Add auto-delete plugin

backend/src/data/DefaultLogMessages.json

@@ -31,6 +31,7 @@
   "MESSAGE_DELETE": "🗑 Message (`{message.id}`) from {userMention(user)} deleted in {channelMention(channel)} (originally posted at **{messageDate}**):{messageSummary(message)}",
   "MESSAGE_DELETE_BULK": "🗑 **{count}** messages deleted in {channelMention(channel)} ({archiveUrl})",
   "MESSAGE_DELETE_BARE": "🗑 Message (`{messageId}`) deleted in {channelMention(channel)} (no more info available)",
+  "MESSAGE_DELETE_AUTO": "🗑 Auto-deleted message (`{message.id}`) from {userMention(user)} in {channelMention(channel)} (originally posted at **{messageDate}**):{messageSummary(message)}",
 
   "VOICE_CHANNEL_JOIN": "🎙 🔵 {userMention(member)} joined **{channel.name}**",
   "VOICE_CHANNEL_MOVE": "🎙 ↔ {userMention(member)} moved from **{oldChannel.name}** to **{newChannel.name}**",

backend/src/data/LogType.ts

@@ -62,4 +62,6 @@ export enum LogType {
 
   SCHEDULED_REPEATED_MESSAGE,
   REPEATED_MESSAGE,
+
+  MESSAGE_DELETE_AUTO,
 }

backend/src/plugins/AutoDelete.ts

@@ -0,0 +1,152 @@
+import { IPluginOptions, logger } from "knub";
+import * as t from "io-ts";
+import { ZeppelinPlugin } from "./ZeppelinPlugin";
+import { GuildSavedMessages } from "../data/GuildSavedMessages";
+import { SavedMessage } from "../data/entities/SavedMessage";
+import { convertDelayStringToMS, MINUTES, sorter, stripObjectToScalars, tDelayString } from "../utils";
+import { GuildLogs } from "../data/GuildLogs";
+import { LogType } from "../data/LogType";
+import moment from "moment-timezone";
+
+const ConfigSchema = t.type({
+  enabled: t.boolean,
+  delay: tDelayString,
+});
+type TConfigSchema = t.TypeOf<typeof ConfigSchema>;
+
+interface IDeletionQueueItem {
+  deleteAt: number;
+  message: SavedMessage;
+}
+
+const MAX_DELAY = 5 * MINUTES;
+
+export class AutoDeletePlugin extends ZeppelinPlugin<TConfigSchema> {
+  public static pluginName = "auto_delete";
+  public static showInDocs = true;
+
+  public static configSchema = ConfigSchema;
+
+  public static pluginInfo = {
+    prettyName: "Auto-delete",
+    description: "Allows Zeppelin to auto-delete messages from a channel after a delay",
+    configurationGuide: "Maximum deletion delay is currently 5 minutes",
+  };
+
+  protected guildSavedMessages: GuildSavedMessages;
+  protected guildLogs: GuildLogs;
+
+  protected onMessageCreateFn;
+  protected onMessageDeleteFn;
+  protected onMessageDeleteBulkFn;
+
+  protected deletionQueue: IDeletionQueueItem[];
+  protected nextDeletion: number;
+  protected nextDeletionTimeout;
+
+  protected maxDelayWarningSent = false;
+
+  public static getStaticDefaultOptions(): IPluginOptions<TConfigSchema> {
+    return {
+      config: {
+        enabled: false,
+        delay: "5s",
+      },
+    };
+  }
+
+  protected onLoad() {
+    this.guildSavedMessages = GuildSavedMessages.getGuildInstance(this.guildId);
+    this.guildLogs = new GuildLogs(this.guildId);
+
+    this.deletionQueue = [];
+
+    this.onMessageCreateFn = this.onMessageCreate.bind(this);
+    this.onMessageDeleteFn = this.onMessageDelete.bind(this);
+    this.onMessageDeleteBulkFn = this.onMessageDeleteBulk.bind(this);
+
+    this.guildSavedMessages.events.on("create", this.onMessageCreateFn);
+    this.guildSavedMessages.events.on("delete", this.onMessageDeleteFn);
+    this.guildSavedMessages.events.on("deleteBulk", this.onMessageDeleteBulkFn);
+  }
+
+  protected onUnload() {
+    this.guildSavedMessages.events.off("create", this.onMessageCreateFn);
+    this.guildSavedMessages.events.off("delete", this.onMessageDeleteFn);
+    this.guildSavedMessages.events.off("deleteBulk", this.onMessageDeleteFn);
+    clearTimeout(this.nextDeletionTimeout);
+  }
+
+  protected addMessageToDeletionQueue(msg: SavedMessage, delay: number) {
+    const deleteAt = Date.now() + delay;
+    this.deletionQueue.push({ deleteAt, message: msg });
+    this.deletionQueue.sort(sorter("deleteAt"));
+
+    this.scheduleNextDeletion();
+  }
+
+  protected scheduleNextDeletion() {
+    if (this.deletionQueue.length === 0) {
+      clearTimeout(this.nextDeletionTimeout);
+      return;
+    }
+
+    const firstDeleteAt = this.deletionQueue[0].deleteAt;
+    clearTimeout(this.nextDeletionTimeout);
+    this.nextDeletionTimeout = setTimeout(() => this.deleteNextItem(), firstDeleteAt - Date.now());
+  }
+
+  protected async deleteNextItem() {
+    const [itemToDelete] = this.deletionQueue.splice(0, 1);
+    if (!itemToDelete) return;
+
+    this.guildLogs.ignoreLog(LogType.MESSAGE_DELETE, itemToDelete.message.id);
+    this.bot.deleteMessage(itemToDelete.message.channel_id, itemToDelete.message.id).catch(logger.warn);
+
+    this.scheduleNextDeletion();
+
+    const user = await this.resolveUser(itemToDelete.message.user_id);
+    const channel = this.guild.channels.get(itemToDelete.message.channel_id);
+    const messageDate = moment(itemToDelete.message.data.timestamp, "x").format("YYYY-MM-DD HH:mm:ss");
+
+    this.guildLogs.log(LogType.MESSAGE_DELETE_AUTO, {
+      message: itemToDelete.message,
+      user: stripObjectToScalars(user),
+      channel: stripObjectToScalars(channel),
+      messageDate,
+    });
+  }
+
+  protected onMessageCreate(msg: SavedMessage) {
+    const config = this.getConfigForMemberIdAndChannelId(msg.user_id, msg.channel_id);
+    if (config.enabled) {
+      let delay = convertDelayStringToMS(config.delay);
+
+      if (delay > MAX_DELAY) {
+        delay = MAX_DELAY;
+        if (!this.maxDelayWarningSent) {
+          this.guildLogs.log(LogType.BOT_ALERT, {
+            body: `Clamped auto-deletion delay in <#${msg.channel_id}> to 5 minutes`,
+          });
+          this.maxDelayWarningSent = true;
+        }
+      }
+
+      this.addMessageToDeletionQueue(msg, delay);
+    }
+  }
+
+  protected onMessageDelete(msg: SavedMessage) {
+    const indexToDelete = this.deletionQueue.findIndex(item => item.message.id === msg.id);
+    if (indexToDelete > -1) {
+      this.deletionQueue.splice(indexToDelete, 1);
+      this.scheduleNextDeletion();
+    }
+  }
+
+  protected onMessageDeleteBulk(messages: SavedMessage[]) {
+    for (const msg of messages) {
+      this.onMessageDelete(msg);
+    }
+  }
+}

backend/src/plugins/availablePlugins.ts

@@ -28,6 +28,7 @@ import { GuildConfigReloader } from "./GuildConfigReloader";
 import { ChannelArchiverPlugin } from "./ChannelArchiver";
 import { AutomodPlugin } from "./Automod";
 import { RolesPlugin } from "./Roles";
+import { AutoDeletePlugin } from "./AutoDelete";
 
 /**
  * Plugins available to be loaded for individual guilds
@@ -60,6 +61,7 @@ export const availablePlugins = [
   LocatePlugin,
   ChannelArchiverPlugin,
   RolesPlugin,
+  AutoDeletePlugin,
 ];
 
 /**