const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');

module.exports = (env, argv) => {
    const dev = argv.mode !== 'production';
    const config = {
        devtool: dev ? 'source-map' : false,
        entry: {
            'scripts': [
                'core-js/modules/es.array.index-of',
                'core-js/modules/es.array.iterator',
                'core-js/modules/es.array.map',
                'core-js/modules/es.function.name',
                'core-js/modules/es.object.create',
                'core-js/modules/es.object.define-property',
                'core-js/modules/es.object.keys',
                'core-js/modules/es.object.set-prototype-of',
                'core-js/modules/es.promise',
                'core-js/modules/es.string.split',
                'core-js/modules/es.symbol',
                'core-js/modules/es.weak-map',
                'core-js/modules/web.dom-collections.iterator',
                'url-polyfill',
                'whatwg-fetch',
                __dirname + '/src/main/assets/scripts.js',
                __dirname + '/src/main/assets/style.css',
                require.resolve('evil-icons/assets/evil-icons.css'),
                require.resolve('evil-icons/assets/evil-icons.js')
            ]
        },
        output: {
            path: __dirname + '/src/main/resources/static',
            filename: '[name].js'
        },
        module: {
            rules: [
                { test: /\.jsx?$/, loader: 'eslint-loader', enforce: 'pre', exclude: /node_modules/, options: { failOnWarning: false, failOnError: true, fix: true } },
                { test: /\.js$/, loader: 'babel-loader' },
                {
                    test: /\.css$/,
                    use: [
                        dev? 'style-loader' : MiniCssExtractPlugin.loader,
                        {
                            loader: 'css-loader'
                        },
                        {
                            loader: 'postcss-loader', options: {
                                plugins: () => [
                                    require('stylelint')(),
                                    require('postcss-preset-env')()
                                ]
                            }
                        }
                    ]
                },
                { test: /\.png$/, loader: 'url-loader' },
                { test: /\.svg$/, loader: 'url-loader' }
            ]
        },
        plugins: [
            new MiniCssExtractPlugin({ filename: 'style.css', allChunks: true })
        ],
    };
    if (!dev) {
        config.optimization = {
            minimizer: [
                new TerserPlugin({
                    cache: true,
                    parallel: true,
                    sourceMap: dev,
                    terserOptions: {
                        output: {
                            comments: /@license/i
                        }
                    },
                    extractComments: true
                }),
            new OptimizeCSSAssetsPlugin({})
            ]
        };
    }
    return config;
};