message: move Media function from context

context.go

@@ -22,9 +22,6 @@ type Context interface {
 	// Message returns stored message if such presented.
 	Message() *Message
 
-	// Media returns message media if such presented.
-	Media() Media
-
 	// Callback returns stored callback if such presented.
 	Callback() *Callback
 
@@ -192,29 +189,6 @@ func (c *nativeContext) Message() *Message {
 	}
 }
 
-func (c *nativeContext) Media() Media {
-	m := c.Message()
-
-	switch {
-	case m.Photo != nil:
-		return m.Photo
-	case m.Voice != nil:
-		return m.Voice
-	case m.Audio != nil:
-		return m.Audio
-	case m.Animation != nil:
-		return m.Animation
-	case m.Document != nil:
-		return m.Document
-	case m.Video != nil:
-		return m.Video
-	case m.VideoNote != nil:
-		return m.VideoNote
-	default:
-		return nil
-	}
-}
-
 func (c *nativeContext) Callback() *Callback {
 	return c.u.Callback
 }

message.go

@@ -367,3 +367,26 @@ func (m *Message) EntityText(e MessageEntity) string {
 
 	return string(utf16.Decode(a[off:end]))
 }
+
+// Media returns the message's media if it contains either photo,
+// voice, audio, animation, document, video or video note.
+func (m *Message) Media() Media {
+	switch {
+	case m.Photo != nil:
+		return m.Photo
+	case m.Voice != nil:
+		return m.Voice
+	case m.Audio != nil:
+		return m.Audio
+	case m.Animation != nil:
+		return m.Animation
+	case m.Document != nil:
+		return m.Document
+	case m.Video != nil:
+		return m.Video
+	case m.VideoNote != nil:
+		return m.VideoNote
+	default:
+		return nil
+	}
+}