const fs = require('fs');
const path = require('path');
const { execSync } = require("child_process");
import svelte from 'rollup-plugin-svelte';
import commonjs from '@rollup/plugin-commonjs';
import resolve from '@rollup/plugin-node-resolve';
import livereload from 'rollup-plugin-livereload';
import { terser } from 'rollup-plugin-terser';
import sveltePreprocess from 'svelte-preprocess';
import css from 'rollup-plugin-css-only';
import svg from 'rollup-plugin-svg';

const production = !process.env.ROLLUP_WATCH;

const buildVersion = execSync("git rev-parse --short HEAD").toString();
fs.writeFileSync('build-info.js', 'export default ' + JSON.stringify({
	buildDate: (new Date()).toISOString().substr(0, 19).replace('T', ' ') + ' UTC',
	buildVersion
}))

function serve() {
	let server;

	function toExit() {
		if (server) server.kill(0);
	}

	return {
		writeBundle() {
			if (server) return;
			server = require('child_process').spawn('npm', ['run', 'start', '--', '--dev'], {
				stdio: ['ignore', 'inherit', 'inherit'],
				shell: true
			});

			process.on('SIGTERM', toExit);
			process.on('exit', toExit);
		}
	};
}

export default [
	{
		input: 'src/main.js',
		output: {
			sourcemap: true,
			format: 'iife',
			name: 'app',
			file: 'public/build/bundle.js',
		},
		plugins: [
			svelte({
				preprocess: sveltePreprocess({sourceMap: !production}),
				compilerOptions: {
					// enable run-time checks when not in production
					dev: !production,
				},
			}),
			// we'll extract any component CSS out into
			// a separate file - better for performance
			css({output: 'bundle.css'}),

			svg(),

			// If you have external dependencies installed from
			// npm, you'll most likely need these plugins. In
			// some cases you'll need additional configuration -
			// consult the documentation for details:
			// https://github.com/rollup/plugins/tree/master/packages/commonjs
			resolve({
				browser: true,
				dedupe: ['svelte'],
			}),
			commonjs(),

			// In dev mode, call `npm run start` once
			// the bundle has been generated
			!production && serve(),

			// Watch the `public` directory and refresh the
			// browser on changes when not in production
			!production && livereload('public'),

			// If we're building for production (npm run build
			// instead of npm run dev), minify
			production && terser(),

			{
				name: 'copy-comlink',
				generateBundle() {
					const buildDir = './public/build'
					if (!fs.existsSync(buildDir)){
						fs.mkdirSync(buildDir);
					}

					fs.copyFileSync(
						path.resolve('./node_modules/comlink/dist/umd/comlink.min.js'),
						path.resolve('./public/build/comlink.min.js'),
					);
				},
			},
		],
		watch: {
			clearScreen: false,
		},
	},

	{
		input: 'src/workers/stats-worker.js',
		output: {
			sourcemap: true,
			format: 'iife',
			name: 'app',
			file: 'public/build/stats-worker.js',
		},
		plugins: [
			// If you have external dependencies installed from
			// npm, you'll most likely need these plugins. In
			// some cases you'll need additional configuration -
			// consult the documentation for details:
			// https://github.com/rollup/plugins/tree/master/packages/commonjs
			resolve({
				browser: true,
				dedupe: ['svelte'],
			}),
			commonjs(),

			// If we're building for production (npm run build
			// instead of npm run dev), minify
			production && terser(),
			{
				name: 'copy-test-worker',
				load() {
					this.addWatchFile(path.resolve('./src/workers/stats-worker.js'));
				},
				generateBundle() {
					const buildDir = './public/build'
					if (!fs.existsSync(buildDir)){
						fs.mkdirSync(buildDir);
					}

					fs.copyFileSync(
						path.resolve('./src/workers/stats-worker.js'),
						path.resolve('./public/build/stats-worker.js'),
					);
				},
			},
		],
	},
];