rtm.js

const {RtmClient, CLIENT_EVENTS, RTM_EVENTS, WebClient} = require('@slack/client');
let moment = require('moment');
let fs = require('fs');

let configa = fs.readFileSync('config.json');
let jsonContenta = JSON.parse(configa);

const token = jsonContenta.webclient_token;

// Cache of data
const appData = {};

// Need a web client to find a channel where the app can post a message
const web = new WebClient(token);

// Load the current channels list asynchrously
let channelListPromise = web.channels.list();

let contents = fs.readFileSync('command.json');
let jsonContent = JSON.parse(contents);
let command = Object.keys(jsonContent);
let tools = {};
tools.date = (rtm, to) => {
    rtm.sendMessage(moment().format('MMMM Do YYYY, h:mm:ss a'), to)
        // Returns a promise that resolves when the message is sent
        .then(() => console.log(`Message sent to channel ${to}`))
        .catch(console.error);
};

tools.sendMessage = (rtm, message, to) => {
    rtm.sendMessage(message, to)
        // Returns a promise that resolves when the message is sent
        .then(() => console.log(`Message sent to channel ${to}`))
        .catch(console.error);
};


// Initialize the RTM client with the recommended settings.
// Using the defaults for these settings is deprecated.
const rtm = new RtmClient(
    token,
    {
        dataStore: false,
        useRtmConnect: true,
    }
);

// The client will emit an RTM.AUTHENTICATED event on when
// the connection data is avaiable (before the connection is open)
rtm.on(CLIENT_EVENTS.RTM.AUTHENTICATED, (connectData) => {
    // Cache the data necessary for this app in memory
    appData.selfId = connectData.self.id;
    console.log(`Logged in as ${appData.selfId} of team ${connectData.team.id}`);
});

// The client will emit an RTM.RTM_CONNECTION_OPENED the connection is ready for
// sending and recieving messages
rtm.on(CLIENT_EVENTS.RTM.RTM_CONNECTION_OPENED, () => {
    console.log(`Ready`);

    channelListPromise.then((res) => {
        // Take any channel for which the bot is a member
        const channel = res.channels.find((c) => c.is_member);

        if (channel) {
            appData.channel = channel;
        } else {
            console.log('This bot does not belong to any channels');
        }
    });
});

rtm.on(RTM_EVENTS.MESSAGE, (message) => {
    // For structure of `message`, see https://api.slack.com/events/message

    // Skip messages that are from a bot or my own user ID
    // (message.subtype && message.subtype === 'bot_message') || (!message.subtype && message.user === appData.selfId) ||
    //
    if ( true) {
        if (command.includes(message.text)) {
            if ( jsonContent[message.text].charAt(0) === '!' ) {
                tools[message.text.substr(1)](rtm, appData.channel.id);
            } else {
                tools.sendMessage(rtm, jsonContent[message.text], appData.channel.id);
            }
        }
    }
    // Log the message
    console.log('New message: ', message.text);
    return;
});

// Start the connecting process
rtm.start();