Allow clients to send 'Gateway Voice State Update' command (#1888)

* Expose SendVoiceStateUpdateAsync API to clients

Fixes #1882

* Revert "Expose SendVoiceStateUpdateAsync API to clients"

This reverts commit 1a11cae7

* Add IAudioChannel.ModifyAsync API

* fix NRE with request options

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>
Co-authored-by: quin lynch <lynchquin@gmail.com>

src/Discord.Net.Core/Entities/Channels/AudioChannelProperties.cs

@@ -0,0 +1,18 @@
+namespace Discord
+{
+    /// <summary>
+    ///     Provides properties that are used to modify an <see cref="IAudioChannel" /> with the specified changes.
+    /// </summary>
+    public class AudioChannelProperties
+    {
+        /// <summary>
+        ///     Sets whether the user should be muted.
+        /// </summary>
+        public Optional<bool> SelfMute { get; set; }
+
+        /// <summary>
+        ///     Sets whether the user should be deafened.
+        /// </summary>
+        public Optional<bool> SelfDeaf { get; set; }
+    }
+}

src/Discord.Net.Core/Entities/Channels/IAudioChannel.cs

@@ -1,4 +1,5 @@
 using Discord.Audio;
+using System;
 using System.Threading.Tasks;
 
 namespace Discord
@@ -27,5 +28,16 @@ namespace Discord
         ///     A task representing the asynchronous operation for disconnecting from the audio channel.
         /// </returns>
         Task DisconnectAsync();
+
+        /// <summary>
+        ///     Modifies this audio channel.
+        /// </summary>
+        /// <param name="func">The properties to modify the channel with.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        /// <seealso cref="AudioChannelProperties"/>
+        Task ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options = null);
     }
 }

src/Discord.Net.Rest/Entities/Channels/RestGroupChannel.cs

@@ -211,6 +211,7 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException">Connecting to a group channel is not supported.</exception>
         Task<IAudioClient> IAudioChannel.ConnectAsync(bool selfDeaf, bool selfMute, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
+        Task IAudioChannel.ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options) { throw new NotSupportedException(); }
         #endregion
 
         #region IChannel        

src/Discord.Net.Rest/Entities/Channels/RestVoiceChannel.cs

@@ -95,6 +95,7 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException">Connecting to a REST-based channel is not supported.</exception>
         Task<IAudioClient> IAudioChannel.ConnectAsync(bool selfDeaf, bool selfMute, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
+        Task IAudioChannel.ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options) { throw new NotSupportedException(); }
         #endregion
 
         #region IGuildChannel

src/Discord.Net.WebSocket/DiscordSocketApiClient.cs

@@ -311,7 +311,6 @@ namespace Discord.API
         }
         public async Task SendVoiceStateUpdateAsync(ulong guildId, ulong? channelId, bool selfDeaf, bool selfMute, RequestOptions options = null)
         {
-            options = RequestOptions.CreateOrClone(options);
             var payload = new VoiceStateUpdateParams
             {
                 GuildId = guildId,
@@ -319,6 +318,12 @@ namespace Discord.API
                 SelfDeaf = selfDeaf,
                 SelfMute = selfMute
             };
+            options = RequestOptions.CreateOrClone(options);
+            await SendGatewayAsync(GatewayOpCode.VoiceStateUpdate, payload, options: options).ConfigureAwait(false);
+        }
+        public async Task SendVoiceStateUpdateAsync(VoiceStateUpdateParams payload, RequestOptions options = null)
+        {
+            options = RequestOptions.CreateOrClone(options);
             await SendGatewayAsync(GatewayOpCode.VoiceStateUpdate, payload, options: options).ConfigureAwait(false);
         }
         public async Task SendGuildSyncAsync(IEnumerable<ulong> guildIds, RequestOptions options = null)

src/Discord.Net.WebSocket/Entities/Channels/SocketGroupChannel.cs

@@ -344,6 +344,7 @@ namespace Discord.WebSocket
         /// <exception cref="NotSupportedException">Connecting to a group channel is not supported.</exception>
         Task<IAudioClient> IAudioChannel.ConnectAsync(bool selfDeaf, bool selfMute, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
+        Task IAudioChannel.ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options) { throw new NotSupportedException(); }
         #endregion
 
         #region IChannel        

src/Discord.Net.WebSocket/Entities/Channels/SocketVoiceChannel.cs

@@ -82,6 +82,12 @@ namespace Discord.WebSocket
         public async Task DisconnectAsync()
             => await Guild.DisconnectAudioAsync();
 
+        /// <inheritdoc />
+        public async Task ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options = null)
+        {
+            await Guild.ModifyAudioAsync(Id, func, options).ConfigureAwait(false);
+        }
+
         /// <inheritdoc />
         public override SocketGuildUser GetUser(ulong id)
         {

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -1,3 +1,4 @@
+using Discord.API.Gateway;
 using Discord.Audio;
 using Discord.Rest;
 using System;
@@ -45,6 +46,7 @@ namespace Discord.WebSocket
         private ImmutableArray<GuildEmote> _emotes;
 
         private AudioClient _audioClient;
+        private VoiceStateUpdateParams _voiceStateUpdateParams;
 #pragma warning restore IDISP002, IDISP006
 
         /// <inheritdoc />
@@ -1593,11 +1595,19 @@ namespace Discord.WebSocket
                 promise = new TaskCompletionSource<AudioClient>();
                 _audioConnectPromise = promise;
 
+                _voiceStateUpdateParams = new VoiceStateUpdateParams
+                {
+                    GuildId = Id,
+                    ChannelId = channelId,
+                    SelfDeaf = selfDeaf,
+                    SelfMute = selfMute
+                };
+
                 if (external)
                 {
 #pragma warning disable IDISP001
                     var _ = promise.TrySetResultAsync(null);
-                    await Discord.ApiClient.SendVoiceStateUpdateAsync(Id, channelId, selfDeaf, selfMute).ConfigureAwait(false);
+                    await Discord.ApiClient.SendVoiceStateUpdateAsync(_voiceStateUpdateParams).ConfigureAwait(false);
                     return null;
 #pragma warning restore IDISP001
                 }
@@ -1632,7 +1642,7 @@ namespace Discord.WebSocket
 #pragma warning restore IDISP003
                 }
 
-                await Discord.ApiClient.SendVoiceStateUpdateAsync(Id, channelId, selfDeaf, selfMute).ConfigureAwait(false);
+                await Discord.ApiClient.SendVoiceStateUpdateAsync(_voiceStateUpdateParams).ConfigureAwait(false);
             }
             catch
             {
@@ -1679,7 +1689,38 @@ namespace Discord.WebSocket
             await Discord.ApiClient.SendVoiceStateUpdateAsync(Id, null, false, false).ConfigureAwait(false);
             _audioClient?.Dispose();
             _audioClient = null;
+            _voiceStateUpdateParams = null;
         }
+
+        internal async Task ModifyAudioAsync(ulong channelId, Action<AudioChannelProperties> func, RequestOptions options)
+        {
+            await _audioLock.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                await ModifyAudioInternalAsync(channelId, func, options).ConfigureAwait(false);
+            }
+            finally
+            {
+                _audioLock.Release();
+            }
+        }
+
+        private async Task ModifyAudioInternalAsync(ulong channelId, Action<AudioChannelProperties> func, RequestOptions options)
+        {
+            if (_voiceStateUpdateParams == null || _voiceStateUpdateParams.ChannelId != channelId)
+                throw new InvalidOperationException("Cannot modify properties of not connected audio channel");
+
+            var props = new AudioChannelProperties();
+            func(props);
+
+            if (props.SelfDeaf.IsSpecified)
+                _voiceStateUpdateParams.SelfDeaf = props.SelfDeaf.Value;
+            if (props.SelfMute.IsSpecified)
+                _voiceStateUpdateParams.SelfMute = props.SelfMute.Value;
+
+            await Discord.ApiClient.SendVoiceStateUpdateAsync(_voiceStateUpdateParams, options).ConfigureAwait(false);
+        }
+
         internal async Task FinishConnectAudio(string url, string token)
         {
             //TODO: Mem Leak: Disconnected/Connected handlers aren't cleaned up

test/Discord.Net.Tests.Unit/MockedEntities/MockedGroupChannel.cs

@@ -41,6 +41,11 @@ namespace Discord
             throw new NotImplementedException();
         }
 
+        public Task ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options)
+        {
+            throw new NotImplementedException();
+        }
+
         public IDisposable EnterTypingState(RequestOptions options = null)
         {
             throw new NotImplementedException();

test/Discord.Net.Tests.Unit/MockedEntities/MockedVoiceChannel.cs

@@ -64,6 +64,11 @@ namespace Discord
             throw new NotImplementedException();
         }
 
+        public Task ModifyAsync(Action<AudioChannelProperties> func, RequestOptions options)
+        {
+            throw new NotImplementedException();
+        }
+
         public Task<ICategoryChannel> GetCategoryAsync(CacheMode mode = CacheMode.AllowDownload, RequestOptions options = null)
         {
             throw new NotImplementedException();