fix long text in telegram

internal/telegram/bot.go

@@ -129,7 +129,7 @@ func (b *Bot) sendMemory(ctx context.Context, mem *search.Memory) {
 		return
 	}
 
-	mainText, captionText := formatMemory(mem, b.publicURL)
+	text := formatMemory(mem, b.publicURL)
 	images := imageAttachments(mem.Memo)
 
 	var downloaded []imageFile
@@ -137,7 +137,7 @@ func (b *Bot) sendMemory(ctx context.Context, mem *search.Memory) {
 		downloaded = b.downloadImages(ctx, images)
 	}
 
-	if err := b.sendWithRetry(ctx, mainText, captionText, downloaded); err != nil {
+	if err := b.sendWithRetry(ctx, text, downloaded); err != nil {
 		b.logger.Error("failed to send telegram message after retries", "error", err)
 	}
 }
@@ -206,12 +206,12 @@ func (b *Bot) downloadImages(ctx context.Context, attachments []memos.Attachment
 }
 
 // sendWithRetry attempts to send the message with up to 3 retries.
-func (b *Bot) sendWithRetry(ctx context.Context, mainText, captionText string, images []imageFile) error {
+func (b *Bot) sendWithRetry(ctx context.Context, text string, images []imageFile) error {
 	backoffs := []time.Duration{30 * time.Second, 60 * time.Second, 120 * time.Second}
 	var lastErr error
 
 	for attempt := range 3 {
-		lastErr = b.send(mainText, captionText, images)
+		lastErr = b.send(text, images)
 		if lastErr == nil {
 			return nil
 		}
@@ -229,35 +229,41 @@ func (b *Bot) sendWithRetry(ctx context.Context, mainText, captionText string, i
 }
 
 // send executes the actual Telegram API calls based on the sending strategy.
-func (b *Bot) send(mainText, captionText string, images []imageFile) error {
+// Long text is split into multiple messages. Images are sent with a caption
+// only if the full text fits within the caption limit.
+func (b *Bot) send(text string, images []imageFile) error {
 	switch {
 	case len(images) == 0:
-		// No images — just text
-		return b.sendText(mainText)
+		return b.sendTextParts(splitText(text, maxMessageLen))
 
-	case len(images) == 1 && len(captionText) <= maxCaptionLen:
-		// Single image with short caption
-		return b.sendPhoto(images[0], captionText)
+	case len(text) <= maxCaptionLen:
+		// Short text — use as caption on image(s)
+		if len(images) == 1 {
+			return b.sendPhoto(images[0], text)
+		}
+		return b.sendMediaGroup(images, text)
 
-	case len(images) > 1 && len(captionText) <= maxCaptionLen:
-		// Multiple images with short caption
-		return b.sendMediaGroup(images, captionText)
-
-	case len(images) >= 1 && len(captionText) > maxCaptionLen:
-		// Images with long text — send text first, then images without caption
-		if err := b.sendText(mainText); err != nil {
+	default:
+		// Long text — send text messages first, then images without caption
+		if err := b.sendTextParts(splitText(text, maxMessageLen)); err != nil {
 			return err
 		}
 		if len(images) == 1 {
 			return b.sendPhoto(images[0], "")
 		}
 		return b.sendMediaGroup(images, "")
-
-	default:
-		return b.sendText(mainText)
 	}
 }
 
+func (b *Bot) sendTextParts(parts []string) error {
+	for _, part := range parts {
+		if err := b.sendText(part); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (b *Bot) sendText(text string) error {
 	msg := tgbotapi.NewMessage(b.chatID, text)
 	msg.ParseMode = tgbotapi.ModeHTML