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 OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
  const UglifyJsPlugin = require('uglifyjs-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,
          publicPath: './',
          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,
          }),
          // 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: 'dependency'
          }),
          // 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