'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 =
  process.env.NODE_ENV === 'testing'
    ? require('../config/test.env')
    : require('../config/prod.env')

// cdn 引入
let externalModules = {}
//cdn 配置
let externalConfig = []
if (process.env.NODE_ENV === 'production') {
  //生产环境
  externalModules = {
    vue: 'Vue',
    'vue-router': 'VueRouter',
    vuex: 'Vuex',
    axios: 'axios',
    'element-ui': 'element-ui',
    echarts: 'echarts',
    highlight: 'hljs',
  }
  externalConfig = [
    {js: 'https://cdn.jsdelivr.net/npm/vue@2.5.2/dist/vue.js', css: ''},
    {
      js: 'https://cdn.bootcdn.net/ajax/libs/vue-router/3.0.1/vue-router.min.js',
      css: '',
    },
    {js: 'https://unpkg.com/axios/dist/axios.min.js', css: ''},
    {js: 'https://cdn.bootcss.com/vuex/3.6.2/vuex.min.js', css: ''},
    {
      js: 'https://unpkg.com/element-ui/lib/index.js',
      css: 'https://unpkg.com/element-ui/lib/theme-chalk/index.css',
    },
    {
      js: 'https://cdn.jsdelivr.net/npm/echarts@5.3.3/dist/echarts.min.js',
      css: '',
    },
    {
      js: 'https://cdn.bootcdn.net/ajax/libs/highlight.js/11.6.0/highlight.min.js',
      css: '',
    },
    {
      js: '',
      css: 'https://cdn.bootcdn.net/ajax/libs/github-markdown-css/5.1.0/github-markdown-light.min.css',
    },
    {
      js: '',
      css: 'https://cdn.bootcdn.net/ajax/libs/nprogress/0.2.0/nprogress.css',
    },
  ]
}

const webpackConfig = merge(baseWebpackConfig, {
  externals: externalModules, //打包忽略
  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].[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:
        process.env.NODE_ENV === 'testing' ? 'index.html' : 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',
      cdnConfig: externalConfig, // cdn配置
      onlyCss: true, //dev下只加载css
    }),
    // 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 myblog_static assets
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../myblog_static'),
        to: config.build.assetsSubDirectory,
        ignore: ['.*'],
      },
    ]),
  ],
})

if (config.build.productionGzip) {
  const CompressionWebpackPlugin = require('compression-webpack-plugin')
  webpackConfig.plugins.push(
    new CompressionWebpackPlugin({
      filename: '[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())
}

if (config.build.isIgnoreLogs) {
  const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
  let optimization = [
    new UglifyJsPlugin({
      uglifyOptions: {
        compress: {
          warnings: false,
          drop_debugger: true, //去掉debugger
          drop_console: true, // 去掉console
          pure_funcs: ['console.log'], // 移除console
        },
      },
      sourceMap: config.build.productionSourceMap,
      parallel: true,
    }),
  ]
  webpackConfig.plugins.push(...optimization)
}

module.exports = webpackConfig