Add scheduled thread closing

A thread can be scheduled to be closed by adding a time parameter to
the !close command. For example, !close 2m would automatically close
the thread in 2 minutes. The actual scheduling is implemented with a
loop that runs every 2 seconds, checking for threads that should be
closed.

db/migrations/20180224235946_add_close_at_to_threads.js

@@ -0,0 +1,15 @@
+exports.up = async function (knex, Promise) {
+  await knex.schema.table('threads', table => {
+    table.dateTime('scheduled_close_at').index().nullable().defaultTo(null).after('channel_id');
+    table.string('scheduled_close_id', 20).nullable().defaultTo(null).after('channel_id');
+    table.string('scheduled_close_name', 128).nullable().defaultTo(null).after('channel_id');
+  });
+};
+
+exports.down = async function(knex, Promise) {
+  await knex.schema.table('threads', table => {
+    table.dropColumn('scheduled_close_at');
+    table.dropColumn('scheduled_close_id');
+    table.dropColumn('scheduled_close_name');
+  });
+};

src/data/Thread.js

@@ -1,6 +1,4 @@
-const fs = require("fs");
 const moment = require('moment');
-const {promisify} = require('util');
 
 const bot = require('../bot');
 const knex = require('../knex');
@@ -18,6 +16,9 @@ const {THREAD_MESSAGE_TYPE, THREAD_STATUS} = require('./constants');
  * @property {String} user_id
  * @property {String} user_name
  * @property {String} channel_id
+ * @property {String} scheduled_close_at
+ * @property {String} scheduled_close_id
+ * @property {String} scheduled_close_name
  * @property {String} created_at
  */
 class Thread {
@@ -89,6 +90,11 @@ class Thread {
       is_anonymous: (isAnonymous ? 1 : 0),
       dm_message_id: dmMessage.id
     });
+
+    if (this.scheduled_close_at) {
+      await this.cancelScheduledClose();
+      await this.postSystemMessage(`Cancelling scheduled closing of this thread due to new reply`);
+    }
   }
 
   /**
@@ -136,6 +142,14 @@ class Thread {
       is_anonymous: 0,
       dm_message_id: msg.id
     });
+
+    if (this.scheduled_close_at) {
+      await this.cancelScheduledClose();
+      await this.postSystemMessage({
+        content: `<@!${this.scheduled_close_id}> Thread that was scheduled to be closed got a new reply. Cancelling.`,
+        disableEveryone: false
+      });
+    }
   }
 
   /**
@@ -181,22 +195,23 @@ class Thread {
 
   /**
    * @param {String} text
+   * @param {*} args
    * @returns {Promise<void>}
    */
-  async postSystemMessage(text) {
+  async postSystemMessage(text, ...args) {
-    const msg = await this.postToThreadChannel(text);
+    const msg = await this.postToThreadChannel(text, ...args);
     await this.addThreadMessageToDB({
       message_type: THREAD_MESSAGE_TYPE.SYSTEM,
       user_id: null,
       user_name: '',
-      body: text,
+      body: typeof text === 'string' ? text : text.content,
       is_anonymous: 0,
       dm_message_id: msg.id
     });
   }
 
   /**
-   * @param {String} text
+   * @param {*} args
    * @returns {Promise<void>}
    */
   async postNonLogMessage(...args) {
@@ -292,6 +307,26 @@ class Thread {
     }
   }
 
+  async scheduleClose(time, user) {
+    await knex('threads')
+      .where('id', this.id)
+      .update({
+        scheduled_close_at: time,
+        scheduled_close_id: user.id,
+        scheduled_close_name: user.username
+      });
+  }
+
+  async cancelScheduledClose() {
+    await knex('threads')
+      .where('id', this.id)
+      .update({
+        scheduled_close_at: null,
+        scheduled_close_id: null,
+        scheduled_close_name: null
+      });
+  }
+
   /**
    * @returns {Promise<String>}
    */

src/data/threads.js

@@ -199,6 +199,17 @@ async function findOrCreateThreadForUser(user) {
   return createNewThreadForUser(user);
 }
 
+async function getThreadsThatShouldBeClosed() {
+  const now = moment.utc().format('YYYY-MM-DD HH:mm:ss');
+  const threads = await knex('threads')
+    .where('status', THREAD_STATUS.OPEN)
+    .whereNotNull('scheduled_close_at')
+    .where('scheduled_close_at', '<=', now)
+    .select();
+
+  return threads.map(thread => new Thread(thread));
+}
+
 module.exports = {
   findById,
   findOpenThreadByUserId,
@@ -207,5 +218,6 @@ module.exports = {
   createNewThreadForUser,
   getClosedThreadsByUserId,
   findOrCreateThreadForUser,
+  getThreadsThatShouldBeClosed,
   createThreadInDB
 };

src/main.js

@@ -164,7 +164,7 @@ if(config.typingProxy || config.typingProxyReverse) {
       const thread = await threads.findByChannelId(channel.id);
       if (! thread) return;
 
-      const dmChannel = await thread.getDMChannel(thread.user_id);
+      const dmChannel = await thread.getDMChannel();
       if (! dmChannel) return;
 
       try {
@@ -174,6 +174,32 @@ if(config.typingProxy || config.typingProxyReverse) {
   });
 }
 
+// Check for threads that are scheduled to be closed and close them
+async function applyScheduledCloses() {
+  const threadsToBeClosed = await threads.getThreadsThatShouldBeClosed();
+  for (const thread of threadsToBeClosed) {
+    await thread.close();
+
+    const logUrl = await thread.getLogUrl();
+    utils.postLog(utils.trimAll(`
+      Modmail thread with ${thread.user_name} (${thread.user_id}) was closed as scheduled by ${thread.scheduled_close_name}
+      Logs: ${logUrl}
+    `));
+  }
+}
+
+async function closeLoop() {
+  try {
+    await applyScheduledCloses();
+  } catch (e) {
+    console.error(e);
+  }
+
+  setTimeout(closeLoop, 2000);
+}
+
+closeLoop();
+
 // Mods can reply to modmail threads using !r or !reply
 // These messages get relayed back to the DM thread between the bot and the user
 addInboxServerCommand('reply', async (msg, args, thread) => {
@@ -202,6 +228,34 @@ bot.registerCommandAlias('ar', 'anonreply');
 // Close a thread. Closing a thread saves a log of the channel's contents and then deletes the channel.
 addInboxServerCommand('close', async (msg, args, thread) => {
   if (! thread) return;
+
+  // Timed close
+  if (args.length) {
+    if (args[0] === 'cancel') {
+      // Cancel timed close
+      if (thread.scheduled_close_at) {
+        await thread.cancelScheduledClose();
+        thread.postSystemMessage(`Cancelled scheduled closing`);
+      }
+
+      return;
+    }
+
+    // Set a timed close
+    const delay = utils.convertDelayStringToMS(args.join(' '));
+    if (delay === 0) {
+      thread.postNonLogMessage(`Invalid delay specified. Format: "1h30m"`);
+      return;
+    }
+
+    const closeAt = moment.utc().add(delay, 'ms');
+    await thread.scheduleClose(closeAt.format('YYYY-MM-DD HH:mm:ss'), msg.author);
+    thread.postSystemMessage(`Thread is scheduled to be closed ${moment.duration(delay).humanize(true)} by ${msg.author.username}. Use \`${config.prefix}close cancel\` to cancel.`);
+
+    return;
+  }
+
+  // Regular close
   await thread.close();
 
   const logUrl = await thread.getLogUrl();

src/utils.js

@@ -185,6 +185,11 @@ function chunk(items, chunkSize) {
   return result;
 }
 
+/**
+ * Trims every line in the string
+ * @param {String} str
+ * @returns {String}
+ */
 function trimAll(str) {
   return str
     .split('\n')
@@ -192,6 +197,25 @@ function trimAll(str) {
     .join('\n');
 }
 
+/**
+ * Turns a "delay string" such as "1h30m" to milliseconds
+ * @param {String} str
+ * @returns {Number}
+ */
+function convertDelayStringToMS(str) {
+  const regex = /([0-9]+)\s*([hms])/g;
+  let match;
+  let ms = 0;
+
+  while (match = regex.exec(str)) {
+    if (match[2] === 'h') ms += match[1] * 1000 * 60 * 60;
+    else if (match[2] === 'm') ms += match[1] * 1000 * 60;
+    else if (match[2] === 's') ms += match[1] * 1000;
+  }
+
+  return ms;
+}
+
 module.exports = {
   BotError,
 
@@ -212,6 +236,7 @@ module.exports = {
   disableLinkPreviews,
   getSelfUrl,
   getMainRole,
+  convertDelayStringToMS,
 
   chunk,
   trimAll,