Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/moon/telegram.go

@@ -1,74 +1,110 @@
 package moon
 
 import (
+	"bunny-bot/internal/elog"
+	"bunny-bot/internal/mylog"
+
 	"github.com/NicoNex/echotron/v3"
 	"github.com/davecgh/go-spew/spew"
 )
 
 // Telegram main goroutine that implements bot.
+//
+// It blocks until a termination signal stops it, so the update listener can be
+// shut down in a defined order rather than simply abandoned when the process
+// exits.
 func Telegram(cfg MyConfig) {
+	// A signal can arrive during startup; then this must not start at all.
+	if !startWorker() {
+		mylog.Info("Telegram not started: shutdown already in progress")
+
+		return
+	}
+
+	defer stopWorker()
+
 	Tg = echotron.NewAPI(cfg.Token)
 
-	Log.Infof("Starting api update poller loop")
+	mylog.Info("Starting api update poller loop")
 
-	for u := range echotron.PollingUpdatesOptions(cfg.Token, true, echotron.UpdateOptions{
-		AllowedUpdates: []echotron.UpdateType{
-			"message",
-			"edited_message",
-			"channel_post",
-			"edited_channel_post",
-			"message_reaction",
-			"message_reaction_count",
-			"inline_query",
-			"chosen_inline_result",
-			"callback_query",
-			"poll",
-			"poll_answer",
-			"my_chat_member",
-			"chat_member",
-			"chat_join_request",
-			"chat_boost",
-			"removed_chat_boost",
-		},
-	}) {
-		telegramMsgParser(u)
+	// The sweeper calls the API too, so it may only start once Tg exists.
+	mylog.Info("Starting greeting sweeper periodic task")
+
+	go SweepGreetings()
+
+	updates := echotron.PollingUpdatesOptions(cfg.Token, true, echotron.UpdateOptions{
+		AllowedUpdates: allowedUpdates,
+	})
+
+	for {
+		select {
+		// Stop between updates, never inside one: the handler currently running
+		// finishes, so nothing is left half-processed when we return.
+		case <-stopRequested:
+			mylog.Info("Telegram update listener stopped")
+
+			return
+
+		case u, ok := <-updates:
+			if !ok {
+				mylog.Info("Telegram update poller ended")
+
+				return
+			}
+
+			telegramMsgParser(u)
+		}
 	}
 }
 
 // telegramMsgParser parses events generated by echotron.
 func telegramMsgParser(msg *echotron.Update) {
+	// The one place an update enters the program, and therefore the one place an
+	// entity with no id is caught. Everything downstream — the caches, the sweeper,
+	// the bans — may then assume the ids it holds are real.
+	if !usableUpdate(msg) {
+		reportBrokenUpdate(msg)
+
+		return
+	}
+
 	switch {
-	case msg.Message != nil && msg.Message.Text != "":
-		textMessage(msg)
-
-	case msg.EditedMessage != nil:
-		editedMessage(msg)
-
+	// Membership status changes: joins, leaves, bans, promotions. Logged only —
+	// moderation is the sweeper's job, on a timer, not the dispatcher's.
+	//
+	// This also catches the membership updates caused by our own bans, so every
+	// ban leaves a second record in the chat log.
 	case msg.ChatMember != nil:
-		chatMemberUpdated(msg)
+		elog.LogUserStatus(msg.ChatMember)
 
-	// New members entered to chat.
+	// New members entered to chat. Checked before the text case so that a
+	// join service message is never mistaken for ordinary chatter.
 	case msg.Message != nil && msg.Message.NewChatMembers != nil:
 		newChatMembers(msg)
 
-	// Chat member leaves chat.
-	case msg.Message != nil && msg.Message.LeftChatMember != nil:
-		leftChatMember(msg)
+	// Ordinary text messages, used as greeting answers.
+	case msg.Message != nil && msg.Message.Text != "":
+		textMessage(msg)
 
-	case msg.Message != nil && msg.Message.Animation != nil:
-		animation(msg)
+	// Everything else that is still a message: a photo with no caption, a
+	// sticker, a location, a leave, a title change. Logged, and deliberately NOT
+	// recorded as a greeting answer — an attachment is not an introduction, and
+	// letting one satisfy the detector would be a one-key bypass for a spammer.
+	//
+	// The condition is deliberately just "there is a message": elog already
+	// renders every media and service field, and already writes nothing for a
+	// message with no describable content, so emptiness is its decision to make.
+	// Testing for a field being non-empty here is what lost these messages.
+	case msg.Message != nil:
+		logOnlyMessage(msg)
 
-	case msg.MessageReaction != nil:
-		reaction(msg)
-
-	case msg.MessageReactionCount != nil:
-		reactionCount(msg)
-
-	case msg.Message != nil && msg.Message.Photo != nil:
-		photo(msg)
+	// An edit revises a message already recorded, so it is a chat-log event
+	// rather than a moderation one.
+	case msg.EditedMessage != nil:
+		elog.LogEditedMessage(msg.EditedMessage)
 
 	default:
-		Log.Debug(spew.Sdump(msg))
+		mylog.Debug(spew.Sdump(msg))
 	}
 }