Send unavailable status to cached chats on disconnect

telegram/connect.go

@@ -3,6 +3,7 @@ package telegram
 import (
 	"github.com/pkg/errors"
 	"math"
+	"strconv"
 
 	"dev.narayana.im/narayana/telegabber/xmpp/gateway"
 
@@ -122,13 +123,22 @@ func (c *Client) Connect() error {
 
 // Disconnect drops TDlib connection
 func (c *Client) Disconnect() {
+	// already disconnected
 	if !c.online {
 		return
 	}
 
 	log.Warn("Disconnecting from Telegram network...")
 
-	// TODO: send unavailable presence to cached chats
+	// we're offline (unsubscribe if logout)
+	for id := range c.cache.chats {
+		gateway.SendPresence(
+			c.xmpp,
+			c.jid,
+			gateway.SPFrom(strconv.FormatInt(id, 10)),
+			gateway.SPType("unavailable"),
+		)
+	}
 
 	c.client.Destroy()
 	c.online = false