handlematrix: implement group chat deletes (#126)

pkg/connector/capabilities.go

@@ -28,6 +28,8 @@ import (
 	"maunium.net/go/mautrix/bridgev2"
 	"maunium.net/go/mautrix/bridgev2/database"
 	"maunium.net/go/mautrix/event"
+
+	"go.mau.fi/mautrix-telegram/pkg/connector/ids"
 )
 
 func (tg *TelegramConnector) GetCapabilities() *bridgev2.NetworkGeneralCapabilities {
@@ -58,7 +60,7 @@ func (tg *TelegramConnector) GetCapabilities() *bridgev2.NetworkGeneralCapabilit
 }
 
 func (tg *TelegramConnector) GetBridgeInfoVersion() (info, capabilities int) {
-	return 1, 6
+	return 1, 7
 }
 
 // TODO get these from getConfig instead of hardcoding?
@@ -208,7 +210,7 @@ func makeTimerList() []jsontime.Milliseconds {
 var telegramTimers = makeTimerList()
 
 func (t *TelegramClient) GetCapabilities(ctx context.Context, portal *bridgev2.Portal) *event.RoomFeatures {
-	baseID := "fi.mau.telegram.capabilities.2025_09_27"
+	baseID := "fi.mau.telegram.capabilities.2025_11_12"
 	feat := &event.RoomFeatures{
 		Formatting:          formattingCaps,
 		File:                fileCaps,
@@ -251,11 +253,22 @@ func (t *TelegramClient) GetCapabilities(ctx context.Context, portal *bridgev2.P
 		feat.File = premiumFileCaps
 		feat.ReactionCount = 3
 	}
-	if portal.RoomType == database.RoomTypeDM {
+	portalMetadata := portal.Metadata.(*PortalMetadata)
+	peerType, _, _ := ids.ParsePortalID(portal.ID)
+
+	switch portal.RoomType {
+	case database.RoomTypeDM:
 		baseID += "+dm"
 		feat.DeleteChat = true
 		feat.DeleteChatForEveryone = true
+	default:
+		// Group creators can delete the chat for everyone, unless it's a large channel
+		if peerType == ids.PeerTypeChat || portalMetadata.ParticipantsCount < 1000 {
+			baseID += "+deletablegroup"
+			feat.DeleteChatForEveryone = true
+		}
 	}
+
 	feat.ID = baseID
 	return feat
 }

pkg/connector/chatinfo.go

@@ -125,6 +125,7 @@ func (t *TelegramClient) getDMChatInfo(ctx context.Context, userID int64) (*brid
 func (t *TelegramClient) getGroupChatInfo(fullChat *tg.MessagesChatFull, chatID int64) (*bridgev2.ChatInfo, bool, error) {
 	var name *string
 	var isBroadcastChannel, isMegagroup bool
+	var participantsCount int
 	for _, c := range fullChat.GetChats() {
 		if c.GetID() == chatID {
 			switch chat := c.(type) {
@@ -134,6 +135,10 @@ func (t *TelegramClient) getGroupChatInfo(fullChat *tg.MessagesChatFull, chatID
 				name = &chat.Title
 				isBroadcastChannel = chat.Broadcast
 				isMegagroup = chat.Megagroup
+
+				if value, ok := chat.GetParticipantsCount(); ok {
+					participantsCount = value
+				}
 			}
 			break
 		}
@@ -154,6 +159,7 @@ func (t *TelegramClient) getGroupChatInfo(fullChat *tg.MessagesChatFull, chatID
 			meta := p.Metadata.(*PortalMetadata)
 			_ = updatePortalLastSyncAt(ctx, p)
 			_ = meta.SetIsSuperGroup(isMegagroup)
+			meta.ParticipantsCount = participantsCount
 
 			if reactions, ok := fullChat.FullChat.GetAvailableReactions(); ok {
 				switch typedReactions := reactions.(type) {
@@ -444,6 +450,7 @@ func (t *TelegramClient) getDMPowerLevels(ghost *bridgev2.Ghost) *bridgev2.Power
 		event.StateRoomAvatar:              0,
 		event.StateTopic:                   0,
 		event.StateBeeperDisappearingTimer: 0,
+		event.BeeperDeleteChat:             0,
 	}
 	return &plo
 }
@@ -500,6 +507,7 @@ func (t *TelegramClient) getPowerLevelOverridesFromBannedRights(entity tg.ChatCl
 		event.StatePowerLevels:             85,
 		event.StateHistoryVisibility:       85,
 		event.StateBeeperDisappearingTimer: 85,
+		event.BeeperDeleteChat:             *creatorPowerLevel,
 	}
 
 	if dbr.ChangeInfo {

pkg/connector/handlematrix.go

@@ -805,22 +805,53 @@ func (t *TelegramClient) HandleMatrixDeleteChat(ctx context.Context, chat *bridg
 	if err != nil {
 		return err
 	}
-	if chat.Portal.RoomType == database.RoomTypeDM {
-		if chat.Content.DeleteForEveryone {
-			_, err := t.client.API().MessagesDeleteHistory(ctx, &tg.MessagesDeleteHistoryRequest{
-				Peer:   &tg.InputPeerUser{UserID: id},
-				Revoke: true,
-				MaxID:  0,
-			})
-			if err != nil {
-				return err
-			}
-		}
-		_, err = t.client.API().MessagesDeleteChat(ctx, id)
+	switch peerType {
+	case ids.PeerTypeUser:
+		accessHash, err := t.ScopedStore.GetAccessHash(ctx, peerType, id)
 		if err != nil {
 			return err
 		}
-	} else {
+		_, err = t.client.API().MessagesDeleteHistory(ctx, &tg.MessagesDeleteHistoryRequest{
+			Peer:      &tg.InputPeerUser{UserID: id, AccessHash: accessHash},
+			JustClear: !chat.Content.DeleteForEveryone,
+			Revoke:    chat.Content.DeleteForEveryone,
+			MaxID:     0,
+		})
+		if err != nil {
+			return err
+		}
+	case ids.PeerTypeChat:
+		if chat.Content.DeleteForEveryone {
+			result, err := t.client.API().MessagesDeleteChat(ctx, id)
+			if err != nil {
+				return err
+			}
+			if !result {
+				return fmt.Errorf("failed to delete chat %d", id)
+			}
+			return nil
+		} else {
+			return fmt.Errorf("deleting chat only supported for group creators")
+		}
+	case ids.PeerTypeChannel:
+		accessHash, err := t.ScopedStore.GetAccessHash(ctx, peerType, id)
+		if err != nil {
+			return err
+		}
+		channel := &tg.InputChannel{
+			ChannelID:  id,
+			AccessHash: accessHash,
+		}
+		if chat.Content.DeleteForEveryone {
+			_, err := t.client.API().ChannelsDeleteChannel(ctx, channel)
+			if err != nil {
+				return err
+			}
+			return nil
+		} else {
+			return fmt.Errorf("deleting chat only supported for channel creators")
+		}
+	default:
 		return fmt.Errorf("deleting chat not supported for peer type %s", peerType)
 	}
 	return nil

pkg/connector/metadata.go

@@ -50,10 +50,11 @@ type GhostMetadata struct {
 }
 
 type PortalMetadata struct {
-	IsSuperGroup     bool          `json:"is_supergroup,omitempty"`
-	ReadUpTo         int           `json:"read_up_to,omitempty"`
-	AllowedReactions []string      `json:"allowed_reactions"`
-	LastSync         jsontime.Unix `json:"last_sync,omitempty"`
+	IsSuperGroup      bool          `json:"is_supergroup,omitempty"`
+	ReadUpTo          int           `json:"read_up_to,omitempty"`
+	AllowedReactions  []string      `json:"allowed_reactions"`
+	LastSync          jsontime.Unix `json:"last_sync,omitempty"`
+	ParticipantsCount int           `json:"member_count,omitempty"`
 }
 
 func (pm *PortalMetadata) SetIsSuperGroup(isSupergroup bool) (changed bool) {