refactor: use methods instead of functions

internal/deezer/song.go

@@ -0,0 +1,45 @@
+package deezer
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+type Song struct {
+	ID         string `json:"SNG_ID"`
+	ArtistName string `json:"ART_NAME"`
+	Title      string `json:"SNG_TITLE"`
+	TrackToken string `json:"TRACK_TOKEN"`
+}
+
+func (s *Song) GetMediaData() (*Media, error) {
+	licenseToken := ""
+	reqBody := fmt.Sprintf(`{"license_token":"%s","media":[{"type":"FULL","formats":[{"cipher":"BF_CBC_STRIPE","format":"FLAC"}]}],"track_tokens":["%s"]}`, licenseToken, s.TrackToken)
+
+	resp, err := http.Post("https://media.deezer.com/v1/get_url", "application/json", bytes.NewBuffer([]byte(reqBody)))
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, _ := io.ReadAll(resp.Body)
+
+	var media Media
+	err = json.Unmarshal(body, &media)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(media.Errors) > 0 {
+		if media.Errors[0].Code == 1000 {
+			return nil, fmt.Errorf("invalid license token")
+		}
+
+		return nil, fmt.Errorf("%s", media.Errors[0].Message)
+	}
+
+	return &media, nil
+}