Rename GroupController into Group

Emby.Server.Implementations/SyncPlay/Group.cs

@@ -0,0 +1,664 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Data.Entities;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Session;
+using MediaBrowser.Controller.SyncPlay;
+using MediaBrowser.Controller.SyncPlay.GroupStates;
+using MediaBrowser.Controller.SyncPlay.Queue;
+using MediaBrowser.Controller.SyncPlay.Requests;
+using MediaBrowser.Model.SyncPlay;
+using Microsoft.Extensions.Logging;
+
+namespace Emby.Server.Implementations.SyncPlay
+{
+    /// <summary>
+    /// Class Group.
+    /// </summary>
+    /// <remarks>
+    /// Class is not thread-safe, external locking is required when accessing methods.
+    /// </remarks>
+    public class Group : IGroupStateContext
+    {
+        /// <summary>
+        /// The logger.
+        /// </summary>
+        private readonly ILogger<Group> _logger;
+
+        /// <summary>
+        /// The logger factory.
+        /// </summary>
+        private readonly ILoggerFactory _loggerFactory;
+
+        /// <summary>
+        /// The user manager.
+        /// </summary>
+        private readonly IUserManager _userManager;
+
+        /// <summary>
+        /// The session manager.
+        /// </summary>
+        private readonly ISessionManager _sessionManager;
+
+        /// <summary>
+        /// The library manager.
+        /// </summary>
+        private readonly ILibraryManager _libraryManager;
+
+        /// <summary>
+        /// The participants, or members of the group.
+        /// </summary>
+        private readonly Dictionary<string, GroupMember> _participants =
+            new Dictionary<string, GroupMember>(StringComparer.OrdinalIgnoreCase);
+
+        /// <summary>
+        /// The internal group state.
+        /// </summary>
+        private IGroupState _state;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Group" /> class.
+        /// </summary>
+        /// <param name="loggerFactory">The logger factory.</param>
+        /// <param name="userManager">The user manager.</param>
+        /// <param name="sessionManager">The session manager.</param>
+        /// <param name="libraryManager">The library manager.</param>
+        public Group(
+            ILoggerFactory loggerFactory,
+            IUserManager userManager,
+            ISessionManager sessionManager,
+            ILibraryManager libraryManager)
+        {
+            _loggerFactory = loggerFactory;
+            _userManager = userManager;
+            _sessionManager = sessionManager;
+            _libraryManager = libraryManager;
+            _logger = loggerFactory.CreateLogger<Group>();
+
+            _state = new IdleGroupState(loggerFactory);
+        }
+
+        /// <summary>
+        /// Gets the default ping value used for sessions.
+        /// </summary>
+        /// <value>The default ping.</value>
+        public long DefaultPing { get; } = 500;
+
+        /// <summary>
+        /// Gets the maximum time offset error accepted for dates reported by clients, in milliseconds.
+        /// </summary>
+        /// <value>The maximum time offset error.</value>
+        public long TimeSyncOffset { get; } = 2000;
+
+        /// <summary>
+        /// Gets the maximum offset error accepted for position reported by clients, in milliseconds.
+        /// </summary>
+        /// <value>The maximum offset error.</value>
+        public long MaxPlaybackOffset { get; } = 500;
+
+        /// <summary>
+        /// Gets the group identifier.
+        /// </summary>
+        /// <value>The group identifier.</value>
+        public Guid GroupId { get; } = Guid.NewGuid();
+
+        /// <summary>
+        /// Gets the group name.
+        /// </summary>
+        /// <value>The group name.</value>
+        public string GroupName { get; private set; }
+
+        /// <summary>
+        /// Gets the group identifier.
+        /// </summary>
+        /// <value>The group identifier.</value>
+        public PlayQueueManager PlayQueue { get; } = new PlayQueueManager();
+
+        /// <summary>
+        /// Gets the runtime ticks of current playing item.
+        /// </summary>
+        /// <value>The runtime ticks of current playing item.</value>
+        public long RunTimeTicks { get; private set; }
+
+        /// <summary>
+        /// Gets or sets the position ticks.
+        /// </summary>
+        /// <value>The position ticks.</value>
+        public long PositionTicks { get; set; }
+
+        /// <summary>
+        /// Gets or sets the last activity.
+        /// </summary>
+        /// <value>The last activity.</value>
+        public DateTime LastActivity { get; set; }
+
+        /// <summary>
+        /// Adds the session to the group.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        private void AddSession(SessionInfo session)
+        {
+            _participants.TryAdd(
+                session.Id,
+                new GroupMember(session)
+                {
+                    Ping = DefaultPing,
+                    IsBuffering = false
+                });
+        }
+
+        /// <summary>
+        /// Removes the session from the group.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        private void RemoveSession(SessionInfo session)
+        {
+            _participants.Remove(session.Id);
+        }
+
+        /// <summary>
+        /// Filters sessions of this group.
+        /// </summary>
+        /// <param name="from">The current session.</param>
+        /// <param name="type">The filtering type.</param>
+        /// <returns>The list of sessions matching the filter.</returns>
+        private IEnumerable<SessionInfo> FilterSessions(SessionInfo from, SyncPlayBroadcastType type)
+        {
+            return type switch
+            {
+                SyncPlayBroadcastType.CurrentSession => new SessionInfo[] { from },
+                SyncPlayBroadcastType.AllGroup => _participants
+                    .Values
+                    .Select(session => session.Session),
+                SyncPlayBroadcastType.AllExceptCurrentSession => _participants
+                    .Values
+                    .Select(session => session.Session)
+                    .Where(session => !session.Id.Equals(from.Id, StringComparison.OrdinalIgnoreCase)),
+                SyncPlayBroadcastType.AllReady => _participants
+                    .Values
+                    .Where(session => !session.IsBuffering)
+                    .Select(session => session.Session),
+                _ => Enumerable.Empty<SessionInfo>()
+            };
+        }
+
+        /// <summary>
+        /// Checks if a given user can access all items of a given queue, that is,
+        /// the user has the required minimum parental access and has access to all required folders.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <param name="queue">The queue.</param>
+        /// <returns><c>true</c> if the user can access all the items in the queue, <c>false</c> otherwise.</returns>
+        private bool HasAccessToQueue(User user, IReadOnlyList<Guid> queue)
+        {
+            // Check if queue is empty.
+            if (queue == null || queue.Count == 0)
+            {
+                return true;
+            }
+
+            foreach (var itemId in queue)
+            {
+                var item = _libraryManager.GetItemById(itemId);
+                if (!item.IsVisibleStandalone(user))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        private bool AllUsersHaveAccessToQueue(IReadOnlyList<Guid> queue)
+        {
+            // Check if queue is empty.
+            if (queue == null || queue.Count == 0)
+            {
+                return true;
+            }
+
+            // Get list of users.
+            var users = _participants
+                .Values
+                .Select(participant => _userManager.GetUserById(participant.Session.UserId));
+
+            // Find problematic users.
+            var usersWithNoAccess = users.Where(user => !HasAccessToQueue(user, queue));
+
+            // All users must be able to access the queue.
+            return !usersWithNoAccess.Any();
+        }
+
+        /// <summary>
+        /// Checks if the group is empty.
+        /// </summary>
+        /// <returns><c>true</c> if the group is empty, <c>false</c> otherwise.</returns>
+        public bool IsGroupEmpty() => _participants.Count == 0;
+
+        /// <summary>
+        /// Initializes the group with the session's info.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="request">The request.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        public void CreateGroup(SessionInfo session, NewGroupRequest request, CancellationToken cancellationToken)
+        {
+            GroupName = request.GroupName;
+            AddSession(session);
+
+            var sessionIsPlayingAnItem = session.FullNowPlayingItem != null;
+
+            RestartCurrentItem();
+
+            if (sessionIsPlayingAnItem)
+            {
+                var playlist = session.NowPlayingQueue.Select(item => item.Id).ToList();
+                PlayQueue.Reset();
+                PlayQueue.SetPlaylist(playlist);
+                PlayQueue.SetPlayingItemById(session.FullNowPlayingItem.Id);
+                RunTimeTicks = session.FullNowPlayingItem.RunTimeTicks ?? 0;
+                PositionTicks = session.PlayState.PositionTicks ?? 0;
+
+                // Maintain playstate.
+                var waitingState = new WaitingGroupState(_loggerFactory)
+                {
+                    ResumePlaying = !session.PlayState.IsPaused
+                };
+                SetState(waitingState);
+            }
+
+            var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupJoined, GetInfo());
+            SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
+
+            _state.SessionJoined(this, _state.Type, session, cancellationToken);
+
+            _logger.LogInformation("Session {SessionId} created group {GroupId}.", session.Id, GroupId.ToString());
+        }
+
+        /// <summary>
+        /// Adds the session to the group.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="request">The request.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        public void SessionJoin(SessionInfo session, JoinGroupRequest request, CancellationToken cancellationToken)
+        {
+            AddSession(session);
+
+            var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupJoined, GetInfo());
+            SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
+
+            var updateOthers = NewSyncPlayGroupUpdate(GroupUpdateType.UserJoined, session.UserName);
+            SendGroupUpdate(session, SyncPlayBroadcastType.AllExceptCurrentSession, updateOthers, cancellationToken);
+
+            _state.SessionJoined(this, _state.Type, session, cancellationToken);
+
+            _logger.LogInformation("Session {SessionId} joined group {GroupId}.", session.Id, GroupId.ToString());
+        }
+
+        /// <summary>
+        /// Removes the session from the group.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="request">The request.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        public void SessionLeave(SessionInfo session, LeaveGroupRequest request, CancellationToken cancellationToken)
+        {
+            _state.SessionLeaving(this, _state.Type, session, cancellationToken);
+
+            RemoveSession(session);
+
+            var updateSession = NewSyncPlayGroupUpdate(GroupUpdateType.GroupLeft, GroupId.ToString());
+            SendGroupUpdate(session, SyncPlayBroadcastType.CurrentSession, updateSession, cancellationToken);
+
+            var updateOthers = NewSyncPlayGroupUpdate(GroupUpdateType.UserLeft, session.UserName);
+            SendGroupUpdate(session, SyncPlayBroadcastType.AllExceptCurrentSession, updateOthers, cancellationToken);
+
+            _logger.LogInformation("Session {SessionId} left group {GroupId}.", session.Id, GroupId.ToString());
+        }
+
+        /// <summary>
+        /// Handles the requested action by the session.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="request">The requested action.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        public void HandleRequest(SessionInfo session, IGroupPlaybackRequest request, CancellationToken cancellationToken)
+        {
+            // The server's job is to maintain a consistent state for clients to reference
+            // and notify clients of state changes. The actual syncing of media playback
+            // happens client side. Clients are aware of the server's time and use it to sync.
+            _logger.LogInformation("Session {SessionId} requested {RequestType} in group {GroupId} that is {StateType}.", session.Id, request.Action, GroupId.ToString(), _state.Type);
+            request.Apply(this, _state, session, cancellationToken);
+        }
+
+        /// <summary>
+        /// Gets the info about the group for the clients.
+        /// </summary>
+        /// <returns>The group info for the clients.</returns>
+        public GroupInfoDto GetInfo()
+        {
+            var participants = _participants.Values.Select(session => session.Session.UserName).Distinct().ToList();
+            return new GroupInfoDto(GroupId, GroupName, _state.Type, participants, DateTime.UtcNow);
+        }
+
+        /// <summary>
+        /// Checks if a user has access to all content in the play queue.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <returns><c>true</c> if the user can access the play queue; <c>false</c> otherwise.</returns>
+        public bool HasAccessToPlayQueue(User user)
+        {
+            var items = PlayQueue.GetPlaylist().Select(item => item.ItemId).ToList();
+            return HasAccessToQueue(user, items);
+        }
+
+        /// <inheritdoc />
+        public void SetIgnoreGroupWait(SessionInfo session, bool ignoreGroupWait)
+        {
+            if (_participants.TryGetValue(session.Id, out GroupMember value))
+            {
+                value.IgnoreGroupWait = ignoreGroupWait;
+            }
+        }
+
+        /// <inheritdoc />
+        public void SetState(IGroupState state)
+        {
+            _logger.LogInformation("Group {GroupId} switching from {FromStateType} to {ToStateType}.", GroupId.ToString(), _state.Type, state.Type);
+            this._state = state;
+        }
+
+        /// <inheritdoc />
+        public Task SendGroupUpdate<T>(SessionInfo from, SyncPlayBroadcastType type, GroupUpdate<T> message, CancellationToken cancellationToken)
+        {
+            IEnumerable<Task> GetTasks()
+            {
+                foreach (var session in FilterSessions(from, type))
+                {
+                    yield return _sessionManager.SendSyncPlayGroupUpdate(session, message, cancellationToken);
+                }
+            }
+
+            return Task.WhenAll(GetTasks());
+        }
+
+        /// <inheritdoc />
+        public Task SendCommand(SessionInfo from, SyncPlayBroadcastType type, SendCommand message, CancellationToken cancellationToken)
+        {
+            IEnumerable<Task> GetTasks()
+            {
+                foreach (var session in FilterSessions(from, type))
+                {
+                    yield return _sessionManager.SendSyncPlayCommand(session, message, cancellationToken);
+                }
+            }
+
+            return Task.WhenAll(GetTasks());
+        }
+
+        /// <inheritdoc />
+        public SendCommand NewSyncPlayCommand(SendCommandType type)
+        {
+            return new SendCommand(
+                GroupId,
+                PlayQueue.GetPlayingItemPlaylistId(),
+                LastActivity,
+                type,
+                PositionTicks,
+                DateTime.UtcNow);
+        }
+
+        /// <inheritdoc />
+        public GroupUpdate<T> NewSyncPlayGroupUpdate<T>(GroupUpdateType type, T data)
+        {
+            return new GroupUpdate<T>(GroupId, type, data);
+        }
+
+        /// <inheritdoc />
+        public long SanitizePositionTicks(long? positionTicks)
+        {
+            var ticks = positionTicks ?? 0;
+            return Math.Clamp(ticks, 0, RunTimeTicks);
+        }
+
+        /// <inheritdoc />
+        public void UpdatePing(SessionInfo session, long ping)
+        {
+            if (_participants.TryGetValue(session.Id, out GroupMember value))
+            {
+                value.Ping = ping;
+            }
+        }
+
+        /// <inheritdoc />
+        public long GetHighestPing()
+        {
+            long max = long.MinValue;
+            foreach (var session in _participants.Values)
+            {
+                max = Math.Max(max, session.Ping);
+            }
+
+            return max;
+        }
+
+        /// <inheritdoc />
+        public void SetBuffering(SessionInfo session, bool isBuffering)
+        {
+            if (_participants.TryGetValue(session.Id, out GroupMember value))
+            {
+                value.IsBuffering = isBuffering;
+            }
+        }
+
+        /// <inheritdoc />
+        public void SetAllBuffering(bool isBuffering)
+        {
+            foreach (var session in _participants.Values)
+            {
+                session.IsBuffering = isBuffering;
+            }
+        }
+
+        /// <inheritdoc />
+        public bool IsBuffering()
+        {
+            foreach (var session in _participants.Values)
+            {
+                if (session.IsBuffering && !session.IgnoreGroupWait)
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        /// <inheritdoc />
+        public bool SetPlayQueue(IReadOnlyList<Guid> playQueue, int playingItemPosition, long startPositionTicks)
+        {
+            // Ignore on empty queue or invalid item position.
+            if (playQueue.Count == 0 || playingItemPosition >= playQueue.Count || playingItemPosition < 0)
+            {
+                return false;
+            }
+
+            // Check if participants can access the new playing queue.
+            if (!AllUsersHaveAccessToQueue(playQueue))
+            {
+                return false;
+            }
+
+            PlayQueue.Reset();
+            PlayQueue.SetPlaylist(playQueue);
+            PlayQueue.SetPlayingItemByIndex(playingItemPosition);
+            var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
+            RunTimeTicks = item.RunTimeTicks ?? 0;
+            PositionTicks = startPositionTicks;
+            LastActivity = DateTime.UtcNow;
+
+            return true;
+        }
+
+        /// <inheritdoc />
+        public bool SetPlayingItem(string playlistItemId)
+        {
+            var itemFound = PlayQueue.SetPlayingItemByPlaylistId(playlistItemId);
+
+            if (itemFound)
+            {
+                var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
+                RunTimeTicks = item.RunTimeTicks ?? 0;
+            }
+            else
+            {
+                RunTimeTicks = 0;
+            }
+
+            RestartCurrentItem();
+
+            return itemFound;
+        }
+
+        /// <inheritdoc />
+        public bool RemoveFromPlayQueue(IReadOnlyList<string> playlistItemIds)
+        {
+            var playingItemRemoved = PlayQueue.RemoveFromPlaylist(playlistItemIds);
+            if (playingItemRemoved)
+            {
+                var itemId = PlayQueue.GetPlayingItemId();
+                if (!itemId.Equals(Guid.Empty))
+                {
+                    var item = _libraryManager.GetItemById(itemId);
+                    RunTimeTicks = item.RunTimeTicks ?? 0;
+                }
+                else
+                {
+                    RunTimeTicks = 0;
+                }
+
+                RestartCurrentItem();
+            }
+
+            return playingItemRemoved;
+        }
+
+        /// <inheritdoc />
+        public bool MoveItemInPlayQueue(string playlistItemId, int newIndex)
+        {
+            return PlayQueue.MovePlaylistItem(playlistItemId, newIndex);
+        }
+
+        /// <inheritdoc />
+        public bool AddToPlayQueue(IReadOnlyList<Guid> newItems, GroupQueueMode mode)
+        {
+            // Ignore on empty list.
+            if (newItems.Count == 0)
+            {
+                return false;
+            }
+
+            // Check if participants can access the new playing queue.
+            if (!AllUsersHaveAccessToQueue(newItems))
+            {
+                return false;
+            }
+
+            if (mode.Equals(GroupQueueMode.QueueNext))
+            {
+                PlayQueue.QueueNext(newItems);
+            }
+            else
+            {
+                PlayQueue.Queue(newItems);
+            }
+
+            return true;
+        }
+
+        /// <inheritdoc />
+        public void RestartCurrentItem()
+        {
+            PositionTicks = 0;
+            LastActivity = DateTime.UtcNow;
+        }
+
+        /// <inheritdoc />
+        public bool NextItemInQueue()
+        {
+            var update = PlayQueue.Next();
+            if (update)
+            {
+                var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
+                RunTimeTicks = item.RunTimeTicks ?? 0;
+                RestartCurrentItem();
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        /// <inheritdoc />
+        public bool PreviousItemInQueue()
+        {
+            var update = PlayQueue.Previous();
+            if (update)
+            {
+                var item = _libraryManager.GetItemById(PlayQueue.GetPlayingItemId());
+                RunTimeTicks = item.RunTimeTicks ?? 0;
+                RestartCurrentItem();
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        /// <inheritdoc />
+        public void SetRepeatMode(GroupRepeatMode mode)
+        {
+            PlayQueue.SetRepeatMode(mode);
+        }
+
+        /// <inheritdoc />
+        public void SetShuffleMode(GroupShuffleMode mode)
+        {
+            PlayQueue.SetShuffleMode(mode);
+        }
+
+        /// <inheritdoc />
+        public PlayQueueUpdate GetPlayQueueUpdate(PlayQueueUpdateReason reason)
+        {
+            var startPositionTicks = PositionTicks;
+
+            if (_state.Type.Equals(GroupStateType.Playing))
+            {
+                var currentTime = DateTime.UtcNow;
+                var elapsedTime = currentTime - LastActivity;
+                // Elapsed time is negative if event happens
+                // during the delay added to account for latency.
+                // In this phase clients haven't started the playback yet.
+                // In other words, LastActivity is in the future,
+                // when playback unpause is supposed to happen.
+                // Adjust ticks only if playback actually started.
+                startPositionTicks += Math.Max(elapsedTime.Ticks, 0);
+            }
+
+            return new PlayQueueUpdate(
+                reason,
+                PlayQueue.LastChange,
+                PlayQueue.GetPlaylist(),
+                PlayQueue.PlayingItemIndex,
+                startPositionTicks,
+                PlayQueue.ShuffleMode,
+                PlayQueue.RepeatMode);
+        }
+    }
+}