Channel playlists cache

Model/ChannelPlaylist.swift

@@ -1,4 +1,5 @@
 import Foundation
+import SwiftyJSON
 
 struct ChannelPlaylist: Identifiable {
     var id: String = UUID().uuidString
@@ -7,4 +8,26 @@ struct ChannelPlaylist: Identifiable {
     var channel: Channel?
     var videos = [Video]()
     var videosCount: Int?
+
+    var json: JSON {
+        [
+            "id": id,
+            "title": title,
+            "thumbnailURL": thumbnailURL?.absoluteString ?? "",
+            "channel": channel?.json.object ?? "",
+            "videos": videos.map { $0.json.object },
+            "videosCount": String(videosCount ?? 0)
+        ]
+    }
+
+    static func from(_ json: JSON) -> Self {
+        ChannelPlaylist(
+            id: json["id"].stringValue,
+            title: json["title"].stringValue,
+            thumbnailURL: json["thumbnailURL"].url,
+            channel: Channel.from(json["channel"]),
+            videos: json["videos"].arrayValue.map { Video.from($0) },
+            videosCount: json["videosCount"].int
+        )
+    }
 }