Add loop messages feature

features/loopMessages/index.js

@@ -0,0 +1,75 @@
+/**
+ * ------------------------------
+ * Loop Messages
+ * ------------------------------
+ * The bot will keep a message as the last one in a channel, with an interval between each post,
+ * to keep important information more visible to users
+ *
+ * How it works:
+ * At startup and repeatedly by a given interval, for each loop message, the bot will:
+ * 1. Get the target channel of the loop message
+ * 2. Fetch the last 50 messages of the channel
+ * 3. If the last message is already the message we want to loop, do nothing (we don't want to spam the channel)
+ * 4. Delete all loop messages (so the channel isn't filled with bot messages)
+ * 5. Send the loop message
+ */
+
+const loopMessages = require("./messages.js");
+
+// time between each check to send a new loop message
+const INTERVAL_TIME = 5 * 60 * 1000; // 5 minutes (ms)
+
+function getContent(loopMessage) {
+  return loopMessage.trim();
+}
+
+function isMessageFromBot(bot, message) {
+  return message.author.id === bot.user.id;
+}
+
+function isLoopMessage(messageToCheck, loopMessage, bot) {
+  return (
+    isMessageFromBot(bot, messageToCheck) &&
+    messageToCheck.content.trim() === getContent(loopMessage.content)
+  );
+}
+
+async function sendLoopMessage(client, loopMessage) {
+  const channel = client.channels.get(loopMessage.channelId);
+  const channelMessages = await channel.fetchMessages({ limit: 50 });
+
+  // if the last message in the channel is from the bot, we don't need to send it again
+  if (isLoopMessage(channelMessages.first(), loopMessage, client)) {
+    return;
+  }
+
+  // search through all the last messages for the loop message, so we can delete it
+  channelMessages.forEach(message => {
+    if (isLoopMessage(message, loopMessage, client)) {
+      message.delete();
+    }
+  });
+
+  // now we can send the loop message in the channel
+  channel.send(getContent(loopMessage.content));
+}
+
+module.exports = {
+  register: (client, logger) => {
+    client.on("ready", () => {
+      const sendLoopMessages = () => {
+        loopMessages.forEach(message => {
+          sendLoopMessage(client, message);
+        });
+      };
+
+      setInterval(() => {
+        sendLoopMessages();
+      }, INTERVAL_TIME);
+
+      sendLoopMessages();
+
+      logger.log("INI", "Registered Loop Messages");
+    });
+  }
+};

features/loopMessages/messages.js

@@ -0,0 +1,19 @@
+module.exports = [
+  {
+    channelId: "600037610005463050", // #another
+    content: `
+
+:arrows_clockwise: __PLEASE READ BEFORE POSTING__ :pushpin:
+
+Job post search: http://jobs.reactiflux.com/
+
+Messages must start with [FORHIRE] or [HIRING].
+Lead with the location of the position and include LOCAL, REMOTE, INTERN, VISA, etc.
+
+Please only post jobs once a week.
+
+Jobs are paid—unpaid and equity-only positions may not be posted here.
+
+`
+  }
+];

index.js

@@ -12,6 +12,7 @@ const autoban = require("./features/autoban").default;
 const commands = require("./features/commands").default;
 const witInvite = require("./features/wit-invite").default;
 const stats = require("./features/stats").default;
+const loopMessages = require("./features/loopMessages");
 
 const bot = new discord.Client();
 bot.login(process.env.DISCORD_HASH);
@@ -81,6 +82,9 @@ logger.add(channelLog(bot, "479862475047567361"));
 // Amplitude metrics
 stats(bot);
 
+// Loop Messages
+loopMessages.register(bot, logger);
+
 // reactiflux
 channelHandlers.addHandler("103882387330457600", jobs);
 channelHandlers.addHandler("541673256596537366", witInvite); // #women-in-tech