PluralKit/PluralKit.Bot/Bot.cs
2021-05-26 22:27:52 +02:00

308 lines
13 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;
using App.Metrics;
using Autofac;
using Myriad.Cache;
using Myriad.Extensions;
using Myriad.Gateway;
using Myriad.Rest;
using Myriad.Rest.Exceptions;
using Myriad.Types;
using NodaTime;
using PluralKit.Core;
using Sentry;
using Serilog;
using Serilog.Context;
namespace PluralKit.Bot
{
public class Bot
{
private readonly ConcurrentDictionary<ulong, GuildMemberPartial> _guildMembers = new();
private readonly Cluster _cluster;
private readonly DiscordApiClient _rest;
private readonly ILogger _logger;
private readonly ILifetimeScope _services;
private readonly PeriodicStatCollector _collector;
private readonly IMetrics _metrics;
private readonly ErrorMessageService _errorMessageService;
private readonly CommandMessageService _commandMessageService;
private readonly IDiscordCache _cache;
private bool _hasReceivedReady = false;
private Timer _periodicTask; // Never read, just kept here for GC reasons
public Bot(ILifetimeScope services, ILogger logger, PeriodicStatCollector collector, IMetrics metrics,
ErrorMessageService errorMessageService, CommandMessageService commandMessageService, Cluster cluster, DiscordApiClient rest, IDiscordCache cache)
{
_logger = logger.ForContext<Bot>();
_services = services;
_collector = collector;
_metrics = metrics;
_errorMessageService = errorMessageService;
_commandMessageService = commandMessageService;
_cluster = cluster;
_rest = rest;
_cache = cache;
}
public void Init()
{
_cluster.EventReceived += OnEventReceived;
// Init the shard stuff
_services.Resolve<ShardInfoService>().Init();
// Not awaited, just needs to run in the background
// Trying our best to run it at whole minute boundaries (xx:00), with ~250ms buffer
// This *probably* doesn't matter in practice but I jut think it's neat, y'know.
var timeNow = SystemClock.Instance.GetCurrentInstant();
var timeTillNextWholeMinute = TimeSpan.FromMilliseconds(60000 - timeNow.ToUnixTimeMilliseconds() % 60000 + 250);
_periodicTask = new Timer(_ =>
{
var __ = UpdatePeriodic();
}, null, timeTillNextWholeMinute, TimeSpan.FromMinutes(1));
}
public PermissionSet PermissionsIn(ulong channelId)
{
var channel = _cache.GetChannel(channelId);
if (channel.GuildId != null)
{
var member = _guildMembers.GetValueOrDefault(channel.GuildId.Value);
return _cache.PermissionsFor(channelId, _cluster.User?.Id ?? default, member?.Roles);
}
return PermissionSet.Dm;
}
private async Task OnEventReceived(Shard shard, IGatewayEvent evt)
{
await _cache.HandleGatewayEvent(evt);
TryUpdateSelfMember(shard, evt);
// HandleEvent takes a type parameter, automatically inferred by the event type
// It will then look up an IEventHandler<TypeOfEvent> in the DI container and call that object's handler method
// For registering new ones, see Modules.cs
if (evt is MessageCreateEvent mc)
await HandleEvent(shard, mc);
if (evt is MessageUpdateEvent mu)
await HandleEvent(shard, mu);
if (evt is MessageDeleteEvent md)
await HandleEvent(shard, md);
if (evt is MessageDeleteBulkEvent mdb)
await HandleEvent(shard, mdb);
if (evt is MessageReactionAddEvent mra)
await HandleEvent(shard, mra);
if (evt is InteractionCreateEvent ic)
await HandleEvent(shard, ic);
// Update shard status for shards immediately on connect
if (evt is ReadyEvent re)
await HandleReady(shard, re);
if (evt is ResumedEvent)
await HandleResumed(shard);
}
private void TryUpdateSelfMember(Shard shard, IGatewayEvent evt)
{
if (evt is GuildCreateEvent gc)
_guildMembers[gc.Id] = gc.Members.FirstOrDefault(m => m.User.Id == shard.User?.Id);
if (evt is MessageCreateEvent mc && mc.Member != null && mc.Author.Id == shard.User?.Id)
_guildMembers[mc.GuildId!.Value] = mc.Member;
if (evt is GuildMemberAddEvent gma && gma.User.Id == shard.User?.Id)
_guildMembers[gma.GuildId] = gma;
if (evt is GuildMemberUpdateEvent gmu && gmu.User.Id == shard.User?.Id)
_guildMembers[gmu.GuildId] = gmu;
}
private Task HandleResumed(Shard shard)
{
return UpdateBotStatus(shard);
}
private Task HandleReady(Shard shard, ReadyEvent _)
{
_hasReceivedReady = true;
return UpdateBotStatus(shard);
}
public async Task Shutdown()
{
// This will stop the timer and prevent any subsequent invocations
await _periodicTask.DisposeAsync();
// Send users a lil status message
// We're not actually properly disconnecting from the gateway (lol) so it'll linger for a few minutes
// Should be plenty of time for the bot to connect again next startup and set the real status
if (_hasReceivedReady)
{
await Task.WhenAll(_cluster.Shards.Values.Select(shard =>
shard.UpdateStatus(new GatewayStatusUpdate
{
Activities = new[]
{
new ActivityPartial
{
Name = "Restarting... (please wait)",
Type = ActivityType.Game
}
},
Status = GatewayStatusUpdate.UserStatus.Idle
})));
}
}
private Task HandleEvent<T>(Shard shard, T evt) where T: IGatewayEvent
{
// We don't want to stall the event pipeline, so we'll "fork" inside here
var _ = HandleEventInner();
return Task.CompletedTask;
async Task HandleEventInner()
{
await Task.Yield();
using var _ = LogContext.PushProperty("EventId", Guid.NewGuid());
_logger
.ForContext("Elastic", "yes?")
.Verbose("Gateway event: {@Event}", evt);
await using var serviceScope = _services.BeginLifetimeScope();
// Also, find a Sentry enricher for the event type (if one is present), and ask it to put some event data in the Sentry scope
var sentryEnricher = serviceScope.ResolveOptional<ISentryEnricher<T>>();
sentryEnricher?.Enrich(serviceScope.Resolve<Scope>(), shard, evt);
// Find an event handler that can handle the type of event (<T>) we're given
var handler = serviceScope.Resolve<IEventHandler<T>>();
var queue = serviceScope.ResolveOptional<HandlerQueue<T>>();
try
{
using var timer = _metrics.Measure.Timer.Time(BotMetrics.EventsHandled,
new MetricTags("event", typeof(T).Name.Replace("Event", "")));
// Delegate to the queue to see if it wants to handle this event
// the TryHandle call returns true if it's handled the event
// Usually it won't, so just pass it on to the main handler
if (queue == null || !await queue.TryHandle(evt))
await handler.Handle(shard, evt);
}
catch (Exception exc)
{
await HandleError(shard, handler, evt, serviceScope, exc);
}
}
}
private async Task HandleError<T>(Shard shard, IEventHandler<T> handler, T evt, ILifetimeScope serviceScope, Exception exc)
where T: IGatewayEvent
{
_metrics.Measure.Meter.Mark(BotMetrics.BotErrors, exc.GetType().FullName);
// Make this beforehand so we can access the event ID for logging
var sentryEvent = new SentryEvent(exc);
_logger
.ForContext("Elastic", "yes?")
.Error(exc, "Exception in event handler: {SentryEventId}", sentryEvent.EventId);
// If the event is us responding to our own error messages, don't bother logging
if (evt is MessageCreateEvent mc && mc.Author.Id == shard.User?.Id)
return;
var shouldReport = exc.IsOurProblem();
if (shouldReport)
{
// Report error to Sentry
// This will just no-op if there's no URL set
var sentryScope = serviceScope.Resolve<Scope>();
// Add some specific info about Discord error responses, as a breadcrumb
// TODO: headers to dict
// if (exc is BadRequestException bre)
// sentryScope.AddBreadcrumb(bre.Response, "response.error", data: new Dictionary<string, string>(bre.Response.Headers));
// if (exc is NotFoundException nfe)
// sentryScope.AddBreadcrumb(nfe.Response, "response.error", data: new Dictionary<string, string>(nfe.Response.Headers));
// if (exc is UnauthorizedException ue)
// sentryScope.AddBreadcrumb(ue.Response, "response.error", data: new Dictionary<string, string>(ue.Response.Headers));
SentrySdk.CaptureEvent(sentryEvent, sentryScope);
// Once we've sent it to Sentry, report it to the user (if we have permission to)
var reportChannel = handler.ErrorChannelFor(evt);
if (reportChannel != null)
{
var botPerms = PermissionsIn(reportChannel.Value);
if (botPerms.HasFlag(PermissionSet.SendMessages | PermissionSet.EmbedLinks))
await _errorMessageService.SendErrorMessage(reportChannel.Value, sentryEvent.EventId.ToString());
}
}
}
private async Task UpdatePeriodic()
{
_logger.Debug("Running once-per-minute scheduled tasks");
await UpdateBotStatus();
// Clean up message cache in postgres
await _commandMessageService.CleanupOldMessages();
// Collect some stats, submit them to the metrics backend
await _collector.CollectStats();
await Task.WhenAll(((IMetricsRoot) _metrics).ReportRunner.RunAllAsync());
_logger.Debug("Submitted metrics to backend");
}
private async Task UpdateBotStatus(Shard specificShard = null)
{
// If we're not on any shards, don't bother (this happens if the periodic timer fires before the first Ready)
if (!_hasReceivedReady) return;
var totalGuilds = await _cache.GetAllGuilds().CountAsync();
try // DiscordClient may throw an exception if the socket is closed (e.g just after OP 7 received)
{
Task UpdateStatus(Shard shard) =>
shard.UpdateStatus(new GatewayStatusUpdate
{
Activities = new[]
{
new ActivityPartial
{
Name = $"pk;help | in {totalGuilds:N0} servers | shard #{shard.ShardInfo?.ShardId}",
Type = ActivityType.Game,
Url = "https://pluralkit.me/"
}
}
});
if (specificShard != null)
await UpdateStatus(specificShard);
else // Run shard updates concurrently
await Task.WhenAll(_cluster.Shards.Values.Select(UpdateStatus));
}
catch (WebSocketException)
{
// TODO: this still thrown?
}
}
}
}