initial implementation of INestedChannel

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 
@@ -9,10 +9,6 @@ namespace Discord
         /// <summary> Gets the position of this channel in the guild's channel list, relative to others of the same type. </summary>
         int Position { get; }
 
-        /// <summary> Gets the parentid (category) of this channel in the guild's channel list. </summary>
-        ulong? CategoryId { get; }
-        /// <summary> Gets the parent channel (category) of this channel. </summary>
-        Task<ICategoryChannel> GetCategoryAsync();
         /// <summary> Gets the guild this channel is a member of. </summary>
         IGuild Guild { get; }
         /// <summary> Gets the id of the guild this channel is a member of. </summary>
@@ -49,4 +45,4 @@ namespace Discord
         /// <summary> Gets a user in this channel with the provided id.</summary>
         new Task<IGuildUser> GetUserAsync(ulong id, CacheMode mode = CacheMode.AllowDownload, RequestOptions options = null);
     }
-}
+}

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

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    /// <summary>
+    /// A type of guild channel that can be nested within a category.
+    /// Contains a CategoryId that is set to the parent category, if it is set.
+    /// </summary>
+    public interface INestedChannel : IGuildChannel
+    {
+        /// <summary> Gets the parentid (category) of this channel in the guild's channel list. </summary>
+        ulong? CategoryId { get; }
+        /// <summary> Gets the parent channel (category) of this channel, if it is set. If unset, returns null.</summary>
+        Task<ICategoryChannel> GetCategoryAsync();
+    }
+}

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

@@ -1,11 +1,11 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 
 namespace Discord
 {
-    public interface ITextChannel : IMessageChannel, IMentionable, IGuildChannel
+    public interface ITextChannel : IMessageChannel, IMentionable, IGuildChannel, INestedChannel
     {
         /// <summary> Checks if the channel is NSFW. </summary>
         bool IsNsfw { get; }
@@ -28,4 +28,4 @@ namespace Discord
         /// <summary> Gets the webhooks for this text channel. </summary>
         Task<IReadOnlyCollection<IWebhook>> GetWebhooksAsync(RequestOptions options = null);
     }
-}
+}

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

@@ -25,23 +25,6 @@ namespace Discord.Rest
         private string DebuggerDisplay => $"{Name} ({Id}, Category)";
 
         // IGuildChannel
-
-        /// <summary>
-        /// Throws a NotSupportedException because Channel Categories cannot be the child of another Channel Category.
-        /// </summary>
-        /// <exception cref="NotSupportedException">A NotSupportedException is always thrown because Channel Categories do not support being nested.</exception>
-        ulong? IGuildChannel.CategoryId
-            => throw new NotSupportedException();
-        /// <summary>
-        /// Throws a NotSupportedException because Channel Categories cannot be the child of another Channel Category.
-        /// </summary>
-        /// <exception cref="NotSupportedException">A NotSupportedException is always thrown because Channel Categories do not support being nested.</exception>
-        Task<ICategoryChannel> IGuildChannel.GetCategoryAsync()
-            => throw new NotSupportedException();
-        IAsyncEnumerable<IReadOnlyCollection<IGuildUser>> IGuildChannel.GetUsersAsync(CacheMode mode, RequestOptions options)
-            => throw new NotSupportedException();
-        Task<IGuildUser> IGuildChannel.GetUserAsync(ulong id, CacheMode mode, RequestOptions options)
-            => throw new NotSupportedException();
         Task<IInviteMetadata> IGuildChannel.CreateInviteAsync(int? maxAge, int? maxUses, bool isTemporary, bool isUnique, RequestOptions options)
             => throw new NotSupportedException();
         Task<IReadOnlyCollection<IInviteMetadata>> IGuildChannel.GetInvitesAsync(RequestOptions options)

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
@@ -16,7 +16,6 @@ namespace Discord.Rest
         internal IGuild Guild { get; }
         public string Name { get; private set; }
         public int Position { get; private set; }
-        public ulong? CategoryId { get; private set; }
         public ulong GuildId => Guild.Id;
 
         internal RestGuildChannel(BaseDiscordClient discord, IGuild guild, ulong id)
@@ -64,13 +63,6 @@ namespace Discord.Rest
         public Task DeleteAsync(RequestOptions options = null)
             => ChannelHelper.DeleteAsync(this, Discord, options);
 
-        public async Task<ICategoryChannel> GetCategoryAsync()
-        {
-            if (CategoryId.HasValue)
-                return (await Guild.GetChannelAsync(CategoryId.Value).ConfigureAwait(false)) as ICategoryChannel;
-            return null;
-        }
-
         public OverwritePermissions? GetPermissionOverwrite(IUser user)
         {
             for (int i = 0; i < _overwrites.Length; i++)

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

@@ -9,9 +9,10 @@ using Model = Discord.API.Channel;
 namespace Discord.Rest
 {
     [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
-    public class RestTextChannel : RestGuildChannel, IRestMessageChannel, ITextChannel
+    public class RestTextChannel : RestGuildChannel, IRestMessageChannel, ITextChannel, INestedChannel
     {
         public string Topic { get; private set; }
+        public ulong? CategoryId { get; private set; }
 
         public string Mention => MentionUtils.MentionChannel(Id);
 
@@ -168,5 +169,13 @@ namespace Discord.Rest
             else
                 return AsyncEnumerable.Empty<IReadOnlyCollection<IGuildUser>>();
         }
+
+        // INestedChannel
+        async Task<ICategoryChannel> INestedChannel.GetCategoryAsync()
+        {
+            if (CategoryId.HasValue)
+                return (await Guild.GetChannelAsync(CategoryId.Value).ConfigureAwait(false)) as ICategoryChannel;
+            return null;
+        }
     }
 }

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

@@ -1,4 +1,4 @@
-using Discord.Audio;
+using Discord.Audio;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -9,10 +9,11 @@ using Model = Discord.API.Channel;
 namespace Discord.Rest
 {
     [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
-    public class RestVoiceChannel : RestGuildChannel, IVoiceChannel, IRestAudioChannel
+    public class RestVoiceChannel : RestGuildChannel, IVoiceChannel, IRestAudioChannel, INestedChannel
     {
         public int Bitrate { get; private set; }
         public int? UserLimit { get; private set; }
+        public ulong? CategoryId { get; private set; }
 
         internal RestVoiceChannel(BaseDiscordClient discord, IGuild guild, ulong id)
             : base(discord, guild, id)
@@ -48,5 +49,13 @@ namespace Discord.Rest
             => Task.FromResult<IGuildUser>(null);
         IAsyncEnumerable<IReadOnlyCollection<IGuildUser>> IGuildChannel.GetUsersAsync(CacheMode mode, RequestOptions options)
             => AsyncEnumerable.Empty<IReadOnlyCollection<IGuildUser>>();
+
+        // INestedChannel
+        async Task<ICategoryChannel> INestedChannel.GetCategoryAsync()
+        {
+            if (CategoryId.HasValue)
+                return (await Guild.GetChannelAsync(CategoryId.Value).ConfigureAwait(false)) as ICategoryChannel;
+            return null;
+        }
     }
 }

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

@@ -11,11 +11,14 @@ using Model = Discord.API.Channel;
 namespace Discord.WebSocket
 {
     [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
-    public class SocketTextChannel : SocketGuildChannel, ITextChannel, ISocketMessageChannel
+    public class SocketTextChannel : SocketGuildChannel, ITextChannel, ISocketMessageChannel, INestedChannel
     {
         private readonly MessageCache _messages;
 
         public string Topic { get; private set; }
+        public ulong? CategoryId { get; private set; }
+        public ICategoryChannel Category
+            => CategoryId.HasValue ? Guild.GetChannel(CategoryId.Value) as ICategoryChannel : null;
 
         private bool _nsfw;
         public bool IsNsfw => _nsfw || ChannelHelper.IsNsfw(this);
@@ -164,5 +167,9 @@ namespace Discord.WebSocket
             => await SendMessageAsync(text, isTTS, embed, options).ConfigureAwait(false);
         IDisposable IMessageChannel.EnterTypingState(RequestOptions options)
             => EnterTypingState(options);
+
+        // INestedChannel
+        Task<ICategoryChannel> INestedChannel.GetCategoryAsync()
+            => Task.FromResult(Category);
     }
 }

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

@@ -1,4 +1,4 @@
-using Discord.Audio;
+using Discord.Audio;
 using Discord.Rest;
 using System;
 using System.Collections.Generic;
@@ -11,10 +11,13 @@ using Model = Discord.API.Channel;
 namespace Discord.WebSocket
 {
     [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
-    public class SocketVoiceChannel : SocketGuildChannel, IVoiceChannel, ISocketAudioChannel
+    public class SocketVoiceChannel : SocketGuildChannel, IVoiceChannel, ISocketAudioChannel, INestedChannel
     {
         public int Bitrate { get; private set; }
         public int? UserLimit { get; private set; }
+        public ulong? CategoryId { get; private set; }
+        public ICategoryChannel Category
+            => CategoryId.HasValue ? Guild.GetChannel(CategoryId.Value) as ICategoryChannel : null;
 
         public override IReadOnlyCollection<SocketGuildUser> Users
             => Guild.Users.Where(x => x.VoiceChannel?.Id == Id).ToImmutableArray();
@@ -61,5 +64,9 @@ namespace Discord.WebSocket
             => Task.FromResult<IGuildUser>(GetUser(id));
         IAsyncEnumerable<IReadOnlyCollection<IGuildUser>> IGuildChannel.GetUsersAsync(CacheMode mode, RequestOptions options)
             => ImmutableArray.Create<IReadOnlyCollection<IGuildUser>>(Users).ToAsyncEnumerable();
+
+        // INestedChannel
+        Task<ICategoryChannel> INestedChannel.GetCategoryAsync()
+            => Task.FromResult(Category);
     }
 }