index.js

const { Client } = require("matrix-org-irc");
const mqtt = require("mqtt");

require('dotenv').config();

function updateIRCTopic(open) {
    const client = new Client(process.env.IRC_SERVER_HOSTNAME, process.env.IRC_CLIENT_NICKNAME, {
        port: Number(process.env.IRC_SERVER_PORT || 6697),
        secure: true,
        sasl: true,
        userName: process.env.IRC_CLIENT_SASL_USERNAME,
        password: process.env.IRC_CLIENT_SASL_PASSWORD,
        realName: process.env.IRC_CLIENT_REALNAME,
        channels: [process.env.IRC_TARGET_CHANNEL],
        autoConnect: true,
        debug: true
    });

    const IRC_TOPIC_MESSAGE_PATTERN = new RegExp(process.env.IRC_TOPIC_MESSAGE_PATTERN);

    client.on("topic", async (channel, topic) => {
        console.info(`Topic for ${channel} is "${topic}"`);

        if (channel !== process.env.IRC_TARGET_CHANNEL) return;

        let newTopic;
        if (IRC_TOPIC_MESSAGE_PATTERN.test(topic)) {
            newTopic = topic.replace(IRC_TOPIC_MESSAGE_PATTERN, open ? process.env.IRC_TOPIC_MESSAGE_OPEN : process.env.IRC_TOPIC_MESSAGE_CLOSED);
        } else {
            newTopic = `${topic} | ${open ? process.env.IRC_TOPIC_MESSAGE_OPEN : process.env.IRC_TOPIC_MESSAGE_CLOSED}`;
        }

        if (topic !== newTopic) {
            console.info(`Setting topic to "${newTopic}"`);
            await client.say("ChanServ", `TOPIC ${channel} ${newTopic}`);
        } else {
            client.disconnect();
        }
    });

    // automatically disconnect after 1 minute in case something happens
    setTimeout(() => { client.disconnect(); }, 60 * 1000);
}


const client = mqtt.connect(process.env.MQTT_URL, {
    clientId: process.env.MQTT_CLIENT_ID,
    will: {
        topic: `heartbeat/${process.env.MQTT_CLIENT_ID}`,
        payload: new Uint8Array([0]),
        qos: 2,
        retain: true,
    },
});

client.on("connect", () => {
    client.publish(`heartbeat/${process.env.MQTT_CLIENT_ID}`, new Uint8Array([1]), { qos: 2, retain: true }, (err) => {
        if (err) console.error("Error publishing heartbeat", err);
    });
    client.subscribe("club/status", (err) => {
        if (err) console.error("Error subscribing to club/status", err);
    });
});

/**
 * Will be null at the start resulting in ignoring the first status message.
 * This is an object in case we want to implement stuff like the club status message.
 * @type {{open: boolean}|null}
 */
let lastStatus = null;

client.on("message", (topic, message) => {
    if (topic === "club/status") {
        console.debug("Got club/status message");
        const open = message.readUInt8(0) === 1;
        console.log(`Space is ${open ? "open" : "closed"}`);

        if (lastStatus && lastStatus.open !== open) {
            console.info("Status changed, updating IRC topic");
            updateIRCTopic(open);
        }
        lastStatus = { ...lastStatus, open };
    }
});

console.info("Starting...");