var
  path = require('path'),
  config = require('../config'),
  cssUtils = require('./css-utils'),
  webpack = require('webpack'),
  merge = require('webpack-merge'),
  baseWebpackConfig = require('./webpack.base.conf'),
  ExtractTextPlugin = require('extract-text-webpack-plugin'),
  HtmlWebpackPlugin = require('html-webpack-plugin')

var webpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: cssUtils.styleRules({
      sourceMap: config.build.productionSourceMap,
      extract: true,
      postcss: true
    })
  },
  devtool: config.build.productionSourceMap ? '#source-map' : false,
  plugins: [
    new webpack.optimize.UglifyJsPlugin({
      sourceMap: config.build.productionSourceMap,
      minimize: true,
      compress: {
        warnings: false
      }
    }),
    // extract css into its own file
    new ExtractTextPlugin({
      filename: '[name].[contenthash].css'
    }),
    new HtmlWebpackPlugin({
      filename: config.build.index,
      template: 'src/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'
    }),
    // split vendor js into its own file
    new webpack.optimize.CommonsChunkPlugin({
      name: 'vendor',
      minChunks: function (module, count) {
        // 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',
      chunks: ['vendor']
    })
  ]
})

if (config.build.productionGzip) {
  var 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
    })
  )
}

module.exports = webpackConfig
