const path = require('path')
const resolve = dir => path.resolve(__dirname, dir)
const IS_PROD = ['production', 'prod'].includes(process.env.NODE_ENV)
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
const CompressionWebpackPlugin = require('compression-webpack-plugin');
const productionGzipExtensions = /\.(js|css|json|txt|html|ico|svg)(\?.*)?$/i;
 
module.exports = {
 transpileDependencies: ['webpack-dev-server/client'],
 
 // 基本路径
 // baseUrl: './',
 publicPath: './',
 // 输出文件目录
 outputDir: 'dist',
 // eslint-loader 是否在保存的时候检查
 lintOnSave: false,
 assetsDir: '', // 相对于outputDir的静态资源(js、css、img、fonts)目录
 // 生产环境是否生成 sourceMap 文件
 productionSourceMap: false,
 
 chainWebpack: config => {
  config.entry.app = ['babel-polyfill', './src/main.js'];
  // 修复HMR
  config.resolve.symlinks(true);
  //修复 Lazy loading routes Error
  config.plugin('html').tap(args => {
   args[0].chunksSortMode = 'none';
   return args;
  });
  // 添加别名
  config.resolve.alias
   .set('@', resolve('src'))
   .set('assets', resolve('src/assets'))
   .set('components', resolve('src/components'))
   .set('layout', resolve('src/layout'))
   .set('base', resolve('src/base'))
   .set('static', resolve('src/static'));
  //压缩图片
  config.module
   .rule("images")
   .use("image-webpack-loader")
   .loader("image-webpack-loader")
   .options({
    mozjpeg: {progressive: true, quality: 65},
    optipng: {enabled: false},
    pngquant: {quality: [0.65, 0.90], speed: 4},
    gifsicle: {interlaced: false},
   });
 
  // 打包分析
  if (process.env.IS_ANALYZ) {
   config.plugin('webpack-report')
    .use(BundleAnalyzerPlugin, [{
     analyzerMode: 'static',
    }]);
  }
 },
 
 configureWebpack: config => {
  if (IS_PROD) {
   const plugins = [];
   //开启 gzip 压缩
   plugins.push(
    new CompressionWebpackPlugin({
     filename: '[path].gz[query]',
     algorithm: 'gzip',
     test: productionGzipExtensions,
     threshold: 10240,
     minRatio: 0.8
    })
   );
 
   config.plugins = [
    ...config.plugins,
    ...plugins
   ];
  }
 },
 // css相关配置
 css: {
  extract: true,
  sourceMap: false,
  loaderOptions: {},
  modules: false
 
 },
 parallel: require('os').cpus().length > 1,
 pwa: {},
 devServer: {
  open: process.platform === 'darwin',
  host: '0.0.0.0',
  port: 8080,
  https: false,
  hotOnly: false,
  proxy: null, // 设置代理
  before: app => {
  }
 },
 
 // 第三方插件配置
 pluginOptions: {}
 
};