'use strict'
const path = require('path')
const defaultSettings = require('./src/settings.js')

function resolve (dir) {
  return path.join(__dirname, dir)
}

const name = defaultSettings.title || 'vue Admin Template' // page title

// If your port is set to 80,
// use administrator privileges to execute the command line.
// For example, Mac: sudo npm run
// You can change the port by the following methods:
// port = 9528 npm run dev OR npm run dev --port = 9528
const port = process.env.port || process.env.npm_config_port || 520 // dev port

let cdn = {
  css: [],
  js: []
}
let externals = {}

// 当当前环境是生产环境才用cdn
if (process.env.NODE_ENV == 'production') {
  externals = {
    // vue不打包
    vue: 'Vue',
    // elementui不打包
    'element-ui': 'ELEMENT',
    // xlsx这个插件不打包
    xlsx: 'XLSX'
  }

  // element-ui分为js和css，所以你要用cdn导入也得导入css和js
  cdn = {
    css: [
      // element-ui css
      'https://unpkg.com/element-ui/lib/theme-chalk/index.css' // 样式表
    ],
    js: [
      // vue must at first!
      'https://cdn.jsdelivr.net/npm/vue@2', // vuejs
      // element-ui js
      'https://unpkg.com/element-ui/lib/index.js', // elementUI
      'https://cdn.jsdelivr.net/npm/xlsx@0.16.6/dist/jszip.min.js',
      'https://cdn.jsdelivr.net/npm/xlsx@0.16.6/dist/xlsx.full.min.js'
    ]
  }
}

// All configuration item explanations can be find in https://cli.vuejs.org/config/
module.exports = {
  /**
   * You will need to set publicPath if you plan to deploy your site under a sub path,
   * for example GitHub Pages. If you plan to deploy your site to https://foo.github.io/bar/,
   * then publicPath should be set to "/bar/".
   * In most cases please use '/' !!!
   * Detail: https://cli.vuejs.org/config/#publicpath
   */
  publicPath: './',
  outputDir: 'dist',
  assetsDir: 'static',
  lintOnSave: process.env.NODE_ENV === 'development',
  productionSourceMap: false,
  devServer: {
    port: port,
    open: true,
    overlay: {
      warnings: false,
      errors: true
    },

    // 设置反向代理的功能
    proxy: {
      // 找到ajax请求中路径有/api标识的请求
      // 把域名替换成localhost:3000
      '/api': {
        target: 'http://localhost:3000',
        // 代表把真正请求的域名，替换成上面写的localhost:3000
        changeOrigin: true
        // 反向代理
        // pathRewrite: {
        //   // 把路径上的/xx替换为/api
        //   '^/xx': '/api'
        // }
      }
    }
  },
  configureWebpack: {
    // provide the app's title in webpack's name field, so that
    // it can be accessed in index.html to inject the correct title.
    name: name,
    resolve: {
      alias: {
        '@': resolve('src')
      }
    },
    // 排除那些插件不打包
    externals: externals
  },
  chainWebpack (config) {
    config.plugin('html').tap(args => {
      args[0].cdn = cdn
      return args
    }),
      // it can improve the speed of the first screen, it is recommended to turn on preload
      config.plugin('preload').tap(() => [
        {
          rel: 'preload',
          // to ignore runtime.js
          // https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/cli-service/lib/config/app.js#L171
          fileBlacklist: [/\.map$/, /hot-update\.js$/, /runtime\..*\.js$/],
          include: 'initial'
        }
      ])

    // when there are many pages, it will cause too many meaningless requests
    config.plugins.delete('prefetch')

    // set svg-sprite-loader
    config.module
      .rule('svg')
      .exclude.add(resolve('src/icons'))
      .end()
    config.module
      .rule('icons')
      .test(/\.svg$/)
      .include.add(resolve('src/icons'))
      .end()
      .use('svg-sprite-loader')
      .loader('svg-sprite-loader')
      .options({
        symbolId: 'icon-[name]'
      })
      .end()

    config.when(process.env.NODE_ENV !== 'development', config => {
      config
        .plugin('ScriptExtHtmlWebpackPlugin')
        .after('html')
        .use('script-ext-html-webpack-plugin', [
          {
            // `runtime` must same as runtimeChunk name. default is `runtime`
            inline: /runtime\..*\.js$/
          }
        ])
        .end()
      config.optimization.splitChunks({
        chunks: 'all',
        cacheGroups: {
          libs: {
            name: 'chunk-libs',
            test: /[\\/]node_modules[\\/]/,
            priority: 10,
            chunks: 'initial' // only package third parties that are initially dependent
          },
          elementUI: {
            name: 'chunk-elementUI', // split elementUI into a single package
            priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
            test: /[\\/]node_modules[\\/]_?element-ui(.*)/ // in order to adapt to cnpm
          },
          commons: {
            name: 'chunk-commons',
            test: resolve('src/components'), // can customize your rules
            minChunks: 3, //  minimum common number
            priority: 5,
            reuseExistingChunk: true
          }
        }
      })
      // https:// webpack.js.org/configuration/optimization/#optimizationruntimechunk
      config.optimization.runtimeChunk('single')
    })
  }
}