const webpack = require('webpack');
const TerserPlugin = require('terser-webpack-plugin');
const path = require('path');
const config = require('sapper/config/webpack.js');
const pkg = require('./package.json');

const mode = process.env.NODE_ENV;
const dev = mode === 'development';

const alias = { svelte: path.resolve('node_modules', 'svelte') };
const extensions = ['.mjs', '.js', '.json', '.svelte', '.html'];
const mainFields = ['svelte', 'module', 'browser', 'main'];

const onwarn = (warning, handler) => warning.code === 'css-unused-selector' || handler(warning);

module.exports = {
	client: {
		entry: config.client.entry(),
		output: config.client.output(),
		resolve: { alias, extensions, mainFields },
		module: {
			rules: [
                {
                    test: /\.(js|mjs|html|svelte)$/,
                    exclude: /(node_modules\/@babel)/,
                    use: {
                        loader: 'babel-loader',
                        options: {
                            presets: [
                                ['@babel/preset-env', {
                                    targets: '> 0.25%, ie >= 8, not dead'
                                }]
                            ],
                            plugins: [
                                '@babel/plugin-syntax-dynamic-import',
					            '@babel/plugin-proposal-object-rest-spread',
					            ['@babel/plugin-transform-runtime', {
                                    regenerator: true
                                }],
                            ],
                            sourceType: 'unambiguous'
                        }
                    }
                },
				{
					test: /\.(svelte|html)$/,
					use: {
						loader: 'svelte-loader',
						options: {
							dev,
                            hydratable: true,
                            hotReload: true,
                            onwarn
						}
					}
                }
			]
		},
		mode,
		plugins: [
			// pending https://github.com/sveltejs/svelte/issues/2377
			// dev && new webpack.HotModuleReplacementPlugin(),
			new webpack.DefinePlugin({
				'process.browser': true,
				'process.env.NODE_ENV': JSON.stringify(mode)
			}),
		].filter(Boolean),
        devtool: dev && 'inline-source-map',
        optimization: {
            minimize: true,
            minimizer: [new TerserPlugin()],
        },
	},

	server: {
		entry: config.server.entry(),
		output: config.server.output(),
		target: 'node',
		resolve: { alias, extensions, mainFields },
		externals: Object.keys(pkg.dependencies).concat('encoding'),
		module: {
			rules: [
				{
					test: /\.(svelte|html)$/,
					use: {
						loader: 'svelte-loader',
						options: {
							css: false,
							generate: 'ssr',
                            dev,
                            onwarn
						}
					}
				}
			]
		},
		mode: process.env.NODE_ENV,
		performance: {
			hints: false // it doesn't matter if server.js is large
		},
	},

	serviceworker: {
		entry: config.serviceworker.entry(),
		output: config.serviceworker.output(),
		mode: process.env.NODE_ENV
	}
};