function checkDependency(serviceName: string, command: string, transform: (x: string) => string): void {
	try {
		const x = execSync(command, { stdio: ['pipe', 'pipe', 'ignore'] });
		const ver = transform(x.toString());
		if (ver !== null) {
			logInfo(`${serviceName} ${ver}`);
		} else {
			logWarn(`Check dependencies error (${serviceName})`);
			logWarn(`Regexp used for version check of ${serviceName} is probably messed up`);
		}
	} catch (e) {
		logWarn(`Unable to find (${serviceName})`);
	}
}

/**
 * Init app
 */
async function init(): Promise<State> {
	console.log('Welcome to Misskey!\n');

	console.log(chalk.bold('Misskey Core <aoi>'));

	let warn = false;

	// Get commit info
	const commit = await prominence(git).getLastCommit();
	console.log(`commit: ${commit.shortHash} ${commit.author.name} <${commit.author.email}>`);
	console.log(`        ${new Date(parseInt(commit.committedOn, 10) * 1000)}`);

	console.log('\nInitializing...\n');

	if (IS_DEBUG) {
		logWarn('It is not in the Production mode. Do not use in the Production environment.');
	}

	logInfo(`environment: ${env}`);

	// Get machine info
	const totalmem = (os.totalmem() / 1024 / 1024 / 1024).toFixed(1);
	const freemem = (os.freemem() / 1024 / 1024 / 1024).toFixed(1);
	logInfo(`MACHINE: ${os.hostname()}`);
	logInfo(`MACHINE: CPU: ${os.cpus().length}core`);
	logInfo(`MACHINE: MEM: ${totalmem}GB (available: ${freemem}GB)`);

	if (!fs.existsSync(require('./config').configPath)) {
		logFailed('Configuration not found');
		return State.failed;
	}

	// Load config
	const conf = require('./config').default;

	logDone('Success to load configuration');
	logInfo(`maintainer: ${conf.maintainer}`);

	checkDependencies();

	// Check if a port is being used
	if (await portUsed.check(conf.port)) {
		logFailed(`Port: ${conf.port} is already used!`);
		return State.failed;
	}

	// Try to connect to MongoDB
	try {
		await initdb(conf);
		logDone('Success to connect to MongoDB');
	} catch (e) {
		logFailed(`MongoDB: ${e}`);
		return State.failed;
	}

	return warn ? State.warn : State.success;
}

function checkDependency(serviceName: string, command: string, transform: (x: string) => string): void {
	const code = {
		success: 0,
		notFound: 127
	};
	const x = exec(command, { silent: true }) as any;
	if (x.code === code.success) {
		logInfo(`DEPS: ${serviceName} ${transform(x.stdout)}`);
	} else if (x.code === code.notFound) {
		logWarn(`Unable to find ${serviceName}`);
	}
}

function notFoundHandler(req: any, res: any): any {
	logWarn(`Request not handled: ${req.method.toUpperCase()} ${req.path}`);
	return res({
		error: 'api-not-found'
	}).code(404);
}