'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

const port = process.env.port || process.env.npm_config_port || 8081 // dev port

let externals = {}
let cdn = { css: [], js: [] }
const isProduction = process.env.NODE_ENV === 'production' // 判断是否是生产环境
if (isProduction) {
  externals = {
    vue: 'Vue',
    'element-ui': 'ELEMENT', // 必须是ELEMENT
    xlsx: 'XLSX'
  }
  cdn = {
    css: [
      'https://unpkg.com/element-ui/lib/theme-chalk/index.css' // element-ui css 样式表
    ],
    js: [
      // vue must at first!
      'https://unpkg.com/vue@2.6.12/dist/vue.js', // vuejs
      'https://unpkg.com/element-ui@2.15.3/lib/index.js', // element-ui js 变化
      'https://cdn.jsdelivr.net/npm/xlsx@0.16.6/dist/xlsx.full.min.js'
    ]
  }
}

module.exports = {
  publicPath: './', // 为了浏览获取静态资源方便
  outputDir: 'dist',
  assetsDir: 'static',
  lintOnSave: process.env.NODE_ENV === 'development',
  productionSourceMap: false,
  // 配置代理转发
  devServer: {
    port: port,
    open: true,
    overlay: {
      warnings: false,
      errors: true
    },
    // 代理跨域的配置
    proxy: {
      // 当请求有/api的时候，就会代理我们的请求地址向另外一个服务器发出请求
      '/api': {
        // 如 localhost:8081/api/login => http://ihrm-java.itheima.net//api/login
        target: 'http://ihrm-java.itheima.net/', // 跨域请求的地址
        changeOrigin: true // 只有这个值为true的情况下 才表示开启跨域
      }
    }
  },
  configureWebpack: {
    // 配置单页面应用程序页面的标题
    name: name,
    resolve: {
      alias: {
        '@': resolve('src')
      }
    },
    // 要排除的包名
    externals: {
      externals: externals
    }
  },
  chainWebpack(config) {
    // 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'
      }
    ])
    // 配置cdn
    // 注入cdn变量 (打包时会执行)
    config.plugin('html').tap((args) => {
      args[0].cdn = cdn // 配置cdn给插件
      return args
    })
    // 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')
    })
  }
}