const path = require('path');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const HtmlMinimizerPlugin = require('html-minimizer-webpack-plugin');
const HtmlInlineScriptPlugin = require('html-inline-script-webpack-plugin');
const HTMLInlineCSSWebpackPlugin =
    require('html-inline-css-webpack-plugin').default;
const Compression = require('compression-webpack-plugin');

module.exports = {
    mode: 'production', // this trigger webpack out-of-box prod optimizations
    entry: path.resolve(__dirname, '../src/index.js'),
    output: {
        filename: `[name].[hash].js`, // [hash] is useful for cache busting!
        path: path.resolve(__dirname, '../dist'),
    },
    module: {
        rules: [
            {
                test: /\.css$/,
                use: [MiniCssExtractPlugin.loader, 'css-loader'],
            },
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: [
                    {
                        loader: 'babel-loader',
                        options: {
                            presets: [
                                [
                                    '@babel/preset-env',
                                    {
                                        useBuiltIns: 'usage',
                                        debug: false,
                                        corejs: 3,
                                        targets: { chrome: '88' },
                                    },
                                ],
                            ],
                        },
                    },
                ],
            },
        ],
    },
    plugins: [
        // always deletes the dist folder first in each build run.
        new CleanWebpackPlugin(),
        new MiniCssExtractPlugin({
            filename: '[name].css',
            chunkFilename: '[id].css',
        }),
        new HtmlWebpackPlugin({
            template: path.join(__dirname, '../src/index.html'),
            inlineSource: '.(js|css)$',
            inject: 'body',
        }),

        new HtmlInlineScriptPlugin({
            scriptMatchPattern: [/.+[.]js$/],
            htmlMatchPattern: [/index.html$/],
        }),
        new HTMLInlineCSSWebpackPlugin(),
        new Compression({
            test: /\.(html)$/,
            filename: '[path][base].gz',
            algorithm: 'gzip',
            exclude: /.map$/,
            deleteOriginalAssets: 'keep-source-map',
        }),
    ],
    optimization: {
        minimize: true,
        minimizer: [
            new HtmlMinimizerPlugin({
                minimizerOptions: {
                    collapseWhitespace: true,
                    minifyCSS: true,
                    minifyJS: true,
                },
                minify: (data, minimizerOptions) => {
                    const htmlMinifier = require('html-minifier-terser');
                    const [[filename, input]] = Object.entries(data);

                    return htmlMinifier.minify(input, minimizerOptions);
                },
            }),
        ],
    },
    devtool: 'source-map', // supposedly the ideal type without bloating bundle size
};