From ce47f456ec4a8f61b5c9842c6334e344fe172164 Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Sat, 13 Nov 2021 04:42:14 +0900
Subject: [PATCH] Change API for retrieving playlist items on join

---
 osu.Game/Online/Multiplayer/IMultiplayerRoomServer.cs  |  5 +++++
 osu.Game/Online/Multiplayer/MultiplayerClient.cs       |  4 ++++
 osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs |  9 +++++++++
 .../Tests/Visual/Multiplayer/TestMultiplayerClient.cs  | 10 ++++++----
 4 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/osu.Game/Online/Multiplayer/IMultiplayerRoomServer.cs b/osu.Game/Online/Multiplayer/IMultiplayerRoomServer.cs
index d6ff4f4993..d00022d6f5 100644
--- a/osu.Game/Online/Multiplayer/IMultiplayerRoomServer.cs
+++ b/osu.Game/Online/Multiplayer/IMultiplayerRoomServer.cs
@@ -77,6 +77,11 @@ namespace osu.Game.Online.Multiplayer
         /// <exception cref="InvalidStateException">If an attempt to start the game occurs when the game's (or users') state disallows it.</exception>
         Task StartMatch();
 
+        /// <summary>
+        /// Requests for all playlist items of the room to be sent to the client.
+        /// </summary>
+        Task RequestAllPlaylistItems();
+
         /// <summary>
         /// Adds an item to the playlist.
         /// </summary>
diff --git a/osu.Game/Online/Multiplayer/MultiplayerClient.cs b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
index 43c1148ba9..638eb30ee9 100644
--- a/osu.Game/Online/Multiplayer/MultiplayerClient.cs
+++ b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
@@ -158,6 +158,8 @@ namespace osu.Game.Online.Multiplayer
                     OnRoomJoined();
                 }, cancellationSource.Token).ConfigureAwait(false);
 
+                await RequestAllPlaylistItems().ConfigureAwait(false);
+
                 // Update room settings.
                 await updateLocalRoomSettings(joinedRoom.Settings, cancellationSource.Token).ConfigureAwait(false);
             }, cancellationSource.Token).ConfigureAwait(false);
@@ -305,6 +307,8 @@ namespace osu.Game.Online.Multiplayer
 
         public abstract Task StartMatch();
 
+        public abstract Task RequestAllPlaylistItems();
+
         public abstract Task AddPlaylistItem(APIPlaylistItem item);
 
         public abstract Task RemovePlaylistItem(long playlistItemId);
diff --git a/osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs b/osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs
index 2f0e1623e7..c7a751500e 100644
--- a/osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs
+++ b/osu.Game/Online/Multiplayer/OnlineMultiplayerClient.cs
@@ -3,6 +3,7 @@
 
 #nullable enable
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -151,6 +152,14 @@ namespace osu.Game.Online.Multiplayer
             return connection.InvokeAsync(nameof(IMultiplayerServer.StartMatch));
         }
 
+        public override Task RequestAllPlaylistItems()
+        {
+            if (!IsConnected.Value)
+                return Task.FromResult(Array.Empty<APIPlaylistItem>());
+
+            return connection.InvokeAsync<APIPlaylistItem[]>(nameof(IMultiplayerServer.RequestAllPlaylistItems));
+        }
+
         public override Task AddPlaylistItem(APIPlaylistItem item)
         {
             if (!IsConnected.Value)
diff --git a/osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs b/osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs
index a4175defa2..dc871de3f5 100644
--- a/osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs
+++ b/osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs
@@ -199,10 +199,6 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             // emulate the server sending this after the join room. scheduler required to make sure the join room event is fired first (in Join).
             changeMatchType(Room.Settings.MatchType).Wait();
-
-            // emulate the server sending all playlist items after room join.
-            var serverSideRoom = roomManager.ServerSideRooms.Single(r => r.RoomID.Value == APIRoom.RoomID.Value);
-            Task.WhenAll(serverSideRoom.Playlist.Select(i => ((IMultiplayerClient)this).PlaylistItemAdded(new APIPlaylistItem(i)))).Wait();
         }
 
         protected override Task LeaveRoomInternal() => Task.CompletedTask;
@@ -298,6 +294,12 @@ namespace osu.Game.Tests.Visual.Multiplayer
             return ((IMultiplayerClient)this).LoadRequested();
         }
 
+        public override async Task RequestAllPlaylistItems()
+        {
+            foreach (var item in playlistItems)
+                await ((IMultiplayerClient)this).PlaylistItemAdded(item).ConfigureAwait(false);
+        }
+
         public override async Task AddPlaylistItem(APIPlaylistItem item)
         {
             Debug.Assert(Room != null);