bot: add system deletion command

PluralKit/Bot/Bot.cs

@@ -94,9 +94,12 @@ namespace PluralKit.Bot
             await _commands.AddModulesAsync(Assembly.GetEntryAssembly(), _services);
 
             _client.Ready += Ready;
-            _client.MessageReceived += MessageReceived;
+
-            _client.ReactionAdded += _proxy.HandleReactionAddedAsync;
+            // Deliberately wrapping in an async function *without* awaiting, we don't want to "block" since this'd hold up the main loop
-            _client.MessageDeleted += _proxy.HandleMessageDeletedAsync;
+            // These handlers return Task so we gotta be careful not to return the Task itself (which would then be awaited) - kinda weird design but eh
+            _client.MessageReceived += async (msg) => MessageReceived(msg);
+            _client.ReactionAdded += async (message, channel, reaction) => _proxy.HandleReactionAddedAsync(message, channel, reaction);
+            _client.MessageDeleted += async (message, channel) => _proxy.HandleMessageDeletedAsync(message, channel);
         }
 
         private async Task UpdatePeriodic()
@@ -118,9 +121,11 @@ namespace PluralKit.Bot
             if (!_result.IsSuccess) {
                 // If this is a PKError (ie. thrown deliberately), show user facing message
                 // If not, log as error
-                var pkError = (_result as ExecuteResult?)?.Exception as PKError;
+                var exception = (_result as ExecuteResult?)?.Exception;
-                if (pkError != null) {
+                if (exception is PKError) {
-                    await ctx.Message.Channel.SendMessageAsync("\u274C " + pkError.Message);
+                    await ctx.Message.Channel.SendMessageAsync($"{Emojis.Error} {exception.Message}");
+                } else if (exception is TimeoutException) {
+                    await ctx.Message.Channel.SendMessageAsync($"{Emojis.Error} Operation timed out. Try being faster");
                 } else {
                     HandleRuntimeError(ctx.Message as SocketMessage, (_result as ExecuteResult?)?.Exception);
                 }

PluralKit/Bot/Commands/SystemCommands.cs

@@ -30,7 +30,7 @@ namespace PluralKit.Bot.Commands
         public async Task New([Remainder] string systemName = null)
         {
             if (ContextEntity != null) throw OTHER_SYSTEM_CONTEXT_ERROR;
-            if (Context.SenderSystem != null) throw new PKError("You already have a system registered with PluralKit. To view it, type `pk;system`. If you'd like to delete your system and start anew, type `pk;system delete`, or if you'd like to unlink this account from it, type `pk;unlink.");
+            if (Context.SenderSystem != null) throw new PKError("You already have a system registered with PluralKit. To view it, type `pk;system`. If you'd like to delete your system and start anew, type `pk;system delete`, or if you'd like to unlink this account from it, type `pk;unlink`.");
 
             var system = await Systems.Create(systemName);
             await Systems.Link(system, Context.User.Id);
@@ -79,6 +79,19 @@ namespace PluralKit.Bot.Commands
             await Context.Channel.SendMessageAsync($"{Emojis.Success} System tag {(newTag != null ? "changed" : "cleared")}.");
         }
 
+        [Command("delete")]
+        public async Task Delete() {
+            if (ContextEntity != null) throw OTHER_SYSTEM_CONTEXT_ERROR;
+            if (Context.SenderSystem == null) throw NO_SYSTEM_ERROR;
+
+            var msg = await Context.Channel.SendMessageAsync($"{Emojis.Warn} Are you sure you want to delete your system? If so, reply to this message with your system's ID (`{Context.SenderSystem.Hid}`).\n**Note: this action is permanent.**");
+            var reply = await Context.AwaitMessage(Context.Channel, Context.User, timeout: TimeSpan.FromMinutes(1));
+            if (reply.Content != Context.SenderSystem.Hid) throw new PKError($"System deletion cancelled. Note that you must reply with your system ID (`{Context.SenderSystem.Hid}`) *verbatim*.");
+
+            await Systems.Delete(Context.SenderSystem);
+            await Context.Channel.SendMessageAsync($"{Emojis.Success} System deleted.");
+        }
+
         public override async Task<PKSystem> ReadContextParameterAsync(string value)
         {
             var res = await new PKSystemTypeReader().ReadAsync(Context, value, _services);

PluralKit/Bot/Utils.cs

@@ -162,33 +162,43 @@ namespace PluralKit.Bot
     public static class ContextExt {
         public static async Task<bool> PromptYesNo(this ICommandContext ctx, IMessage message, TimeSpan? timeout = null) {
             await ctx.Message.AddReactionsAsync(new[] {new Emoji(Emojis.Success), new Emoji(Emojis.Error)});
-            var reaction = await ctx.WaitForReaction(ctx.Message, message.Author, (r) => r.Emote.Name == Emojis.Success || r.Emote.Name == Emojis.Error);
+            var reaction = await ctx.AwaitReaction(ctx.Message, message.Author, (r) => r.Emote.Name == Emojis.Success || r.Emote.Name == Emojis.Error, timeout);
             return reaction.Emote.Name == Emojis.Success;
         }
 
-        public static async Task<SocketReaction> WaitForReaction(this ICommandContext ctx, IUserMessage message, IUser user = null, Func<SocketReaction, bool> predicate = null, TimeSpan? timeout = null) {
+        public static async Task<SocketReaction> AwaitReaction(this ICommandContext ctx, IUserMessage message, IUser user = null, Func<SocketReaction, bool> predicate = null, TimeSpan? timeout = null) {
             var tcs = new TaskCompletionSource<SocketReaction>();
-
             Task Inner(Cacheable<IUserMessage, ulong> _message, ISocketMessageChannel _channel, SocketReaction reaction) {
-                // Ignore reactions for different messages
+                if (message.Id != _message.Id) return Task.CompletedTask; // Ignore reactions for different messages
-                if (message.Id != _message.Id) return Task.CompletedTask;
+                if (user != null && user.Id != reaction.UserId) return Task.CompletedTask; // Ignore messages from other users if a user was defined
-
+                if (predicate != null && !predicate.Invoke(reaction)) return Task.CompletedTask; // Check predicate
-                // Ignore messages from other users if a user was defined
-                if (user != null && user.Id != reaction.UserId) return Task.CompletedTask;
-                
-                // Check the predicate, if true - accept the reaction
-                if (predicate?.Invoke(reaction) ?? true) {
                 tcs.SetResult(reaction);
-                }
                 return Task.CompletedTask;
             }
 
-            (ctx as BaseSocketClient).ReactionAdded += Inner;
+            (ctx.Client as BaseSocketClient).ReactionAdded += Inner;
-
             try {
                 return await (tcs.Task.TimeoutAfter(timeout));
             } finally {
-                (ctx as BaseSocketClient).ReactionAdded -= Inner;
+                (ctx.Client as BaseSocketClient).ReactionAdded -= Inner;
+            }
+        }
+
+        public static async Task<IUserMessage> AwaitMessage(this ICommandContext ctx, IMessageChannel channel, IUser user = null, Func<SocketMessage, bool> predicate = null, TimeSpan? timeout = null) {
+            var tcs = new TaskCompletionSource<IUserMessage>();
+            Task Inner(SocketMessage msg) {
+                if (channel != msg.Channel) return Task.CompletedTask; // Ignore messages in a different channel
+                if (user != null && user != msg.Author) return Task.CompletedTask; // Ignore messages from other users
+                if (predicate != null && !predicate.Invoke(msg)) return Task.CompletedTask; // Check predicate
+                tcs.SetResult(msg as IUserMessage);
+                return Task.CompletedTask;
+            }
+
+            (ctx.Client as BaseSocketClient).MessageReceived += Inner;
+            try {
+                return await (tcs.Task.TimeoutAfter(timeout));
+            } finally {
+                (ctx.Client as BaseSocketClient).MessageReceived -= Inner;
             }
         }
     }