'use strict';

const winston = require('winston');
const express = require('express');
const bodyParser = require('body-parser');
const fs = require('fs');
const path = require('path');
const childProcess = require('child_process');
const less = require('less');
const util = require('util');

const lessRenderAsync = util.promisify(
	(style, opts, cb) => less.render(String(style), opts, cb)
);
const uglify = require('uglify-es');
const nconf = require('nconf');

const Benchpress = require('benchpressjs');
const mkdirp = require('mkdirp');
const { paths } = require('../src/constants');

const app = express();
let server;

const formats = [
	winston.format.colorize(),
];

const timestampFormat = winston.format((info) => {
	const dateString = `${new Date().toISOString()} [${global.process.pid}]`;
	info.level = `${dateString} - ${info.level}`;
	return info;
});
formats.push(timestampFormat());
formats.push(winston.format.splat());
formats.push(winston.format.simple());

winston.configure({
	level: 'verbose',
	format: winston.format.combine.apply(null, formats),
	transports: [
		new winston.transports.Console({
			handleExceptions: true,
		}),
		new winston.transports.File({
			filename: 'logs/webinstall.log',
			handleExceptions: true,
		}),
	],
});

const web = module.exports;

const scripts = [
	'node_modules/jquery/dist/jquery.js',
	'node_modules/xregexp/xregexp-all.js',
	'public/src/modules/slugify.js',
	'public/src/utils.js',
	'public/src/installer/install.js',
	'node_modules/zxcvbn/dist/zxcvbn.js',
];

let installing = false;
let success = false;
let error = false;
let launchUrl;

const viewsDir = path.join(paths.baseDir, 'build/public/templates');

web.install = async function (port) {
	port = port || 4567;
	winston.info(`Launching web installer on port ${port}`);

	app.use(express.static('public', {}));
	app.engine('tpl', (filepath, options, callback) => {
		filepath = filepath.replace(/\.tpl$/, '.js');

		Benchpress.__express(filepath, options, callback);
	});
	app.set('view engine', 'tpl');
	app.set('views', viewsDir);
	app.use(bodyParser.urlencoded({
		extended: true,
	}));
	try {
		await Promise.all([
			compileTemplate(),
			compileLess(),
			compileJS(),
			copyCSS(),
			loadDefaults(),
		]);
		setupRoutes();
		launchExpress(port);
	} catch (err) {
		winston.error(err.stack);
	}
};


function launchExpress(port) {
	server = app.listen(port, () => {
		winston.info('Web installer listening on http://%s:%s', '0.0.0.0', port);
	});
}

function setupRoutes() {
	app.get('/', welcome);
	app.post('/', install);
	app.post('/launch', launch);
	app.get('/ping', ping);
	app.get('/sping', ping);
}

function ping(req, res) {
	res.status(200).send(req.path === '/sping' ? 'healthy' : '200');
}

function welcome(req, res) {
	const dbs = ['redis', 'mongo', 'postgres'];
	const databases = dbs.map((databaseName) => {
		const questions = require(`../src/database/${databaseName}`).questions.filter(question => question && !question.hideOnWebInstall);

		return {
			name: databaseName,
			questions: questions,
		};
	});

	const defaults = require('./data/defaults');

	res.render('install/index', {
		url: nconf.get('url') || (`${req.protocol}://${req.get('host')}`),
		launchUrl: launchUrl,
		skipGeneralSetup: !!nconf.get('url'),
		databases: databases,
		skipDatabaseSetup: !!nconf.get('database'),
		error: error,
		success: success,
		values: req.body,
		minimumPasswordLength: defaults.minimumPasswordLength,
		minimumPasswordStrength: defaults.minimumPasswordStrength,
		installing: installing,
	});
}

function install(req, res) {
	if (installing) {
		return welcome(req, res);
	}
	req.setTimeout(0);
	installing = true;
	const setupEnvVars = nconf.get();
	for (const [key, value] of Object.entries(req.body)) {
		if (!process.env.hasOwnProperty(key)) {
			setupEnvVars[key.replace(':', '__')] = value;
		}
	}

	// Flatten any objects in setupEnvVars
	const pushToRoot = function (parentKey, key) {
		setupEnvVars[`${parentKey}__${key}`] = setupEnvVars[parentKey][key];
	};
	for (const [parentKey, value] of Object.entries(setupEnvVars)) {
		if (typeof value === 'object' && value !== null && !Array.isArray(value)) {
			Object.keys(value).forEach(key => pushToRoot(parentKey, key));
			delete setupEnvVars[parentKey];
		} else if (Array.isArray(value)) {
			setupEnvVars[parentKey] = JSON.stringify(value);
		}
	}

	winston.info('Starting setup process');
	winston.info(setupEnvVars);
	launchUrl = setupEnvVars.url;

	const child = require('child_process').fork('app', ['--setup'], {
		env: setupEnvVars,
	});

	child.on('close', (data) => {
		installing = false;
		success = data === 0;
		error = data !== 0;

		welcome(req, res);
	});
}

async function launch(req, res) {
	try {
		res.json({});
		server.close();
		req.setTimeout(0);
		let child;

		if (!nconf.get('launchCmd')) {
			child = childProcess.spawn('node', ['loader.js'], {
				detached: true,
				stdio: ['ignore', 'ignore', 'ignore'],
			});

			console.log('\nStarting NodeBB');
			console.log('    "./nodebb stop" to stop the NodeBB server');
			console.log('    "./nodebb log" to view server output');
			console.log('    "./nodebb restart" to restart NodeBB');
		} else {
			// Use launchCmd instead, if specified
			child = childProcess.exec(nconf.get('launchCmd'), {
				detached: true,
				stdio: ['ignore', 'ignore', 'ignore'],
			});
		}

		const filesToDelete = [
			'installer.css',
			'installer.min.js',
			'bootstrap.min.css',
		];
		await Promise.all(
			filesToDelete.map(
				filename => fs.promises.unlink(path.join(__dirname, '../public', filename))
			)
		);
		child.unref();
		process.exit(0);
	} catch (err) {
		winston.error(err.stack);
		throw err;
	}
}

// this is necessary because otherwise the compiled templates won't be available on a clean install
async function compileTemplate() {
	const sourceFile = path.join(__dirname, '../src/views/install/index.tpl');
	const destTpl = path.join(viewsDir, 'install/index.tpl');
	const destJs = path.join(viewsDir, 'install/index.js');

	const source = await fs.promises.readFile(sourceFile, 'utf8');

	const [compiled] = await Promise.all([
		Benchpress.precompile(source, { filename: 'install/index.tpl' }),
		mkdirp(path.dirname(destJs)),
	]);

	await Promise.all([
		fs.promises.writeFile(destJs, compiled),
		fs.promises.writeFile(destTpl, source),
	]);
}

async function compileLess() {
	try {
		const installSrc = path.join(__dirname, '../public/less/install.less');
		const style = await fs.promises.readFile(installSrc);
		const css = await lessRenderAsync(style, { filename: path.resolve(installSrc) });
		await fs.promises.writeFile(path.join(__dirname, '../public/installer.css'), css.css);
	} catch (err) {
		winston.error(`Unable to compile LESS: \n${err.stack}`);
		throw err;
	}
}

async function compileJS() {
	let code = '';

	for (const srcPath of scripts) {
		// eslint-disable-next-line no-await-in-loop
		const buffer = await fs.promises.readFile(path.join(__dirname, '..', srcPath));
		code += buffer.toString();
	}
	const minified = uglify.minify(code, {
		compress: false,
	});
	if (!minified.code) {
		throw new Error('[[error:failed-to-minify]]');
	}
	await fs.promises.writeFile(path.join(__dirname, '../public/installer.min.js'), minified.code);
}

async function copyCSS() {
	const src = await fs.promises.readFile(
		path.join(__dirname, '../node_modules/bootstrap/dist/css/bootstrap.min.css'), 'utf8'
	);
	await fs.promises.writeFile(path.join(__dirname, '../public/bootstrap.min.css'), src);
}

async function loadDefaults() {
	const setupDefaultsPath = path.join(__dirname, '../setup.json');
	try {
		await fs.promises.access(setupDefaultsPath, fs.constants.F_OK + fs.constants.R_OK);
	} catch (err) {
		// setup.json not found or inaccessible, proceed with no defaults
		if (err.code !== 'ENOENT') {
			throw err;
		}
	}
	winston.info('[installer] Found setup.json, populating default values');
	nconf.file({
		file: setupDefaultsPath,
	});
}