Support Discord game invites in multiplayer lobbies

osu.Desktop/DiscordRichPresence.cs

@@ -2,17 +2,24 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Diagnostics;
 using System.Text;
 using DiscordRPC;
 using DiscordRPC.Message;
+using Newtonsoft.Json;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Development;
 using osu.Framework.Graphics;
 using osu.Framework.Logging;
+using osu.Game;
 using osu.Game.Configuration;
 using osu.Game.Extensions;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests.Responses;
+using osu.Game.Online.Multiplayer;
+using osu.Game.Online.Rooms;
+using osu.Game.Overlays;
 using osu.Game.Rulesets;
 using osu.Game.Users;
 using LogLevel = osu.Framework.Logging.LogLevel;
@@ -21,7 +28,7 @@ namespace osu.Desktop
 {
     internal partial class DiscordRichPresence : Component
     {
-        private const string client_id = "367827983903490050";
+        private const string client_id = "1216669957799018608";
 
         private DiscordRpcClient client = null!;
 
@@ -33,27 +40,48 @@ internal partial class DiscordRichPresence : Component
         [Resolved]
         private IAPIProvider api { get; set; } = null!;
 
+        [Resolved]
+        private OsuGame game { get; set; } = null!;
+
+        private LoginOverlay? login { get; set; }
+
+        [Resolved]
+        private MultiplayerClient multiplayerClient { get; set; } = null!;
+
         private readonly IBindable<UserStatus?> status = new Bindable<UserStatus?>();
         private readonly IBindable<UserActivity> activity = new Bindable<UserActivity>();
 
         private readonly Bindable<DiscordRichPresenceMode> privacyMode = new Bindable<DiscordRichPresenceMode>();
 
+        private int usersCurrentlyInLobby;
+
         private readonly RichPresence presence = new RichPresence
         {
-            Assets = new Assets { LargeImageKey = "osu_logo_lazer", }
+            Assets = new Assets { LargeImageKey = "osu_logo_lazer" },
+            Secrets = new Secrets
+            {
+                JoinSecret = null,
+                SpectateSecret = null,
+            },
         };
 
         [BackgroundDependencyLoader]
         private void load(OsuConfigManager config)
         {
+            login = game.Dependencies.Get<LoginOverlay>();
+
             client = new DiscordRpcClient(client_id)
             {
                 SkipIdenticalPresence = false // handles better on discord IPC loss, see updateStatus call in onReady.
             };
 
             client.OnReady += onReady;
+            client.OnError += (_, e) => Logger.Log($"An error occurred with Discord RPC Client: {e.Code} {e.Message}", LoggingTarget.Network, LogLevel.Error);
 
-            client.OnError += (_, e) => Logger.Log($"An error occurred with Discord RPC Client: {e.Code} {e.Message}", LoggingTarget.Network);
+            // A URI scheme is required to support game invitations, as well as informing Discord of the game executable path to support launching the game when a user clicks on join/spectate.
+            client.RegisterUriScheme();
+            client.Subscribe(EventType.Join);
+            client.OnJoin += onJoin;
 
             config.BindWith(OsuSetting.DiscordRichPresence, privacyMode);
 
@@ -78,11 +106,13 @@ private void load(OsuConfigManager config)
         private void onReady(object _, ReadyMessage __)
         {
             Logger.Log("Discord RPC Client ready.", LoggingTarget.Network, LogLevel.Debug);
-            updateStatus();
+            Schedule(updateStatus);
         }
 
         private void updateStatus()
         {
+            Debug.Assert(ThreadSafety.IsUpdateThread);
+
             if (!client.IsInitialized)
                 return;
 
@@ -92,10 +122,10 @@ private void updateStatus()
                 return;
             }
 
+            bool hideIdentifiableInformation = privacyMode.Value == DiscordRichPresenceMode.Limited || status.Value == UserStatus.DoNotDisturb;
+
             if (activity.Value != null)
             {
-                bool hideIdentifiableInformation = privacyMode.Value == DiscordRichPresenceMode.Limited || status.Value == UserStatus.DoNotDisturb;
-
                 presence.State = truncate(activity.Value.GetStatus(hideIdentifiableInformation));
                 presence.Details = truncate(activity.Value.GetDetails(hideIdentifiableInformation) ?? string.Empty);
 
@@ -121,6 +151,41 @@ private void updateStatus()
                 presence.Details = string.Empty;
             }
 
+            if (!hideIdentifiableInformation && multiplayerClient.Room != null)
+            {
+                MultiplayerRoom room = multiplayerClient.Room;
+
+                if (room.Users.Count == usersCurrentlyInLobby)
+                    return;
+
+                presence.Party = new Party
+                {
+                    Privacy = string.IsNullOrEmpty(room.Settings.Password) ? Party.PrivacySetting.Public : Party.PrivacySetting.Private,
+                    ID = room.RoomID.ToString(),
+                    // technically lobbies can have infinite users, but Discord needs this to be set to something.
+                    // to make party display sensible, assign a powers of two above participants count (8 at minimum).
+                    Max = (int)Math.Max(8, Math.Pow(2, Math.Ceiling(Math.Log2(room.Users.Count)))),
+                    Size = room.Users.Count,
+                };
+
+                RoomSecret roomSecret = new RoomSecret
+                {
+                    RoomID = room.RoomID,
+                    Password = room.Settings.Password,
+                };
+
+                presence.Secrets.JoinSecret = JsonConvert.SerializeObject(roomSecret);
+                usersCurrentlyInLobby = room.Users.Count;
+            }
+            else
+            {
+                presence.Party = null;
+                presence.Secrets.JoinSecret = null;
+                usersCurrentlyInLobby = 0;
+            }
+
+            Logger.Log($"Updating Discord RPC presence with activity status: {presence.State}, details: {presence.Details}", LoggingTarget.Network, LogLevel.Debug);
+
             // update user information
             if (privacyMode.Value == DiscordRichPresenceMode.Limited)
                 presence.Assets.LargeImageText = string.Empty;
@@ -139,9 +204,38 @@ private void updateStatus()
             client.SetPresence(presence);
         }
 
+        private void onJoin(object sender, JoinMessage args)
+        {
+            game.Window?.Raise();
+
+            if (!api.IsLoggedIn)
+            {
+                Schedule(() => login?.Show());
+                return;
+            }
+
+            Logger.Log($"Received room secret from Discord RPC Client: \"{args.Secret}\"", LoggingTarget.Network, LogLevel.Debug);
+
+            // Stable and lazer share the same Discord client ID, meaning they can accept join requests from each other.
+            // Since they aren't compatible in multi, see if stable's format is being used and log to avoid confusion.
+            if (args.Secret[0] != '{' || !tryParseRoomSecret(args.Secret, out long roomId, out string? password))
+            {
+                Logger.Log("Could not join multiplayer room, invitation is invalid or incompatible.", LoggingTarget.Network, LogLevel.Important);
+                return;
+            }
+
+            var request = new GetRoomRequest(roomId);
+            request.Success += room => Schedule(() =>
+            {
+                game.PresentMultiplayerMatch(room, password);
+            });
+            request.Failure += _ => Logger.Log($"Could not join multiplayer room, room could not be found (room ID: {roomId}).", LoggingTarget.Network, LogLevel.Important);
+            api.Queue(request);
+        }
+
         private static readonly int ellipsis_length = Encoding.UTF8.GetByteCount(new[] { '…' });
 
-        private string truncate(string str)
+        private static string truncate(string str)
         {
             if (Encoding.UTF8.GetByteCount(str) <= 128)
                 return str;
@@ -160,7 +254,31 @@ private string truncate(string str)
             });
         }
 
-        private int? getBeatmapID(UserActivity activity)
+        private static bool tryParseRoomSecret(string secretJson, out long roomId, out string? password)
+        {
+            roomId = 0;
+            password = null;
+
+            RoomSecret? roomSecret;
+
+            try
+            {
+                roomSecret = JsonConvert.DeserializeObject<RoomSecret>(secretJson);
+            }
+            catch
+            {
+                return false;
+            }
+
+            if (roomSecret == null) return false;
+
+            roomId = roomSecret.RoomID;
+            password = roomSecret.Password;
+
+            return true;
+        }
+
+        private static int? getBeatmapID(UserActivity activity)
         {
             switch (activity)
             {
@@ -179,5 +297,14 @@ protected override void Dispose(bool isDisposing)
             client.Dispose();
             base.Dispose(isDisposing);
         }
+
+        private class RoomSecret
+        {
+            [JsonProperty(@"roomId", Required = Required.Always)]
+            public long RoomID { get; set; }
+
+            [JsonProperty(@"password", Required = Required.AllowNull)]
+            public string? Password { get; set; }
+        }
     }
 }