[ifcbrk] feature: Implement Client Status Support (#1247)

* Implement Client Status Support

Adds support for using the client_status as sent as part of the Presence model. This value can be used to determine if a user is active on the native desktop app, the mobile app, or the website.

* lint: whitespace in IPresence

* Remove breaking change to IPresence interface with a note for 2.1

* update comment to not reference 2.1

* re-add interface break to IPresence

* add example payload for client_status

* use inline declaration for Enum.TryParse

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -325,7 +325,7 @@ namespace Discord.WebSocket
             {
                 var user = SocketGlobalUser.Create(this, state, model);
                 user.GlobalUser.AddRef();
-                user.Presence = new SocketPresence(UserStatus.Online, null);
+                user.Presence = new SocketPresence(UserStatus.Online, null, null);
                 return user;
             });
         }
@@ -433,7 +433,7 @@ namespace Discord.WebSocket
                 return;
             var status = Status;
             var statusSince = _statusSince;
-            CurrentUser.Presence = new SocketPresence(status, Activity);
+            CurrentUser.Presence = new SocketPresence(status, Activity, null);
 
             var gameModel = new GameModel();
             // Discord only accepts rich presence over RPC, don't even bother building a payload

src/Discord.Net.WebSocket/Entities/Users/SocketPresence.cs

@@ -1,3 +1,6 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics;
 using Model = Discord.API.Presence;
 
@@ -13,15 +16,42 @@ namespace Discord.WebSocket
         public UserStatus Status { get; }
         /// <inheritdoc />
         public IActivity Activity { get; }
-
-        internal SocketPresence(UserStatus status, IActivity activity)
+        /// <inheritdoc />
+        public IImmutableSet<ClientType> ActiveClients { get; }
+        internal SocketPresence(UserStatus status, IActivity activity, IImmutableSet<ClientType> activeClients)
         {
             Status = status;
             Activity= activity;
+            ActiveClients = activeClients;
         }
         internal static SocketPresence Create(Model model)
         {
-            return new SocketPresence(model.Status, model.Game?.ToEntity());
+            var clients = ConvertClientTypesDict(model.ClientStatus.GetValueOrDefault());
+            return new SocketPresence(model.Status, model.Game?.ToEntity(), clients);
+        }
+        /// <summary>
+        ///     Creates a new <see cref="IReadOnlyCollection{T}"/> containing all of the client types
+        ///     where a user is active from the data supplied in the Presence update frame.
+        /// </summary>
+        /// <param name="clientTypesDict">
+        ///     A dictionary keyed by the <see cref="ClientType"/>
+        ///     and where the value is the <see cref="UserStatus"/>.
+        /// </param>
+        /// <returns>
+        ///     A collection of all <see cref="ClientType"/>s that this user is active.
+        /// </returns>
+        private static IImmutableSet<ClientType> ConvertClientTypesDict(IDictionary<string, string> clientTypesDict)
+        {
+            if (clientTypesDict == null || clientTypesDict.Count == 0)
+                return ImmutableHashSet<ClientType>.Empty;
+            var set = new HashSet<ClientType>();
+            foreach (var key in clientTypesDict.Keys)
+            {
+                if (Enum.TryParse(key, true, out ClientType type))
+                    set.Add(type);
+                // quietly discard ClientTypes that do not match
+            }
+            return set.ToImmutableHashSet();
         }
 
         /// <summary>

src/Discord.Net.WebSocket/Entities/Users/SocketUnknownUser.cs

@@ -24,8 +24,8 @@ namespace Discord.WebSocket
         
         /// <inheritdoc />
         public override bool IsWebhook => false;
-
-        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null); } set { } }
+        /// <inheritdoc />
+        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null, null); } set { } }
         /// <inheritdoc />
         /// <exception cref="NotSupportedException">This field is not supported for an unknown user.</exception>
         internal override SocketGlobalUser GlobalUser =>

src/Discord.Net.WebSocket/Entities/Users/SocketUser.cs

@@ -38,6 +38,8 @@ namespace Discord.WebSocket
         public IActivity Activity => Presence.Activity;
         /// <inheritdoc />
         public UserStatus Status => Presence.Status;
+        /// <inheritdoc />
+        public IImmutableSet<ClientType> ActiveClients => Presence.ActiveClients;
         /// <summary>
         ///     Gets mutual guilds shared with this user.
         /// </summary>

src/Discord.Net.WebSocket/Entities/Users/SocketWebhookUser.cs

@@ -29,8 +29,8 @@ namespace Discord.WebSocket
 
         /// <inheritdoc />
         public override bool IsWebhook => true;
-
-        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null); } set { } }
+        /// <inheritdoc />
+        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null, null); } set { } }
         internal override SocketGlobalUser GlobalUser => 
             throw new NotSupportedException();