import resolve from '@rollup/plugin-node-resolve'
import replace from '@rollup/plugin-replace'
import commonjs from 'rollup-plugin-commonjs'
import svelte from 'rollup-plugin-svelte'
import babel from 'rollup-plugin-babel'
import sveltePreprocess from 'svelte-preprocess'
import { terser } from 'rollup-plugin-terser'
import config from 'sapper/config/rollup.js'
import pkg from './package.json'

// Define environment
const mode = process.env.NODE_ENV
const dev = mode === 'development'
const legacy = !!process.env.SAPPER_LEGACY_BUILD

const onwarn = (warning, onwarn) => (warning.code === 'CIRCULAR_DEPENDENCY' && /[/\\]@sapper[/\\]/.test(warning.message)) || onwarn(warning)
const dedupe = importee => importee === 'svelte' || importee.startsWith('svelte/')

// Preprocessors
const preprocess = sveltePreprocess({
	scss: {
		includePaths: ['node_modules', 'src']
	},
	postcss: {
		configFilePath: './'
	}
})

// Sapper Rollup config
export default {
	client: {
		input: config.client.input(),
		output: config.client.output(),
		experimentalCodeSplitting: true,
		plugins: [
			replace({
				'process.browser': true,
				'process.env.NODE_ENV': JSON.stringify(mode)
			}),
			svelte({
				css: css => {
					css.write('public/bundle.css')
				},
				preprocess,
				dev,
				hydratable: true,
				emitCss: true,
			}),
			resolve({
				browser: true,
				dedupe
			}),
			commonjs(),

			legacy && babel({
				extensions: ['.js', '.mjs', '.html', '.svelte'],
				exclude: ['node_modules/@babel/**'],
				runtimeHelpers: true
			}),

			!dev && terser({
				module: true
			})
		],

		onwarn,
	},

	server: {
		input: config.server.input(),
		output: config.server.output(),
		plugins: [
			replace({
				'process.browser': false,
				'process.env.NODE_ENV': JSON.stringify(mode)
			}),
			svelte({
				preprocess,
				generate: 'ssr',
				dev
			}),
			resolve({
				browser: true,
				dedupe
			}),
			commonjs(),
		],
		external: Object.keys(pkg.dependencies).concat(
			require('module').builtinModules || Object.keys(process.binding('natives'))
		),

		onwarn,
	},

	// serviceworker: {
	// 	input: config.serviceworker.input(),
	// 	output: config.serviceworker.output(),
	// 	plugins: [
	// 		resolve(),
	// 		replace({
	// 			'process.browser': true,
	// 			'process.env.NODE_ENV': JSON.stringify(mode)
	// 		}),
	// 		commonjs(),
	// 		!dev && terser()
	// 	],

	// 	onwarn,
	// }
}