1 files changed, 224 insertions, 0 deletions
diff --git a/MediaBrowser.Controller/SyncPlay/GroupStates/AbstractGroupState.cs b/MediaBrowser.Controller/SyncPlay/GroupStates/AbstractGroupState.cs
new file mode 100644
index 000000000..91a13fb28
--- /dev/null
+++ b/MediaBrowser.Controller/SyncPlay/GroupStates/AbstractGroupState.cs
@@ -0,0 +1,224 @@
+#nullable disable
+
+using System.Threading;
+using MediaBrowser.Controller.Session;
+using MediaBrowser.Controller.SyncPlay.PlaybackRequests;
+using MediaBrowser.Model.SyncPlay;
+using Microsoft.Extensions.Logging;
+
+namespace MediaBrowser.Controller.SyncPlay.GroupStates
+{
+    /// <summary>
+    /// Class AbstractGroupState.
+    /// </summary>
+    /// <remarks>
+    /// Class is not thread-safe, external locking is required when accessing methods.
+    /// </remarks>
+    public abstract class AbstractGroupState : IGroupState
+    {
+        /// <summary>
+        /// The logger.
+        /// </summary>
+        private readonly ILogger<AbstractGroupState> _logger;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AbstractGroupState"/> class.
+        /// </summary>
+        /// <param name="loggerFactory">Instance of the <see cref="ILoggerFactory"/> interface.</param>
+        protected AbstractGroupState(ILoggerFactory loggerFactory)
+        {
+            LoggerFactory = loggerFactory;
+            _logger = loggerFactory.CreateLogger<AbstractGroupState>();
+        }
+
+        /// <inheritdoc />
+        public abstract GroupStateType Type { get; }
+
+        /// <summary>
+        /// Gets the logger factory.
+        /// </summary>
+        protected ILoggerFactory LoggerFactory { get; }
+
+        /// <inheritdoc />
+        public abstract void SessionJoined(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken);
+
+        /// <inheritdoc />
+        public abstract void SessionLeaving(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken);
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(IGroupPlaybackRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(PlayGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(SetPlaylistItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(RemoveFromPlaylistGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            var playingItemRemoved = context.RemoveFromPlayQueue(request.PlaylistItemIds);
+
+            var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.RemoveItems);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+
+            if (playingItemRemoved && !context.PlayQueue.IsItemPlaying())
+            {
+                _logger.LogDebug("Play queue in group {GroupId} is now empty.", context.GroupId.ToString());
+
+                IGroupState idleState = new IdleGroupState(LoggerFactory);
+                context.SetState(idleState);
+                var stopRequest = new StopGroupRequest();
+                idleState.HandleRequest(stopRequest, context, Type, session, cancellationToken);
+            }
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(MovePlaylistItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            var result = context.MoveItemInPlayQueue(request.PlaylistItemId, request.NewIndex);
+
+            if (!result)
+            {
+                _logger.LogError("Unable to move item in group {GroupId}.", context.GroupId.ToString());
+                return;
+            }
+
+            var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.MoveItem);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(QueueGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            var result = context.AddToPlayQueue(request.ItemIds, request.Mode);
+
+            if (!result)
+            {
+                _logger.LogError("Unable to add items to play queue in group {GroupId}.", context.GroupId.ToString());
+                return;
+            }
+
+            var reason = request.Mode switch
+            {
+                GroupQueueMode.QueueNext => PlayQueueUpdateReason.QueueNext,
+                _ => PlayQueueUpdateReason.Queue
+            };
+            var playQueueUpdate = context.GetPlayQueueUpdate(reason);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(UnpauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(PauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(StopGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(SeekGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(BufferGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(ReadyGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(NextItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(PreviousItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            UnhandledRequest(request);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(SetRepeatModeGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            context.SetRepeatMode(request.Mode);
+            var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.RepeatMode);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(SetShuffleModeGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            context.SetShuffleMode(request.Mode);
+            var playQueueUpdate = context.GetPlayQueueUpdate(PlayQueueUpdateReason.ShuffleMode);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.PlayQueue, playQueueUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(PingGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Collected pings are used to account for network latency when unpausing playback.
+            context.UpdatePing(session, request.Ping);
+        }
+
+        /// <inheritdoc />
+        public virtual void HandleRequest(IgnoreWaitGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            context.SetIgnoreGroupWait(session, request.IgnoreWait);
+        }
+
+        /// <summary>
+        /// Sends a group state update to all group.
+        /// </summary>
+        /// <param name="context">The context of the state.</param>
+        /// <param name="reason">The reason of the state change.</param>
+        /// <param name="session">The session.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        protected void SendGroupStateUpdate(IGroupStateContext context, IGroupPlaybackRequest reason, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Notify relevant state change event.
+            var stateUpdate = new GroupStateUpdate(Type, reason.Action);
+            var update = context.NewSyncPlayGroupUpdate(GroupUpdateType.StateUpdate, stateUpdate);
+            context.SendGroupUpdate(session, SyncPlayBroadcastType.AllGroup, update, cancellationToken);
+        }
+
+        private void UnhandledRequest(IGroupPlaybackRequest request)
+        {
+            _logger.LogWarning("Unhandled request of type {RequestType} in {StateType} state.", request.Action, Type);
+        }
+    }
+}