'use strict';

const fs = require('fs');
const path = require('path');
const util = require('util');
const child = require('child_process');
const tmp = require('tmp-promise');
const fsx = require('fs-extra');
const config = require('./config');

const readFile = util.promisify(fs.readFile);

function spawn(path, params, ...args) {
	console.log(`> ${path} ${params.join(' ')}`);
	const proc = child.spawn(path, params, ...args);
	proc.promise = new Promise((res, rejraw) => {
		function rej(e) {
			rejraw(`${path} ${params.join(' ')}: ${e}`);
		}
		proc.on('error', rej);
		proc.on('exit', (code, sig) => {
			if(sig) rej('signal: ' + sig);
			if(code !== 0) rej('code: ' + code);
			res();
		});
	});
	return proc;
}

function luaser(obj) {
	if(Array.isArray(obj))
		return `{${obj.map(luaser).join(',')}}`;
	if(!!obj && typeof obj === 'object' && obj.toString() === '[object Object]')
		return `{${Object.keys(obj)
			.map(k => ({
				k: /^[A-Za-z_][A-Za-z0-9_]*$/.test(k) ? k : JSON.stringify(k), 
				v: luaser(obj[k])
			}))
			.filter(x => x.v !== 'nil')
			.map(x => x.k + '=' + x.v)}}`;
	if(typeof obj === 'number' || typeof obj === 'boolean')
		return `${obj}`;
	if(typeof obj === 'string' || obj instanceof String)
		return JSON.stringify(obj);
	if(!obj || typeof obj === 'function')
		return 'nil';
	return JSON.stringify(obj.toString());
}

module.exports = async () => {
	const luahook = `config = ${luaser(config)}\n\n` +
		(await readFile('luahook.lua'))
		.toString();

	const tmpdir = await tmp.dir({
		mode: parseInt('700', 8),
		prefix: 'cdbrelease-'
	});
	try {
		const git = config.execgit || 'git';
		const tar = config.exectar || 'tar';
		const lua = config.execlua || 'lua5.1';

		const repodir = path.join(tmpdir.path, 'repo');
		await spawn(git, [
				'clone',
				'--bare',
				'--depth=1',
				'-b', config.branch,
				config.fromgit,
				repodir
			], {
				stdio: 'inherit'
			})
			.promise;

		const outdir = path.join(tmpdir.path, 'export');
		await fsx.emptyDir(outdir);
		const garch = spawn(git, [
			'--git-dir=' + repodir,
			'archive',
			'--format=tar',
			config.branch
		], {
			stdio: ['inherit', 'pipe', 'inherit']
		});
		const untar = spawn(tar, [
			'-C', outdir,
			'-xf', '-'
		], {
			stdio: ['pipe', 'inherit', 'inherit']
		});
		garch.stdout.pipe(untar.stdin);
		await garch.promise;
		await untar.promise;

		let buff = '';
		const hook = spawn(lua, ['-'], {
			stdio: ['pipe', 'pipe', 'inherit'],
			cwd: outdir
		});
		hook.stdout.on('data', x => buff += x.toString());
		hook.stdin.write(luahook);
		hook.stdin.end();
		await hook.promise;

		const spec = JSON.parse(buff);
		config.set('fromgit', spec);

		const scanned = require('./modscan')(outdir);
		config.set('modscan', scanned);
	} finally {
		await fsx.emptyDir(tmpdir.path);
		await tmpdir.cleanup();
	}
};