'use strict'
const path = require('path')
require("babel-polyfill");
const productionGzipExtensions = ['js', 'css'];
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const CompressionWebpackPlugin = require('compression-webpack-plugin');
const isProduction = process.env.NODE_ENV === 'production';
const myTheme = path.resolve(__dirname, "src/assets/css/var.less");
function resolve(dir) {
  return path.join(__dirname, dir)
}


// 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 method:
// port = 8080 npm run dev OR npm run dev --port = 8080
const port = process.env.port || process.env.npm_config_port || 8080 // dev port

// 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: false,//process.env.NODE_ENV === 'development'
  productionSourceMap: false,
  devServer: {
    port: port,
    open: true,
    overlay: {
      warnings: false,
      errors: true
    },
  },
  css: {
    loaderOptions: {
      less: {
        modifyVars: {
          hack: `true; @import "${myTheme}";`
        }
      },
    }
  },
  configureWebpack: config => {
    // 入口文件
    config.entry.app = ["babel-polyfill", "./src/main.js"];
    config.externals = {
        'vue': 'Vue',
        axios: "axios",
        'vue-router': 'VueRouter'
    };
    if (isProduction) {
        config.plugins.push(new CompressionWebpackPlugin({
            algorithm: 'gzip',
            test: new RegExp('\\.(' + productionGzipExtensions.join('|') + ')$'),
            threshold: 10240,
            // deleteOriginalAssets:true, //删除源文件，不建议
            minRatio: 0.7
        }))
    }
    // 删除console插件
    let plugins = [
        new UglifyJsPlugin({
            uglifyOptions: {
                compress: {
                    // warnings: false, // `warnings` is not a supported option
                    drop_console: true,
                    drop_debugger: true
                },
                output: {
                    // 去掉注释内容
                    comments: true
                }
            },
            cache: true, //启用/禁用文件缓存（类型可布尔也可是字符串）
            sourceMap: false,
            parallel: true
        })
    ];
    // 只有打包生产环境才需要将console删除
    if (isProduction) {
        config.plugins = [...config.plugins, ...plugins];
    }
},

  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/icons'))
      .end()
    config.module
      .rule('icons')
      .test(/\.svg$/)
      .include.add(resolve('src/icons'))
      .end()
      .use('svg-sprite-loader')
      .loader('svg-sprite-loader')
      .options({
        symbolId: 'icon-[name]'
      })
      .end()
//process.env.NODE_ENV !== 'development'
    config
      .when(true,
        config => {
          config
            .plugin('ScriptExtHtmlWebpackPlugin')
            .after('html')
            .use('script-ext-html-webpack-plugin', [{
              // `runtime` must same as runtimeChunk name. default is `runtime`
              inline: /runtime\..*\.js$/
            }])
            .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')
        }
      )
  }
}