Use time.Duration for track lengths

model.go

@@ -1,9 +1,11 @@
 package gavalink
 
 import (
+	"encoding/json"
 	"io"
 	"net/http"
 	"os"
+	"time"
 )
 
 const (
@@ -27,7 +29,7 @@ type Tracks struct {
 	// NoMatches, or LoadFailed
 	Type         string        `json:"loadType"`
 	PlaylistInfo *PlaylistInfo `json:"playlistInfo"`
-	Tracks       []Track       `json:"tracks"`
+	Tracks       []*Track      `json:"tracks"`
 }
 
 // PlaylistInfo contains information about a loaded playlist
@@ -42,20 +44,46 @@ type PlaylistInfo struct {
 // Track contains information about a loaded track
 type Track struct {
 	// Data contains the base64 encoded Lavaplayer track
-	Data string    `json:"track"`
-	Info TrackInfo `json:"info"`
+	Data string     `json:"track"`
+	Info *TrackInfo `json:"info"`
 }
 
 // TrackInfo contains more data about a loaded track
 type TrackInfo struct {
-	Identifier string `json:"identifier"`
-	Title      string `json:"title"`
-	Author     string `json:"author"`
-	URI        string `json:"uri"`
-	Seekable   bool   `json:"isSeekable"`
-	Stream     bool   `json:"isStream"`
-	Length     int    `json:"length"`
-	Position   int    `json:"position"`
+	Identifier string        `json:"identifier"`
+	Title      string        `json:"title"`
+	Author     string        `json:"author"`
+	URI        string        `json:"uri"`
+	Seekable   bool          `json:"isSeekable"`
+	Stream     bool          `json:"isStream"`
+	Length     time.Duration `json:"length"`
+	Position   int           `json:"position"`
+}
+
+func (t *TrackInfo) MarshalJSON() ([]byte, error) {
+	type Alias TrackInfo
+	return json.Marshal(&struct {
+		Length int64 `json:"length"`
+		*Alias
+	}{
+		Length: int64(t.Length / time.Millisecond),
+		Alias:  (*Alias)(t),
+	})
+}
+
+func (t *TrackInfo) UnmarshalJSON(data []byte) error {
+	type Alias TrackInfo
+	aux := &struct {
+		Length int64 `json:"length"`
+		*Alias
+	}{
+		Alias: (*Alias)(t),
+	}
+	if err := json.Unmarshal(data, &aux); err != nil {
+		return err
+	}
+	t.Length = time.Duration(aux.Length) * time.Millisecond
+	return nil
 }
 
 const (