'use strict'
const path = require('path')
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const { merge } = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin')
const TerserPlugin = require('terser-webpack-plugin')

const env = require('../config/prod.env')

const webpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.build.productionSourceMap, extract: true, usePostCSS: true })
  },
  devtool: config.build.productionSourceMap ? config.build.devtool : false,
  output: {
    path: config.build.assetsRoot,
    filename: utils.assetsPath('js/[name].[contenthash].js'),
    chunkFilename: utils.assetsPath('js/[id].[contenthash].js')
  },
  optimization: {
    minimize: true,
    minimizer: [
      new TerserPlugin({
          terserOptions: {
            compress: {
              warnings: false
            }
          },
          parallel: true
        }),
      new CssMinimizerPlugin({
        minimizerOptions: {
          preset: [
            'default',
            {
              discardComments: { removeAll: true },
            },
          ],
        },
      })
    ],
    splitChunks: {
      chunks: 'all',
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name: 'vendor',
          chunks: 'all'
        }
      }
    },
    runtimeChunk: 'single'
  },
  plugins: [
    // http://vuejs.github.io/vue-loader/en/workflow/production.html
    new webpack.DefinePlugin({
      'process.env': env
    }),
    // extract css into its own file
    new MiniCssExtractPlugin({
      filename: utils.assetsPath('css/[name].[contenthash].css'),
      chunkFilename: utils.assetsPath('css/[id].[contenthash].css')
    }),
    // generate dist index.html with correct asset hash for caching.
    // you can customize output by editing /index.html
    // see https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: config.build.index,
      template: 'index.html',
      inject: true,
      minify: {
        removeComments: true,
        collapseWhitespace: true,
        removeAttributeQuotes: true
        // more options:
        // https://github.com/kangax/html-minifier#options-quick-reference
      },
      chunksSortMode: 'auto'
    }),
    // keep module.id stable when vendor modules does not change
    new webpack.ids.HashedModuleIdsPlugin(),

    // copy custom static assets
      new CopyWebpackPlugin({
        patterns: [
          {
            from: path.resolve(__dirname, '../static'),
            to: config.build.assetsSubDirectory,
            globOptions: {
              ignore: ['**/.*']
            }
          }
        ]
      })
  ]
})

if (config.build.productionGzip) {
  const CompressionWebpackPlugin = require('compression-webpack-plugin')

  webpackConfig.plugins.push(
    new CompressionWebpackPlugin({
      asset: '[path].gz[query]',
      algorithm: 'gzip',
      test: new RegExp(
        '\\.(' +
        config.build.productionGzipExtensions.join('|') +
        ')$'
      ),
      threshold: 10240,
      minRatio: 0.8
    })
  )
}

if (config.build.bundleAnalyzerReport) {
  const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
  webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}

module.exports = webpackConfig