IrcProvider.cs

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using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
 
using Meebey.SmartIrc4net;
using Microsoft.Extensions.Logging;
 
using Newtonsoft.Json;
 
using Tgstation.Server.Api.Models;
using Tgstation.Server.Host.Components.Interop;
using Tgstation.Server.Host.Configuration;
using Tgstation.Server.Host.Extensions;
using Tgstation.Server.Host.IO;
using Tgstation.Server.Host.Jobs;
using Tgstation.Server.Host.System;
using Tgstation.Server.Host.Utils;
 
namespace Tgstation.Server.Host.Components.Chat.Providers
{
    sealed class IrcProvider : Provider
    {
        const int PreambleMessageLength = 12;
 
        const int MessageBytesLimit = 512;
 
        public override bool Connected => client.IsConnected;
 
        public override string BotMention => client.Nickname;
 
        readonly string address;
 
        readonly ushort port;
 
        readonly bool ssl;
 
        readonly string nickname;
 
        readonly string password;
 
        readonly IrcPasswordType? passwordType;
 
        readonly Dictionary<ulong, string?> channelIdMap;
 
        readonly Dictionary<ulong, string> queryChannelIdMap;
 
        readonly IAssemblyInformationProvider assemblyInfo;
 
        readonly FileLoggingConfiguration loggingConfiguration;
 
        IrcFeatures client;
 
        Task? listenTask;
 
        ulong channelIdCounter;
 
        public IrcProvider(
            IJobManager jobManager,
            IAsyncDelayer asyncDelayer,
            ILogger<IrcProvider> logger,
            IAssemblyInformationProvider assemblyInformationProvider,
            Models.ChatBot chatBot,
            FileLoggingConfiguration loggingConfiguration)
            : base(jobManager, asyncDelayer, logger, chatBot)
        {
            ArgumentNullException.ThrowIfNull(assemblyInformationProvider);
            ArgumentNullException.ThrowIfNull(loggingConfiguration);
 
            var builder = chatBot.CreateConnectionStringBuilder();
            if (builder == null || !builder.Valid || builder is not IrcConnectionStringBuilder ircBuilder)
                throw new InvalidOperationException("Invalid ChatConnectionStringBuilder!");
 
            address = ircBuilder.Address!;
            port = ircBuilder.Port!.Value;
            ssl = ircBuilder.UseSsl!.Value;
            nickname = ircBuilder.Nickname!;
 
            password = ircBuilder.Password!;
            passwordType = ircBuilder.PasswordType;
 
            assemblyInfo = assemblyInformationProvider ?? throw new ArgumentNullException(nameof(assemblyInformationProvider));
            this.loggingConfiguration = loggingConfiguration ?? throw new ArgumentNullException(nameof(loggingConfiguration));
 
            client = InstantiateClient();
 
            channelIdMap = new Dictionary<ulong, string?>();
            queryChannelIdMap = new Dictionary<ulong, string>();
            channelIdCounter = 1;
        }
 
        public override async ValueTask DisposeAsync()
        {
            await base.DisposeAsync();
 
            // DCT: None available
            await HardDisconnect(CancellationToken.None);
        }
 
        public override async ValueTask SendMessage(Message? replyTo, MessageContent message, ulong channelId, CancellationToken cancellationToken)
        {
            ArgumentNullException.ThrowIfNull(message);
 
            await Task.Factory.StartNew(
                () =>
                {
                    // IRC doesn't allow newlines
                    // Explicitly ignore embeds
                    var messageText = message.Text;
                    messageText ??= $"Embed Only: {JsonConvert.SerializeObject(message.Embed)}";
 
                    messageText = String.Concat(
                        messageText
                            .Where(x => x != '\r')
                            .Select(x => x == '\n' ? '|' : x));
 
                    var channelName = channelIdMap[channelId];
                    SendType sendType;
                    if (channelName == null)
                    {
                        channelName = queryChannelIdMap[channelId];
                        sendType = SendType.Notice;
                    }
                    else
                        sendType = SendType.Message;
 
                    var messageSize = Encoding.UTF8.GetByteCount(messageText) + Encoding.UTF8.GetByteCount(channelName) + PreambleMessageLength;
                    var messageTooLong = messageSize > MessageBytesLimit;
                    if (messageTooLong)
                        messageText = $"TGS: Could not send message to IRC. Line write exceeded protocol limit of {MessageBytesLimit}B.";
 
                    try
                    {
                        client.SendMessage(sendType, channelName, messageText);
                    }
                    catch (Exception e)
                    {
                        Logger.LogWarning(e, "Unable to send to channel {channelName}!", channelName);
                        return;
                    }
 
                    if (messageTooLong)
                        Logger.LogWarning(
                            "Failed to send to channel {channelId}: Message size ({messageSize}B) exceeds IRC limit of 512B",
                            channelId,
                            messageSize);
                },
                cancellationToken,
                DefaultIOManager.BlockingTaskCreationOptions,
                TaskScheduler.Current);
        }
 
        public override async ValueTask<Func<string?, string, ValueTask<Func<bool, ValueTask>>>> SendUpdateMessage(
            Models.RevisionInformation revisionInformation,
            EngineVersion engineVersion,
            DateTimeOffset? estimatedCompletionTime,
            string? gitHubOwner,
            string? gitHubRepo,
            ulong channelId,
            bool localCommitPushed,
            CancellationToken cancellationToken)
        {
            ArgumentNullException.ThrowIfNull(revisionInformation);
            ArgumentNullException.ThrowIfNull(engineVersion);
 
            var commitInsert = revisionInformation.CommitSha![..7];
            string remoteCommitInsert;
            if (revisionInformation.CommitSha == revisionInformation.OriginCommitSha)
            {
                commitInsert = String.Format(CultureInfo.InvariantCulture, localCommitPushed ? "^{0}" : "{0}", commitInsert);
                remoteCommitInsert = String.Empty;
            }
            else
                remoteCommitInsert = String.Format(CultureInfo.InvariantCulture, ". Remote commit: ^{0}", revisionInformation.OriginCommitSha![..7]);
 
            var testmergeInsert = (revisionInformation.ActiveTestMerges?.Count ?? 0) == 0
                ? String.Empty
                : String.Format(
                    CultureInfo.InvariantCulture,
                    " (Test Merges: {0})",
                    String.Join(
                        ", ",
                        revisionInformation
                            .ActiveTestMerges!
                            .Select(x => x.TestMerge)
                            .Select(x =>
                            {
                                var result = String.Format(CultureInfo.InvariantCulture, "#{0} at {1}", x.Number, x.TargetCommitSha![..7]);
                                if (x.Comment != null)
                                    result += String.Format(CultureInfo.InvariantCulture, " ({0})", x.Comment);
                                return result;
                            })));
 
            var prefix = GetEngineCompilerPrefix(engineVersion.Engine!.Value);
            await SendMessage(
                null,
                new MessageContent
                {
                    Text = String.Format(
                        CultureInfo.InvariantCulture,
                        $"{prefix}: Deploying revision: {0}{1}{2} BYOND Version: {3}{4}",
                        commitInsert,
                        testmergeInsert,
                        remoteCommitInsert,
                        engineVersion.ToString(),
                        estimatedCompletionTime.HasValue
                            ? $" ETA: {estimatedCompletionTime - DateTimeOffset.UtcNow}"
                            : String.Empty),
                },
                channelId,
                cancellationToken);
 
            return async (errorMessage, dreamMakerOutput) =>
            {
                await SendMessage(
                    null,
                    new MessageContent
                    {
                        Text = $"{prefix}: Deployment {(errorMessage == null ? "complete" : "failed")}!",
                    },
                    channelId,
                    cancellationToken);
 
                return active => ValueTask.CompletedTask;
            };
        }
 
        protected override async ValueTask<Dictionary<Models.ChatChannel, IEnumerable<ChannelRepresentation>>> MapChannelsImpl(
            IEnumerable<Models.ChatChannel> channels,
            CancellationToken cancellationToken)
            => await Task.Factory.StartNew(
                () =>
                {
                    if (channels.Any(x => x.IrcChannel == null))
                        throw new InvalidOperationException("ChatChannel missing IrcChannel!");
                    lock (client)
                    {
                        var channelsWithKeys = new Dictionary<string, string>();
                        var hs = new HashSet<string>(); // for unique inserts
                        foreach (var channel in channels)
                        {
                            var name = channel.GetIrcChannelName();
                            var key = channel.GetIrcChannelKey();
                            if (hs.Add(name) && key != null)
                                channelsWithKeys.Add(name, key);
                        }
 
                        var toPart = new List<string>();
                        foreach (var activeChannel in client.JoinedChannels)
                            if (!hs.Remove(activeChannel))
                                toPart.Add(activeChannel);
 
                        foreach (var channelToLeave in toPart)
                            client.RfcPart(channelToLeave, "Pretty nice abscond!");
                        foreach (var channelToJoin in hs)
                            if (channelsWithKeys.TryGetValue(channelToJoin, out var key))
                                client.RfcJoin(channelToJoin, key);
                            else
                                client.RfcJoin(channelToJoin);
 
                        return new Dictionary<Models.ChatChannel, IEnumerable<ChannelRepresentation>>(
                            channels
                                .Select(dbChannel =>
                                {
                                    var channelName = dbChannel.GetIrcChannelName();
                                    ulong? id = null;
                                    if (!channelIdMap.Any(y =>
                                    {
                                        if (y.Value != channelName)
                                            return false;
                                        id = y.Key;
                                        return true;
                                    }))
                                    {
                                        id = channelIdCounter++;
                                        channelIdMap.Add(id.Value, channelName);
                                    }
 
                                    return new KeyValuePair<Models.ChatChannel, IEnumerable<ChannelRepresentation>>(
                                        dbChannel,
                                        new List<ChannelRepresentation>
                                        {
                                            new(address, channelName, id!.Value)
                                            {
                                                Tag = dbChannel.Tag,
                                                IsAdminChannel = dbChannel.IsAdminChannel == true,
                                                IsPrivateChannel = false,
                                                EmbedsSupported = false,
                                            },
                                        });
                                }));
                    }
                },
                cancellationToken,
                DefaultIOManager.BlockingTaskCreationOptions,
                TaskScheduler.Current);
 
        protected override async ValueTask Connect(CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            try
            {
                await Task.Factory.StartNew(
                    () =>
                    {
                        client = InstantiateClient();
                        client.Connect(address, port);
                    },
                    cancellationToken,
                    DefaultIOManager.BlockingTaskCreationOptions,
                    TaskScheduler.Current)
                    .WaitAsync(cancellationToken);
 
                cancellationToken.ThrowIfCancellationRequested();
 
                listenTask = Task.Factory.StartNew(
                    () =>
                    {
                        Logger.LogTrace("Starting blocking listen...");
                        try
                        {
                            client.Listen();
                        }
                        catch (Exception ex)
                        {
                            Logger.LogWarning(ex, "IRC Main Listen Exception!");
                        }
 
                        Logger.LogTrace("Exiting listening task...");
                    },
                    cancellationToken,
                    DefaultIOManager.BlockingTaskCreationOptions,
                    TaskScheduler.Current);
 
                Logger.LogTrace("Authenticating ({passwordType})...", passwordType);
                switch (passwordType)
                {
                    case IrcPasswordType.Server:
                        client.RfcPass(password);
                        await Login(client, nickname, cancellationToken);
                        break;
                    case IrcPasswordType.NickServ:
                        await Login(client, nickname, cancellationToken);
                        cancellationToken.ThrowIfCancellationRequested();
                        client.SendMessage(SendType.Message, "NickServ", String.Format(CultureInfo.InvariantCulture, "IDENTIFY {0}", password));
                        break;
                    case IrcPasswordType.Sasl:
                        await SaslAuthenticate(cancellationToken);
                        break;
                    case IrcPasswordType.Oper:
                        await Login(client, nickname, cancellationToken);
                        cancellationToken.ThrowIfCancellationRequested();
                        client.RfcOper(nickname, password, Priority.Critical);
                        break;
                    case null:
                        await Login(client, nickname, cancellationToken);
                        break;
                    default:
                        throw new InvalidOperationException($"Invalid IrcPasswordType: {passwordType.Value}");
                }
 
                cancellationToken.ThrowIfCancellationRequested();
 
                Logger.LogTrace("Connection established!");
            }
            catch (Exception e) when (e is not OperationCanceledException)
            {
                throw new JobException(ErrorCode.ChatCannotConnectProvider, e);
            }
        }
 
        protected override async ValueTask DisconnectImpl(CancellationToken cancellationToken)
        {
            try
            {
                await Task.Factory.StartNew(
                    () =>
                    {
                        try
                        {
                            client.RfcQuit("Mr. Stark, I don't feel so good...", Priority.Critical); // priocritical otherwise it wont go through
                        }
                        catch (Exception e)
                        {
                            Logger.LogWarning(e, "Error quitting IRC!");
                        }
                    },
                    cancellationToken,
                    DefaultIOManager.BlockingTaskCreationOptions,
                    TaskScheduler.Current);
                await HardDisconnect(cancellationToken);
            }
            catch (OperationCanceledException)
            {
                throw;
            }
            catch (Exception e)
            {
                Logger.LogWarning(e, "Error disconnecting from IRC!");
            }
        }
 
        async ValueTask Login(IrcFeatures client, string nickname, CancellationToken cancellationToken)
        {
            var promise = new TaskCompletionSource<object>();
 
            void Callback(object? sender, EventArgs e)
            {
                Logger.LogTrace("IRC Registered.");
                promise.TrySetResult(e);
            }
 
            client.OnRegistered += Callback;
 
            client.Login(nickname, nickname, 0, nickname);
 
            using var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
            cts.CancelAfter(TimeSpan.FromSeconds(30));
 
            try
            {
                await promise.Task.WaitAsync(cts.Token);
                client.OnRegistered -= Callback;
            }
            catch (OperationCanceledException)
            {
                if (client.IsConnected)
                    client.Disconnect();
                throw new JobException("Timed out waiting for IRC Registration");
            }
        }
 
        void HandleMessage(IrcEventArgs e, bool isPrivate)
        {
            if (e.Data.Nick.Equals(client.Nickname, StringComparison.OrdinalIgnoreCase))
                return;
 
            var username = e.Data.Nick;
            var channelName = isPrivate ? username : e.Data.Channel;
 
            ulong MapAndGetChannelId(Dictionary<ulong, string?> dicToCheck)
            {
                ulong? resultId = null;
                if (!dicToCheck.Any(x =>
                {
                    if (x.Value != channelName)
                        return false;
                    resultId = x.Key;
                    return true;
                }))
                {
                    resultId = channelIdCounter++;
                    dicToCheck.Add(resultId.Value, channelName);
                    if (dicToCheck == queryChannelIdMap)
                        channelIdMap.Add(resultId.Value, null);
                }
 
                return resultId!.Value;
            }
 
            ulong userId, channelId;
            lock (client)
            {
                userId = MapAndGetChannelId(new Dictionary<ulong, string?>(queryChannelIdMap
                    .Cast<KeyValuePair<ulong, string?>>())); // NRT my beloathed
                channelId = isPrivate ? userId : MapAndGetChannelId(channelIdMap);
            }
 
            var channelFriendlyName = isPrivate ? String.Format(CultureInfo.InvariantCulture, "PM: {0}", channelName) : channelName;
            var message = new Message(
                new ChatUser(
                    new ChannelRepresentation(address, channelFriendlyName, channelId)
                    {
                        IsPrivateChannel = isPrivate,
                        EmbedsSupported = false,
 
                        // isAdmin and Tag populated by manager
                    },
                    username,
                    username,
                    userId),
                e.Data.Message);
 
            EnqueueMessage(message);
        }
 
        void Client_OnQueryMessage(object sender, IrcEventArgs e) => HandleMessage(e, true);
 
        void Client_OnChannelMessage(object sender, IrcEventArgs e) => HandleMessage(e, false);
 
        Task NonBlockingListen(CancellationToken cancellationToken) => Task.Factory.StartNew(
            () =>
            {
                try
                {
                    client.Listen(false);
                }
                catch (Exception ex)
                {
                    Logger.LogWarning(ex, "IRC Non-Blocking Listen Exception!");
                }
            },
            cancellationToken,
            TaskCreationOptions.None,
            TaskScheduler.Current)
            .WaitAsync(cancellationToken);
 
        async ValueTask SaslAuthenticate(CancellationToken cancellationToken)
        {
            client.WriteLine("CAP REQ :sasl", Priority.Critical); // needs to be put in the buffer before anything else
            cancellationToken.ThrowIfCancellationRequested();
 
            Logger.LogTrace("Logging in...");
            client.Login(nickname, nickname, 0, nickname);
            cancellationToken.ThrowIfCancellationRequested();
 
            // wait for the SASL ack or timeout
            var receivedAck = false;
            var receivedPlus = false;
 
            void AuthenticationDelegate(object sender, ReadLineEventArgs e)
            {
                if (e.Line.Contains("ACK :sasl", StringComparison.Ordinal))
                    receivedAck = true;
                else if (e.Line.Contains("AUTHENTICATE +", StringComparison.Ordinal))
                    receivedPlus = true;
            }
 
            Logger.LogTrace("Performing handshake...");
            client.OnReadLine += AuthenticationDelegate;
            try
            {
                using var timeoutCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
                timeoutCts.CancelAfter(TimeSpan.FromSeconds(25));
                var timeoutToken = timeoutCts.Token;
 
                var listenTimeSpan = TimeSpan.FromMilliseconds(10);
                for (; !receivedAck;
                    await AsyncDelayer.Delay(listenTimeSpan, timeoutToken))
                    await NonBlockingListen(cancellationToken);
 
                client.WriteLine("AUTHENTICATE PLAIN", Priority.Critical);
                timeoutToken.ThrowIfCancellationRequested();
 
                for (; !receivedPlus;
                    await AsyncDelayer.Delay(listenTimeSpan, timeoutToken))
                    await NonBlockingListen(cancellationToken);
            }
            finally
            {
                client.OnReadLine -= AuthenticationDelegate;
            }
 
            cancellationToken.ThrowIfCancellationRequested();
 
            // Stolen! https://github.com/znc/znc/blob/1e697580155d5a38f8b5a377f3b1d94aaa979539/modules/sasl.cpp#L196
            Logger.LogTrace("Sending credentials...");
            var authString = String.Format(
                CultureInfo.InvariantCulture,
                "{0}{1}{0}{1}{2}",
                nickname,
                '\0',
                password);
            var b64 = Convert.ToBase64String(Encoding.UTF8.GetBytes(authString));
            var authLine = $"AUTHENTICATE {b64}";
            client.WriteLine(authLine, Priority.Critical);
            cancellationToken.ThrowIfCancellationRequested();
 
            Logger.LogTrace("Finishing authentication...");
            client.WriteLine("CAP END", Priority.Critical);
        }
 
        async ValueTask HardDisconnect(CancellationToken cancellationToken)
        {
            if (!Connected)
            {
                Logger.LogTrace("Not hard disconnecting, already offline");
                return;
            }
 
            Logger.LogTrace("Hard disconnect");
 
            // This call blocks permanently randomly sometimes
            // Frankly I don't give a shit
            var disconnectTask = Task.Factory.StartNew(
                () =>
                {
                    try
                    {
                        client.Disconnect();
                    }
                    catch (Exception e)
                    {
                        Logger.LogWarning(e, "Error disconnecting IRC!");
                    }
                },
                cancellationToken,
                DefaultIOManager.BlockingTaskCreationOptions,
                TaskScheduler.Current);
 
            await Task.WhenAny(
                Task.WhenAll(
                    disconnectTask,
                    listenTask ?? Task.CompletedTask),
                AsyncDelayer.Delay(TimeSpan.FromSeconds(5), cancellationToken).AsTask());
        }
 
        IrcFeatures InstantiateClient()
        {
            var newClient = new IrcFeatures
            {
                SupportNonRfc = true,
                CtcpUserInfo = "You are going to play. And I am going to watch. And everything will be just fine...",
                AutoRejoin = true,
                AutoRejoinOnKick = true,
                AutoRelogin = false,
                AutoRetry = false,
                AutoReconnect = false,
                ActiveChannelSyncing = true,
                AutoNickHandling = true,
                CtcpVersion = assemblyInfo.VersionString,
                UseSsl = ssl,
                EnableUTF8Recode = true,
            };
            if (ssl)
                newClient.ValidateServerCertificate = true; // dunno if it defaults to that or what
 
            newClient.OnChannelMessage += Client_OnChannelMessage;
            newClient.OnQueryMessage += Client_OnQueryMessage;
 
            if (loggingConfiguration.ProviderNetworkDebug)
            {
                newClient.OnReadLine += (sender, e) => Logger.LogTrace("READ: {line}", e.Line);
                newClient.OnWriteLine += (sender, e) => Logger.LogTrace("WRITE: {line}", e.Line);
            }
 
            newClient.OnError += (sender, e) =>
            {
                Logger.LogError("IRC ERROR: {error}", e.ErrorMessage);
                newClient.Disconnect();
            };
 
            return newClient;
        }
    }
}