DiscordSendService.js

import os from 'os';
import console from 'node:console';
import Buffer from 'node:buffer';

import discordJs from 'discord.js';

const hostname = os.hostname();
const IMAGE_URL = 'https://cdn.futura-sciences.com/buildsv6/images/wide1920/6/5/2/652a7adb1b_98148_01-intro-773.jpg';
const {EmbedBuilder, WebhookClient} = discordJs;

export default class DiscordSendService {

    constructor(applicationProperties) {
        this._config = applicationProperties;
        this.discordWebhookUrl = this._config.discordWebhookUrl;// https://discord.com/api/webhooks/xxx/yyy
        const {id, token} = extractFromDiscordUrl(this.discordWebhookUrl);
        this.discordWebhookId = id;
        this.discordWebhookToken = token;
        this.isEnabled = (isSet(this.discordWebhookId) && isSet(this.discordWebhookToken));
        if (this.isEnabled) {
            this.username = hostname + "-" + this._config.nodeEnv;
            this.hook = new WebhookClient({id: this.discordWebhookId, token: this.discordWebhookToken});
            this.embed = new EmbedBuilder().setColor(0xFF00FF);
        }
    }

    isDiscordEnabled() {
        return this.isEnabled;
    }

    async sendMessage(content) {
        if (!this.isDiscordEnabled()) {
            console.log("* DISCORD DISABLED * | " + content);
            return Promise.resolve();
        }
        // https://discordjs.guide/popular-topics/webhooks.html#sending-messages
        if (content.length < 2000) {
            await this.hook.send({content, username: this.username, avatarURL: IMAGE_URL});
        } else {
            const name = `msg-${nowTs()}.txt`;
            const attachment = Buffer.from(content);
            const partialContent = content.substring(0, 500) + '...';
            /// send with 'files' produces a warn about buffer.Blob is an experimental feature // files: array of https://discord.js.org/#/docs/main/stable/typedef/MessageFile
            await this.hook.send({
                content: partialContent,
                username: this.username,
                avatarURL: IMAGE_URL,
                files: [{attachment, name}]
            });
        }
        return Promise.resolve();
    }

}

function nowTs() {
    return new Date().getTime();
}

function isSet(variable) {
    return (variable !== undefined && variable !== null);
}

function extractFromDiscordUrl(url) {
    // url: https://discord.com/api/webhooks/(id)/(token)
    const regexp = "https://discord.com/api/webhooks/([^/]*)/([^/]*)(/)?";
    if (!isSet(url)) {
        return {};
    }
    const result = url.match(regexp);
    // DEBUG // console.log("extractFromDiscordUrl", result);
    if (!isSet(result)) {
        return {};
    }
    const id = isSet(result[1]) ? result[1] : null;
    const token = isSet(result[2]) ? result[2] : null;
    return {id, token};
}