feat: download artist's top tracks with --limit flag

internal/deezer/artist.go

@@ -0,0 +1,82 @@
+package deezer
+
+import (
+	"encoding/json"
+	"fmt"
+	"path"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/flytam/filenamify"
+)
+
+type Artist struct {
+	Results struct {
+		Data struct {
+			Name string `json:"ART_NAME"`
+		} `json:"DATA"`
+		Songs struct {
+			Data []*Song `json:"data"`
+		} `json:"TOP"`
+	} `json:"results"`
+}
+
+func (a *Artist) GetType() string {
+	return "Artist"
+}
+
+func (a *Artist) GetTitle() string {
+	return a.Results.Data.Name
+}
+
+func (a *Artist) GetSongs() []*Song {
+	return a.Results.Songs.Data
+}
+
+func (a *Artist) SetSongs(s []*Song) {
+	a.Results.Songs.Data = s
+}
+
+func (a *Artist) GetOutputDir(outputDir string) string {
+	base, _ := filenamify.Filenamify(a.GetTitle(), filenamify.Options{})
+	return path.Join(outputDir, base)
+}
+
+func (a *Artist) Unmarshal(data []byte) error {
+	return json.Unmarshal(data, a)
+}
+
+func (a *Artist) String() string {
+	tracks := a.GetSongs()
+	count := len(tracks)
+
+	limit := 3
+	if count < limit {
+		limit = count
+	}
+
+	totalSec := 0
+	for _, s := range tracks {
+		if d, err := strconv.Atoi(s.Duration); err == nil {
+			totalSec += d
+		}
+	}
+	totalDuration := time.Duration(totalSec) * time.Second
+
+	var b strings.Builder
+	fmt.Fprintf(&b, "============= [ Artist Info ] =============\n")
+	fmt.Fprintf(&b, "Artist:   %s\n", a.GetTitle())
+	fmt.Fprintf(&b, "Tracks:   %d\n", count)
+	fmt.Fprintf(&b, "Playtime: %s\n", totalDuration)
+	fmt.Fprintf(&b, "-------------------------------------------\n")
+	fmt.Fprintf(&b, "Top %d most popular tracks:\n", limit)
+	for i := 0; i < limit; i++ {
+		s := tracks[i]
+		title := s.GetTitle()
+		fmt.Fprintf(&b, "    %2d. %s – %s\n", i+1, s.Artist, title)
+	}
+	fmt.Fprintf(&b, "===========================================\n")
+
+	return b.String()
+}