Refactor command message deletion

PluralKit.Bot/Bot.cs

@@ -36,13 +36,13 @@ namespace PluralKit.Bot
         private readonly PeriodicStatCollector _collector;
         private readonly IMetrics _metrics;
         private readonly ErrorMessageService _errorMessageService;
-        private readonly IDatabase _db;
+        private readonly CommandMessageService _commandMessageService;
 
         private bool _hasReceivedReady = false;
         private Timer _periodicTask; // Never read, just kept here for GC reasons
 
         public Bot(DiscordShardedClient client, ILifetimeScope services, ILogger logger, PeriodicStatCollector collector, IMetrics metrics, 
-            ErrorMessageService errorMessageService, IDatabase db)
+            ErrorMessageService errorMessageService, CommandMessageService commandMessageService)
         {
             _client = client;
             _logger = logger.ForContext<Bot>();
@@ -50,7 +50,7 @@ namespace PluralKit.Bot
             _collector = collector;
             _metrics = metrics;
             _errorMessageService = errorMessageService;
-            _db = db;
+            _commandMessageService = commandMessageService;
         }
 
         public void Init()
@@ -183,7 +183,7 @@ namespace PluralKit.Bot
             await UpdateBotStatus();
 
             // Clean up message cache in postgres
-            await _db.Execute(conn => conn.QueryAsync("select from cleanup_command_message()"));
+            await _commandMessageService.CleanupOldMessages();
 
             // Collect some stats, submit them to the metrics backend
             await _collector.CollectStats();

PluralKit.Bot/CommandSystem/Context.cs

@@ -28,6 +28,7 @@ namespace PluralKit.Bot
         private readonly ModelRepository _repo;
         private readonly PKSystem _senderSystem;
         private readonly IMetrics _metrics;
+        private readonly CommandMessageService _commandMessageService;
 
         private Command _currentCommand;
 
@@ -44,6 +45,7 @@ namespace PluralKit.Bot
             _repo = provider.Resolve<ModelRepository>();
             _metrics = provider.Resolve<IMetrics>();
             _provider = provider;
+            _commandMessageService = provider.Resolve<CommandMessageService>();
             _parameters = new Parameters(message.Content.Substring(commandParseOffset));
         }
 
@@ -73,10 +75,14 @@ namespace PluralKit.Bot
             if (embed != null && !this.BotHasAllPermissions(Permissions.EmbedLinks))
                 throw new PKError("PluralKit does not have permission to send embeds in this channel. Please ensure I have the **Embed Links** permission enabled.");
             var msg = await Channel.SendMessageFixedAsync(text, embed: embed, mentions: mentions);
+
             if (embed != null)
+            {
                 // Sensitive information that might want to be deleted by :x: reaction is typically in an embed format (member cards, for example)
                 // This may need to be changed at some point but works well enough for now
-                await _db.Execute(conn => _repo.SaveCommandMessage(conn, msg.Id, Author.Id));
+                await _commandMessageService.RegisterMessage(msg.Id, Author.Id);
+            }
+
             return msg;
         }
         

PluralKit.Bot/Handlers/ReactionAdded.cs

@@ -15,14 +15,16 @@ namespace PluralKit.Bot
     {
         private readonly IDatabase _db;
         private readonly ModelRepository _repo;
+        private readonly CommandMessageService _commandMessageService;
         private readonly EmbedService _embeds;
         private readonly ILogger _logger;
 
-        public ReactionAdded(EmbedService embeds, ILogger logger, IDatabase db, ModelRepository repo)
+        public ReactionAdded(EmbedService embeds, ILogger logger, IDatabase db, ModelRepository repo, CommandMessageService commandMessageService)
         {
             _embeds = embeds;
             _db = db;
             _repo = repo;
+            _commandMessageService = commandMessageService;
             _logger = logger.ForContext<ReactionAdded>();
         }
 
@@ -44,39 +46,53 @@ namespace PluralKit.Bot
             // Ignore reactions from bots (we can't DM them anyway)
             if (evt.User.IsBot) return;
             
-            Task<FullMessage> GetMessage() => 
-                _db.Execute(c => _repo.GetMessage(c, evt.Message.Id));
-
-            FullMessage msg;
-            CommandMessage cmdmsg;
             switch (evt.Emoji.Name)
             {
                 // Message deletion
                 case "\u274C": // Red X
-                    if ((msg = await GetMessage()) != null)
+                {
-                        await HandleDeleteReaction(evt, msg);
+                    await using var conn = await _db.Obtain();
-                    else if ((cmdmsg = await _db.Execute(conn => _repo.GetCommandMessage(conn, evt.Message.Id))) != null)
+                    var msg = await _repo.GetMessage(conn, evt.Message.Id);
-                        await HandleCommandDeleteReaction(evt, cmdmsg);
+                    if (msg != null)
+                    {
+                        await HandleProxyDeleteReaction(evt, msg);
+                        break;
+                    }
+
+                    var commandMsg = await _commandMessageService.GetCommandMessage(conn, evt.Message.Id);
+                    if (commandMsg != null) 
+                        await HandleCommandDeleteReaction(evt, commandMsg);
+
                     break;
+                }
 
                 case "\u2753": // Red question mark
                 case "\u2754": // White question mark
-                    if ((msg = await GetMessage()) != null) 
+                {
+                    await using var conn = await _db.Obtain();
+                    var msg = await _repo.GetMessage(conn, evt.Message.Id);
+                    if (msg != null)
                         await HandleQueryReaction(evt, msg);
+                    
                     break;
+                }
 
                 case "\U0001F514": // Bell
                 case "\U0001F6CE": // Bellhop bell
                 case "\U0001F3D3": // Ping pong paddle (lol)
                 case "\u23F0": // Alarm clock
                 case "\u2757": // Exclamation mark
-                    if ((msg = await GetMessage()) != null)
+                {
+                    await using var conn = await _db.Obtain();
+                    var msg = await _repo.GetMessage(conn, evt.Message.Id);
+                    if (msg != null)
                         await HandlePingReaction(evt, msg);
                     break;
+                }
             }
         }
 
-        private async ValueTask HandleDeleteReaction(MessageReactionAddEventArgs evt, FullMessage msg)
+        private async ValueTask HandleProxyDeleteReaction(MessageReactionAddEventArgs evt, FullMessage msg)
         {
             if (!evt.Channel.BotHasAllPermissions(Permissions.ManageMessages)) return;
             
@@ -97,10 +113,12 @@ namespace PluralKit.Bot
 
         private async ValueTask HandleCommandDeleteReaction(MessageReactionAddEventArgs evt, CommandMessage msg)
         {
-            if (!evt.Channel.BotHasAllPermissions(Permissions.ManageMessages)) return;
+            if (!evt.Channel.BotHasAllPermissions(Permissions.ManageMessages)) 
+                return;
 
             // Can only delete your own message
-            if (msg.author_id != evt.User.Id) return;
+            if (msg.AuthorId != evt.User.Id) 
+                return;
 
             try
             {

PluralKit.Bot/Modules.cs

@@ -74,6 +74,7 @@ namespace PluralKit.Bot
             builder.RegisterType<LastMessageCacheService>().AsSelf().SingleInstance();
             builder.RegisterType<LoggerCleanService>().AsSelf().SingleInstance();
             builder.RegisterType<ErrorMessageService>().AsSelf().SingleInstance();
+            builder.RegisterType<CommandMessageService>().AsSelf().SingleInstance();
             
             // Sentry stuff
             builder.Register(_ => new Scope(null)).AsSelf().InstancePerLifetimeScope();

PluralKit.Bot/Services/CommandMessageService.cs

@@ -0,0 +1,50 @@
+using System.Threading.Tasks;
+
+using NodaTime;
+
+using PluralKit.Core;
+
+using Serilog;
+
+namespace PluralKit.Bot
+{
+    public class CommandMessageService
+    {
+        private static readonly Duration CommandMessageRetention = Duration.FromSeconds(2);
+        
+        private readonly IDatabase _db;
+        private readonly ModelRepository _repo;
+        private readonly IClock _clock;
+        private readonly ILogger _logger;
+        
+        public CommandMessageService(IDatabase db, ModelRepository repo, IClock clock, ILogger logger)
+        {
+            _db = db;
+            _repo = repo;
+            _clock = clock;
+            _logger = logger;
+        }
+
+        public async Task RegisterMessage(ulong messageId, ulong authorId)
+        {
+            _logger.Debug("Registering command response {MessageId} from author {AuthorId}", messageId, authorId);
+            await _db.Execute(conn => _repo.SaveCommandMessage(conn, messageId, authorId));
+        }
+
+        public async Task<CommandMessage> GetCommandMessage(IPKConnection conn, ulong messageId)
+        {
+            return await _repo.GetCommandMessage(conn, messageId);
+        }
+
+        public async Task CleanupOldMessages()
+        {
+            var deleteThresholdInstant = _clock.GetCurrentInstant() - CommandMessageRetention;
+            var deleteThresholdSnowflake = DiscordUtils.InstantToSnowflake(deleteThresholdInstant);
+
+            var deletedRows = await _db.Execute(conn => _repo.DeleteCommandMessagesBefore(conn, deleteThresholdSnowflake));
+            
+            _logger.Information("Pruned {DeletedRows} command messages older than retention {Retention} (older than {DeleteThresholdInstant} / {DeleteThresholdSnowflake})",
+                deletedRows, CommandMessageRetention, deleteThresholdInstant, deleteThresholdSnowflake);
+        }
+    }
+}

PluralKit.Core/Database/Migrations/11.sql

@@ -1,17 +1,10 @@
--- SCHEMA VERSION 11: (insert date) --
+-- SCHEMA VERSION 11: 2020-10-23  --
 -- Create command message table --
 
-create table command_message
+create table command_messages
 (
-	message_id bigint primary key,
+	message_id bigint primary key not null,
-	author_id bigint not null,
+	author_id bigint not null
-	timestamp timestamp not null default now()
 );
 
-create function cleanup_command_message() returns void as $$
-begin
-    delete from command_message where timestamp < now() - interval '2 hours';
-end;
-$$ language plpgsql;
-
 update info set schema_version = 11;

PluralKit.Core/Database/Repository/ModelRepository.CommandMessage.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-using System.Data;
 using System.Threading.Tasks;
 
 using Dapper;
@@ -8,17 +6,22 @@ namespace PluralKit.Core
 {
     public partial class ModelRepository
 	{
-		public Task SaveCommandMessage(IPKConnection conn, ulong message_id, ulong author_id) =>
+		public Task SaveCommandMessage(IPKConnection conn, ulong messageId, ulong authorId) =>
-			conn.QueryAsync("insert into command_message (message_id, author_id) values (@Message, @Author)",
+			conn.QueryAsync("insert into command_messages (message_id, author_id) values (@Message, @Author)",
-				new {Message = message_id, Author = author_id });
+				new {Message = messageId, Author = authorId });
 
-		public Task<CommandMessage> GetCommandMessage(IPKConnection conn, ulong message_id) =>
+		public Task<CommandMessage> GetCommandMessage(IPKConnection conn, ulong messageId) =>
-			conn.QuerySingleOrDefaultAsync<CommandMessage>("select message_id, author_id from command_message where message_id = @Message", 
+			conn.QuerySingleOrDefaultAsync<CommandMessage>("select * from command_messages where message_id = @Message", 
-				new {Message = message_id});
+				new {Message = messageId});
-	}
+
+        public Task<int> DeleteCommandMessagesBefore(IPKConnection conn, ulong messageIdThreshold) =>
+            conn.ExecuteAsync("delete from command_messages where message_id < @Threshold",
+                new {Threshold = messageIdThreshold});
+    }
 
 	public class CommandMessage
 	{
-		public ulong author_id { get; set; }
+        public ulong AuthorId { get; set; }
+        public ulong MessageId { get; set; }
 	}
 }