text: '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 ExtractTextPlugin = require('extract-text-webpack-plugin')
  const MiniCssExtractPlugin = require('mini-css-extract-plugin')
  const OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
  const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
  
  const env = config.build.env
  
  const webpackConfig = merge(baseWebpackConfig, {
      mode: 'production',
      module: {
          rules: utils.styleLoaders({
              sourceMap: config.build.productionSourceMap,
              extract: false,
              usePostCSS: true
          })
      },
      optimization: {
          splitChunks: {
              cacheGroups: {
                  common: {
                      name: 'common',
                      chunks: 'all',
                      test: /vue/
                  },
                  vendors: {
                      test: /[\\/]node_modules[\\/]/,
                      chunks: 'initial',
                      name: 'vendors',
                  },
                  'async-vendors': {
                      test: /[\\/]node_modules[\\/]/,
                      minChunks: 2,
                      chunks: 'async',
                      name: 'async-vendors'
                  }
              }
          },
          runtimeChunk: { name: 'runtime' }
      },
      devtool: config.build.productionSourceMap ? config.build.devtool : false,
      output: {
          publicPath: './',
          path: config.build.assetsRoot,
          filename: utils.assetsPath('js/[name].[chunkhash].js'),
          chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
      },
      plugins: [
          // http://vuejs.github.io/vue-loader/en/workflow/production.html
          new webpack.DefinePlugin({
              'process.env': env
          }),
          // new UglifyJsPlugin({
          //     uglifyOptions: {
          //         compress: {
          //             warnings: false
          //         }
          //     },
          //     sourceMap: config.build.productionSourceMap,
          //     parallel: true
          // }),
          // extract css into its own file
          // new ExtractTextPlugin({
          //     filename: utils.assetsPath('css/[name].[contenthash].css'),
          //     // Setting the following option to `false` will not extract CSS from codesplit chunks.
          //     // Their CSS will instead be inserted dynamically with style-loader when the codesplit chunk has been loaded by webpack.
          //     // It's currently set to `true` because we are seeing that sourcemaps are included in the codesplit bundle as well when it's `false`, 
          //     // increasing file size: https://github.com/vuejs-templates/webpack/issues/1110
          //     allChunks: true,
          // }),
          new MiniCssExtractPlugin({
              filename: utils.assetsPath('css/[name].[contenthash].css'),
              allChunks: true,
            }),
          // Compress extracted CSS. We are using this plugin so that possible
          // duplicated CSS from different components can be deduped.
          new OptimizeCSSPlugin({
              cssProcessorOptions: config.build.productionSourceMap
                  ? { safe: true, map: { inline: false } }
                  : { safe: true }
          }),
          // 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
              },
              // necessary to consistently work with multiple chunks via CommonsChunkPlugin
              chunksSortMode: 'none'
          }),
          // keep module.id stable when vendor modules does not change
          new webpack.HashedModuleIdsPlugin(),
          // enable scope hoisting
          // new webpack.optimize.ModuleConcatenationPlugin(),
          // split vendor js into its own file
          // new webpack.optimize.CommonsChunkPlugin({
          //     name: 'vendor',
          //     minChunks(module) {
          //         // any required modules inside node_modules are extracted to vendor
          //         return (
          //             module.resource &&
          //             /\.js$/.test(module.resource) &&
          //             module.resource.indexOf(
          //                 path.join(__dirname, '../node_modules')
          //             ) === 0
          //         )
          //     }
          // }),
          // extract webpack runtime and module manifest to its own file in order to
          // prevent vendor hash from being updated whenever app bundle is updated
          // new webpack.optimize.CommonsChunkPlugin({
          //     name: 'manifest',
          //     minChunks: Infinity
          // }),
          // This instance extracts shared chunks from code splitted chunks and bundles them
          // in a separate chunk, similar to the vendor chunk
          // see: https://webpack.js.org/plugins/commons-chunk-plugin/#extra-async-commons-chunk
          // new webpack.optimize.CommonsChunkPlugin({
          //     name: 'app',
          //     async: 'vendor-async',
          //     children: true,
          //     minChunks: 3
          // }),
  
          // copy custom static assets
          new CopyWebpackPlugin([
              {
                  from: path.resolve(__dirname, '../static'),
                  to: config.build.assetsSubDirectory,
                  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
  