index.js

(async () => {
	const http = require('http');
	const url = require('url');
	const querystring = require('querystring');
	const fsPromise = require('fs').promises;
	const __ = require('./utils');

	/* config */
	const PORT = +process.env.PORT || 3020;
	const COUNTER = +process.env.COUNTER || 0;
	const DEBUG = process.env.DEBUG || false;

	var track = '';
	if (process.env.TRACKER_CONFIG_FILE)
		var [err, track] = await __.to(fsPromise.readFile(process.env.TRACKER_CONFIG_FILE));
	if (!track && process.env.TRACKER_SECRET_FILE)
		var [err, track] = await __.to(fsPromise.readFile('/run/secrets/' + process.env.TRACKER_SECRET_FILE));

	var embed = '';
	if (process.env.EMBED_FILE) var [err, embed] = await __.to(fsPromise.readFile(process.env.EMBED_FILE));

	const TRACKER = track || '';
	const EMBED = embed || '';

	console.log('APP_CONFIG', {
		PORT,
		COUNTER,
		DEBUG,
		TRACKER: !!TRACKER,
		EMBED: !!EMBED,
	});

	/* prepare content */
	let tsStart = new Date().getTime();

	//css
	let css = await fsPromise.readFile('./public/css/style.css');
	css = __.minimizeCSS(css.toString());

	//images
	let favicon = await fsPromise.readFile('./public/favicon.ico');
	let telegram_png = await fsPromise.readFile('./public/img/telegram-512.png');

	//html
	let htmlPages = {
		indexPage: await fsPromise.readFile('./html/index.html'),
		redirectPage: await fsPromise.readFile('./html/redirect.html'),
	};
	let globalVars = {
		COUNTER,
		TRACKER,
		EMBED,
		CSS: css,
	};

	//translation
	let translatedHTML = {
		indexPage: {},
		redirectPage: {},
	};
	const LANG_DICT = require('./data/language.js');
	Object.keys(LANG_DICT).forEach(lang => {
		Object.keys(translatedHTML).forEach(page => {
			translatedHTML[page][lang] = __.passVariables(
				htmlPages[page].toString(),
				Object.assign(LANG_DICT[lang], globalVars, { language: lang }),
			);
			//translatedHTML[page][lang] = __.minimizeHTML(translatedHTML[page][lang]);
		});
	});

	//utility
	let robots = await fsPromise.readFile('./public/robots.txt');
	let ads = await fsPromise.readFile('./public/ads.txt');
	let sitemap_ru = await fsPromise.readFile('./public/sitemap_ru.xml');
	let sitemap_en = await fsPromise.readFile('./public/sitemap_en.xml');

	//garbage
	delete htmlPages;
	delete globalVars;
	delete css;
	delete fsPromise;
	delete LANG_DICT;

	if (DEBUG) console.log('content prepeared', '+' + ((new Date().getTime() - tsStart) / 1000).toFixed(2) + ' sec');

	/* serve requests */
	const server = http.createServer(async (request, response) => {
		let { pathname, query } = url.parse(request.url);
		query = querystring.parse(query);
		let queryLang = query.lang && (query.lang == 'ru' || query.lang == 'en') ? query.lang : false;

		let language = queryLang ? queryLang : __.detectLanguage(request);
		if (DEBUG) console.log('req', language, request.headers.host, pathname);

		response.setHeader('Access-Control-Allow-Origin', '*');
		response.setHeader('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
		response.setHeader('Content-Language', language);
		response.setHeader('status', 200);

		if (pathname == '/') {
			response.setHeader('Content-Type', 'text/html; charset=utf-8');
			response.end(translatedHTML.indexPage[language]);
		} else if (pathname == '/favicon.ico') {
			response.setHeader('Content-Type', 'image/x-icon');
			response.end(favicon);
		} else if (pathname == '/img/telegram.png') {
			response.setHeader('Content-Type', 'image/png');
			response.end(telegram_png);
		} else if (pathname == '/robots.txt') {
			response.setHeader('Content-Type', 'text/plain');
			response.end(robots);
		} else if (pathname == '/sitemap_ru.xml') {
			response.setHeader('Content-Type', 'application/xml');
			response.end(sitemap_ru);
		} else if (pathname == '/sitemap_en.xml') {
			response.setHeader('Content-Type', 'application/xml');
			response.end(sitemap_en);
		} else if (pathname == '/ads.txt') {
			response.setHeader('Content-Type', 'aptext/plainml');
			response.end(ads);
		} else {
			response.setHeader('Content-Type', 'text/html; charset=utf-8');
			response.end(translatedHTML.redirectPage[language]);
		}
	});

	/* start server */
	server.listen(PORT, err => {
		if (err) return console.log('something bad happened', err.message);
		console.log(`server is listening on ${PORT}`);
	});
})();