Begin handling playback of local media

ios/App/Shared/models/LocalLibraryExtensions.swift

@@ -58,6 +58,53 @@ extension LocalLibraryItem {
         self.serverAddress = server.address
         self.serverUserId = server.userId
     }
+    
+    func getDuration() -> Double {
+        var total = 0.0
+        self.media?.tracks.forEach { track in total += track.duration }
+        return total
+    }
+    
+    func getPlaybackSession(episode: LocalPodcastEpisode?) -> PlaybackSession {
+        let localEpisodeId = episode?.id
+        let sessionId = "play_local_\(UUID().uuidString)"
+        
+        // Get current progress from local media
+        let mediaProgressId = (localEpisodeId != nil) ? "\(self.id)-\(localEpisodeId!)" : self.id
+        let mediaProgress = Database.shared.getLocalMediaProgress(localMediaProgressId: mediaProgressId)
+        
+        // TODO: Clean up add mediaType methods for displayTitle and displayAuthor
+        let mediaMetadata = self.media?.metadata
+        let audioTracks = self.media?.tracks
+        let authorName = mediaMetadata?.authorName
+        
+        if let episode = episode {
+            // TODO: Implement podcast
+        }
+        
+        let dateNow = Date().timeIntervalSince1970
+        return PlaybackSession(
+            id: sessionId,
+            userId: self.serverUserId,
+            libraryItemId: self.libraryItemId,
+            episodeId: episode?.serverEpisodeId,
+            mediaType: self.mediaType,
+            chapters: [],
+            displayTitle: mediaMetadata?.title,
+            displayAuthor: authorName,
+            coverPath: nil,
+            duration: self.getDuration(),
+            playMethod: 3,
+            startedAt: dateNow,
+            updatedAt: 0,
+            timeListening: 0.0,
+            audioTracks: [],
+            currentTime: mediaProgress?.currentTime ?? 0.0,
+            libraryItem: nil,
+            serverConnectionConfigId: self.serverConnectionConfigId,
+            serverAddress: self.serverAddress
+        )
+    }
 }
 
 extension LocalMediaType {