Rewrite syncplay using a state design pattern

MediaBrowser.Controller/SyncPlay/ISyncPlayStateContext.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MediaBrowser.Model.SyncPlay;
+using MediaBrowser.Controller.Session;
+
+namespace MediaBrowser.Controller.SyncPlay
+{
+    /// <summary>
+    /// Interface ISyncPlayStateContext.
+    /// </summary>
+    public interface ISyncPlayStateContext
+    {
+        /// <summary>
+        /// Gets the context's group.
+        /// </summary>
+        /// <value>The group.</value>
+        GroupInfo GetGroup();
+
+        /// <summary>
+        /// Sets a new state.
+        /// </summary>
+        /// <param name="state">The new state.</param>
+        void SetState(ISyncPlayState state);
+
+        /// <summary>
+        /// Sends a GroupUpdate message to the interested sessions.
+        /// </summary>
+        /// <param name="from">The current session.</param>
+        /// <param name="type">The filtering type.</param>
+        /// <param name="message">The message to send.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <value>The task.</value>
+        Task SendGroupUpdate<T>(SessionInfo from, SyncPlayBroadcastType type, GroupUpdate<T> message, CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Sends a playback command to the interested sessions.
+        /// </summary>
+        /// <param name="from">The current session.</param>
+        /// <param name="type">The filtering type.</param>
+        /// <param name="message">The message to send.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <value>The task.</value>
+        Task SendCommand(SessionInfo from, SyncPlayBroadcastType type, SendCommand message, CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Builds a new playback command with some default values.
+        /// </summary>
+        /// <param name="type">The command type.</param>
+        /// <value>The SendCommand.</value>
+        SendCommand NewSyncPlayCommand(SendCommandType type);
+
+        /// <summary>
+        /// Builds a new group update message.
+        /// </summary>
+        /// <param name="type">The update type.</param>
+        /// <param name="data">The data to send.</param>
+        /// <value>The GroupUpdate.</value>
+        GroupUpdate<T> NewSyncPlayGroupUpdate<T>(GroupUpdateType type, T data);
+
+        /// <summary>
+        /// Converts DateTime to UTC string.
+        /// </summary>
+        /// <param name="date">The date to convert.</param>
+        /// <value>The UTC string.</value>
+        string DateToUTCString(DateTime date);
+
+        /// <summary>
+        /// Sanitizes the PositionTicks, considers the current playing item when available.
+        /// </summary>
+        /// <param name="positionTicks">The PositionTicks.</param>
+        /// <value>The sanitized PositionTicks.</value>
+        long SanitizePositionTicks(long? positionTicks);
+    }
+}