refactor

internal/converter/converter.go

@@ -0,0 +1,137 @@
+package converter
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"sub-cli/internal/format/lrc"
+	"sub-cli/internal/format/srt"
+	"sub-cli/internal/model"
+)
+
+// ErrUnsupportedFormat is returned when trying to convert to/from an unsupported format
+var ErrUnsupportedFormat = errors.New("unsupported format")
+
+// Convert converts a file from one format to another
+func Convert(sourceFile, targetFile string) error {
+	sourceFmt := strings.TrimPrefix(filepath.Ext(sourceFile), ".")
+	targetFmt := strings.TrimPrefix(filepath.Ext(targetFile), ".")
+
+	switch sourceFmt {
+	case "lrc":
+		return convertFromLRC(sourceFile, targetFile, targetFmt)
+	case "srt":
+		return convertFromSRT(sourceFile, targetFile, targetFmt)
+	default:
+		return fmt.Errorf("%w: %s", ErrUnsupportedFormat, sourceFmt)
+	}
+}
+
+// convertFromLRC converts an LRC file to another format
+func convertFromLRC(sourceFile, targetFile, targetFmt string) error {
+	sourceLyrics, err := lrc.Parse(sourceFile)
+	if err != nil {
+		return fmt.Errorf("error parsing source LRC file: %w", err)
+	}
+
+	switch targetFmt {
+	case "txt":
+		return lrcToTxt(sourceLyrics, targetFile)
+	case "srt":
+		return lrcToSRT(sourceLyrics, targetFile)
+	case "lrc":
+		return lrc.Generate(sourceLyrics, targetFile)
+	default:
+		return fmt.Errorf("%w: %s", ErrUnsupportedFormat, targetFmt)
+	}
+}
+
+// convertFromSRT converts an SRT file to another format
+func convertFromSRT(sourceFile, targetFile, targetFmt string) error {
+	entries, err := srt.Parse(sourceFile)
+	if err != nil {
+		return fmt.Errorf("error parsing source SRT file: %w", err)
+	}
+
+	switch targetFmt {
+	case "txt":
+		return srtToTxt(entries, targetFile)
+	case "lrc":
+		lyrics := srt.ConvertToLyrics(entries)
+		return lrc.Generate(lyrics, targetFile)
+	case "srt":
+		return srt.Generate(entries, targetFile)
+	default:
+		return fmt.Errorf("%w: %s", ErrUnsupportedFormat, targetFmt)
+	}
+}
+
+// lrcToTxt converts LRC lyrics to a plain text file
+func lrcToTxt(lyrics model.Lyrics, targetFile string) error {
+	file, err := os.Create(targetFile)
+	if err != nil {
+		return fmt.Errorf("error creating target file: %w", err)
+	}
+	defer file.Close()
+
+	for _, content := range lyrics.Content {
+		if _, err := fmt.Fprintln(file, content); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// lrcToSRT converts LRC lyrics to an SRT file
+func lrcToSRT(lyrics model.Lyrics, targetFile string) error {
+	var entries []model.SRTEntry
+
+	for i, content := range lyrics.Content {
+		if i >= len(lyrics.Timeline) {
+			break
+		}
+
+		startTime := lyrics.Timeline[i]
+		endTime := startTime
+		
+		// If there's a next timeline entry, use it for end time
+		// Otherwise add a few seconds to the start time
+		if i+1 < len(lyrics.Timeline) {
+			endTime = lyrics.Timeline[i+1]
+		} else {
+			endTime.Seconds += 3
+		}
+
+		entry := model.SRTEntry{
+			Number:    i + 1,
+			StartTime: startTime,
+			EndTime:   endTime,
+			Content:   content,
+		}
+
+		entries = append(entries, entry)
+	}
+
+	return srt.Generate(entries, targetFile)
+}
+
+// srtToTxt converts SRT entries to a plain text file
+func srtToTxt(entries []model.SRTEntry, targetFile string) error {
+	file, err := os.Create(targetFile)
+	if err != nil {
+		return fmt.Errorf("error creating target file: %w", err)
+	}
+	defer file.Close()
+
+	for _, entry := range entries {
+		if _, err := fmt.Fprintln(file, entry.Content); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}