feat: download single tracks (#5)

Introduces the `godeez download track <ID>` command, allowing users to download individual songs directly.

Single tracks are saved into a "Singles" folder by default to keep them organized. The README has been updated with documentation and examples for this new functionality.

README.md

@@ -19,7 +19,7 @@ A simple Go tool for downloading music from [Deezer](https://www.deezer.com).
 
 ## Features
 
-* Download playlists, albums, and artists' top tracks from Deezer
+* Download playlists, albums, artists' top tracks, and individual tracks from Deezer
 * Select audio quality: MP3 128kbps, MP3 320kbps (default), or FLAC (⚠️ non-premium accounts are limited to 128kbps)
 * Automatically adds metadata tags to downloaded files
 * Fetch and tag songs with BPM and musical key
@@ -122,6 +122,7 @@ Available Commands:
   album       Download songs from an album
   artist      Download top songs from an artist
   playlist    Download songs from a playlist
+  track       Download a single track
 
 Flags:
       --bpm                fetch BPM/key and add to file tags
@@ -134,6 +135,27 @@ Flags:
 Use "godeez download [command] --help" for more information about a command.
 ```
 
+### Examples
+
+Here are some examples of how to use the different download commands:
+
+```bash
+# Download an album
+godeez download album 12345678
+
+# Download a playlist
+godeez download playlist 87654321
+
+# Download top tracks from an artist
+godeez download artist 11223344 --limit 5
+
+# Download a single track
+godeez download track 98765432
+
+# Download with specific quality and BPM data
+godeez download track 98765432 --quality flac --bpm
+```
+
 ## Contributing
 
 Contributions help make **GoDeez** a better tool for everyone, and any help is greatly appreciated.

cmd/download.go

@@ -35,6 +35,7 @@ func init() {
 		newDownloadCmd("album"),
 		newDownloadCmd("playlist"),
 		newDownloadCmd("artist"),
+		newDownloadCmd("track"),
 	)
 }
 
@@ -82,5 +83,9 @@ func newDownloadCmd(resourceType string) *cobra.Command {
 		cmd.Short = "Download top songs from an artist"
 	}
 
+	if resourceType == "track" {
+		cmd.Short = "Download a single track"
+	}
+
 	return cmd
 }

internal/deezer/client.go

@@ -45,6 +45,8 @@ func (c *Client) FetchResource(ctx context.Context, resource Resource, id string
 		payload["alb_id"] = id
 	case *Artist:
 		payload["art_id"] = id
+	case *Track:
+		payload["sng_id"] = id
 	default:
 		return fmt.Errorf("unsupported resource type: %T", r)
 	}
@@ -84,6 +86,9 @@ func (c *Client) FetchResource(ctx context.Context, resource Resource, id string
 	if strings.Contains(string(body), `"DATA_ERROR":"artist::getData"`) {
 		return fmt.Errorf("invalid artist ID")
 	}
+	if strings.Contains(string(body), `"DATA_ERROR":"song::getData"`) {
+		return fmt.Errorf("invalid track ID")
+	}
 	if strings.Contains(string(body), `"results":{}`) {
 		return fmt.Errorf("unexpected response")
 	}

internal/deezer/track.go

@@ -0,0 +1,81 @@
+package deezer
+
+import (
+	"encoding/json"
+	"fmt"
+	"path"
+	"time"
+
+	"github.com/flytam/filenamify"
+)
+
+type Track struct {
+	Results struct {
+		Data *Song `json:"DATA"`
+	} `json:"results"`
+}
+
+func (t *Track) String() string {
+	if t.Results.Data == nil {
+		return "Track: No data available"
+	}
+
+	duration := "Unknown"
+	if t.Results.Data.Duration != "" {
+		if d, err := time.ParseDuration(t.Results.Data.Duration + "s"); err == nil {
+			duration = d.String()
+		}
+	}
+
+	return fmt.Sprintf(
+		`================= [ Track Info ] =================
+Title:    %s
+Artist:   %s
+Duration: %s
+==================================================`,
+		t.Results.Data.GetTitle(),
+		t.Results.Data.Artist,
+		duration,
+	)
+}
+
+func (t *Track) GetType() string {
+	return "Track"
+}
+
+func (t *Track) GetTitle() string {
+	if t.Results.Data == nil {
+		return ""
+	}
+	return t.Results.Data.GetTitle()
+}
+
+func (t *Track) GetSongs() []*Song {
+	if t.Results.Data == nil {
+		return []*Song{}
+	}
+	return []*Song{t.Results.Data}
+}
+
+func (t *Track) SetSongs(songs []*Song) {
+	if len(songs) > 0 {
+		t.Results.Data = songs[0]
+	}
+}
+
+func (t *Track) GetOutputDir(outputDir string) string {
+	if t.Results.Data == nil {
+		return outputDir
+	}
+
+	// For single tracks, create a simple "Singles" folder
+	base := "Singles"
+	base, _ = filenamify.Filenamify(base, filenamify.Options{})
+	outputDir = path.Join(outputDir, base)
+
+	return outputDir
+}
+
+func (t *Track) Unmarshal(data []byte) error {
+	return json.Unmarshal(data, t)
+}

internal/downloader/client.go

@@ -63,6 +63,8 @@ func (c *Client) Run(ctx context.Context, opts Options, id string) error {
 		resource = &deezer.Playlist{}
 	case "artist":
 		resource = &deezer.Artist{}
+	case "track":
+		resource = &deezer.Track{}
 	default:
 		return fmt.Errorf("unsupported resource type: %s", c.resourceType)
 	}