feat(subtitles): Automatically select single subtitle track if only one available

Enhance subtitle track selection in MKV parsing by automatically selecting the track when only one is available. Retain interactive selection for multiple tracks, improving usability and user experience.

Author: luispater

internal/video/mkv.go

@@ -273,43 +273,49 @@ func ExtractSubtitlesFromMKV(mkvPath string) (string, error) {
 		return "", errors.NewValidationError("no subtitle tracks found in MKV", nil)
 	}
 
-	logger.Info("Available subtitle tracks:")
-	for i, tr := range tracks {
-		lines := len(tr.Entries)
-		name := strings.TrimSpace(tr.Name)
-		lang := tr.Language
-		bcp := languages.BCP47FromMKV(lang)
-		if bcp != "" {
-			if name != "" {
-				lang = fmt.Sprintf("%s (%s)", bcp, name)
-			} else {
-				lang = fmt.Sprintf("%s", bcp)
+	var selectedIdx int
+	if len(tracks) == 1 {
+		// Only one subtitle track is available; select it automatically
+		logger.Info("Only one subtitle track found; selecting it automatically.")
+		selectedIdx = 0
+	} else {
+		logger.Info("Available subtitle tracks:")
+		for i, tr := range tracks {
+			lines := len(tr.Entries)
+			name := strings.TrimSpace(tr.Name)
+			lang := tr.Language
+			bcp := languages.BCP47FromMKV(lang)
+			if bcp != "" {
+				if name != "" {
+					lang = fmt.Sprintf("%s (%s)", bcp, name)
+				} else {
+					lang = fmt.Sprintf("%s", bcp)
+				}
 			}
+			logger.Info(fmt.Sprintf("[%d] Language: %s, Lines:%d", i+1, lang, lines))
 		}
-		logger.Info(fmt.Sprintf("[%d] Language: %s, Lines:%d", i+1, lang, lines))
-	}
 
-	var selectedIdx int
-	for {
-		input := logger.InputPrompt("Select track number to extract: ")
-		input = strings.TrimSpace(input)
-		if input == "" {
-			best, errSel := parser.SelectBestEnglishTrack()
-			if errSel == nil && best != nil {
-				for i := range tracks {
-					if tracks[i].Number == best.Number {
-						selectedIdx = i
-						break
+		for {
+			input := logger.InputPrompt("Select track number to extract: ")
+			input = strings.TrimSpace(input)
+			if input == "" {
+				best, errSel := parser.SelectBestEnglishTrack()
+				if errSel == nil && best != nil {
+					for i := range tracks {
+						if tracks[i].Number == best.Number {
+							selectedIdx = i
+							break
+						}
 					}
+					break
 				}
+			}
+			if n, errAtoi := strconv.Atoi(input); errAtoi == nil && n >= 1 && n <= len(tracks) {
+				selectedIdx = n - 1
 				break
 			}
+			logger.Warning("Invalid selection. Enter a valid number.")
 		}
-		if n, errAtoi := strconv.Atoi(input); errAtoi == nil && n >= 1 && n <= len(tracks) {
-			selectedIdx = n - 1
-			break
-		}
-		logger.Warning("Invalid selection. Enter a valid number.")
 	}
 
 	selected := tracks[selectedIdx]