const webpack = require('webpack');
const path = require('path');
const HtmlWebPackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
const ESLintPlugin = require('eslint-webpack-plugin');
const ErrorOverlayPlugin = require('error-overlay-webpack-plugin');

module.exports = (env, argv) => {
    const dev = argv.mode !== 'production';
    const config = {
        devtool: dev ? 'cheap-module-source-map' : false,
        mode: dev ? 'development' : 'production',
        entry: {
            'Juick': [
                'core-js/modules/es.array.map',
                'core-js/modules/es.map',
                'core-js/modules/es.object.create',
                'core-js/modules/es.object.define-property',
                'core-js/modules/es.object.set-prototype-of',
                'core-js/modules/es.promise',
                'core-js/modules/es.set',
                'core-js/modules/es.symbol',
                'core-js/modules/web.dom-collections.iterator',
                'url-polyfill',
                __dirname + '/src/index.js',
                require.resolve('evil-icons/assets/evil-icons.css')
            ]
        },
        output: {
            filename: dev ? '[name].js' : '[name].[contenthash].bundle.js',
            chunkFilename: dev ? '[name].js' : '[name].[contenthash].bundle.js',
            publicPath: '/',
            path: path.resolve(__dirname, 'dist')
        },
        module: {
            rules: [
                {
                    test: /\.css$/,
                    use: [
                        dev ? 'style-loader' : MiniCssExtractPlugin.loader,
                        {
                            loader: 'css-loader'
                        },
                        {
                            loader: 'postcss-loader',
                            options: {
                                postcssOptions: {
                                    plugins: [
                                        'stylelint',
                                        ['postcss-preset-env', { stage: 0 } ]
                                    ]
                                }
                            }
                        }
                    ]
                },
                {
                    test: /\.html$/,
                    use: [
                        {
                            loader: 'html-loader',
                            options: { minimize: false }
                        }
                    ]
                },
                {
                    test: /\.js$/,
                    exclude: /node_modules/,
                    loader: 'babel-loader'
                },
                {
                    test: /\.(jpe?g|png|gif|svg)$/i,
                    loader: 'file-loader',
                    options: {
                        hash: 'sha512',
                        digest: 'hex',
                        name: '[contenthash].[ext]'
                    }
                }
            ]
        },
        plugins: [
            new webpack.IgnorePlugin({
                resourceRegExp: /^\.\/locale$/,
                contextRegExp: /moment$/,
              }),
            new MiniCssExtractPlugin({
                filename: 'Juick.[contenthash].css'
            }),
            new HtmlWebPackPlugin({
                template: './src/index.html',
                filename: './index.html'
            }),
            new ESLintPlugin({ 
                files: 'src', 
                lintDirtyModulesOnly: true, 
                failOnWarning: false, 
                failOnError: true, 
                fix: false 
            }),
            new ErrorOverlayPlugin()
        ],
        devServer: {
            historyApiFallback: true,
            hot: true,
            client: {
                overlay: true
            }
        }
    };

    if (!dev) {
        config.optimization = {
            minimizer: [
                '...',
                new CssMinimizerPlugin({})
            ],
            splitChunks: {
                chunks: 'all'
            }
        };
    }
    return config;
};