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

using Discord.Audio;
using Discord.Rest;
using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Model = Discord.API.Channel;

namespace Discord.WebSocket
{
    /// <summary>
    ///     Represents a WebSocket-based voice channel in a guild.
    /// </summary>
    [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
    public class SocketVoiceChannel : SocketGuildChannel, IVoiceChannel, ISocketAudioChannel
    {
        /// <inheritdoc />
        public int Bitrate { get; private set; }
        /// <inheritdoc />
        public int? UserLimit { get; private set; }
        public ulong? CategoryId { get; private set; }
        public ICategoryChannel Category
            => CategoryId.HasValue ? Guild.GetChannel(CategoryId.Value) as ICategoryChannel : null;

        /// <inheritdoc />
        public override IReadOnlyCollection<SocketGuildUser> Users
            => Guild.Users.Where(x => x.VoiceChannel?.Id == Id).ToImmutableArray();

        internal SocketVoiceChannel(DiscordSocketClient discord, ulong id, SocketGuild guild)
            : base(discord, id, guild)
        {
        }
        internal new static SocketVoiceChannel Create(SocketGuild guild, ClientState state, Model model)
        {
            var entity = new SocketVoiceChannel(guild.Discord, model.Id, guild);
            entity.Update(state, model);
            return entity;
        }
        internal override void Update(ClientState state, Model model)
        {
            base.Update(state, model);
            CategoryId = model.CategoryId;
            Bitrate = model.Bitrate.Value;
            UserLimit = model.UserLimit.Value != 0 ? model.UserLimit.Value : (int?)null;
        }

        /// <inheritdoc />
        public Task ModifyAsync(Action<VoiceChannelProperties> func, RequestOptions options = null)
            => ChannelHelper.ModifyAsync(this, Discord, func, options);

        /// <inheritdoc />
        public async Task<IAudioClient> ConnectAsync(bool selfDeaf, bool selfMute, bool external)
        {
            return await Guild.ConnectAudioAsync(Id, selfDeaf, selfMute, external).ConfigureAwait(false);
        }

        public async Task DisconnectAsync()
            => await Guild.DisconnectAudioAsync();

        /// <inheritdoc />
        public override SocketGuildUser GetUser(ulong id)
        {
            var user = Guild.GetUser(id);
            if (user?.VoiceChannel?.Id == Id)
                return user;
            return null;
        }

        private string DebuggerDisplay => $"{Name} ({Id}, Voice)";
        internal new SocketVoiceChannel Clone() => MemberwiseClone() as SocketVoiceChannel;

        //IGuildChannel
        /// <inheritdoc />
        Task<IGuildUser> IGuildChannel.GetUserAsync(ulong id, CacheMode mode, RequestOptions options)
            => Task.FromResult<IGuildUser>(GetUser(id));
        /// <inheritdoc />
        IAsyncEnumerable<IReadOnlyCollection<IGuildUser>> IGuildChannel.GetUsersAsync(CacheMode mode, RequestOptions options)
            => ImmutableArray.Create<IReadOnlyCollection<IGuildUser>>(Users).ToAsyncEnumerable();

        // INestedChannel
        Task<ICategoryChannel> INestedChannel.GetCategoryAsync(CacheMode mode, RequestOptions options)
            => Task.FromResult(Category);
    }
}