matrixfmt: cut off long messages

pkg/connector/handlematrix.go

@@ -431,6 +431,38 @@ func parseRandomID(txnID networkid.RawTransactionID) int64 {
 	return rand.Int64()
 }
 
+func (tc *TelegramClient) getMaxMessageLength(ctx context.Context, isMedia bool) (val int) {
+	if !isMedia {
+		return 4096
+	}
+	config, err := tc.getAppConfigCached(ctx)
+	if err != nil {
+		return 1024
+	}
+	myGhost, err := tc.main.Bridge.GetGhostByID(ctx, tc.userID)
+	if err != nil {
+		return 1024
+	}
+	isPremium := myGhost.Metadata.(*GhostMetadata).IsPremium
+	if isPremium {
+		val = 4096
+	} else {
+		val = 1024
+	}
+	tc.isPremiumCache.Store(isPremium)
+	var configLimit float64
+	var ok bool
+	if isPremium {
+		configLimit, ok = config["caption_length_limit_premium"].(float64)
+	} else {
+		configLimit, ok = config["caption_length_limit_default"].(float64)
+	}
+	if ok {
+		val = int(configLimit)
+	}
+	return
+}
+
 func (tc *TelegramClient) HandleMatrixMessage(ctx context.Context, msg *bridgev2.MatrixMessage) (resp *bridgev2.MatrixMessageResponse, err error) {
 	if msg.Portal.RoomType == database.RoomTypeSpace {
 		return nil, fmt.Errorf("can't send messages to space portals")
@@ -455,7 +487,7 @@ func (tc *TelegramClient) HandleMatrixMessage(ctx context.Context, msg *bridgev2
 
 	noWebpage := msg.Content.BeeperLinkPreviews != nil && len(msg.Content.BeeperLinkPreviews) == 0
 
-	message, entities := matrixfmt.Parse(ctx, tc.matrixParser, msg.Content, msg.Portal)
+	message, entities := matrixfmt.Parse(ctx, tc.matrixParser, msg.Content, msg.Portal, tc.getMaxMessageLength(ctx, msg.Content.MsgType.IsMedia()))
 
 	var replyTo tg.InputReplyToClass
 	if msg.ReplyTo != nil {
@@ -657,7 +689,7 @@ func (tc *TelegramClient) HandleMatrixEdit(ctx context.Context, msg *bridgev2.Ma
 		return err
 	}
 
-	message, entities := matrixfmt.Parse(ctx, tc.matrixParser, msg.Content, msg.Portal)
+	message, entities := matrixfmt.Parse(ctx, tc.matrixParser, msg.Content, msg.Portal, tc.getMaxMessageLength(ctx, msg.Content.MsgType.IsMedia()))
 
 	var newContentURI id.ContentURIString
 	req := tg.MessagesEditMessageRequest{

pkg/connector/matrixfmt/convert.go

@@ -88,7 +88,9 @@ func toTelegramEntity(br telegramfmt.BodyRange) tg.MessageEntityClass {
 	}
 }
 
-func Parse(ctx context.Context, parser *HTMLParser, content *event.MessageEventContent, portal *bridgev2.Portal) (string, []tg.MessageEntityClass) {
+const cutoffText = " [long message cut off]"
+
+func Parse(ctx context.Context, parser *HTMLParser, content *event.MessageEventContent, portal *bridgev2.Portal, maxLength int) (string, []tg.MessageEntityClass) {
 	if content.MsgType.IsMedia() && (content.FileName == "" || content.FileName == content.Body) {
 		// The body is the filename.
 		return "", nil
@@ -103,6 +105,10 @@ func Parse(ctx context.Context, parser *HTMLParser, content *event.MessageEventC
 	if parsed == nil {
 		return "", nil
 	}
+	if len(parsed.String) > maxLength {
+		cutoffTextEntity := NewEntityString(cutoffText).Format(telegramfmt.Style{Type: telegramfmt.StyleItalic})
+		parsed = parsed.Substring(maxLength - len(cutoffText)).Append(cutoffTextEntity)
+	}
 	var entities []tg.MessageEntityClass
 	if len(parsed.Entities) > 0 {
 		entities = make([]tg.MessageEntityClass, len(parsed.Entities))

pkg/connector/matrixfmt/html.go

@@ -211,6 +211,29 @@ func (es *EntityString) AppendString(other string) *EntityString {
 	return es
 }
 
+func (es *EntityString) Substring(end int) *EntityString {
+	if es == nil {
+		return nil
+	}
+	if end >= len(es.String) {
+		return es
+	}
+	DebugLog("SUBSTRING %d %q %+v\n", end, es.String, es.Entities)
+	newEntities := make(telegramfmt.BodyRangeList, 0, len(es.Entities))
+	for _, ent := range es.Entities {
+		ent = *ent.TruncateEnd(end)
+		if ent.Length > 0 {
+			newEntities = append(newEntities, ent)
+		}
+	}
+	newES := &EntityString{
+		String:   es.String[:end],
+		Entities: newEntities,
+	}
+	DebugLog("  -> %q %+v\n", newES.String, newES.Entities)
+	return newES
+}
+
 type TagStack []string
 
 func (ts TagStack) Index(tag string) int {