Implemented scrobbler.log writer

backends/scrobblerlog.go

@@ -60,16 +60,16 @@ func (b ScrobblerLogBackend) ExportListens(oldestTimestamp time.Time) ([]Listen,
 		return nil, err
 	}
 
-	csvReader := csv.NewReader(reader)
+	tsvReader := csv.NewReader(reader)
-	csvReader.Comma = '\t'
+	tsvReader.Comma = '\t'
 	// Row length is often flexible
-	csvReader.FieldsPerRecord = -1
+	tsvReader.FieldsPerRecord = -1
 
 	listens := make([]Listen, 0)
 	for {
 		// A row is:
 		// artistName	releaseName	trackName	trackNumber	duration	rating	timestamp	recordingMbid
-		row, err := csvReader.Read()
+		row, err := tsvReader.Read()
 		if err == io.EOF {
 			break
 		} else if err != nil {
@@ -80,7 +80,7 @@ func (b ScrobblerLogBackend) ExportListens(oldestTimestamp time.Time) ([]Listen,
 
 		// We consider only the last field (recording MBID) optional
 		if len(row) < 7 {
-			line, _ := csvReader.FieldPos(0)
+			line, _ := tsvReader.FieldPos(0)
 			return nil, errors.New(fmt.Sprintf(
 				"Invalid record in %s line %v", b.filePath, line))
 		}
@@ -101,6 +101,56 @@ func (b ScrobblerLogBackend) ExportListens(oldestTimestamp time.Time) ([]Listen,
 	return listens, nil
 }
 
+func (b ScrobblerLogBackend) ImportListens(listens []Listen, oldestTimestamp time.Time) (ImportResult, error) {
+	result := ImportResult{
+		Count:         0,
+		LastTimestamp: oldestTimestamp,
+	}
+
+	file, err := os.Create(b.filePath)
+	if err != nil {
+		return result, err
+	}
+
+	defer file.Close()
+
+	err = writeHeader(file)
+	if err != nil {
+		return result, err
+	}
+
+	tsvWriter := csv.NewWriter(file)
+	tsvWriter.Comma = '\t'
+
+	for _, listen := range listens {
+		result.Count += 1
+		if listen.ListenedAt.Unix() > result.LastTimestamp.Unix() {
+			result.LastTimestamp = listen.ListenedAt
+		}
+
+		// A row is:
+		// artistName	releaseName	trackName	trackNumber	duration	rating	timestamp	recordingMbid
+		rating := listen.AdditionalInfo["rockbox_rating"]
+		if rating == "" {
+			rating = "L"
+		}
+		tsvWriter.Write([]string{
+			listen.ArtistName(),
+			listen.ReleaseName,
+			listen.TrackName,
+			strconv.Itoa(listen.TrackNumber),
+			strconv.Itoa(int(listen.Duration.Seconds())),
+			rating,
+			strconv.Itoa(int(listen.ListenedAt.Unix())),
+			string(listen.RecordingMbid),
+		})
+	}
+
+	tsvWriter.Flush()
+
+	return result, nil
+}
+
 func readHeader(reader *bufio.Reader) (client string, err error) {
 	// Skip header
 	for i := 0; i < 3; i++ {
@@ -130,6 +180,21 @@ func readHeader(reader *bufio.Reader) (client string, err error) {
 	return client, nil
 }
 
+func writeHeader(writer io.Writer) error {
+	headers := []string{
+		"#AUDIOSCROBBLER/1.1\n",
+		"#TZ/UNKNOWN\n",
+		"#CLIENT/Rockbox sansaclipplus $Revision$\n",
+	}
+	for _, line := range headers {
+		_, err := writer.Write([]byte(line))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func rowToListen(row []string, client string) (Listen, error) {
 	var listen Listen
 	trackNumber, err := strconv.Atoi(row[3])
@@ -153,7 +218,7 @@ func rowToListen(row []string, client string) (Listen, error) {
 			ReleaseName: row[1],
 			TrackName:   row[2],
 			TrackNumber: trackNumber,
-			Duration:    time.Duration(duration),
+			Duration:    time.Duration(duration * int(time.Second)),
 			AdditionalInfo: AdditionalInfo{
 				"rockbox_rating": row[5],
 				"media_player":   client,