'use strict';

require('dotenv').config();

var CSR = require('@root/csr');
var Enc = require('@root/encoding/base64');
var PEM = require('@root/pem');
var punycode = require('punycode');
var ACME = require('../acme.js');
var Keypairs = require('@root/keypairs');
var acme = ACME.create({
	// debug: true
});

// TODO exec npm install --save-dev CHALLENGE_MODULE

var config = {
	env: process.env.ENV,
	email: process.env.SUBSCRIBER_EMAIL,
	domain: process.env.BASE_DOMAIN,
	challengeType: process.env.CHALLENGE_TYPE,
	challengeModule: process.env.CHALLENGE_PLUGIN,
	challengeOptions: JSON.parse(process.env.CHALLENGE_OPTIONS)
};
config.debug = !/^PROD/i.test(config.env);
var pluginPrefix = 'acme-' + config.challengeType + '-';
var pluginName = config.challengeModule;
var plugin;

function badPlugin(err) {
	if ('MODULE_NOT_FOUND' !== err.code) {
		console.error(err);
		return;
	}
	console.error("Couldn't find '" + pluginName + "'. Is it installed?");
	console.error("\tnpm install --save-dev '" + pluginName + "'");
}
try {
	plugin = require(pluginName);
} catch (err) {
	if (
		'MODULE_NOT_FOUND' !== err.code ||
		0 === pluginName.indexOf(pluginPrefix)
	) {
		badPlugin(err);
		process.exit(1);
	}
	try {
		pluginName = pluginPrefix + pluginName;
		plugin = require(pluginName);
	} catch (e) {
		badPlugin(e);
		process.exit(1);
	}
}

config.challenger = plugin.create(config.challengeOptions);
if (!config.challengeType || !config.domain) {
	console.error(
		new Error('Missing config variables. Check you .env and the docs')
			.message
	);
	console.error(config);
	process.exit(1);
}

var challenges = {};
challenges[config.challengeType] = config.challenger;

async function happyPath(accKty, srvKty, rnd) {
	var agreed = false;
	var metadata = await acme.init(
		'https://acme-staging-v02.api.letsencrypt.org/directory'
	);

	// Ready to use, show page
	if (config.debug) {
		console.info('ACME.js initialized');
		console.info(metadata);
		console.info();
		console.info();
	}

	var accountKeypair = await Keypairs.generate({ kty: accKty });
	if (config.debug) {
		console.info('Account Key Created');
		console.info(JSON.stringify(accountKeypair, null, 2));
		console.info();
		console.info();
	}

	var account = await acme.accounts.create({
		agreeToTerms: agree,
		// TODO detect jwk/pem/der?
		accountKeypair: { privateKeyJwk: accountKeypair.private },
		subscriberEmail: config.email
	});

	// TODO top-level agree
	function agree(tos) {
		if (config.debug) {
			console.info('Agreeing to Terms of Service:');
			console.info(tos);
			console.info();
			console.info();
		}
		agreed = true;
		return Promise.resolve(tos);
	}
	if (config.debug) {
		console.info('New Subscriber Account');
		console.info(JSON.stringify(account, null, 2));
		console.info();
		console.info();
	}
	if (!agreed) {
		throw new Error('Failed to ask the user to agree to terms');
	}

	var certKeypair = await Keypairs.generate({ kty: srvKty });
	var pem = await Keypairs.export({
		jwk: certKeypair.private,
		encoding: 'pem'
	});
	if (config.debug) {
		console.info('Server Key Created');
		console.info('privkey.jwk.json');
		console.info(JSON.stringify(certKeypair, null, 2));
		// This should be saved as `privkey.pem`
		console.info();
		console.info('privkey.' + srvKty.toLowerCase() + '.pem:');
		console.info(pem);
		console.info();
	}

	// 'subject' should be first in list
	var domains = randomDomains(rnd);
	if (config.debug) {
		console.info('Get certificates for random domains:');
		console.info(
			domains
				.map(function(puny) {
					var uni = punycode.toUnicode(puny);
					if (puny !== uni) {
						return puny + ' (' + uni + ')';
					}
					return puny;
				})
				.join('\n')
		);
		console.info();
	}

	// Create CSR
	var csrDer = await CSR.csr({
		jwk: certKeypair.private,
		domains: domains,
		encoding: 'der'
	});
	var csr = Enc.bufToUrlBase64(csrDer);
	var csrPem = PEM.packBlock({
		type: 'CERTIFICATE REQUEST',
		bytes: csrDer /* { jwk: jwk, domains: opts.domains } */
	});
	if (config.debug) {
		console.info('Certificate Signing Request');
		console.info(csrPem);
		console.info();
	}

	var results = await acme.certificates.create({
		account: account,
		accountKeypair: { privateKeyJwk: accountKeypair.private },
		csr: csr,
		domains: domains,
		challenges: challenges, // must be implemented
		customerEmail: null
	});

	if (config.debug) {
		console.info('Got SSL Certificate:');
		console.info(Object.keys(results));
		console.info(results.expires);
		console.info(results.cert);
		console.info(results.chain);
		console.info();
		console.info();
	}
}

// Try EC + RSA
var rnd = random();
happyPath('EC', 'RSA', rnd)
	.then(function() {
		// Now try RSA + EC
		rnd = random();
		return happyPath('RSA', 'EC', rnd).then(function() {
			console.info('success');
		});
	})
	.catch(function(err) {
		console.error('Error:');
		console.error(err.stack);
	});

function randomDomains(rnd) {
	return ['foo-acmejs', 'bar-acmejs', '*.baz-acmejs', 'baz-acmejs'].map(
		function(pre) {
			return punycode.toASCII(pre + '-' + rnd + '.' + config.domain);
		}
	);
}

function random() {
	return (
		parseInt(
			Math.random()
				.toString()
				.slice(2, 99),
			10
		)
			.toString(16)
			.slice(0, 4) + '例'
	);
}