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

const mode = process.env.NODE_ENV || 'development'

module.exports = {
  optimization: {
    minimizer: [
      new TerserPlugin({
        cache: true,
        extractComments: true,
        parallel: true,
        sourceMap: true
      }),
      new OptimizeCSSAssetsPlugin({})
    ]
  },
  entry: [
    'core-js/fn/array/from',
    'core-js/fn/array/includes',
    './src/app.js'
  ],
  mode: mode,
  output: {
    filename: '[name].[contenthash].js',
    path: path.resolve(__dirname, 'dist')
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: 'src/index.html',
      minify: mode === 'production' ? {
        collapseWhitespace: true,
        removeComments: true,
        removeRedundantAttributes: true,
        removeScriptTypeAttributes: true,
        removeStyleLinkTypeAttributes: true,
        useShortDoctype: true
      } : false
    }),
    new MiniCssExtractPlugin({
      filename: '[name].[contenthash].css'
    })
  ],
  module: {
    rules: [
      {
        test: /\.html$/,
        loader: 'html-loader',
        options: {
          interpolate: true
        }
      },
      {
        test: /\.(scss)$/,
        use: [
          {
            loader: mode == 'production' ? MiniCssExtractPlugin.loader : 'style-loader'
          },
          {
            // Interprets `@import` and `url()` like `import/require()` and will resolve them
            loader: 'css-loader'
          },
          {
            // Loader for webpack to process CSS with PostCSS
            loader: 'postcss-loader',
            options: {
              plugins: function () {
                return [
                  require('autoprefixer')
                ]
              }
            }
          },
          {
            // Loads a SASS/SCSS file and compiles it to CSS
            loader: 'sass-loader'
          }
        ]
      }
    ]
  }
}