const webpack = require('webpack');
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
const CompressionPlugin = require("compression-webpack-plugin");
const TerserPlugin = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const cssnano = require("cssnano");

const {
  projectRoot
} = require('./helpers');

module.exports = {
  mode: 'production',
  recordsOutputPath: projectRoot('webpack.records.json'),
  plugins: [
    new webpack.EnvironmentPlugin({
      'process.env': {
        'NODE_ENV': JSON.stringify('production'),
        'AOT': true
      }
    }),

    new BundleAnalyzerPlugin({
      analyzerMode: 'disabled', // change it to `server` to view bundle stats
      reportFilename: 'report.html',
      generateStatsFile: true,
      statsFilename: 'stats.json',
    }),


    new CompressionPlugin({
      filename: "[path].gz[query]",
      algorithm: "gzip",
      test: /\.js$|\.css$|\.html$/,
      threshold: 10240,
      minRatio: 0.8
    })

  ],
  optimization: {
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          beautify: false,
          mangle: false,
          output: {
            comments: false
          },
          compress: {
            conditionals: false,
            unused: true,
            comparisons: true,
            sequences: true,
            dead_code: true,
            evaluate: true,
            if_return: true,
            join_vars: true,
            negate_iife: true
          },
          sourceMap: true,
          warnings: false
        }
      }),
      new OptimizeCSSAssetsPlugin({
        cssProcessor: cssnano,
        cssProcessorOptions: {
          discardComments: {
            removeAll: true,
          }
        },
        safe: true
      })
    ]
  },
};