const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CssnanoPlugin = require('cssnano-webpack-plugin');
const EsLintPlugin = require('eslint-webpack-plugin');
const StylelintPlugin = require('stylelint-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = (env) => ({
  mode: env.production ? 'production' : 'development',
  target: 'web',
  entry: './src/js/index.js',
  output: {
    filename: env.production ? '[name].[contenthash].bundle.js' : '[name].bundle.js',
    path: path.resolve(__dirname, 'dist'),
  },
  devtool: env.production ? 'cheap-source-map' : 'inline-source-map',
  devServer: {
    contentBase: './dist',
    hot: true,
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: env.production ? '[name].[contenthash].css' : '[name].css',
    }),
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      template: './src/templates/index.ejs',
    }),
    new EsLintPlugin(),
    new StylelintPlugin(),
  ],
  module: {
    rules: [
      {
        test: /\.ejs$/,
        use: {
          loader: 'ejs-compiled-loader',
          options: {}, // supply empty options object because of https://github.com/bazilio91/ejs-compiled-loader/issues/46
        },
      },
      {
        test: /\.js?/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env'],
          },
        },
      },
      {
        test: /\.inline\.css$/i,
        include: path.resolve(__dirname, 'src/css'),
        use: [
          {
            loader: 'style-loader',
            options: {
              insert: function insertAtTop(element) {
                const parent = document.querySelector('head');
                // eslint-disable-next-line no-underscore-dangle
                const lastInsertedElement = window._lastElementInsertedByStyleLoader;

                if (!lastInsertedElement) {
                  parent.insertBefore(element, parent.firstChild);
                } else if (lastInsertedElement.nextSibling) {
                  parent.insertBefore(element, lastInsertedElement.nextSibling);
                } else {
                  parent.appendChild(element);
                }

                // eslint-disable-next-line no-underscore-dangle
                window._lastElementInsertedByStyleLoader = element;
              },
            },
          },
          'css-loader',
          'postcss-loader'],
      },
      {
        test: /\.css$/i,
        include: path.resolve(__dirname, 'src/css'),
        exclude: /\.inline\.css$/i,
        use: [MiniCssExtractPlugin.loader, 'css-loader', 'postcss-loader'],
      },
      {
        test: /.(png|svg|jpg|jpeg|gif)$/i,
        include: path.resolve(__dirname, 'src'),
        type: 'asset',
      },
    ],
  },
  optimization: {
    minimizer: [
      new CssnanoPlugin({
        sourceMap: true,
      }),
      '...', // access defaults (defaults are overridden when specifying minimizer: array)
    ],
  },
});