using System; using System.Threading.Tasks; using App.Metrics; using Autofac; using DSharpPlus; using DSharpPlus.Entities; using DSharpPlus.EventArgs; using PluralKit.Core; namespace PluralKit.Bot { public class MessageCreated: IEventHandler { private readonly CommandTree _tree; private readonly DiscordShardedClient _client; private readonly LastMessageCacheService _lastMessageCache; private readonly LoggerCleanService _loggerClean; private readonly IMetrics _metrics; private readonly ProxyService _proxy; private readonly ILifetimeScope _services; private readonly IDatabase _db; private readonly ModelRepository _repo; private readonly BotConfig _config; public MessageCreated(LastMessageCacheService lastMessageCache, LoggerCleanService loggerClean, IMetrics metrics, ProxyService proxy, DiscordShardedClient client, CommandTree tree, ILifetimeScope services, IDatabase db, BotConfig config, ModelRepository repo) { _lastMessageCache = lastMessageCache; _loggerClean = loggerClean; _metrics = metrics; _proxy = proxy; _client = client; _tree = tree; _services = services; _db = db; _config = config; _repo = repo; } public DiscordChannel ErrorChannelFor(MessageCreateEventArgs evt) => evt.Channel; private bool IsDuplicateMessage(DiscordMessage evt) => // We consider a message duplicate if it has the same ID as the previous message that hit the gateway _lastMessageCache.GetLastMessage(evt.ChannelId) == evt.Id; public async Task Handle(DiscordClient shard, MessageCreateEventArgs evt) { if (evt.Author?.Id == _client.CurrentUser?.Id) return; if (evt.Message.MessageType != MessageType.Default) return; if (IsDuplicateMessage(evt.Message)) return; // Log metrics and message info _metrics.Measure.Meter.Mark(BotMetrics.MessagesReceived); _lastMessageCache.AddMessage(evt.Channel.Id, evt.Message.Id); // Get message context from DB (tracking w/ metrics) MessageContext ctx; await using (var conn = await _db.Obtain()) using (_metrics.Measure.Timer.Time(BotMetrics.MessageContextQueryTime)) ctx = await _repo.GetMessageContext(conn, evt.Author.Id, evt.Channel.GuildId, evt.Channel.Id); // Try each handler until we find one that succeeds if (await TryHandleLogClean(evt, ctx)) return; // Only do command/proxy handling if it's a user account if (evt.Message.Author.IsBot || evt.Message.WebhookMessage || evt.Message.Author.IsSystem == true) return; if (await TryHandleCommand(shard, evt, ctx)) return; await TryHandleProxy(shard, evt, ctx); } private async ValueTask TryHandleLogClean(MessageCreateEventArgs evt, MessageContext ctx) { if (!evt.Message.Author.IsBot || evt.Message.Channel.Type != ChannelType.Text || !ctx.LogCleanupEnabled) return false; await _loggerClean.HandleLoggerBotCleanup(evt.Message); return true; } private async ValueTask TryHandleCommand(DiscordClient shard, MessageCreateEventArgs evt, MessageContext ctx) { var content = evt.Message.Content; if (content == null) return false; // Check for command prefix if (!HasCommandPrefix(content, out var cmdStart)) return false; // Trim leading whitespace from command without actually modifying the string // This just moves the argPos pointer by however much whitespace is at the start of the post-argPos string var trimStartLengthDiff = content.Substring(cmdStart).Length - content.Substring(cmdStart).TrimStart().Length; cmdStart += trimStartLengthDiff; try { var system = ctx.SystemId != null ? await _db.Execute(c => _repo.GetSystem(c, ctx.SystemId.Value)) : null; await _tree.ExecuteCommand(new Context(_services, shard, evt.Message, cmdStart, system, ctx)); } catch (PKError) { // Only permission errors will ever bubble this far and be caught here instead of Context.Execute // so we just catch and ignore these. TODO: this may need to change. } return true; } private bool HasCommandPrefix(string message, out int argPos) { // First, try prefixes defined in the config var prefixes = _config.Prefixes ?? BotConfig.DefaultPrefixes; foreach (var prefix in prefixes) { if (!message.StartsWith(prefix, StringComparison.InvariantCultureIgnoreCase)) continue; argPos = prefix.Length; return true; } // Then, check mention prefix (must be the bot user, ofc) argPos = -1; if (DiscordUtils.HasMentionPrefix(message, ref argPos, out var id)) return id == _client.CurrentUser.Id; return false; } private async ValueTask TryHandleProxy(DiscordClient shard, MessageCreateEventArgs evt, MessageContext ctx) { try { return await _proxy.HandleIncomingMessage(shard, evt.Message, ctx, allowAutoproxy: true); } catch (PKError e) { // User-facing errors, print to the channel properly formatted var msg = evt.Message; if (msg.Channel.Guild == null || msg.Channel.BotHasAllPermissions(Permissions.SendMessages)) await msg.Channel.SendMessageFixedAsync($"{Emojis.Error} {e.Message}"); } return false; } } }