const path = require('path')

const name = process.env['VUE_APP_TITLE ']

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

module.exports = {
  publicPath: '/',
  lintOnSave: process.env.NODE_ENV === 'development',
  productionSourceMap: false,
  devServer: {
    disableHostCheck: true,
    open: true,
    port: 8888,
    // 开发环境默认开启反向代理，如果不需要请自行注释
    proxy: {
      '/tduck-api': {
        target: 'http://localhost:8999',
        changeOrigin: true
      }
    }
  },
  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')
      }
    }
  },
  chainWebpack(config) {
    // it can improve the speed of the first screen, it is recommended to turn on preload
    // 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/assets/icons'))
      .end()
    config.module
      .rule('icons')
      .test(/\.svg$/)
      .include.add(resolve('src/assets/icons'))
      .end()
      .use('svg-sprite-loader')
      .loader('svg-sprite-loader')
      .options({
        symbolId: 'icon-[name]'
      })
      .end()
    config.plugin('html')
      .tap(args => {
        args[0].title = process.env.VUE_APP_TITLE
        args[0].debugTool = process.env.VUE_APP_DEBUG_TOOL
        return args
      })
      .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')
        }
      )
  }
}