From c548cdf277319bb06c86718f4034059806075ebe Mon Sep 17 00:00:00 2001
From: mdosch <spam-github@mdosch.de>
Date: Sun, 26 May 2019 20:20:34 +0200
Subject: [PATCH] Added a few interactions (help, source, feeds).

---
 feed-to-muc.go | 71 ++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 66 insertions(+), 5 deletions(-)

diff --git a/feed-to-muc.go b/feed-to-muc.go
index 4594ea8..ded5462 100644
--- a/feed-to-muc.go
+++ b/feed-to-muc.go
@@ -138,7 +138,7 @@ func main() {
 	go pingMUC(client, config.BotJid, config.Muc, config.MucNick)
 
 	// Starting goroutine to process received stanzas.
-	go processStanzas(client)
+	go processStanzas(client, config.Muc, config.MucNick, config.Feeds)
 
 	// Set RefreshTime to 30 seconds if not defined.
 	if config.RefreshTime == 0 {
@@ -171,12 +171,12 @@ func main() {
 }
 
 // Send a ping every 30 seconds after last successful ping to check if the MUC is still available.
-func pingMUC(client *xmpp.Client, botJid string, Muc string, MucNick string) {
+func pingMUC(client *xmpp.Client, botJid string, muc string, mucNick string) {
 	for {
 		time.Sleep(30 * time.Second)
 
 		// Send ping to own MUC participant to check we are still joined.
-		id, err = client.RawInformation(botJid, Muc+"/"+MucNick, sid.Id(),
+		id, err = client.RawInformation(botJid, muc+"/"+mucNick, sid.Id(),
 			"get", "<ping xmlns='urn:xmpp:ping'/>")
 		if err != nil {
 			log.Fatal(err)
@@ -213,15 +213,76 @@ func pingServer(client *xmpp.Client, server string, botJid string) {
 	}
 }
 
-func processStanzas(client *xmpp.Client) {
+func processStanzas(client *xmpp.Client, muc string, mucNick string, feeds []string) {
 	for { // Receive stanzas. ToDo: Receive stanzas continiously without 30s delay.
 		stanza, err := client.Recv()
 		if err != nil {
 			log.Fatal(err)
 		}
 
-		// Check IQs for ping results and disco#info queries.
+		// Check stanzas, maybe we want to reply.
 		switch v := stanza.(type) {
+		// Reply to requests for source and feeds.
+		case xmpp.Chat:
+			// Get first word of the message and transform it to lower case.
+			var mention string
+			mention = strings.ToLower(strings.Split(v.Text, " ")[0])
+
+			// If it is not the bots nick remove one trailing character as
+			// a lot of clients append `:` or `,` to mentions.
+			if mention != strings.ToLower(mucNick) {
+				mentionLength := len(mention)
+				// Leave if mentionLength is <= 0
+				if mentionLength <= 0 {
+					break
+				}
+				mention = mention[:mentionLength-1]
+				// Leave if the message is not addressed to the bot.
+				if mention != strings.ToLower(mucNick) {
+					break
+				}
+			}
+
+			// Check for the second word (command).
+			switch strings.ToLower(strings.Split(v.Text, " ")[1]) {
+
+			// Reply with a short summary of available commands for `help`.
+			case "help":
+				_, err = client.Send(xmpp.Chat{Remote: muc,
+					Type: "groupchat", Text: strings.Split(v.Remote, "/")[1] +
+						": The following commands are available:\n" +
+						"feeds\t" + "List feeds I'm following.\n" +
+						"source\t" + "Show source code URL."})
+				if err != nil {
+					log.Fatal(err)
+				}
+			// Reply with repo address for `source`.
+			case "source":
+				_, err = client.Send(xmpp.Chat{Remote: muc,
+					Type: "groupchat", Text: strings.Split(v.Remote, "/")[1] +
+						": My source can be found at " +
+						"https://salsa.debian.org/mdosch-guest/feed-to-muc"})
+				if err != nil {
+					log.Fatal(err)
+				}
+			// Reply with the list of monitored feeds for `feeds`.
+			case "feeds":
+				var feedList string
+				for _, feed := range feeds {
+					// Add next feed element and a newline.
+					feedList = feedList + feed + "\n"
+				}
+
+				_, err = client.Send(xmpp.Chat{Remote: muc,
+					Type: "groupchat", Text: strings.Split(v.Remote, "/")[1] +
+						": Feeds I'm following:\n" + feedList})
+				if err != nil {
+					log.Fatal(err)
+				}
+
+			}
+
+		// Reply to pings and disco queries.
 		case xmpp.IQ:
 			if (v.Type == "error") && (v.ID == id) {
 				log.Fatal("MUC not available.")