Add support for sender_chat (telegram) (#1677)

* Add support for sender_chat (telegram)

Fixes #1654
https://core.telegram.org/bots/api#december-7-2021

* Add debuglevel option

Add `debuglevel=1` in telegram config to increase debug

bridge/telegram/handlers.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/42wim/matterbridge/bridge/helper"
+	"github.com/davecgh/go-spew/spew"
 	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
 )
 
@@ -123,6 +124,25 @@ func (b *Btelegram) handleUsername(rmsg *config.Message, message *tgbotapi.Messa
 		}
 	}
 
+	if message.SenderChat != nil { //nolint:nestif
+		rmsg.UserID = strconv.FormatInt(message.SenderChat.ID, 10)
+		if b.GetBool("UseFirstName") {
+			rmsg.Username = message.SenderChat.FirstName
+		}
+
+		if rmsg.Username == "" || rmsg.Username == "Channel_Bot" {
+			rmsg.Username = message.SenderChat.UserName
+
+			if rmsg.Username == "" || rmsg.Username == "Channel_Bot" {
+				rmsg.Username = message.SenderChat.FirstName
+			}
+		}
+		// only download avatars if we have a place to upload them (configured mediaserver)
+		if b.General.MediaServerUpload != "" || (b.General.MediaServerDownload != "" && b.General.MediaDownloadPath != "") {
+			b.handleDownloadAvatar(message.SenderChat.ID, rmsg.Channel)
+		}
+	}
+
 	// if we really didn't find a username, set it to unknown
 	if rmsg.Username == "" {
 		rmsg.Username = unknownUser
@@ -139,6 +159,10 @@ func (b *Btelegram) handleRecv(updates <-chan tgbotapi.Update) {
 			continue
 		}
 
+		if b.GetInt("debuglevel") == 1 {
+			spew.Dump(update.Message)
+		}
+
 		var message *tgbotapi.Message
 
 		rmsg := config.Message{Account: b.Account, Extra: make(map[string][]interface{})}