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

import sqlite3
import asyncio

from sqlite3 import Error
from datetime import date

import confighandler

# from eliot import start_action, to_file
# # with start_action(action_type="list_subscriptions()", db=db_file):
# # with start_action(action_type="last_entries()", num=num):
# # with start_action(action_type="get_subscriptions()"):
# # with start_action(action_type="remove_entry()", source=source):
# # with start_action(action_type="search_entries()", query=query):
# # with start_action(action_type="check_entry()", link=link):

# aiosqlite
DBLOCK = asyncio.Lock()

CURSORS = {}

def create_connection(db_file):
    """
    Create a database connection to the SQLite database
    specified by db_file.
    
    :param db_file: Database filename.
    :return: Connection object or None.
    """
    conn = None
    try:
        conn = sqlite3.connect(db_file)
        return conn
    except Error as e:
        print(e)
    return conn


def create_tables(db_file):
    """
    Create SQLite tables.

    :param db_file: Database filename.
    """
    with create_connection(db_file) as conn:
        feeds_table_sql = """
            CREATE TABLE IF NOT EXISTS feeds (
                id integer PRIMARY KEY,
                name text,
                address text NOT NULL,
                enabled integer NOT NULL,
                scanned text,
                updated text,
                status integer,
                valid integer
            ); """
        entries_table_sql = """
            CREATE TABLE IF NOT EXISTS entries (
                id integer PRIMARY KEY,
                title text NOT NULL,
                summary text NOT NULL,
                link text NOT NULL,
                source text,
                read integer
            ); """
        # statistics_table_sql = """
        #     CREATE TABLE IF NOT EXISTS statistics (
        #         id integer PRIMARY KEY,
        #         title text NOT NULL,
        #         number integer
        #     ); """
        settings_table_sql = """
            CREATE TABLE IF NOT EXISTS settings (
                id integer PRIMARY KEY,
                key text NOT NULL,
                value integer
            ); """
        cur = conn.cursor()
        # cur = get_cursor(db_file)
        cur.execute(feeds_table_sql)
        cur.execute(entries_table_sql)
        # cur.execute(statistics_table_sql)
        cur.execute(settings_table_sql)


def get_cursor(db_file):
    """
    Allocate a cursor to connection per database.

    :param db_file: Database filename.
    :return: Cursor.
    """
    if db_file in CURSORS:
        return CURSORS[db_file]
    else:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            CURSORS[db_file] = cur
    return CURSORS[db_file]


async def add_feed(db_file, title, url, res):
    """
    Add a new feed into the feeds table.

    :param db_file: Database filename.
    :param title: Feed title.
    :param url: URL.
    :param res: XML document.
    :return: Message.
    """
    #TODO consider async with DBLOCK
    #conn = create_connection(db_file)

    # with create_connection(db_file) as conn:
    #     #exist = await check_feed_exist(conn, url)
    #     exist = await check_feed_exist(db_file, url)

    # if not exist:
    #     res = await main.download_feed(url)
    # else:
    #     return "News source is already listed in the subscription list"

    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            # title = feed["feed"]["title"]
            feed = (title, url, 1, res[1], 1)
            sql = """INSERT INTO feeds(name, address, enabled, status, valid)
                     VALUES(?, ?, ?, ?, ?) """
            cur.execute(sql, feed)

    source = title if title else '<' + url + '>'
    msg = """> {}\nNews source \"{}\" has been added to subscription list.
          """.format(url, source)
    return msg


async def remove_feed(db_file, ix):
    """
    Delete a feed by feed id.

    :param db_file: Database filename.
    :param ix: Index of feed.
    :return: Message.
    """
    with create_connection(db_file) as conn:
        async with DBLOCK:
            cur = conn.cursor()
            try:
                sql = "SELECT address FROM feeds WHERE id = ?"
                # cur
                # for i in url:
                #     url = i[0]
                url = cur.execute(sql, (ix,)).fetchone()[0]
                sql = "SELECT name FROM feeds WHERE id = ?"
                name = cur.execute(sql, (ix,)).fetchone()[0]
                # NOTE Should we move DBLOCK to this line? 2022-12-23
                sql = "DELETE FROM entries WHERE source = ?"
                cur.execute(sql, (url,))
                sql = "DELETE FROM feeds WHERE id = ?"
                cur.execute(sql, (ix,))
                msg = "> {}\nNews source \"{}\" has been removed from subscription list.".format(url, name)
            except:
                msg = "No news source with ID {}.".format(ix)
    return msg


async def check_feed_exist(db_file, url):
    """
    Check whether a feed exists.
    Query for feeds by given url.

    :param db_file: Database filename.
    :param url: URL.
    :return: Index ID and Name or None.
    """
    cur = get_cursor(db_file)
    sql = "SELECT id, name FROM feeds WHERE address = ?"
    result = cur.execute(sql, (url,)).fetchone()
    return result


async def get_number_of_items(db_file, str):
    """
    Return number of entries or feeds.

    :param cur: Cursor object.
    :param str: "entries" or "feeds".
    :return: Number of rows.
    """
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT count(id) FROM {}".format(str)
        count = cur.execute(sql).fetchone()[0]
        return count


async def get_number_of_feeds_active(db_file):
    """
    Return number of active feeds.

    :param db_file: Database filename.
    :param cur: Cursor object.
    :return: Number of rows.
    """
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT count(id) FROM feeds WHERE enabled = 1"
        count = cur.execute(sql).fetchone()[0]
        return count


async def get_number_of_entries_unread(db_file):
    """
    Return number of unread items.
    
    :param db_file: Database filename.
    :param cur: Cursor object.
    :return: Number of rows.
    """
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT count(id) FROM entries WHERE read = 0"
        count = cur.execute(sql).fetchone()[0]
        return count


async def get_entry_unread(db_file):
    """
    Check read status of entry.
    
    :param db_file: Database filename.
    :return: News item as message.
    """
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT id FROM entries WHERE read = 0"
        ix = cur.execute(sql).fetchone()
        if ix is None:
            return False
        ix = ix[0]
        sql = "SELECT title FROM entries WHERE id = :id"
        title = cur.execute(sql, (ix,)).fetchone()[0]
        sql = "SELECT summary FROM entries WHERE id = :id"
        summary = cur.execute(sql, (ix,)).fetchone()[0]
        sql = "SELECT link FROM entries WHERE id = :id"
        link = cur.execute(sql, (ix,)).fetchone()[0]
        entry = "{}\n\n{}\n\n{}".format(title, summary, link)
        async with DBLOCK:
            await mark_as_read(cur, ix)
        # async with DBLOCK:
        #     await update_statistics(db_file)
        return entry


async def mark_as_read(cur, ix):
    """
    Set read status of entry.
    
    :param cur: Cursor object.
    :param ix: Index of entry.
    """
    sql = "UPDATE entries SET summary = '', read = 1 WHERE id = ?"
    cur.execute(sql, (ix,))


async def statistics(db_file):
    """
    Return table statistics.

    :param db_file: Database filename.
    :return: News item as message.
    """
    feeds = await get_number_of_items(db_file, 'feeds')
    active_feeds = await get_number_of_feeds_active(db_file)
    entries = await get_number_of_items(db_file, 'entries')
    unread_entries = await get_number_of_entries_unread(db_file)
    # msg = """You have {} unread news items out of {} from {} news sources.
    #       """.format(unread_entries, entries, feeds)
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT value FROM settings WHERE key = \"enabled\""
        status = cur.execute(sql).fetchone()[0]
        sql = "SELECT value FROM settings WHERE key = \"interval\""
        interval = cur.execute(sql).fetchone()[0]
        msg = """News items: {} ({})\nNews sources: {} ({})\nUpdate interval: {}\nOperation status: {}
              """.format(unread_entries, entries, active_feeds, feeds, interval, status)
    return msg


#TODO statistics
async def update_statistics(cur):
    """
    Update table statistics.
    
    :param cur: Cursor object.
    """
    stat_dict = {}
    stat_dict["feeds"] = await get_number_of_items(cur, 'feeds')
    stat_dict["entries"] = await get_number_of_items(cur, 'entries')
    stat_dict["unread"] = await get_number_of_entries_unread(cur=cur)
    for i in stat_dict:
        sql = "SELECT id FROM statistics WHERE title = ?"
        cur.execute(sql, (i,))
        if cur.fetchone():
            sql = "UPDATE statistics SET number = :num WHERE title = :title"
            cur.execute(sql, {"title": i, "num": stat_dict[i]})
        else:
            sql = "SELECT count(id) FROM statistics"
            count = cur.execute(sql).fetchone()[0]
            ix = count + 1
            sql = "INSERT INTO statistics VALUES(?,?,?)"
            cur.execute(sql, (ix, i, stat_dict[i]))


# TODO mark_all_read for entries of feed
async def toggle_status(db_file, ix):
    """
    Toggle status of feed.
    
    :param db_file: Database filename.
    :param ix: Index of entry.
    :return: Message
    """
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            try:
                #cur = get_cursor(db_file)
                sql = "SELECT name FROM feeds WHERE id = :id"
                title = cur.execute(sql, (ix,)).fetchone()[0]
                sql = "SELECT enabled FROM feeds WHERE id = ?"
                # NOTE [0][1][2]
                status = cur.execute(sql, (ix,)).fetchone()[0]
                # FIXME always set to 1
                # NOTE Maybe because is not integer
                # TODO Reset feed table before further testing
                if status == 1:
                    status = 0
                    state =  "disabled"
                else:
                    status = 1
                    state = "enabled"
                sql = "UPDATE feeds SET enabled = :status WHERE id = :id"
                cur.execute(sql, {"status": status, "id": ix})
                msg = "Updates for '{}' are now {}.".format(title, state)
            except:
                msg = "No news source with ID {}.".format(ix)
    return msg


async def set_date(cur, url):
    """
    Set last update date of feed.

    :param cur: Cursor object.
    :param url: URL.
    """
    today = date.today()
    sql = "UPDATE feeds SET updated = :today WHERE address = :url"
    # cur = conn.cursor()
    cur.execute(sql, {"today": today, "url": url})


async def add_entry_and_set_date(db_file, source, entry):
    """
    TODO
    """
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            await add_entry(cur, entry)
            await set_date(cur, source)


async def update_source_status(db_file, status, source):
    """
    TODO
    """
    sql = "UPDATE feeds SET status = :status, scanned = :scanned WHERE address = :url"
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            cur.execute(sql, {"status": status, "scanned": date.today(), "url": source})


async def update_source_validity(db_file, source, valid):
    """
    TODO
    """
    sql = "UPDATE feeds SET valid = :validity WHERE address = :url"
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            cur.execute(sql, {"validity": valid, "url": source})


async def add_entry(cur, entry):
    """
    Add a new entry into the entries table.

    :param cur: Cursor object.
    :param entry:
    """
    sql = """ INSERT INTO entries(title, summary, link, source, read)
              VALUES(?, ?, ?, ?, ?) """
    cur.execute(sql, entry)


# This function doesn't work as expected with bbs and wiki feeds
async def remove_entry(db_file, source, length):
    """
    Maintain list of entries equal to feed.
    Check the number returned by feed and delete
    existing entries up to the same returned amount.
    
    :param db_file: Database filename.
    :param source:
    :param length:
    :return:
    """
    # FIXED
    # Dino empty titles are not counted https://dino.im/index.xml
    # SOLVED
    # Add text if is empty
    # title = '*** No title ***' if not entry.title else entry.title
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            sql = "SELECT count(id) FROM entries WHERE source = ?"
            count = cur.execute(sql, (source,)).fetchone()[0]
            limit = count - length
            if limit:
                limit = limit;
                sql = """DELETE FROM entries WHERE id IN (
                         SELECT id FROM entries
                         WHERE source = :source
                         ORDER BY id
                         ASC LIMIT :limit)"""
                cur.execute(sql, {"source": source, "limit": limit})


async def remove_nonexistent_entries(db_file, feed, source):
    """
    Remove entries that don't exist in a given parsed feed.
    Check the entries returned from feed and delete non
    existing entries

    :param db_file: Database filename.
    :param feed: URL of parsed feed.
    :param source: URL of associated feed.
    """
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            sql = "SELECT id, title, link FROM entries WHERE source = ?"
            entries_db = cur.execute(sql, (source,)).fetchall()
            for entry_db in entries_db:
                exist = False
                for entry_feed in feed.entries:
                    # TODO better check and don't repeat code
                    if entry_feed.has_key("title"):
                        title = entry_feed.title
                    else:
                        title = feed["feed"]["title"]
    
                    if entry_feed.has_key("link"):
                        link = entry_feed.link
                    else:
                        link = source
                    # TODO better check and don't repeat code
                    if entry_db[1] == title and entry_db[2] == link:
                        exist = True
                        break
                if not exist:
                    # TODO Send to table archive
                    # TODO Also make a regular/routine check for sources that have been changed (though that can only happen when manually editing)
                    sql = "DELETE FROM entries WHERE id = ?"
                    cur.execute(sql, (entry_db[0],))


async def get_subscriptions(db_file):
    """
    Query table feeds.
    
    :param db_file: Database filename.
    :return: List of feeds.
    """
    with create_connection(db_file) as conn:
        cur = conn.cursor()
        sql = "SELECT address FROM feeds WHERE enabled = 1"
        result = cur.execute(sql).fetchall()
        return result


async def list_subscriptions(db_file):
    """
    Query table feeds and list items.

    :param db_file: Database filename.
    :return: List of feeds.
    """
    cur = get_cursor(db_file)
    sql = "SELECT name, address, updated, id, enabled FROM feeds"
    results = cur.execute(sql)

    feeds_list = "List of subscriptions: \n"
    counter = 0
    for result in results:
        counter += 1
        feeds_list += """\n{} \n{} \nLast updated: {} \nID: {} [{}]
        """.format(str(result[0]), str(result[1]), str(result[2]),
                   str(result[3]), str(result[4]))
    if counter:
        return feeds_list + "\n Total of {} subscriptions".format(counter)
    else:
        msg = ("List of subscriptions is empty. \n"
               "To add feed, send a message as follows: \n"
               "feed add URL \n"
               "Example: \n"
               "add https://reclaimthenet.org/feed/")
        return msg


async def last_entries(db_file, num):
    """
    Query entries
    
    :param db_file: Database filename.
    :param num: Number
    :return: List of recent N entries
    """
    num = int(num)
    if num > 50:
        num = 50
    elif num < 1:
        num = 1
    cur = get_cursor(db_file)
    sql = "SELECT title, link FROM entries ORDER BY ROWID DESC LIMIT :num"
    results = cur.execute(sql, (num,))


    titles_list = "Recent {} titles: \n".format(num)
    for result in results:
        titles_list += "\n{} \n{}".format(str(result[0]), str(result[1]))
    return titles_list


async def search_entries(db_file, query):
    """
    Query entries
    
    :param db_file: Database filename.
    :param query: Search query
    :return: Entries with specified keywords
    """
    if len(query) < 2:
        return "Please enter at least 2 characters to search"

    cur = get_cursor(db_file)
    sql = "SELECT title, link FROM entries WHERE title LIKE ? LIMIT 50"
    results = cur.execute(sql, [f'%{query}%'])

    results_list = "Search results for '{}': \n".format(query)
    counter = 0
    for result in results:
        counter += 1
        results_list += """\n{} \n{}
        """.format(str(result[0]), str(result[1]))
    if counter:
        return results_list + "\n Total of {} results".format(counter)
    else:
        return "No results found for: {}".format(query)


async def check_entry_exist(db_file, title, link):
    """
    Check whether an entry exists.
    Query entries by title and link.

    :param db_file: Database filename.
    :param link: Entry URL.
    :param title: Entry title.
    :return: Index ID or None.
    """
    cur = get_cursor(db_file)
    sql = "SELECT id FROM entries WHERE title = :title and link = :link"
    result = cur.execute(sql, {"title": title, "link": link}).fetchone()
    return result

# TODO dictionary
# settings = {
#     "enabled"   : {
#         "message": "Updates are {}".format(status),
#         "value": val
#         },
#     "interval" : {
#         "message": "Updates will be sent every {} minutes".format(val),
#         "value": val
#         },
#     "quantom"  : {
#         "message": "Every updates will contain {} news items".format(val),
#         "value": val
#         }
#     }

async def set_settings_value(db_file, key_value):
    """
    Set settings value.

    :param db_file: Database filename.
    :param key_value: List of key ("enabled", "interval", "quantum") and value (Integer).
    :return: Message.
    """
    # if isinstance(key_value, list):
    #     key = key_value[0]
    #     val = key_value[1]
    # elif key_value == "enable":
    #     key = "enabled"
    #     val = 1
    # else:
    #     key = "enabled"
    #     val = 0
    key = key_value[0]
    val = key_value[1]
    async with DBLOCK:
        with create_connection(db_file) as conn:
            cur = conn.cursor()
            await set_settings_value_default(cur, key)
            sql = "UPDATE settings SET value = :value WHERE key = :key"
            cur.execute(sql, {"key": key, "value": val})
    if key == 'quantum':
        msg = "Each update will contain {} news items.".format(val)
    elif key == 'interval':
        msg = "Updates will be sent every {} minutes.".format(val)
    else:
        if val:
            status = "disabled"
        else:
            status = "enabled"
        msg = "Updates are {}.".format(status)
    return msg


async def set_settings_value_default(cur, key):
# async def set_settings_value_default(cur):
#     keys = ["enabled", "interval", "quantum"]
#     for i in keys:
#         sql = "SELECT id FROM settings WHERE key = ?"
#         cur.execute(sql, (i,))
#         if not cur.fetchone():
#             val = await settings.get_value_default(i)
#             sql = "INSERT INTO settings(key,value) VALUES(?,?)"
#             cur.execute(sql, (i, val))
    sql = "SELECT id FROM settings WHERE key = ?"
    cur.execute(sql, (key,))
    if not cur.fetchone():
        val = await confighandler.get_value_default(key)
        sql = "INSERT INTO settings(key,value) VALUES(?,?)"
        cur.execute(sql, (key, val))
        return val


async def get_settings_value(db_file, key):
    """
    Get settings value.

    :param db_file: Database filename.
    :param key: "enabled", "interval", "quantum".
    """
    # try:
    #     with create_connection(db_file) as conn:
    #         cur = conn.cursor()
    #         sql = "SELECT value FROM settings WHERE key = ?"
    #         cur.execute(sql, (key,))
    #         result = cur.fetchone()
    # except:
    #     result = await settings.get_value_default(key)
    # if not result:
    #     result = await settings.get_value_default(key)
    # return result
    with create_connection(db_file) as conn:
        try:
            cur = conn.cursor()
            sql = "SELECT value FROM settings WHERE key = ?"
            result = cur.execute(sql, (key,)).fetchone()[0]
        except:
            result = await set_settings_value_default(cur, key)
        if not result:
            result = await set_settings_value_default(cur, key)
        return result