in accounts:
                xmpp_instance = accounts[jabber_id]
                #await xmpp_instance.plugin['xep_0060'].delete_node(jabber_id, node_id_public)

                for node_properties in nodes:
                    properties = nodes[node_properties]
                    if not await XmppPubsub.is_node_exist(xmpp_instance, properties['name']):
                        iq = XmppPubsub.create_node_atom(
                            xmpp_instance, jabber_id, properties['name'],
                            properties['title'], properties['subtitle'],
                            properties['access_model'])
                        await iq.send(timeout=15)

                    #await XmppPubsub.set_node_private(xmpp_instance, node_id_private)
                    #await XmppPubsub.set_node_private(xmpp_instance, node_id_read)
                    #configuration_form = await xmpp_instance['xep_0060'].get_node_config(jabber_id, properties['name'])
                    #print(configuration_form)
                node_id = nodes['public']['name']
                result, reason = await Data.update_cache_and_database(xmpp_instance, jabber_id, 'public', node_id)
                if result == 'error':
                    message = 'XMPP system message » {}.'.format(reason)
                    description = 'IQ Error'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                else:
                    iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, 'xmpp:blasta:settings:0', 'routine')
                    if isinstance(iq, slixmpp.stanza.iq.Iq):
                        payload = iq['pubsub']['items']['item']['payload']
                        routine = payload.text if payload else None
                    else:
                        routine = None
                    match routine:
                        case 'private':
                            response = RedirectResponse(url='/private')
                        case 'read':
                            response = RedirectResponse(url='/read')
                        case _:
                            response = RedirectResponse(url='/jid/' + jabber_id)

            else:
                #del accounts[jabber_id]
                #del sessions[jabber_id]
                message = 'Blasta system message » Authorization has failed.'
                description = 'Connection has failed'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.post('/message')
        async def message_post(request: Request,
                               jid: str = Form(...),
                               body: str = Form(...)):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                #headline = 'This is a message from Blasta'
                xmpp_instance = accounts[jabber_id]
                XmppMessage.send(xmpp_instance, jid, body)
                alias = jid.split('@')[0]
                message = 'Your message has been sent to {}.'.format(alias)
                description = 'Message has been sent'
                path = 'message'
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
            return result_post(request, jabber_id, description, message, path)

        @self.app.get('/now')
        def now_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'now.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/private', response_class=HTMLResponse)
        @self.app.post('/private')
        async def private_get(request: Request, response : Response):
            node_type = 'private'
            path = 'private'
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                node_id = nodes[node_type]['name']
                result, reason = await Data.update_cache_and_database(xmpp_instance, jabber_id, node_type, node_id)
                if result == 'error':
                    message = 'Blasta system message » {}.'.format(reason)
                    description = 'Directory "private" appears to be empty'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                else:
                    response = await jid_main_get(request, node_type, path)
                    return response
            else:
                description = 'An XMPP account is required'
                message = 'Blasta system message » Please connect with your XMPP account to view this directory.'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        @self.app.get('/profile')
        async def profile_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                if not await XmppPubsub.is_node_exist(xmpp_instance, 'xmpp:blasta:settings:0'):
                    iq = XmppPubsub.create_node_config(xmpp_instance, jabber_id)
                    await iq.send(timeout=15)
                access_models = {}
                for node_type in nodes:
                    node_id = nodes[node_type]['name']
                    iq = await XmppPubsub.get_node_configuration(xmpp_instance, jabber_id, node_id)
                    access_model = iq['pubsub_owner']['configure']['form']['values']['pubsub#access_model']
                    access_models[node_type] = access_model
                settings = {}
                for setting in ['enrollment', 'routine']:
                    iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, 'xmpp:blasta:settings:0', setting)
                    if isinstance(iq, slixmpp.stanza.iq.Iq):
                        payload = iq['pubsub']['items']['item']['payload']
                        if payload: settings[setting] = payload.text
                template_file = 'profile.xhtml'
                template_dict = {
                    'access_models' : access_models,
                    'enroll' : settings['enrollment'] if 'enrollment' in settings else None,
                    'request' : request,
                    'routine' : settings['routine'] if 'routine' in settings else None,
                    'jabber_id' : jabber_id,
                    'journal' : journal}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.post('/profile')
        async def profile_post(request: Request,
                               routine: str = Form(None),
                               enroll: str = Form(None)):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                if routine:
                    message = 'The routine directory has been set to {}'.format(routine)
                    payload = Xml.create_setting_entry(routine)
                    iq = await XmppPubsub.publish_node_item(
                        xmpp_instance, jabber_id, 'xmpp:blasta:settings:0', 'routine', payload)
                if enroll:
                    if enroll == '1': message = 'Your database is shared with the Blasta system'
                    else: message = 'Your database is excluded from the Blasta system'
                    payload = Xml.create_setting_entry(enroll)
                    iq = await XmppPubsub.publish_node_item(
                        xmpp_instance, jabber_id, 'xmpp:blasta:settings:0', 'enrollment', payload)
                description = 'Setting has been saved'
                template_file = 'result.xhtml'
                template_dict = {
                    'description' : description,
                    'enroll' : enroll,
                    'jabber_id' : jabber_id,
                    'journal' : journal,
                    'message' : message,
                    'request' : request,
                    'routine' : routine}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.get('/profile/export/{node_type}/{filetype}')
        async def profile_export_get(request: Request, node_type, filetype):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                node_id = nodes[node_type]['name']
                iq = await XmppPubsub.get_node_items(xmpp_instance, jabber_id, node_id)
                if isinstance(iq, slixmpp.stanza.iq.Iq):
                    entries = Data.extract_iq_items(iq, jabber_id)
                    # TODO Append a bookmark or bookmarks of Blasta
                    if entries:
                        filename = 'export/' + jabber_id + '_' + node_type + '.' + filetype
                        #filename = 'export/{}_{}.{}'.format(jabber_id, node_type, filetype)
                        #filename = 'export_' + node_type + '/' + jabber_id + '_' + '.' + filetype
                        #filename = 'export_{}/{}.{}'.format(node_type, jabber_id, filetype)
                        match filetype:
                            case 'json':
                                Data.save_to_json(filename, entries)
                            case 'toml':
                                # NOTE Should the dict be named with 'entries' or 'private'/'public'/'read'?
                                data = {'entries' : entries}
                                Data.save_to_toml(filename, data)
                    response = FileResponse(filename)
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.post('/profile/import')
#        def profile_import_post(file: UploadFile = File(...)):
        async def profile_import_post(request: Request,
                                      file: UploadFile | None = None,
                                      merge: str = Form(None),
                                      node: str = Form(...),
                                      override: str = Form(None)):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                if file:

                    # TODO If node does not exist, redirect to result page with
                    #      a message that bookmarks are empty.
                    # NOTE No.

                    node_id = nodes[node]['name']
                    node_title = nodes[node]['title']
                    node_subtitle = nodes[node]['subtitle']
                    node_access_model = nodes[node]['access_model']
                    if not await XmppPubsub.is_node_exist(xmpp_instance, node_id):
                        iq = XmppPubsub.create_node_atom(
                            xmpp_instance, jabber_id, node_id, node_title,
                            node_subtitle, node_access_model)
                        await iq.send(timeout=15)

                    #return {"filename": file.filename}
                    content = file.file.read().decode()

                    # TODO Add match/case for filetype.

                    entries = tomllib.loads(content)
                    # entries_node = entries[node]

                    #breakpoint()
                    #for entry in entries: print(entry)

                    name = jabber_id.split('@')[0]
                    # timestamp = datetime.now().isoformat()
                    db_file = 'main.sqlite'
                    counter = 0

                    for entry_type in entries:
                        for entry in entries[entry_type]:
                            url_hash = item_id = Utilities.hash_url_to_md5(entry['link'])
                            instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                            entry_new = {
                                'title' : entry['title'],
                                'link' : entry['link'],
                                'summary' : entry['summary'],
                                'published' : entry['published'],
                                'updated' : entry['published'],
                                #'updated' : entry['updated'],
                                'tags' : entry['tags'],
                                'url_hash' : url_hash,
                                'jid' : jabber_id,
                                'name' : name,
                                'instances' : instances}
                            xmpp_instance = accounts[jabber_id]
                            payload = Syndication.create_rfc4287_entry(entry_new)
                            iq = await XmppPubsub.publish_node_item(
                                xmpp_instance, jabber_id, node_id, item_id, payload)
                            #await iq.send(timeout=15)
                            counter += 1

                    message = 'Blasta system message » Imported {} items.'.format(counter)
                    description = 'Import successful'
                    path = 'profile'
                    return result_post(request, jabber_id, description, message, path)
                else:
                    message = 'Blasta system message » Error: No upload file sent.'
                    description = 'Import error'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        @self.app.get('/save')
        async def save_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                param_url = request.query_params.get('url', '')
                url_hash = Utilities.hash_url_to_md5(param_url)
                for node_type in nodes:
                    node_id = nodes[node_type]['name']
                    iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, node_id, url_hash)
                    #if len(iq['pubsub']['items']):
                    if (isinstance(iq, slixmpp.stanza.iq.Iq) and
                        url_hash == iq['pubsub']['items']['item']['id']):
                        return RedirectResponse(url='/url/' + url_hash + '/edit')
                iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, 'xmpp:blasta:settings:0', 'routine')
                if isinstance(iq, slixmpp.stanza.iq.Iq):
                    payload = iq['pubsub']['items']['item']['payload']
                    routine = payload.text if payload else None
                else:
                    routine = None
                # NOTE Is "message" missing?
                description = 'Add a new bookmark' # 'Enter properties for a bookmark'
                param_title = request.query_params.get('title', '')
                param_tags = request.query_params.get('tags', '')
                param_summary = request.query_params.get('summary', '')
                path = 'save'
                if request.query_params:
                    message = message_link = None
                else:
                    message = 'For greater ease, you migh want to try our'
                    message_link = {'href' : '/help/utilities#buttons', 'text' : 'bookmarklets'}
                template_file = 'edit.xhtml'
                template_dict = {
                    'request' : request,
                    'description' : description,
                    'jabber_id' : jabber_id,
                    'journal' : journal,
                    'message' : message,
                    'message_link' : message_link,
                    'path' : path,
                    'routine' : routine,
                    'summary' : param_summary,
                    'tags' : param_tags,
                    'title' : param_title,
                    'url' : param_url}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.post('/save')
        async def save_post(request: Request,
                            node: str = Form(...),
                            summary: str = Form(''),
                            tags: str = Form(''),
                            title: str = Form(...),
                            url: str = Form(...)):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                url_hash = Utilities.hash_url_to_md5(url)
                for node_type in nodes:
                    node_id = nodes[node_type]['name']
                    iq = await XmppPubsub.get_node_item(
                        xmpp_instance, jabber_id, node_id, url_hash)
                    if (isinstance(iq, slixmpp.stanza.iq.Iq) and
                        url_hash == iq['pubsub']['items']['item']['id']):
                        return RedirectResponse(url='/url/' + url_hash + '/edit')
                description = 'Confirm properties of a bookmark'
                path = 'save'
                published = datetime.now().isoformat()
                template_file = 'edit.xhtml'
                template_dict = {
                    'request' : request,
                    'confirm' : True,
                    'description' : description,
                    'jabber_id' : jabber_id,
                    'journal' : journal,
                    'node' : node,
                    'path' : path,
                    'published' : published,
                    'summary' : summary,
                    'tags' : tags,
                    'title' : title,
                    'url' : url,
                    'url_hash' : url_hash}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
                return response
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        @self.app.get('/read', response_class=HTMLResponse)
        @self.app.post('/read')
        async def read_get(request: Request, response : Response):
            node_type = 'read'
            path = 'read'
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                xmpp_instance = accounts[jabber_id]
                node_id = nodes[node_type]['name']
                result, reason = await Data.update_cache_and_database(xmpp_instance, jabber_id, node_type, node_id)
                if result == 'error':
                    message = 'Blasta system message » {}.'.format(reason)
                    description = 'Directory "read" appears to be empty'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                else:
                    response = await jid_main_get(request, node_type, path)
                    return response
            else:
                description = 'An XMPP account is required'
                message = 'Blasta system message » Please connect with your XMPP account to view this directory.'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        def result_post(request: Request, jabber_id: str, description: str, message: str, path: str, http_code=None):
            template_file = 'result.xhtml'
            template_dict = {
                'description' : description,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'message' : message,
                'path' : path,
                'request' : request}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/register')
        def register_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            template_file = 'register.xhtml'
            template_dict = {
                'request' : request,
                'jabber_id' : jabber_id,
                'journal' : journal}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/rss')
        def rss(request: Request):
            return RedirectResponse(url='/help/syndication')

        @self.app.get('/search')
        async def search_get(request: Request):
            response = RedirectResponse(url='/search/all')
            return response

        @self.app.get('/search/all')
        async def search_all_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            description = 'Search for public bookmarks'
            form_action = '/query'
            input_id = input_name = label_for = 'q'
            input_placeholder = 'Enter a search query.'
            input_type = 'search'
            label = 'Search'
            message = 'Search for bookmarks in the Blasta system.'
            path = 'all'
            template_file = 'search.xhtml'
            template_dict = {
                'request' : request,
                'description' : description,
                'form_action' : form_action,
                'input_id' : input_id,
                'input_name' : input_name,
                'input_placeholder' : input_placeholder,
                'input_type' : input_type,
                'label' : label,
                'label_for' : label_for,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'message' : message,
                'path' : path}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/search/jid/{jid}')
        async def search_jid_get(request: Request, jid):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                if jabber_id == jid:
                    description = 'Search your own bookmarks'
                    message = 'Search for bookmarks from your own directory.'
                else:
                    description = 'Search bookmarks of {}'.format(jid)
                    message = 'Search for bookmarks of a given Jabber ID.'
                form_action = '/jid/' + jid
                input_id = input_name = label_for = 'q'
                input_placeholder = 'Enter a search query.'
                input_type = 'search'
                label = 'Search'
                path = 'jid'
                template_file = 'search.xhtml'
                template_dict = {
                    'request' : request,
                    'description' : description,
                    'form_action' : form_action,
                    'input_id' : input_id,
                    'input_name' : input_name,
                    'input_placeholder' : input_placeholder,
                    'input_type' : input_type,
                    'jabber_id' : jabber_id,
                    'jid' : jid,
                    'label' : label,
                    'label_for' : label_for,
                    'journal' : journal,
                    'message' : message,
                    'path' : path}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            else:
                response = RedirectResponse(url='/search/all')
            return response

        @self.app.get('/search/url')
        async def search_url_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            description = 'Search for a bookmark'
            form_action = None # This is not relevant due to function middleware. Maybe / or /url.
            input_id = input_name = label_for = 'url'
            input_placeholder = 'Enter a URL.'
            input_type = 'url'
            label = 'URL'
            message = 'Search for a bookmark by a URL.'
            path = 'url'
            template_file = 'search.xhtml'
            template_dict = {
                'request' : request,
                'description' : description,
#                'form_action' : form_action,
                'input_id' : input_id,
                'input_name' : input_name,
                'input_placeholder' : input_placeholder,
                'input_type' : input_type,
                'label' : label,
                'label_for' : label_for,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'message' : message,
                'path' : path}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/tag')
        def tag_get(request: Request):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            db_file = 'main.sqlite'
            tag_list = SQLite.get_tags_500(db_file)
            message = 'Common 500 tags sorted by name and sized by commonality.'
            description = 'Common tags'
            template_file = 'tag.xhtml'
            template_dict = {
                'request' : request,
                'description' : description,
                'jabber_id' : jabber_id,
                'journal' : journal,
                'message' : message,
                'tag_list' : tag_list}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/tag/{jid}')
        def tag_get_jid(request: Request, jid):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            # NOTE Consider retrieval of tags from cache file.
            #      This is relevant to private and read nodes.
            #if jabber_id == jid or node_type in ('private', 'read'):
            db_file = 'main.sqlite'
            tag_list = SQLite.get_500_tags_by_jid_sorted_by_name(db_file, jid)
            message = 'Common 500 tags sorted by name and sized by commonality.'
            description = 'Common tags of {}'.format(jid)
            template_file = 'tag.xhtml'
            template_dict = {
                'request' : request,
                'description' : description,
                'jabber_id' : jabber_id,
                'jid' : jid,
                'journal' : journal,
                'message' : message,
                'tag_list' : tag_list}
            response = templates.TemplateResponse(template_file, template_dict)
            response.headers["Content-Type"] = "application/xhtml+xml"
            return response

        @self.app.get('/url')
        async def url_get(request: Request):
            response = RedirectResponse(url='/search/url')
            return response

        @self.app.get('/url/{url_hash}')
        async def url_hash_get(request: Request, url_hash):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            node_id = 'hash:{}'.format(url_hash)
            param_hash = url_hash
            syndicate = path = 'url'
            db_file = 'main.sqlite'
            entries = []
            exist = False
            if len(url_hash) == 32:
                if jabber_id:
                    xmpp_instance = accounts[jabber_id]
                    for node in nodes:
                        node_id = nodes[node]['name']
                        iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, node_id, url_hash)
                        if isinstance(iq, slixmpp.stanza.iq.Iq):
                            # TODO If URL exist in visitor's bookmarks, display its properties (summary, tags title etc.) before data of others.
                            iq_item = iq['pubsub']['items']['item']
                            item_payload = iq_item['payload']
                            if item_payload:
                                exist = True
                                break
                        else:
                            message = 'XMPP system message » Error: {}.'.format(iq)
                            description = 'The requested bookmark could not be retrieved'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                    if exist:
                        # TODO Perhaps adding a paragraph with "your tags" and "who else has tagged this link"
                        #      and keep the (5 item) limit.
                        #entry = Syndication.extract_items(item_payload)
                        # NOTE Display only 5 items, as all the other tags appear at the list of "Related tags".
                        entry = Syndication.extract_items(item_payload, limit=True)
                        if entry:
                            #url_hash = iq_item['id']
                            url_hash = Utilities.hash_url_to_md5(entry['link'])
                            # TODO Add a check: if iq_item['id'] == url_hash:
                            instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                            entry['instances'] = instances
                            entry['jid'] = jabber_id
                            name = jabber_id.split('@')[0]
                            entry['name'] = name
                            entry['url_hash'] = url_hash
                            entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                            #entry['tags'] = entry['tags'][:5]
                            entries.append(entry)
                            tags_list = {}
                            tags_and_instances = SQLite.get_tags_and_instances_by_url_hash(db_file, url_hash)
                            for tag, tag_instances in tags_and_instances: tags_list[tag] = tag_instances
                        else: # NOTE Is it possible to activate this else statement? Consider removal.
                            # https://fastapi.tiangolo.com/tutorial/handling-errors/
                            #raise HTTPException(status_code=404, detail="Item not found")
                            message = 'Blasta system message » Error: Not found.'
                            description = 'The requested bookmark does not exist'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                            return response
                    else:
                        entry = SQLite.get_entry_by_url_hash(db_file, url_hash)
                        tags_sorted = []
                        if entry:
                            for tag in SQLite.get_tags_by_entry_id(db_file, entry[0]):
                                tags_sorted.append(tag[0])
                            tags_list = {}
                            tags_and_instances = SQLite.get_tags_and_instances_by_entry_id(db_file, entry[0])
                            for tag, tag_instances in tags_and_instances: tags_list[tag] = tag_instances
                            jid = SQLite.get_jid_by_jid_id(db_file, entry[5])
                            instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                            entries.append(
                                {'title' : entry[3],
                                 'link' : entry[2],
                                 'summary' : entry[4],
                                 'published' : entry[6],
                                 'published_mod' : Utilities.convert_iso8601_to_readable(entry[6]),
                                 'updated' : entry[7],
                                 'tags' : tags_sorted,
                                 'url_hash' : url_hash,
                                 'jid' : jid,
                                 'name' : jid, # jid.split('@')[0] if '@' in jid else jid,
                                 'instances' : instances})
    #                        message = 'XMPP system message » {}.'.format(iq)
    #                        if iq == 'Node not found':
    #                            description = 'An error has occurred'
    #                        else:
    #                            description = 'An unknown error has occurred'
                        else:
                            # https://fastapi.tiangolo.com/tutorial/handling-errors/
                            #raise HTTPException(status_code=404, detail="Item not found")
                            message = 'Blasta system message » Error: Not found.'
                            description = 'The requested bookmark does not exist'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                            return response
                else:
                    entry = SQLite.get_entry_by_url_hash(db_file, url_hash)
                    if entry:
                        tags_sorted = []
                        for tag in SQLite.get_tags_by_entry_id(db_file, entry[0]):
                            tags_sorted.append(tag[0])
                        tags_list = {}
                        tags_and_instances = SQLite.get_tags_and_instances_by_entry_id(db_file, entry[0])
                        for tag, tag_instances in tags_and_instances: tags_list[tag] = tag_instances
                        jid = SQLite.get_jid_by_jid_id(db_file, entry[5])
                        instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                        entries.append(
                            {'title' : entry[3],
                             'link' : entry[2],
                             'summary' : entry[4],
                             'published' : entry[6],
                             'published_mod' : Utilities.convert_iso8601_to_readable(entry[6]),
                             'updated' : entry[7],
                             'tags' : tags_sorted,
                             'url_hash' : url_hash,
                             'jid' : jid,
                             'name' : jid, # jid.split('@')[0] if '@' in jid else jid,
                             'instances' : instances})
                    else:
                        # https://fastapi.tiangolo.com/tutorial/handling-errors/
                        #raise HTTPException(status_code=404, detail="Item not found")
                        message = 'Blasta system message » Error: Not found.'
                        description = 'The requested bookmark does not exist'
                        path = 'error'
                        return result_post(request, jabber_id, description, message, path)
                message = 'Information for URI {}'.format(entries[0]['link']) # entry[2]
                if instances > 1:
                    description = 'Discover new resources and see who shares them'
                    template_file = 'people.xhtml'
                    people_list = {}
                    jids_and_tags = SQLite.get_jids_and_tags_by_url_hash(db_file, url_hash)
                    for jid, tag in jids_and_tags:
                        if jid in people_list and isinstance(people_list[jid], list):
                            people_list[jid].append(tag)
                        else:
                            people_list[jid] = [tag]
                else:
                    people_list = None
                    description = 'Resource properties'
                    template_file = 'browse.xhtml'
                template_dict = {
                    'request' : request,
                    'description' : description,
                    'entries' : entries,
                    'exist' : exist,
                    'jabber_id' : jabber_id,
                    'journal' : journal,
                    'message' : message,
                    'node_id' : node_id,
                    'param_hash' : param_hash,
                    'path' : path,
                    'people' : people_list,
                    'pubsub_jid' : jabber_id_pubsub,
                    'syndicate' : syndicate,
                    'tags' : tags_list}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
            else:
                message = 'Blasta system message » Error: MD5 message-digest algorithm.'
                description = 'The argument for URL does not appear to be a valid MD5 Checksum'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.post('/url/{url_hash}')
        async def url_hash_post(request: Request,
                                url_hash,
                                node: str = Form(...),
                                published: str = Form(...),
                                summary: str = Form(''),
                                tags: str = Form(''),
                                #tags_old: str = Form(...),
                                tags_old: str = Form(''),
                                title: str = Form(...),
                                url: str = Form(...)):
            node_id = 'hash:{}'.format(url_hash)
            param_hash = url_hash
            syndicate = path = 'url'
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            if jabber_id:
                name = jabber_id.split('@')[0]
                db_file = 'main.sqlite'
                instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                timestamp = datetime.now().isoformat()
                tags_new = Data.organize_tags(tags) if tags else ''
                entry = {'title' : title.strip(),
                         'link' : url.strip(),
                         'summary' : summary.strip() if summary else '',
                         'published' : published,
                         'updated' : timestamp,
                         'tags' : tags_new,
                         'url_hash' : url_hash,
                         'jid' : jabber_id,
                         'name' : name,
                         'instances' : instances or 1}
                message = 'Information for URL {}'.format(url)
                description = 'Bookmark properties'
                xmpp_instance = accounts[jabber_id]
                payload = Syndication.create_rfc4287_entry(entry)
                # TODO Add try/except for IQ
                print('Publish item')
                # TODO Check.
                # NOTE You might not need to append to an open node before appending to a whitelist node.
                node_id = nodes[node]['name']
                iq = await XmppPubsub.publish_node_item(
                    xmpp_instance, jabber_id, node_id, url_hash, payload)
                match node:
                    case 'private':
                        print('Set item as private (XEP-0223)')
                        #iq = await XmppPubsub.publish_node_item_private(
                        #    xmpp_instance, node_id_private, url_hash, iq)
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_public, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'public', url_hash)
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_read, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'read', url_hash)
                    case 'public':
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_private, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'private', url_hash)
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_read, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'read', url_hash)
                    case 'read':
                        #iq = await XmppPubsub.publish_node_item_private(
                        #    xmpp_instance, node_id_read, url_hash, iq)
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_public, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'public', url_hash)
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id_private, url_hash)
                        Data.remove_item_from_cache(jabber_id, 'private', url_hash)
                if isinstance(iq, str):
                    description = 'Could not save bookmark'
                    message = 'XMPP system message » {}.'.format(iq)
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
                #await iq.send(timeout=15)
                # Save changes to cache file
                entries_cache_filename = 'items/' + jabber_id + '.toml'
                entries_cache = Data.open_file_toml(entries_cache_filename)
                entries_cache_node = entries_cache[node] if node in entries_cache else []
                entries_cache_mod = []
                #for entry_cache in entries_cache_node:
                #    if entry_cache['url_hash'] == url_hash:
                #        entry_cache = entry
                #        break
                is_entry_modified = False
                # You already have this code in the HTML form, which indicates that this is an edit of an existing item
                # <input type="hidden" id="update" name="update" value="yes" required/>
                for entry_cache in entries_cache_node:
                    if entry_cache['url_hash'] == url_hash:
                        is_entry_modified = True
                        entries_cache_mod.append(entry)
                    else:
                        entries_cache_mod.append(entry_cache)
                if not is_entry_modified: entries_cache_mod.append(entry)
                entries_cache[node] = entries_cache_mod
                entries_cache_data = entries_cache
                Data.save_to_toml(entries_cache_filename, entries_cache_data)
                # Save changes to database
                if node == 'public':
                    tags_valid = []
                    tags_invalid = []
                    #tags_list_new = tags.split(',')
                    tags_list_new = tags_new
                    tags_list_old = tags_old.split(', ')
                    for tag in tags_list_old:
                        tag_trim = tag.strip()
                        if tag not in tags_list_new:
                            tags_invalid.append(tag_trim)
                    for tag in tags_list_new:
                        if tag:
                            tag_trim = tag.strip()
                            if tag_trim not in tags_list_old:
                                tags_valid.append(tag_trim)
                                # FIXME Variable tags_valid is not in use.
                                # NOTE Variable tags_valid might not be needed. See function associate_entries_tags_jids.
                    entry['tags'] = tags_valid
                    await SQLite.add_tags(db_file, [entry])
                    # Slow (high I/O)
                    entry_id = SQLite.get_entry_id_by_url_hash(db_file, url_hash)
                    if not entry_id:
                        await SQLite.add_new_entries(db_file, [entry]) # Is this line needed?
                        await SQLite.associate_entries_tags_jids(db_file, entry)
                    #elif not SQLite.is_jid_associated_with_url_hash(db_file, jabber_id, url_hash):
                    #    await SQLite.associate_entries_tags_jids(db_file, entry)
                    else:
                        await SQLite.associate_entries_tags_jids(db_file, entry)
                    print('tags_new')
                    print(tags_new)
                    print('tags_old')
                    print(tags_old)
                    print('tags_valid')
                    print(tags_valid)
                    print('tags_invalid')
                    print(tags_invalid)
                    print(url_hash)
                    print(jabber_id)
                    await SQLite.delete_combination_row_by_url_hash_and_tag_and_jid(db_file, url_hash, tags_invalid, jabber_id)
                # Entry for HTML
                entry['published_mod'] = Utilities.convert_iso8601_to_readable(published)
                entry['updated_mod'] = Utilities.convert_iso8601_to_readable(timestamp)
                entry['tags'] = entry['tags'][:5]
                entries = [entry]
                template_file = 'browse.xhtml'
                template_dict = {
                    'request': request,
                    'description': description,
                    'entries': entries,
                    'exist': True,
                    'jabber_id': jabber_id,
                    'journal': journal,
                    'message': message,
                    'node_id': node_id,
                    'param_hash': param_hash,
                    'path': path,
                    'pubsub_jid': jabber_id_pubsub,
                    'syndicate': syndicate,
                    'tags' : tags_new}
                response = templates.TemplateResponse(template_file, template_dict)
                response.headers["Content-Type"] = "application/xhtml+xml"
                return response
            else:
                message = 'Blasta system message » Error: No active session.'
                description = 'You are not connected'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)

        @self.app.get('/url/{url_hash}/confirm')
        async def url_hash_confirm_get(request: Request, url_hash):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            node_id = 'hash:{}'.format(url_hash)
            param_hash = url_hash
            syndicate = path = 'url'
            if len(url_hash) == 32:
                if jabber_id:
                    xmpp_instance = accounts[jabber_id]
                    exist = False
                    for node in nodes:
                        node_id = nodes[node]['name']
                        iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, node_id, url_hash)
                        if isinstance(iq, slixmpp.stanza.iq.Iq):
                            # TODO If URL exist in visitor's bookmarks, display its properties (summary, tags title etc.) before data of others.
                            iq_item = iq['pubsub']['items']['item']
                            item_payload = iq_item['payload']
                            if item_payload:
                                exist = True
                                break
                        else:
                            message = 'XMPP system message » {}.'.format(iq)
                            if iq == 'Node not found':
                                description = 'An error has occurred'
                            else:
                                description = 'An unknown error has occurred'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                    if exist:
                        # TODO Add a check: if iq_item['id'] == url_hash:
                        entries = []
                        entry = Syndication.extract_items(item_payload)
                        db_file = 'main.sqlite'
                        instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                        entry['instances'] = instances
                        entry['jid'] = jabber_id
                        name = jabber_id.split('@')[0]
                        entry['name'] = name
                        entry['url_hash'] = url_hash
                        entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                        entries.append(entry)
                        description = 'Confirm deletion of a bookmark'
                        message = 'Details for bookmark {}'.format(entries[0]['link'])
                        template_file = 'browse.xhtml'
                        template_dict = {
                            'request' : request,
                            'delete' : True,
                            'description' : description,
                            'entries' : entries,
                            'jabber_id' : jabber_id,
                            'journal' : journal,
                            'message' : message,
                            'node_id' : node_id,
                            'param_hash' : param_hash,
                            'path' : path,
                            'pubsub_jid' : jabber_id_pubsub,
                            'syndicate' : syndicate}
                        response = templates.TemplateResponse(template_file, template_dict)
                        response.headers["Content-Type"] = "application/xhtml+xml"
                    else:
                        response = RedirectResponse(url='/jid/' + jabber_id)
                else:
                    message = 'Blasta system message » Error: No active session.'
                    description = 'You are not connected'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
            else:
                message = 'Blasta system message » Error: MD5 message-digest algorithm.'
                description = 'The argument for URL does not appear to be a valid MD5 Checksum'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.get('/url/{url_hash}/delete')
        async def url_hash_delete_get(request: Request, url_hash):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
            node_id = 'hash:{}'.format(url_hash)
            param_hash = url_hash
            syndicate = path = 'url'
            if len(url_hash) == 32:
                if jabber_id:
                    xmpp_instance = accounts[jabber_id]
                    exist = False
                    for node_type in nodes:
                        node_id = nodes[node_type]['name']
                        iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, node_id, url_hash)
                        if isinstance(iq, slixmpp.stanza.iq.Iq):
                            # TODO If URL exist in visitor's bookmarks, display its properties (summary, tags title etc.) before data of others.
                            iq_item = iq['pubsub']['items']['item']
                            item_payload = iq_item['payload']
                            if item_payload:
                                exist = True
                                break
                        else:
                            message = 'XMPP system message » {}.'.format(iq)
                            if iq == 'Node not found':
                                description = 'An error has occurred'
                            else:
                                description = 'An unknown error has occurred'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                    if exist:
                        # TODO Add a check: if iq_item['id'] == url_hash:
                        entries = []
                        entry = Syndication.extract_items(item_payload)
                        db_file = 'main.sqlite'
                        instances = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                        entry['instances'] = instances
                        entry['jid'] = jabber_id
                        name = jabber_id.split('@')[0]
                        entry['name'] = name
                        entry['url_hash'] = url_hash
                        entry['published_mod'] = Utilities.convert_iso8601_to_readable(entry['published'])
                        entries.append(entry)

                        # Set a title
                        description = 'A bookmark has been deleted'
                        # Set a message
                        message = 'Details for bookmark {}'.format(entry['link'])

                        # Create a link to restore bookmark
                        link_save = ('/save?url=' + urllib.parse.quote(entry['link']) +
                                     '&title=' + urllib.parse.quote(entry['title']) +
                                     '&summary=' + urllib.parse.quote(entry['summary']) +
                                     '&tags=' + urllib.parse.quote(','.join(entry['tags'])))

                        # Remove the item from node
                        xmpp_instance = accounts[jabber_id]
                        await XmppPubsub.del_node_item(xmpp_instance, jabber_id, node_id, url_hash)

                        # Remove the item association from database
                        await SQLite.delete_combination_row_by_jid_and_url_hash(db_file, url_hash, jabber_id)
                        #await SQLite.delete_combination_row_by_url_hash_and_tag_and_jid(db_file, url_hash, entry['tags'], jabber_id)

                        # Remove the item from cache
                        Data.remove_item_from_cache(jabber_id, node_type, url_hash)

                        template_file = 'browse.xhtml'
                        template_dict = {
                            'request' : request,
                            'description' : description,
                            'entries' : entries,
                            'jabber_id' : jabber_id,
                            'journal' : journal,
                            'link_save' : link_save,
                            'message' : message,
                            'node_id' : node_id,
                            'param_hash' : param_hash,
                            'path' : path,
                            'pubsub_jid' : jabber_id_pubsub,
                            'restore' : True,
                            'syndicate' : syndicate}
                        response = templates.TemplateResponse(template_file, template_dict)
                        response.headers["Content-Type"] = "application/xhtml+xml"
                    else:
                        response = RedirectResponse(url='/jid/' + jabber_id)
                else:
                    message = 'Blasta system message » Error: No active session.'
                    description = 'You are not connected'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
            else:
                message = 'Blasta system message » Error: MD5 message-digest algorithm.'
                description = 'The argument for URL does not appear to be a valid MD5 Checksum'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

        @self.app.get('/url/{url_hash}/edit')
        @self.app.post('/url/{url_hash}/edit')
        async def url_hash_edit_get(request: Request, url_hash):
            jabber_id = Utilities.is_jid_matches_to_session(accounts, sessions, request)
#           node_id = 'hash:{}'.format(url_hash)
            if len(url_hash) == 32:
                if jabber_id:
                    xmpp_instance = accounts[jabber_id]
                    exist = False
                    for node in nodes:
                        node_id = nodes[node]['name']
                        iq = await XmppPubsub.get_node_item(xmpp_instance, jabber_id, node_id, url_hash)
                        if isinstance(iq, slixmpp.stanza.iq.Iq):
                            name = jabber_id.split('@')[0]
                            iq_item = iq['pubsub']['items']['item']
                            # TODO Add a check: if iq_item['id'] == url_hash:
                            # Is this valid entry['url_hash'] = iq['id'] or should it be iq_item['id']
                            db_file = 'main.sqlite'
                            entry = None
                            item_payload = iq_item['payload']
                            if item_payload:
                                exist = True
                                break
                        else:
                            message = 'XMPP system message » {}.'.format(iq)
                            if iq == 'Node not found':
                                description = 'An error has occurred'
                            else:
                                description = 'An unknown error has occurred'
                            path = 'error'
                            return result_post(request, jabber_id, description, message, path)
                        
                    if exist:
                        path = 'edit'
                        description = 'Edit an existing bookmark'
                        entry = Syndication.extract_items(item_payload)
                        entry['instances'] = SQLite.get_entry_instances_by_url_hash(db_file, url_hash)
                        print(jabber_id)
                        print(entry['tags'])
                    else:
                        # TODO Consider redirect to path /save (function save_get)
                        # NOTE This seems to be the best to do, albeit, perhaps the pathname should be /save instead of /url/hash/edit.
                        path = 'save' # 'add'
                        description = 'Add a new bookmark'
                        result = SQLite.get_entry_by_url_hash(db_file, url_hash)
                        tags_sorted = []
                        if result:
                            for tag in SQLite.get_tags_by_entry_id(db_file, result[0]):
                                tags_sorted.append(tag[0])
                        entry = {'title' : result[3],
                                 'link' : result[2],
                                 'summary' : result[4],
                                 'published' : result[6],
                                 'updated' : result[7],
                                 'tags' : tags_sorted}
                                 #'instances' : result[8],
                                 #'jid' = jabber_id,
                                 #'name' : name,
                                 #'url_hash' : url_hash
                    if entry:
                        entry['jid'] = jabber_id
                        entry['name'] = name
                        entry['url_hash'] = url_hash
                    else:
                        message = 'XMPP system message » {}.'.format(iq)
                        if iq == 'Node not found':
                            description = 'An error has occurred'
                        else:
                            description = 'An unknown error has occurred'
                        path = 'error'
                        return result_post(request, jabber_id, description, message, path)
                    template_file = 'edit.xhtml'
                    template_dict = {
                        'request' : request,
                        'description' : description,
                        'edit' : True,
                        'jabber_id' : jabber_id,
                        'journal' : journal,
                        'node' : node,
                        'path' : path,
                        'published' : entry['published'],
                        'summary' : entry['summary'],
                        'tags' : ', '.join(entry['tags']),
                        'title' : entry['title'],
                        'url' : entry['link'],
                        'url_hash' : url_hash}
                    response = templates.TemplateResponse(template_file, template_dict)
                    response.headers["Content-Type"] = "application/xhtml+xml"
                else:
                    message = 'Blasta system message » Error: No active session.'
                    description = 'You are not connected'
                    path = 'error'
                    return result_post(request, jabber_id, description, message, path)
            else:
                message = 'Blasta system message » Error: MD5 message-digest algorithm.'
                description = 'The argument for URL does not appear to be a valid MD5 Checksum'
                path = 'error'
                return result_post(request, jabber_id, description, message, path)
            return response

class SQLite:

    #from slixfeed.log import Logger
    #from slixfeed.utilities import DateAndTime, Url
    
    # DBLOCK = Lock()
    
    #logger = Logger(__name__)
    
    def create_connection(db_file):
        """
        Create a database connection to the SQLite database
        specified by db_file.
    
        Parameters
        ----------
        db_file : str
            Path to database file.
    
        Returns
        -------
        conn : object
            Connection object or None.
        """
        time_begin = time.time()
        function_name = sys._getframe().f_code.co_name
#        message_log = '{}'
#        logger.debug(message_log.format(function_name))
        conn = None
        try:
            conn = connect(db_file)
            conn.execute("PRAGMA foreign_keys = ON")
            # return conn
        except Error as e:
            print(e)
#            logger.warning('Error creating a connection to database {}.'.format(db_file))
#            logger.error(e)
        time_end = time.time()
        difference = time_end - time_begin
        if difference > 1: logger.warning('{} (time: {})'.format(function_name,
                                                                 difference))
        return conn
    
    
    def create_tables(db_file):
        """
        Create SQLite tables.
    
        Parameters
        ----------
        db_file : str
            Path to database file.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        with SQLite.create_connection(db_file) as conn:
            sql_table_main_entries = (
                """
                CREATE TABLE IF NOT EXISTS main_entries (
                    id INTEGER NOT NULL,
                    url_hash TEXT NOT NULL UNIQUE,
                    url TEXT NOT NULL UNIQUE,
                    title TEXT NOT NULL,
                    summary TEXT,
                    jid_id TEXT NOT NULL,
                    date_first TEXT NOT NULL,
                    date_last TEXT NOT NULL,
                    instances INTEGER NOT NULL DEFAULT 1,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_main_jids = (
                """
                CREATE TABLE IF NOT EXISTS main_jids (
                    id INTEGER NOT NULL,
                    jid TEXT NOT NULL UNIQUE,
                    opt_in INTEGER NOT NULL DEFAULT 0,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_main_tags = (
                """
                CREATE TABLE IF NOT EXISTS main_tags (
                    id INTEGER NOT NULL,
                    tag TEXT NOT NULL UNIQUE,
                    instances INTEGER NOT NULL DEFAULT 1,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_main_statistics = (
                """
                CREATE TABLE IF NOT EXISTS main_statistics (
                    id INTEGER NOT NULL,
                    type TEXT NOT NULL UNIQUE,
                    count INTEGER NOT NULL DEFAULT 0,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_combination_entries_tags_jids = (
                """
                CREATE TABLE IF NOT EXISTS combination_entries_tags_jids (
                    id INTEGER NOT NULL,
                    entry_id INTEGER NOT NULL,
                    tag_id INTEGER NOT NULL,
                    jid_id INTEGER NOT NULL,
                    FOREIGN KEY ("entry_id") REFERENCES "main_entries" ("id")
                      ON UPDATE CASCADE
                      ON DELETE CASCADE,
                    FOREIGN KEY ("tag_id") REFERENCES "main_tags" ("id")
                      ON UPDATE CASCADE
                      ON DELETE CASCADE,
                    FOREIGN KEY ("jid_id") REFERENCES "main_jids" ("id")
                      ON UPDATE CASCADE
                      ON DELETE CASCADE,
                    PRIMARY KEY ("id")
                  );
                """
                )
            # NOTE Digit for JID which is authorized;
            #      Zero (0) for private;
            #      Empty (no row) for public.
            sql_table_authorization_entries_jids = (
                """
                CREATE TABLE IF NOT EXISTS authorization_entries_jids (
                    id INTEGER NOT NULL,
                    entry_id INTEGER NOT NULL,
                    jid_id INTEGER NOT NULL,
                    authorization INTEGER NOT NULL,
                    FOREIGN KEY ("entry_id") REFERENCES "main_entries" ("id")
                      ON UPDATE CASCADE
                      ON DELETE CASCADE,
                    FOREIGN KEY ("jid_id") REFERENCES "main_jids" ("id")
                      ON UPDATE CASCADE
                      ON DELETE CASCADE,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_report_entries = (
                """
                CREATE TABLE IF NOT EXISTS report_entries (
                    id INTEGER NOT NULL,
                    url_hash_subject TEXT NOT NULL,
                    jid_reporter TEXT NOT NULL,
                    type TEXT,
                    comment TEXT,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_table_report_jids = (
                """
                CREATE TABLE IF NOT EXISTS report_jids (
                    id INTEGER NOT NULL,
                    jid_subject TEXT NOT NULL,
                    jid_reporter TEXT NOT NULL,
                    type TEXT,
                    comment TEXT,
                    PRIMARY KEY ("id")
                  );
                """
                )
            sql_trigger_instances_entry_decrease = (
                """
                CREATE TRIGGER instances_entry_decrease
                AFTER DELETE ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    UPDATE main_entries
                    SET instances = (
                        SELECT COUNT(DISTINCT jid_id)
                        FROM combination_entries_tags_jids
                        WHERE entry_id = OLD.entry_id
                    )
                    WHERE id = OLD.entry_id;
                END;
                """
                )
            sql_trigger_instances_entry_increase = (
                """
                CREATE TRIGGER instances_entry_increase
                AFTER INSERT ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    UPDATE main_entries
                    SET instances = (
                        SELECT COUNT(DISTINCT jid_id)
                        FROM combination_entries_tags_jids
                        WHERE entry_id = NEW.entry_id
                    )
                    WHERE id = NEW.entry_id;
                END;
                """
                )
            sql_trigger_instances_entry_update = (
                """
                CREATE TRIGGER instances_entry_update
                AFTER UPDATE ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    -- Decrease instances for the old tag_id
                    UPDATE main_entries
                    SET instances = (
                        SELECT COUNT(DISTINCT jid_id)
                        FROM combination_entries_tags_jids
                        WHERE entry_id = OLD.entry_id
                    )
                    WHERE id = OLD.entry_id;
                
                    -- Increase instances for the new tag_id
                    UPDATE main_entries
                    SET instances = (
                        SELECT COUNT(DISTINCT jid_id)
                        FROM combination_entries_tags_jids
                        WHERE entry_id = NEW.entry_id
                    )
                    WHERE id = NEW.entry_id;
                END;
                """
                )
            sql_trigger_instances_tag_decrease = (
                """
                CREATE TRIGGER instances_tag_decrease
                AFTER DELETE ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    UPDATE main_tags
                    SET instances = (
                        SELECT COUNT(*)
                        FROM combination_entries_tags_jids
                        WHERE tag_id = OLD.tag_id
                    )
                    WHERE id = OLD.tag_id;
                END;
                """
                )
            sql_trigger_instances_tag_increase = (
                """
                CREATE TRIGGER instances_tag_increase
                AFTER INSERT ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    UPDATE main_tags
                    SET instances = (
                        SELECT COUNT(*)
                        FROM combination_entries_tags_jids
                        WHERE tag_id = NEW.tag_id
                    )
                    WHERE id = NEW.tag_id;
                END;
                """
                )
            sql_trigger_instances_tag_update = (
                """
                CREATE TRIGGER instances_tag_update
                AFTER UPDATE ON combination_entries_tags_jids
                FOR EACH ROW
                BEGIN
                    -- Decrease instances for the old tag_id
                    UPDATE main_tags
                    SET instances = (
                        SELECT COUNT(*)
                        FROM combination_entries_tags_jids
                        WHERE tag_id = OLD.tag_id
                    )
                    WHERE id = OLD.tag_id;
                
                    -- Increase instances for the new tag_id
                    UPDATE main_tags
                    SET instances = (
                        SELECT COUNT(*)
                        FROM combination_entries_tags_jids
                        WHERE tag_id = NEW.tag_id
                    )
                    WHERE id = NEW.tag_id;
                END;
                """
                )
            sql_trigger_entry_count_increase = (
                """
                CREATE TRIGGER entry_count_increase
                AFTER INSERT ON main_entries
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_entries
                    )
                    WHERE type = 'entries';
                END;
                """
                )
            sql_trigger_entry_count_decrease = (
                """
                CREATE TRIGGER entry_count_decrease
                AFTER DELETE ON main_entries
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_entries
                    )
                    WHERE type = 'entries';
                END;
                """
                )
            sql_trigger_entry_count_update = (
                """
                CREATE TRIGGER entry_count_update
                AFTER UPDATE ON main_entries
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_entries
                    )
                    WHERE type = 'entries';
                END;
                """
                )
            sql_trigger_entry_remove = (
                """
                CREATE TRIGGER entry_remove
                AFTER UPDATE ON main_entries
                FOR EACH ROW
                WHEN NEW.instances < 1
                BEGIN
                    DELETE FROM main_entries WHERE id = OLD.id;
                END;
                """
                )
            sql_trigger_jid_count_increase = (
                """
                CREATE TRIGGER jid_count_increase
                AFTER INSERT ON main_jids
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_jids
                    )
                    WHERE type = 'jids';
                END;
                """
                )
            sql_trigger_jid_count_decrease = (
                """
                CREATE TRIGGER jid_count_decrease
                AFTER DELETE ON main_jids
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_jids
                    )
                    WHERE type = 'jids';
                END;
                """
                )
            sql_trigger_jid_count_update = (
                """
                CREATE TRIGGER jid_count_update
                AFTER UPDATE ON main_jids
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_jids
                    )
                    WHERE type = 'jids';
                END;
                """
                )
            sql_trigger_tag_count_increase = (
                """
                CREATE TRIGGER tag_count_increase
                AFTER INSERT ON main_tags
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_tags
                    )
                    WHERE type = 'tags';
                END;
                """
                )
            sql_trigger_tag_count_decrease = (
                """
                CREATE TRIGGER tag_count_decrease
                AFTER DELETE ON main_tags
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_tags
                    )
                    WHERE type = 'tags';
                END;
                """
                )
            sql_trigger_tag_count_update = (
                """
                CREATE TRIGGER tag_count_update
                AFTER UPDATE ON main_tags
                BEGIN
                    UPDATE main_statistics
                    SET count = (
                        SELECT COUNT(*)
                        FROM main_tags
                    )
                    WHERE type = 'tags';
                END;
                """
                )
            sql_trigger_tag_remove = (
                """
                CREATE TRIGGER tag_remove
                AFTER UPDATE ON main_tags
                FOR EACH ROW
                WHEN NEW.instances < 1
                BEGIN
                    DELETE FROM main_tags WHERE id = OLD.id;
                END;
                """
                )
            cur = conn.cursor()
            cur.execute(sql_table_main_entries)
            cur.execute(sql_table_main_jids)
            cur.execute(sql_table_main_tags)
            cur.execute(sql_table_main_statistics)
            cur.execute(sql_table_combination_entries_tags_jids)
            cur.execute(sql_table_authorization_entries_jids)
            cur.execute(sql_table_report_entries)
            cur.execute(sql_table_report_jids)
            cur.execute(sql_trigger_instances_entry_decrease)
            cur.execute(sql_trigger_instances_entry_increase)
            cur.execute(sql_trigger_instances_entry_update)
            cur.execute(sql_trigger_instances_tag_decrease)
            cur.execute(sql_trigger_instances_tag_increase)
            cur.execute(sql_trigger_instances_tag_update)
            cur.execute(sql_trigger_entry_count_increase)
            cur.execute(sql_trigger_entry_count_decrease)
            cur.execute(sql_trigger_entry_count_update)
            cur.execute(sql_trigger_entry_remove)
            cur.execute(sql_trigger_jid_count_increase)
            cur.execute(sql_trigger_jid_count_decrease)
            cur.execute(sql_trigger_jid_count_update)
            cur.execute(sql_trigger_tag_count_increase)
            cur.execute(sql_trigger_tag_count_decrease)
            cur.execute(sql_trigger_tag_count_update)
            cur.execute(sql_trigger_tag_remove)

    def add_statistics(db_file):
        """
        Batch insertion of tags.
    
        Parameters
        ----------
        db_file : str
            Path to database file.
        entries : list
            Set of entries.

        Returns
        -------
        None.

        Note
        ----
        This function is executed immediately after the creation of the database
        and, therefore, the directive "async with DBLOCK:" is not necessary.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        sql = (
            """
            INSERT
            INTO main_statistics(
                type)
            VALUES ('entries'),
                    ('jids'),
                    ('tags');
            """
            )
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            try:
                cur.execute(sql)
            except IntegrityError as e:
                print(e)

    async def associate_entries_tags_jids(db_file, entry):
        async with DBLOCK:
            with SQLite.create_connection(db_file) as conn:
                cur = conn.cursor()
                jid = entry['jid']
                url_hash = entry['url_hash']
                entry_id = SQLite.get_entry_id_by_url_hash(db_file, url_hash)
                jid_id = SQLite.get_jid_id_by_jid(db_file, jid)
                if entry_id:
                    for tag in entry['tags']:
                        tag_id = SQLite.get_tag_id_by_tag(db_file, tag)
                        cet_id = SQLite.get_combination_id_by_entry_id_tag_id_jid_id(db_file, entry_id, tag_id, jid_id)
                        if not cet_id:
                            sql = (
                                """
                                INSERT
                                INTO combination_entries_tags_jids (
                                    entry_id, tag_id, jid_id)
                                VALUES (
                                    ?, ?, ?);
                                """
                                )
                            par = (entry_id, tag_id, jid_id)
                            try:
                                cur.execute(sql, par)
                            except IntegrityError as e:
                                print('associate_entries_tags_jids')
                                print(e)

    async def add_tags(db_file, entries):
        """
        Batch insertion of tags.
    
        Parameters
        ----------
        db_file : str
            Path to database file.
        entries : list
            Set of entries.

        Returns
        -------
        None.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        async with DBLOCK:
            with SQLite.create_connection(db_file) as conn:
                cur = conn.cursor()
                for entry in entries:
                    tags = entry['tags']
                    for tag in tags:
#                        sql = (
#                            """
#                            INSERT OR IGNORE INTO main_tags(tag) VALUES (?);
#                            """
#                            )
                        if not SQLite.get_tag_id_by_tag(db_file, tag):
                            sql = (
                                """
                                INSERT INTO main_tags(tag) VALUES(?);
                                """
                                )
                            par = (tag,)
                            try:
                                cur.execute(sql, par)
                            except IntegrityError as e:
                                print(e)

    async def add_new_entries(db_file, entries):
        """
        Batch insert of new entries into table entries.
    
        Parameters
        ----------
        db_file : str
            Path to database file.
        entries : list
            Set of entries.

        Returns
        -------
        None.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        async with DBLOCK:

            with SQLite.create_connection(db_file) as conn:
                cur = conn.cursor()

                for entry in entries:
                    url_hash = entry['url_hash']
                    url = entry['link']
                    title = entry['title']
                    summary = entry['summary']
                    jid = entry['jid']
                    date_first = entry['published']
                    date_last = entry['published']
    #               instances = entry['instances']

                    # Import entries
                    jid_id = SQLite.get_jid_id_by_jid(db_file, jid)
                    sql = (
                        """
                        INSERT
                        INTO main_entries(
                            url_hash, url, title, summary, jid_id, date_first, date_last)
                        VALUES(
                            ?, ?, ?, ?, ?, ?, ?);
                        """
                        )
                    par = (url_hash, url, title, summary, jid_id, date_first, date_last)

                    try:
                        cur.execute(sql, par)
                    except IntegrityError as e:
                        print(e)
                        print(jid_id)
                        print(entry)
#                        logger.warning("Skipping: " + str(url))
#                        logger.error(e)

    # TODO An additional function to ssociate jid_id (jid) with entry_id (hash_url)
    async def set_jid(db_file, jid):
        """
        Add a JID to database.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            A Jabber ID.

        Returns
        -------
        None.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {}'
#                    .format(function_name, db_file, jid))
        sql = (
            """
            INSERT
            INTO main_jids(
                jid)
            VALUES(
                ?);
            """
            )
        par = (jid, )
        async with DBLOCK:
            with SQLite.create_connection(db_file) as conn:
                cur = conn.cursor()
                try:
                    cur.execute(sql, par)
                except IntegrityError as e:
                    print(e)
#                            logger.warning("Skipping: " + str(url))
#                            logger.error(e)

    def get_entries_count(db_file):
        """
        Get entries count.

        Parameters
        ----------
        db_file : str
            Path to database file.

        Returns
        -------
        result : tuple
            Number.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        sql = (
            """
            SELECT count
            FROM main_statistics
            WHERE type = "entries";
            """
            )
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_combination_id_by_entry_id_tag_id_jid_id(db_file, entry_id, tag_id, jid_id):
        """
        Get ID by a given Entry ID and a given Tag ID and a given Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        entry_id : str
            Entry ID.
        tag_id : str
            Tag ID.
        jid_id : str
            Jabber ID.

        Returns
        -------
        result : tuple
            ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} entry_id: {} tag_id: {} jid_id: {}'
#                    .format(function_name, db_file, entry_id, tag_id, jid_id))
        sql = (
            """
            SELECT id
            FROM combination_entries_tags_jids
            WHERE entry_id = :entry_id AND tag_id = :tag_id AND jid_id = :jid_id;
            """
            )
        par = {
            "entry_id": entry_id,
            "tag_id": tag_id,
            "jid_id": jid_id
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    async def delete_combination_row_by_url_hash_and_tag_and_jid(db_file, url_hash, tags, jid):
        """
        Delete a row by a given entry ID and a given Jabber ID and given tags.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            URL hash.
        tags : list
            Tags.
        jid : str
            Jabber ID.

        Returns
        -------
        None.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} url_hash: {} tag_id: {} jid_id: {}'
#                    .format(function_name, db_file, url_hash, tag_id, jid_id))
        sql = (
            """
            DELETE
            FROM combination_entries_tags_jids
            WHERE
                entry_id = (SELECT id FROM main_entries WHERE url_hash = :url_hash) AND
                tag_id = (SELECT id FROM main_tags WHERE tag = :tag) AND
                jid_id = (SELECT id FROM main_jids WHERE jid = :jid);
            """
            )
        async with DBLOCK:
            with SQLite.create_connection(db_file) as conn:
                for tag in tags:
                    par = {
                        "url_hash": url_hash,
                        "tag": tag,
                        "jid": jid
                        }
                    cur = conn.cursor()
                    cur.execute(sql, par)

    def get_tag_id_and_instances_by_tag(db_file, tag):
        """
        Get a tag ID and instances by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            Tag.

        Returns
        -------
        result : tuple
            Tag ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT id, instances
            FROM main_tags
            WHERE tag = ?;
            """
            )
        par = (tag,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
#            return result[0] if result else None, None
            if not result: result = None, None
            return result

    def get_tags_and_instances_by_url_hash(db_file, url_hash):
        """
        Get tags and instances by a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            A hash of a URL.

        Returns
        -------
        result : tuple
            Tags and instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT mt.tag, mt.instances
            FROM main_tags AS mt
            INNER JOIN combination_entries_tags_jids AS co ON mt.id = co.tag_id
            INNER JOIN main_entries AS me ON me.id = co.entry_id
            WHERE me.url_hash = ?
            ORDER BY mt.instances DESC;
            """
            )
        par = (url_hash,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_tags_and_instances_by_entry_id(db_file, entry_id):
        """
        Get tags and instances by a given ID entry.

        Parameters
        ----------
        db_file : str
            Path to database file.
        entry_id : str
            An ID of an entry.

        Returns
        -------
        result : tuple
            Tags and instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT main_tags.tag, main_tags.instances
            FROM main_tags
            INNER JOIN combination_entries_tags_jids ON main_tags.id = combination_entries_tags_jids.tag_id
            WHERE combination_entries_tags_jids.entry_id = ?
            ORDER BY main_tags.instances DESC;
            """
            )
        par = (entry_id,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_jids_and_tags_by_entry_id(db_file, entry_id):
        """
        Get JIDs and tags by a given ID entry.

        Parameters
        ----------
        db_file : str
            Path to database file.
        entry_id : str
            An ID of an entry.

        Returns
        -------
        result : tuple
            JIDs and tags.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT main_jids.jid, main_tags.tag
            FROM main_tags
            INNER JOIN combination_entries_tags_jids ON main_tags.id = combination_entries_tags_jids.tag_id
            INNER JOIN main_jids ON main_jids.id = combination_entries_tags_jids.jid_id
            WHERE combination_entries_tags_jids.entry_id = ?
            ORDER BY main_tags.instances DESC;
            """
            )
        par = (entry_id,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_jids_and_tags_by_url_hash(db_file, url_hash):
        """
        Get JIDs and tags by a given URI hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            A URL hash of an entry.

        Returns
        -------
        result : tuple
            JIDs and tags.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT main_jids.jid, main_tags.tag
            FROM main_tags
            INNER JOIN combination_entries_tags_jids ON main_tags.id = combination_entries_tags_jids.tag_id
            INNER JOIN main_jids ON main_jids.id = combination_entries_tags_jids.jid_id
            INNER JOIN main_entries ON main_entries.id = combination_entries_tags_jids.entry_id
            WHERE main_entries.url_hash = ?
            ORDER BY main_tags.instances DESC;
            """
            )
        par = (url_hash,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_tag_id_by_tag(db_file, tag):
        """
        Get a tag ID by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            Tag.

        Returns
        -------
        result : tuple
            Tag ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT id
            FROM main_tags
            WHERE tag = ?;
            """
            )
        par = (tag,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entry_id_by_url_hash(db_file, url_hash):
        """
        Get an entry ID by a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            MD5 hash of URL.

        Returns
        -------
        result : tuple
            Entry ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} url_hash: {}'
#                    .format(function_name, db_file, url_hash))
        sql = (
            """
            SELECT id
            FROM main_entries
            WHERE url_hash = ?;
            """
            )
        par = (url_hash,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entry_instances_by_url_hash(db_file, url_hash):
        """
        Get value of entry instances by a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            MD5 hash of URL.

        Returns
        -------
        result : tuple
            Value of entry instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} url_hash: {}'
#                    .format(function_name, db_file, url_hash))
        sql = (
            """
            SELECT instances
            FROM main_entries
            WHERE url_hash = ?;
            """
            )
        par = (url_hash,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entry_by_url_hash(db_file, url_hash):
        """
        Get entry of a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        url_hash : str
            MD5 hash of URL.

        Returns
        -------
        result : tuple
            Entry properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} url_hash: {}'
#                    .format(function_name, db_file, url_hash))
        sql = (
            """
            SELECT *
            FROM main_entries
            WHERE url_hash = ?;
            """
            )
        par = (url_hash,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_new(db_file, index_first):
        """
        Get new entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT *
            FROM main_entries
            ORDER BY date_first DESC
            LIMIT 10
            OFFSET ?;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_popular(db_file, index_first):
        """
        Get popular entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT *
            FROM main_entries
            ORDER BY instances DESC
            LIMIT 10
            OFFSET ?;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_recent(db_file, index_first):
        """
        Get recent entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT *
            FROM main_entries
            ORDER BY date_last DESC
            LIMIT 10
            OFFSET ?;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_by_query(db_file, query, index_first):
        """
        Get entries by a query.

        Parameters
        ----------
        db_file : str
            Path to database file.
        query : str
            Search query.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT *
            FROM main_entries
            WHERE title LIKE :query OR url LIKE :query OR summary LIKE :query
            ORDER BY instances DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "query": f'%{query}%',
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_count_by_query(db_file, query):
        """
        Get entries count by a query.

        Parameters
        ----------
        db_file : str
            Path to database file.
        query : str
            Search query.

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        # NOTE Consider date_first
        sql = (
            """
            SELECT COUNT(id)
            FROM main_entries
            WHERE title LIKE :query OR url LIKE :query OR summary LIKE :query
            ORDER BY instances DESC;
            """
            )
        par = {
            "query": f'%{query}%',
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_by_jid_and_tag(db_file, jid, tag, index_first):
        """
        Get entries by a tag and a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            Tag.
        jid : str
            Jabber ID.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {} jid: {} index_first: {}'
#                    .format(function_name, db_file, tag, jid, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT DISTINCT me.*
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE mj.jid = :jid AND mt.tag = :tag
            ORDER BY instances DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "jid": jid,
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_count_by_jid_and_tag(db_file, jid, tag):
        """
        Get entries count by a tag and a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            Tag.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {} jid: {}'
#                    .format(function_name, db_file, tag, jid))
        # NOTE Consider date_first
        sql = (
            """
            SELECT COUNT(DISTINCT me.id)
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE mj.jid = :jid AND mt.tag = :tag;
            """
            )
        par = {
            "jid": jid,
            "tag": tag
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_by_jid_and_query(db_file, jid, query, index_first):
        """
        Get entries by a query and a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        query : str
            Search query.
        jid : str
            Jabber ID.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} query: {} jid: {} index_first: {}'
#                    .format(function_name, db_file, query, jid, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT DISTINCT me.*
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            WHERE mj.jid = :jid AND (title LIKE :query OR url LIKE :query OR summary LIKE :query)
            ORDER BY instances DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "jid": jid,
            "query": f'%{query}%',
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_count_by_jid_and_query(db_file, jid, query):
        """
        Get entries count by a query and a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        query : str
            Search query.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} query: {} jid: {}'
#                    .format(function_name, db_file, query, jid))
        # NOTE Consider date_first
        sql = (
            """
            SELECT COUNT(DISTINCT me.id)
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            WHERE mj.jid = :jid AND (title LIKE :query OR url LIKE :query OR summary LIKE :query);
            """
            )
        par = {
            "jid": jid,
            "query": f'%{query}%'
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_by_jid(db_file, jid, index_first):
        """
        Get entries by a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {} index_first: {}'
#                    .format(function_name, db_file, jid, index_first))
        # NOTE Consider date_first
        sql = (
            """
            SELECT DISTINCT me.*
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            WHERE mj.jid = :jid
            ORDER BY instances DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "jid": jid,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_count_by_jid(db_file, jid):
        """
        Get entries count by a Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Entries properties.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {}'
#                    .format(function_name, db_file, jid))
        # NOTE Consider date_first
        sql = (
            """
            SELECT COUNT(DISTINCT me.id)
            FROM main_entries AS me
            INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
            INNER JOIN main_jids AS mj ON mj.id = co.jid_id
            WHERE mj.jid = :jid;
            """
            )
        par = {
            "jid": jid
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_count_by_tag(db_file, tag):
        """
        Get entries count by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            A tag.

        Returns
        -------
        result : tuple
            Entries.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT COUNT(entries.id)
            FROM main_entries AS entries
            INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
            INNER JOIN main_tags AS tags ON tags.id = co.tag_id
            WHERE tags.tag = :tag;
            """
            )
        par = (tag,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_entries_popular_by_tag(db_file, tag, index_first):
        """
        Get popular entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            A tag.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT DISTINCT entries.*
            FROM main_entries AS entries
            INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
            INNER JOIN main_tags AS tags ON tags.id = co.tag_id
            WHERE tags.tag = :tag
            ORDER BY entries.instances DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_recent_by_tag(db_file, tag, index_first):
        """
        Get recent entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            A tag.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT DISTINCT entries.*
            FROM main_entries AS entries
            INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
            INNER JOIN main_tags AS tags ON tags.id = co.tag_id
            WHERE tags.tag = :tag
            ORDER BY date_last DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_entries_new_by_tag(db_file, tag, index_first):
        """
        Get new entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        tag : str
            A tag.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Entries.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} tag: {}'
#                    .format(function_name, db_file, tag))
        sql = (
            """
            SELECT DISTINCT entries.*
            FROM main_entries AS entries
            INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
            INNER JOIN main_tags AS tags ON tags.id = co.tag_id
            WHERE tags.tag = :tag
            ORDER BY date_first DESC
            LIMIT 10
            OFFSET :index_first;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_tags_30(db_file):
        """
        Get 30 tags.

        Parameters
        ----------
        db_file : str
            Path to database file.

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT tag, instances
            FROM main_tags
            ORDER BY instances DESC
            LIMIT 30;
            """
            )
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql).fetchall()
            return result

    def get_30_tags_by_entries_popular(db_file, index_first):
        """
        Get 30 tags by currently viewed popular entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT id
                FROM main_entries
                ORDER BY instances DESC
                LIMIT 10
                OFFSET ?
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_new_by_tag(db_file, tag, index_first):
        """
        Get 30 tags by currently viewed new entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT DISTINCT entries.id
                FROM main_entries AS entries
                INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
                INNER JOIN main_tags AS tags ON tags.id = co.tag_id
                WHERE tags.tag = :tag
                ORDER BY date_first DESC
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_popular_by_tag(db_file, tag, index_first):
        """
        Get 30 tags by currently viewed popular entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT DISTINCT entries.id
                FROM main_entries AS entries
                INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
                INNER JOIN main_tags AS tags ON tags.id = co.tag_id
                WHERE tags.tag = :tag
                ORDER BY entries.instances DESC
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_recent_by_tag(db_file, tag, index_first):
        """
        Get 30 tags by currently viewed recent entries by a given tag.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT DISTINCT entries.id
                FROM main_entries AS entries
                INNER JOIN combination_entries_tags_jids AS co ON entries.id = co.entry_id
                INNER JOIN main_tags AS tags ON tags.id = co.tag_id
                WHERE tags.tag = :tag
                ORDER BY date_last DESC
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_new(db_file, index_first):
        """
        Get 30 tags by currently viewed new entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT id
                FROM main_entries
                ORDER BY date_first DESC
                LIMIT 10
                OFFSET ?
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_recent(db_file, index_first):
        """
        Get 30 tags by currently viewed recent entries.

        Parameters
        ----------
        db_file : str
            Path to database file.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT id
                FROM main_entries
                ORDER BY date_last DESC
                LIMIT 10
                OFFSET ?
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = (index_first,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_entries_by_query_recent(db_file, query, index_first):
        """
        Get 30 tags by currently viewed entries by query.

        Parameters
        ----------
        db_file : str
            Path to database file.
        query : str
            A search query.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT id
                FROM main_entries
                WHERE title LIKE :query OR url LIKE :query OR summary LIKE :query
                ORDER BY instances DESC
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "query": f'%{query}%',
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_jid_and_tag(db_file, jid, tag, index_first):
        """
        Get 30 tags by Jabber ID and tags.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.
        tag : str
            A tag.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT co.entry_id
                FROM main_entries AS me
                INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
                INNER JOIN main_jids AS mj ON mj.id = co.jid_id
                INNER JOIN main_tags AS mt ON mt.id = co.tag_id
                WHERE mj.jid = :jid AND mt.tag = :tag
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "jid": jid,
            "tag": tag,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_jid_and_query(db_file, jid, query, index_first):
        """
        Get 30 tags by Jabber ID and query.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.
        query : str
            A search query.
        index_first : str
            .

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT co.entry_id
                FROM main_entries AS me
                INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
                INNER JOIN main_jids AS mj ON mj.id = co.jid_id
                INNER JOIN main_tags AS mt ON mt.id = co.tag_id
                WHERE mj.jid = :jid AND (title LIKE :query OR url LIKE :query OR summary LIKE :query)
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "jid": jid,
            "query": f'%{query}%',
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_30_tags_by_jid(db_file, jid, index_first):
        """
        Get 30 tags by Jabber ID.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT mt.tag, mt.instances
            FROM combination_entries_tags_jids AS co
            INNER JOIN main_tags AS mt ON mt.id = co.tag_id
            WHERE co.entry_id IN (
                SELECT DISTINCT me.id
                FROM main_entries AS me
                INNER JOIN combination_entries_tags_jids AS co ON co.entry_id = me.id
                INNER JOIN main_jids AS mj ON mj.id = co.jid_id
                WHERE mj.jid = :jid
                ORDER BY instances DESC
                LIMIT 10
                OFFSET :index_first
            )
            ORDER BY mt.instances DESC
            LIMIT 30;
            """
            )
        par = {
            "jid": jid,
            "index_first": index_first
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_tags_500(db_file):
        """
        Get 500 tags.

        Parameters
        ----------
        db_file : str
            Path to database file.

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {}'
#                    .format(function_name, db_file))
        sql = (
            """
            WITH Common500Tags AS (
                SELECT tag, instances
                FROM main_tags
                ORDER BY instances DESC
                LIMIT 500
            )
            SELECT tag, instances
            FROM Common500Tags
            ORDER BY tag ASC;
            """
            )
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql).fetchall()
            return result

    def get_500_tags_by_jid_sorted_by_name(db_file, jid):
        """
        Get 500 tags by Jabber ID, sorted by name.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT mt.tag, COUNT(*) AS instances
            FROM main_tags mt
            JOIN combination_entries_tags_jids combination ON mt.id = combination.tag_id
            JOIN main_jids mj ON combination.jid_id = mj.id
            WHERE mj.jid = :jid
            GROUP BY mt.tag
            LIMIT 500;
            """
            )
        par = {
            "jid": jid
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_500_tags_by_jid_sorted_by_instance(db_file, jid):
        """
        Get 500 tags by Jabber ID, sorted by instance.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            Tags and number of instances.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT mt.tag, COUNT(*) AS instances
            FROM main_tags mt
            JOIN combination_entries_tags_jids combination ON mt.id = combination.tag_id
            JOIN main_jids mj ON combination.jid_id = mj.id
            WHERE mj.jid = :jid
            GROUP BY mt.tag
            ORDER BY instances DESC
            LIMIT 500;
            """
            )
        par = {
            "jid": jid
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    # FIXME It appear that the wrong table is fetched
    # The table to be fetched is combination_entries_tags_jids
    def is_jid_associated_with_url_hash(db_file, jid, url_hash):
        """
        Check whether a given Jabber ID is associated with a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            A Jabber ID.
        url_hash : str
            An MD5 checksuum of a URL.

        Returns
        -------
        result : tuple
            Tags.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {} url_hash: {}'
#                    .format(function_name, db_file, jid, url_hash))
        sql = (
            """
            SELECT mj.jid, me.url_hash
            FROM main_jids AS mj
            INNER JOIN combination_entries_tags_jids AS co ON mj.id = co.jid_id
            INNER JOIN main_entries AS me ON me.id = co.entry_id
            WHERE mj.jid = :jid AND me.url_hash = :url_hash;
            """
            )
        par = {
            "jid": jid,
            "url_hash": url_hash
            }
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    #deassociate_entry_from_jid
    async def delete_combination_row_by_jid_and_url_hash(db_file, url_hash, jid):
        """
        Remove association of a given Jabber ID and a given URL hash.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            A Jabber ID.
        url_hash : str
            An MD5 checksuum of a URL.

        Returns
        -------
        None.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {} url_hash: {}'
#                    .format(function_name, db_file, jid, url_hash))
        sql = (
            """
            DELETE FROM combination_entries_tags_jids
            WHERE id IN (
                SELECT co.id
                FROM combination_entries_tags_jids co
                JOIN main_entries me ON co.entry_id = me.id
                JOIN main_jids mj ON co.jid_id = mj.id
                WHERE me.url_hash = :url_hash AND mj.jid = :jid
            );
            """
            )
        par = {
            "jid": jid,
            "url_hash": url_hash
            }
        async with DBLOCK:
            with SQLite.create_connection(db_file) as conn:
                cur = conn.cursor()
                cur.execute(sql, par)

    # NOTE The result was ordered by number of instances
    #      ORDER BY main_tags.instances DESC
    #      And has been changed to order of alphabet
    #      ORDER BY main_tags.tag ASC
    def get_tags_by_entry_id(db_file, entry_id):
        """
        Get tags by an ID entry.

        Parameters
        ----------
        db_file : str
            Path to database file.
        entry_id : str
            An ID of an entry.

        Returns
        -------
        result : tuple
            Tags.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} index_first: {}'
#                    .format(function_name, db_file, index_first))
        sql = (
            """
            SELECT DISTINCT main_tags.tag
            FROM main_tags
            INNER JOIN combination_entries_tags_jids ON main_tags.id = combination_entries_tags_jids.tag_id
            WHERE combination_entries_tags_jids.entry_id = ?
            ORDER BY main_tags.tag ASC
            LIMIT 5;
            """
            )
        par = (entry_id,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchall()
            return result

    def get_jid_id_by_jid(db_file, jid):
        """
        Get id of a given jid.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid : str
            Jabber ID.

        Returns
        -------
        result : tuple
            ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid: {}'
#                    .format(function_name, db_file, jid))
        sql = (
            """
            SELECT id
            FROM main_jids
            WHERE jid = ?;
            """
            )
        par = (jid,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

    def get_jid_by_jid_id(db_file, jid_id):
        """
        Get jid of a given jid_id.

        Parameters
        ----------
        db_file : str
            Path to database file.
        jid_id : str
            ID of Jabber ID.

        Returns
        -------
        result : tuple
            ID.
        """
        function_name = sys._getframe().f_code.co_name
#        logger.debug('{}: db_file: {} jid_id: {}'
#                    .format(function_name, db_file, jid_id))
        sql = (
            """
            SELECT jid
            FROM main_jids
            WHERE id = ?;
            """
            )
        par = (jid_id,)
        with SQLite.create_connection(db_file) as conn:
            cur = conn.cursor()
            result = cur.execute(sql, par).fetchone()
            return result[0] if result and len(result) == 1 else result

class Syndication:

    def create_rfc4287_entry(feed_entry):
        node_entry = ET.Element('entry')
        node_entry.set('xmlns', 'http://www.w3.org/2005/Atom')
        # Title
        title = ET.SubElement(node_entry, 'title')
        title.set('type', 'text')
        title.text = feed_entry['title']
        # Summary
        summary = ET.SubElement(node_entry, 'summary') # TODO Try 'content'
        summary.set('type', 'text')
        #summary.set('lang', feed_entry['summary_lang'])
        summary.text = feed_entry['summary']
        # Tags
        if feed_entry['tags']:
            for term in feed_entry['tags']:
                tag = ET.SubElement(node_entry, 'category')
                tag.set('term', term)
        # Link
        link = ET.SubElement(node_entry, "link")
        link.set('href', feed_entry['link'])
        # Links
#        for feed_entry_link in feed_entry['links']:
#            link = ET.SubElement(node_entry, "link")
#            link.set('href', feed_entry_link['url'])
#            link.set('type', feed_entry_link['type'])
#            link.set('rel', feed_entry_link['rel'])
        # Date saved
        if 'published' in feed_entry and feed_entry['published']:
            published = ET.SubElement(node_entry, 'published')
            published.text = feed_entry['published']
        # Date edited
        if 'updated' in feed_entry and feed_entry['updated']:
            updated = ET.SubElement(node_entry, 'updated')
            updated.text = feed_entry['updated']
        return node_entry

    def extract_items(item_payload, limit=False):
        namespace = '{http://www.w3.org/2005/Atom}'
        title = item_payload.find(namespace + 'title')
        links = item_payload.find(namespace + 'link')
        if (not isinstance(title, ET.Element) and
            not isinstance(links, ET.Element)): return None
        title_text = '' if title == None else title.text
        if isinstance(links, ET.Element):
            for link in item_payload.findall(namespace + 'link'):
                link_href = link.attrib['href'] if 'href' in link.attrib else ''
                if link_href: break
        contents = item_payload.find(namespace + 'summary')
        summary_text = ''
        if isinstance(contents, ET.Element):
            for summary in item_payload.findall(namespace + 'summary'):
                summary_text = summary.text or ''
                if summary_text: break
        published = item_payload.find(namespace + 'published')
        published_text = '' if published == None else published.text
        categories = item_payload.find(namespace + 'category')
        tags = []
        if isinstance(categories, ET.Element):
            for category in item_payload.findall(namespace + 'category'):
                if 'term' in category.attrib and category.attrib['term']:
                    category_term = category.attrib['term']
                    if len(category_term) < 20:
                        tags.append(category_term)
                    elif len(category_term) < 50:
                        tags.append(category_term)
                    if limit and len(tags) > 4: break
    
    
        identifier = item_payload.find(namespace + 'id')
        if identifier and identifier.attrib: print(identifier.attrib)
        identifier_text = '' if identifier == None else identifier.text
    
        instances = '' # TODO Check the Blasta database for instances.
    
        entry = {'title' : title_text,
                 'link' : link_href,
                 'summary' : summary_text,
                 'published' : published_text,
                 'updated' : published_text, # TODO "Updated" is missing
                 'tags' : tags}
        return entry

class Utilities:

    def convert_iso8601_to_readable(timestamp):
        old_date_format = datetime.fromisoformat(timestamp.replace("Z", "+00:00"))
        new_date_format = old_date_format.strftime("%B %d, %Y")
        return new_date_format

    def hash_url_to_md5(url):
        url_encoded = url.encode()
        url_hashed = hashlib.md5(url_encoded)
        url_digest = url_hashed.hexdigest()
        return url_digest

    def is_jid_matches_to_session(accounts, sessions, request):
        jabber_id = request.cookies.get('jabber_id')
        session_key = request.cookies.get('session_key')
        if (jabber_id and
            jabber_id in accounts and
            jabber_id in sessions and
            session_key == sessions[jabber_id]):
            return jabber_id

class Xml:

    def create_setting_entry(value : str):
        element = ET.Element('value')
        element.text = value
        return element

class Configuration:

    def instantiate_database(db_file):
#        db_dir = get_default_data_directory()
#        if not os.path.isdir(db_dir):
#            os.mkdir(db_dir)
#        if not os.path.isdir(db_dir + "/sqlite"):
#            os.mkdir(db_dir + "/sqlite")
#        db_file = os.path.join(db_dir, "sqlite", r"{}.db".format(jid_file))
        SQLite.create_tables(db_file)
        SQLite.add_statistics(db_file)
        return db_file

class XmppInstance(ClientXMPP):
    def __init__(self, jid, password):
        super().__init__(jid, password)
        #self.add_event_handler("connection_failed", self.on_connection_failed)
        #self.add_event_handler("failed_auth", self.on_failed_auth)
        self.add_event_handler("session_start", self.on_session_start)
        self.register_plugin('xep_0004') # XEP-0004: Data Forms
        self.register_plugin('xep_0030') # XEP-0030: Service Discovery
        self.register_plugin('xep_0059') # XEP-0059: Result Set Management
        self.register_plugin('xep_0060') # XEP-0060: Publish-Subscribe
        self.register_plugin('xep_0078') # XEP-0078: Non-SASL Authentication
        self.register_plugin('xep_0163') # XEP-0163: Personal Eventing Protocol
        self.register_plugin('xep_0223') # XEP-0223: Persistent Storage of Private Data via PubSub
        self.connect()
        # self.process(forever=False)

        self.connection_accepted = False

#    def on_connection_failed(self, event):
#        self.connection_accepted = False

#    def on_failed_auth(self, event):
#        self.connection_accepted = False

    def on_session_start(self, event):
        self.connection_accepted = True

class XmppMessage:

    def send(self, jid, message_body):
        jid_from = str(self.boundjid) if self.is_component else None
        self.send_message(
            mto=jid,
            mfrom=jid_from,
            mbody=message_body,
            mtype='chat')

    # NOTE It appears to not work.
    def send_headline(self, jid, message_subject, message_body):
        jid_from = str(self.boundjid) if self.is_component else None
        self.send_message(
            mto=jid,
            mfrom=jid_from,
            msubject=message_subject,
            mbody=message_body,
            mtype='headline')

class XmppPubsub:

    # TODO max-items might be limited (CanChat: 255), so iterate from a bigger number to a smaller.
    # NOTE This function was copied from atomtopubsub
    def create_node_atom(xmpp_instance, jid, node, title, subtitle, access_model):
        jid_from = str(xmpp_instance.boundjid) if xmpp_instance.is_component else None
        iq = xmpp_instance.Iq(stype='set',
                              sto=jid,
                              sfrom=jid_from)
        iq['pubsub']['create']['node'] = node
        form = iq['pubsub']['configure']['form']
        form['type'] = 'submit'
        form.addField('pubsub#access_model',
                        ftype='list-single',
                        value=access_model)
        form.addField('pubsub#deliver_payloads',
                        ftype='boolean',
                        value=0)
        form.addField('pubsub#description',
                        ftype='text-single',
                        value=subtitle)
        form.addField('pubsub#max_items',
                        ftype='text-single',
                        value='255')
        form.addField('pubsub#notify_retract',
                        ftype='boolean',
                        value=1)
        form.addField('pubsub#persist_items',
                        ftype='boolean',
                        value=1)
        form.addField('pubsub#send_last_published_item',
                        ftype='text-single',
                        value='never')
        form.addField('pubsub#title',
                        ftype='text-single',
                        value=title)
        form.addField('pubsub#type',
                        ftype='text-single',
                        value='http://www.w3.org/2005/Atom')
        return iq

    def create_node_config(xmpp_instance, jid):
        jid_from = str(xmpp_instance.boundjid) if xmpp_instance.is_component else None
        iq = xmpp_instance.Iq(stype='set',
                              sto=jid,
                              sfrom=jid_from)
        iq['pubsub']['create']['node'] = 'xmpp:blasta:settings:0'
        form = iq['pubsub']['configure']['form']
        form['type'] = 'submit'
        form.addField('pubsub#access_model',
                        ftype='list-single',
                        value='whitelist')
        form.addField('pubsub#deliver_payloads',
                        ftype='boolean',
                        value=0)
        form.addField('pubsub#description',
                        ftype='text-single',
                        value='Settings of the Blasta PubSub bookmarks system')
        form.addField('pubsub#max_items',
                        ftype='text-single',
                        value='30')
        form.addField('pubsub#notify_retract',
                        ftype='boolean',
                        value=1)
        form.addField('pubsub#persist_items',
                        ftype='boolean',
                        value=1)
        form.addField('pubsub#send_last_published_item',
                        ftype='text-single',
                        value='never')
        form.addField('pubsub#title',
                        ftype='text-single',
                        value='Blasta Settings')
        form.addField('pubsub#type',
                        ftype='text-single',
                        value='settings')
        return iq

    async def del_node_item(xmpp_instance, pubsub, node, item_id):
        try:
            iq = await xmpp_instance.plugin['xep_0060'].retract(
                pubsub, node, item_id, timeout=5, notify=None)
            result = iq
        except IqError as e:
            result = e.iq['error']['text']
            print(e)
        except IqTimeout as e:
            result = 'Timeout'
            print(e)
        print(result)
        return result
    
    def get_iterator(xmpp_instance, pubsub, node, max_items, iterator):
        iterator = xmpp_instance.plugin['xep_0060'].get_items(
            pubsub, node, timeout=5, max_items=max_items, iterator=iterator)
        return iterator

    async def get_node_configuration(xmpp_instance, pubsub, node):
        try:
          iq = await xmpp_instance.plugin['xep_0060'].get_node_config(
              pubsub, node)
          return iq
        except (IqError, IqTimeout) as e:
          print(e)

    async def get_node_item(xmpp_instance, pubsub, node, item_id):
        try:
            iq = await xmpp_instance.plugin['xep_0060'].get_item(
                pubsub, node, item_id, timeout=5)
            result = iq
        except IqError as e:
            result = e.iq['error']['text']
            print(e)
        except IqTimeout as e:
            result = 'Timeout'
            print(e)
        return result

    async def get_node_item_ids(xmpp_instance, pubsub, node):
        try:
            iq = await xmpp_instance.plugin['xep_0030'].get_items(
                pubsub, node)
            # Broken. See https://codeberg.org/poezio/slixmpp/issues/3548
            #iq = await xmpp_instance.plugin['xep_0060'].get_item_ids(
            #    pubsub, node, timeout=5)
            result = iq
        except IqError as e:
            if e.iq['error']['text'] == 'Node not found':
                result = 'Node not found'
            elif e.iq['error']['condition'] == 'item-not-found':
                result = 'Item not found'
            else:
                result = None
            print(e)
        except IqTimeout as e:
            result = 'Timeout'
            print(e)
        return result

    async def get_node_item_private(xmpp_instance, node, item_id):
        try:
            iq = await xmpp_instance.plugin['xep_0223'].retrieve(
                node, item_id, timeout=5)
            result = iq
        except IqError as e:
            result = e.iq['error']['text']
            print(e)
        except IqTimeout as e:
            result = 'Timeout'
            print(e)
        return result
    
    async def get_node_items(xmpp_instance, pubsub, node, item_ids=None, max_items=None):
        try:
            if max_items:
                iq = await xmpp_instance.plugin['xep_0060'].get_items(
                    pubsub, node, timeout=5)
                it = xmpp_instance.plugin['xep_0060'].get_items(
                    pubsub, node, timeout=5, max_items=max_items, iterator=True)
                q = rsm.Iq()
                q['to'] = pubsub
                q['disco_items']['node'] = node
                async for item in rsm.ResultIterator(q, 'disco_items', '10'):
                    print(item['disco_items']['items'])

            else:
                iq = await xmpp_instance.plugin['xep_0060'].get_items(
                    pubsub, node, timeout=5, item_ids=item_ids)
            result = iq
        except IqError as e:
            if e.iq['error']['text'] == 'Node not found':
                result = 'Node not found'
            elif e.iq['error']['condition'] == 'item-not-found':
                result = 'Item not found'
            else:
                result = None
            print(e)
        except IqTimeout as e:
            result = 'Timeout'
            print(e)
        return result

    async def get_nodes(xmpp_instance):
        try:
          iq = await xmpp_instance.plugin['xep_0060'].get_nodes()
          return iq
        except (IqError, IqTimeout) as e:
          print(e)

    async def is_node_exist(xmpp_instance, node_name):
        iq = await XmppPubsub.get_nodes(xmpp_instance)
        nodes = iq['disco_items']['items']
        for node in nodes:
            if node[1] == node_name:
                return True

    async def publish_node_item(xmpp_instance, jid, node, item_id, payload):
        try:
          iq = await xmpp_instance.plugin['xep_0060'].publish(
                jid, node, id=item_id, payload=payload)
          print(iq)
          return iq
        except (IqError, IqTimeout) as e:
          print(e)

    async def publish_node_item_private(xmpp_instance, node, item_id, stanza):
        try:
          iq = await xmpp_instance.plugin['xep_0223'].store(
                stanza, node, item_id)
          print(iq)
          return iq
        except (IqError, IqTimeout) as e:
          print(e)
          if e.iq['error']['text'] == 'Field does not match: access_model':
              return 'Error: Could not set private bookmark due to Access Model mismatch'

    async def set_node_private(xmpp_instance, node):
        try:
          iq = await xmpp_instance.plugin['xep_0223'].configure(node)
          print(iq)
          return iq
        except (IqError, IqTimeout) as e:
          print(e)

def main():
    if not exists('main.sqlite') or not getsize('main.sqlite'):
        Configuration.instantiate_database('main.sqlite')
    accounts = {}
    sessions = {}
    http_instance = HttpInstance(accounts, sessions)
    return http_instance.app

app = main()
webbrowser.open('http://localhost:8000/help/about')
# TODO Check first time
webbrowser.open_new_tab('http://localhost:8000')

# FIXME
if __name__ == '__main__':
    uvicorn.run(app, host='localhost', port=8000, reload=True)