1 files changed, 170 insertions, 0 deletions
diff --git a/MediaBrowser.Controller/SyncPlay/GroupStates/PlayingGroupState.cs b/MediaBrowser.Controller/SyncPlay/GroupStates/PlayingGroupState.cs
new file mode 100644
index 000000000..cb1cadf0b
--- /dev/null
+++ b/MediaBrowser.Controller/SyncPlay/GroupStates/PlayingGroupState.cs
@@ -0,0 +1,170 @@
+#nullable disable
+
+using System;
+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 PlayingGroupState.
+    /// </summary>
+    /// <remarks>
+    /// Class is not thread-safe, external locking is required when accessing methods.
+    /// </remarks>
+    public class PlayingGroupState : AbstractGroupState
+    {
+        /// <summary>
+        /// The logger.
+        /// </summary>
+        private readonly ILogger<PlayingGroupState> _logger;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PlayingGroupState"/> class.
+        /// </summary>
+        /// <param name="loggerFactory">Instance of the <see cref="ILoggerFactory"/> interface.</param>
+        public PlayingGroupState(ILoggerFactory loggerFactory)
+            : base(loggerFactory)
+        {
+            _logger = LoggerFactory.CreateLogger<PlayingGroupState>();
+        }
+
+        /// <inheritdoc />
+        public override GroupStateType Type { get; } = GroupStateType.Playing;
+
+        /// <summary>
+        /// Gets or sets a value indicating whether requests for buffering should be ignored.
+        /// </summary>
+        public bool IgnoreBuffering { get; set; }
+
+        /// <inheritdoc />
+        public override void SessionJoined(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Wait for session to be ready.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.SessionJoined(context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void SessionLeaving(IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Do nothing.
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(PlayGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(UnpauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            if (!prevState.Equals(Type))
+            {
+                // Pick a suitable time that accounts for latency.
+                var delayMillis = Math.Max(context.GetHighestPing() * 2, context.DefaultPing);
+
+                // Unpause group and set starting point in future.
+                // Clients will start playback at LastActivity (datetime) from PositionTicks (playback position).
+                // The added delay does not guarantee, of course, that the command will be received in time.
+                // Playback synchronization will mainly happen client side.
+                context.LastActivity = DateTime.UtcNow.AddMilliseconds(delayMillis);
+
+                var command = context.NewSyncPlayCommand(SendCommandType.Unpause);
+                context.SendCommand(session, SyncPlayBroadcastType.AllGroup, command, cancellationToken);
+
+                // Notify relevant state change event.
+                SendGroupStateUpdate(context, request, session, cancellationToken);
+            }
+            else
+            {
+                // Client got lost, sending current state.
+                var command = context.NewSyncPlayCommand(SendCommandType.Unpause);
+                context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
+            }
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(PauseGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var pausedState = new PausedGroupState(LoggerFactory);
+            context.SetState(pausedState);
+            pausedState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(StopGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var idleState = new IdleGroupState(LoggerFactory);
+            context.SetState(idleState);
+            idleState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(SeekGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(BufferGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            if (IgnoreBuffering)
+            {
+                return;
+            }
+
+            // Change state.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(ReadyGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            if (prevState.Equals(Type))
+            {
+                // Group was not waiting, make sure client has latest state.
+                var command = context.NewSyncPlayCommand(SendCommandType.Unpause);
+                context.SendCommand(session, SyncPlayBroadcastType.CurrentSession, command, cancellationToken);
+            }
+            else if (prevState.Equals(GroupStateType.Waiting))
+            {
+                // Notify relevant state change event.
+                SendGroupStateUpdate(context, request, session, cancellationToken);
+            }
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(NextItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+
+        /// <inheritdoc />
+        public override void HandleRequest(PreviousItemGroupRequest request, IGroupStateContext context, GroupStateType prevState, SessionInfo session, CancellationToken cancellationToken)
+        {
+            // Change state.
+            var waitingState = new WaitingGroupState(LoggerFactory);
+            context.SetState(waitingState);
+            waitingState.HandleRequest(request, context, Type, session, cancellationToken);
+        }
+    }
+}