const path = require('path')

const TerserPlugin = require('terser-webpack-plugin')

module.exports = {
  publicPath: process.env.VUE_APP_PUBLIC_PATH,
  lintOnSave: process.env.NODE_ENV !== 'production',
  // 不输出为编译警告
  runtimeCompiler: true,
  productionSourceMap: false,
  devServer: {
    // proxy: 'http://test.cspg_api.ecspg.com/public/index.php/'
    // '/': {
    //   target: 'http://test.cspg_api.ecspg.com/public/index.php/',
    //   changeOrigin: true
    // }
  },
  configureWebpack: {
    resolve: {
      alias: {
        // 确保路径解析正确
        'html2canvas': 'html2canvas/dist/html2canvas.min.js'
      }
    }
  },
  chainWebpack: (config) => {
    // babel-polyfill 加入 entry
    const entry = config.entry('app')
    entry
      .add('babel-polyfill')
      .end()
    config.plugins.delete('preload') // TODO: need test
    config.plugins.delete('prefetch') // TODO: need test

    config.optimization.minimizer([
      new TerserPlugin({
        terserOptions: {
          compress: {
            // turn off flags with small gains to speed up minification
            arrows: false,
            collapse_vars: false, // 0.3kb
            comparisons: false,
            computed_props: false,
            hoist_funs: false,
            hoist_props: false,
            hoist_vars: false,
            inline: false,
            loops: false,
            negate_iife: false,
            properties: false,
            reduce_funcs: false,
            reduce_vars: false,
            switches: false,
            toplevel: false,
            typeofs: false,

            // a few flags with noticable gains/speed ratio
            // numbers based on out of the box vendor bundle
            booleans: true, // 0.7kb
            if_return: true, // 0.4kb
            sequences: true, // 0.7kb
            unused: true, // 2.3kb

            // required features to drop conditional branches
            conditionals: true,
            dead_code: true,
            evaluate: true,
            drop_console: true
          },
          mangle: {
            safari10: true
          }
        },
        sourceMap: false,
        cache: true,
        parallel: true
      })
    ])
  },
  css: {
    // 不生成cssMap文件，生成map文件方便调试
    sourceMap: false,
    loaderOptions: {
      less: {
        // @是src的别名
        data: '@import "@/styles/color.less";'
      }
    }
  },
  // 加载less全局变量 https://cli.vuejs.org/zh/guide/css.html#%E9%A2%84%E5%A4%84%E7%90%86%E5%99%A8
  // 第三方插件
  pluginOptions: {
    'style-resources-loader': {
      preProcessor: 'less',
      patterns: [path.resolve(__dirname, 'src/styles/color.less')]
    }
  }
}