SocketUnknownChannel.cs

using Discord.Rest;
using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace Discord.WebSocket
{
    public class SocketUnknownChannel : SocketChannel, ISocketMessageChannel
    {
        public string Name => null;

        public ulong? GuildId { get; private set; }

        public IReadOnlyCollection<SocketMessage> CachedMessages => ImmutableArray.Create<SocketMessage>();

        internal SocketUnknownChannel(DiscordSocketClient discord, ulong id)
            : base(discord, id)
        {
        }
        internal static SocketUnknownChannel Create(DiscordSocketClient discord, ClientState state, ulong channelId, ulong? guildId)
        {
            var entity = new SocketUnknownChannel(discord, channelId);
            entity.Update(state, guildId);
            return entity;
        }
        internal override void Update(ClientState state, API.Channel model)
        {
        }
        internal void Update(ClientState state, ulong? guildId)
        {
            GuildId = guildId;
        }

        internal override SocketUser GetUserInternal(ulong id)
            => null;
        internal override IReadOnlyCollection<SocketUser> GetUsersInternal()
            => ImmutableArray.Create<SocketUser>();
        internal void AddMessage(SocketMessage msg)
        {
        }
        internal SocketMessage RemoveMessage(ulong id)
            => null;

        /// <summary>
        ///     Gets a message from this message channel.
        /// </summary>
        /// <remarks>
        ///     This method follows the same behavior as described in <see cref="IMessageChannel.GetMessageAsync"/>.
        ///     Please visit its documentation for more details on this method.
        /// </remarks>
        /// <param name="id">The snowflake identifier of the message.</param>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <returns>
        ///     A task that represents an asynchronous get operation for retrieving the message. The task result contains
        ///     the retrieved message; <c>null</c> if no message is found with the specified identifier.
        /// </returns>
        public async Task<IMessage> GetMessageAsync(ulong id, RequestOptions options = null)
            => await ChannelHelper.GetMessageAsync(this, Discord, id, options).ConfigureAwait(false);

        /// <summary>
        ///     Gets the last N messages from this message channel.
        /// </summary>
        /// <remarks>
        ///     This method follows the same behavior as described in <see cref="IMessageChannel.GetMessagesAsync(int, CacheMode, RequestOptions)"/>.
        ///     Please visit its documentation for more details on this method.
        /// </remarks>
        /// <param name="limit">The numbers of message to be gotten from.</param>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <returns>
        ///     Paged collection of messages.
        /// </returns>
        public IAsyncEnumerable<IReadOnlyCollection<IMessage>> GetMessagesAsync(int limit = DiscordConfig.MaxMessagesPerBatch, RequestOptions options = null)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, null, Direction.Before, limit, CacheMode.AllowDownload, options);
        /// <summary>
        ///     Gets a collection of messages in this channel.
        /// </summary>
        /// <remarks>
        ///     This method follows the same behavior as described in <see cref="IMessageChannel.GetMessagesAsync(ulong, Direction, int, CacheMode, RequestOptions)"/>.
        ///     Please visit its documentation for more details on this method.
        /// </remarks>
        /// <param name="fromMessageId">The ID of the starting message to get the messages from.</param>
        /// <param name="dir">The direction of the messages to be gotten from.</param>
        /// <param name="limit">The numbers of message to be gotten from.</param>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <returns>
        ///     Paged collection of messages.
        /// </returns>
        public IAsyncEnumerable<IReadOnlyCollection<IMessage>> GetMessagesAsync(ulong fromMessageId, Direction dir, int limit = DiscordConfig.MaxMessagesPerBatch, RequestOptions options = null)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, fromMessageId, dir, limit, CacheMode.AllowDownload, options);
        /// <summary>
        ///     Gets a collection of messages in this channel.
        /// </summary>
        /// <remarks>
        ///     This method follows the same behavior as described in <see cref="IMessageChannel.GetMessagesAsync(IMessage, Direction, int, CacheMode, RequestOptions)"/>.
        ///     Please visit its documentation for more details on this method.
        /// </remarks>
        /// <param name="fromMessage">The starting message to get the messages from.</param>
        /// <param name="dir">The direction of the messages to be gotten from.</param>
        /// <param name="limit">The numbers of message to be gotten from.</param>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <returns>
        ///     Paged collection of messages.
        /// </returns>
        public IAsyncEnumerable<IReadOnlyCollection<IMessage>> GetMessagesAsync(IMessage fromMessage, Direction dir, int limit = DiscordConfig.MaxMessagesPerBatch, RequestOptions options = null)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, fromMessage.Id, dir, limit, CacheMode.AllowDownload, options);

        /// <inheritdoc />
        /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null)
            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, options);

        /// <inheritdoc />
        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null)
            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, options, isSpoiler);

        /// <inheritdoc />
        /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null)
            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, options, isSpoiler);

        /// <inheritdoc />
        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);

        /// <inheritdoc />
        public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
            => ChannelHelper.DeleteMessageAsync(this, messageId, Discord, options);
        /// <inheritdoc />
        public Task DeleteMessageAsync(IMessage message, RequestOptions options = null)
            => ChannelHelper.DeleteMessageAsync(this, message.Id, Discord, options);

        /// <inheritdoc />
        public Task TriggerTypingAsync(RequestOptions options = null)
            => ChannelHelper.TriggerTypingAsync(this, Discord, options);
        /// <inheritdoc />
        public IDisposable EnterTypingState(RequestOptions options = null)
            => ChannelHelper.EnterTypingState(this, Discord, options);

        /// <inheritdoc />
        public Task<IReadOnlyCollection<RestMessage>> GetPinnedMessagesAsync(RequestOptions options = null)
            => ChannelHelper.GetPinnedMessagesAsync(this, Discord, options);

        /// <summary>
        ///     Gets a user in this channel.
        /// </summary>
        /// <param name="id">The snowflake identifier of the user.</param>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <exception cref="InvalidOperationException">
        /// Resolving permissions requires the parent guild to be downloaded.
        /// </exception>
        /// <returns>
        ///     A task representing the asynchronous get operation. The task result contains a guild user object that
        ///     represents the user; <c>null</c> if none is found.
        /// </returns>
        public Task<RestGuildUser> GetUserAsync(ulong id, RequestOptions options = null)
            => Task.FromResult<RestGuildUser>(null);

        /// <summary>
        ///     Gets a collection of users that are able to view the channel.
        /// </summary>
        /// <param name="options">The options to be used when sending the request.</param>
        /// <exception cref="InvalidOperationException">
        /// Resolving permissions requires the parent guild to be downloaded.
        /// </exception>
        /// <returns>
        ///     A paged collection containing a collection of guild users that can access this channel. Flattening the
        ///     paginated response into a collection of users with 
        ///     <see cref="AsyncEnumerableExtensions.FlattenAsync{T}"/> is required if you wish to access the users.
        /// </returns>
        public IAsyncEnumerable<IReadOnlyCollection<RestGuildUser>> GetUsersAsync(RequestOptions options = null)
            => AsyncEnumerable.Empty<IReadOnlyCollection<RestGuildUser>>();

        /// <inheritdoc />
        public SocketMessage GetCachedMessage(ulong id)
            => null;
        /// <inheritdoc />
        public IReadOnlyCollection<SocketMessage> GetCachedMessages(int limit = 100)
            => ImmutableArray.Create<SocketMessage>();
        /// <inheritdoc />
        public IReadOnlyCollection<SocketMessage> GetCachedMessages(ulong fromMessageId, Direction dir, int limit = 100)
            => ImmutableArray.Create<SocketMessage>();
        /// <inheritdoc />
        public IReadOnlyCollection<SocketMessage> GetCachedMessages(IMessage fromMessage, Direction dir, int limit = 100)
            => ImmutableArray.Create<SocketMessage>();

        //IMessageChannel
        /// <inheritdoc />
        async Task<IMessage> IMessageChannel.GetMessageAsync(ulong id, CacheMode mode, RequestOptions options)
        {
            if (mode == CacheMode.AllowDownload)
                return await GetMessageAsync(id, options).ConfigureAwait(false);
            else
                return GetCachedMessage(id);
        }
        /// <inheritdoc />
        IAsyncEnumerable<IReadOnlyCollection<IMessage>> IMessageChannel.GetMessagesAsync(int limit, CacheMode mode, RequestOptions options)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, null, Direction.Before, limit, mode, options);
        /// <inheritdoc />
        IAsyncEnumerable<IReadOnlyCollection<IMessage>> IMessageChannel.GetMessagesAsync(ulong fromMessageId, Direction dir, int limit, CacheMode mode, RequestOptions options)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, fromMessageId, dir, limit, mode, options);
        /// <inheritdoc />
        IAsyncEnumerable<IReadOnlyCollection<IMessage>> IMessageChannel.GetMessagesAsync(IMessage fromMessage, Direction dir, int limit, CacheMode mode, RequestOptions options)
            => SocketChannelHelper.GetMessagesAsync(this, Discord, null, fromMessage.Id, dir, limit, mode, options);

        /// <inheritdoc />
        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference)
            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference).ConfigureAwait(false);
        /// <inheritdoc />
        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference)
            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference).ConfigureAwait(false);
        /// <inheritdoc />
        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference)
            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference).ConfigureAwait(false);

        /// <inheritdoc />
        async Task<IReadOnlyCollection<IMessage>> IMessageChannel.GetPinnedMessagesAsync(RequestOptions options)
            => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
    }
}