/*eslint-disable*/
const BundleAnalyzerPlugin = require("webpack-bundle-analyzer")
  .BundleAnalyzerPlugin
const autoprefixer = require("autoprefixer")
const cssmixins = require("postcss-mixins")
const cssvars = require("postcss-simple-vars")
const webpack = require("webpack")

const TerserPlugin = require("terser-webpack-plugin")
const HtmlWebpackPlugin = require("html-webpack-plugin")
const ExtractTextPlugin = require("extract-text-webpack-plugin")
const ManifestPlugin = require("webpack-manifest-plugin")
const MiniCssExtractPlugin = require("mini-css-extract-plugin")
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin")

const url = require("url")
const paths = require("./paths")
const getClientEnvironment = require("./env")

const cssvariables = require(`${paths.appSrc}/theme/variables`)

const postcssPlugins = [
  autoprefixer({
    overrideBrowserslist: [
      ">1%",
      "last 4 versions",
      "Firefox ESR",
      "not ie < 9" // React doesn't support IE8 anyway
    ]
  }),
  cssmixins,
  cssvars({
    variables() {
      return Object.assign({}, cssvariables)
    },
    silent: true
  })
]

function ensureSlash(path, needsSlash) {
  const hasSlash = path.endsWith("/")
  if (hasSlash && !needsSlash) {
    return path.substr(path, path.length - 1)
  } else if (!hasSlash && needsSlash) {
    return `${path}/`
  }
  return path
}

// We use "homepage" field to infer "public path" at which the app is served.
// Webpack needs to know it to put the right <script> hrefs into HTML even in
// single-page apps that may serve index.html for nested URLs like /todos/42.
// We can't use a relative path in HTML because we don't want to load something
// like /todos/42/static/js/bundle.7289d.js. We have to know the root.
const homepagePath = require(paths.appPackageJson).homepage
//  var homepagePathname = homepagePath ? url.parse(homepagePath).pathname : '/';
const homepagePathname = "/"
// Webpack uses `publicPath` to determine where the app is being served from.
// It requires a trailing slash, or the file assets will get an incorrect path.
const publicPath = ensureSlash(homepagePathname, true)
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
const publicUrl = ensureSlash(homepagePathname, false)
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl)

// Assert this just to be safe.
// Development builds of React are slow and not intended for production.
if (env["process.env"].NODE_ENV !== '"production"') {
  throw new Error("Production builds must have NODE_ENV=production.")
}

// This is the production configuration.
// It compiles slowly and is focused on producing a fast and minimal bundle.
// The development configuration is different and lives in a separate file.
module.exports = {
  mode: "production",
  // Don't attempt to continue if there are any errors.
  bail: true,
  optimization: {
    splitChunks: {
      chunks: "all"
      /* https://stackoverflow.com/questions/48985780/webpack-4-create-vendor-chunk
      cacheGroups: {
        vendor: {
          test: /node_modules/,
          name: 'vendor',
          chunks: 'all',
          enforce: true,
          minSize: 1,
        },
      },
      */
    },
    minimize: true,
    minimizer: [
      new TerserPlugin({
        terserOptions: {
          parse: {
            ecma: 8
          },
          compress: {
            ecma: 5,
            warnings: false,
            comparisons: false,
            inline: 2,
          },
          mangle: {
            safari10: true
          },
          output: {
            ecma: 5,
            comments: false,
            ascii_only: true
          }
        }
      }),
      new OptimizeCSSAssetsPlugin({})
    ]
  },
  entry: [require.resolve("./polyfills"), paths.appIndexJs],
  output: {
    // The build folder.
    path: paths.appBuild,
    // Generated JS file names (with nested folders).
    // There will be one main bundle, and one file per asynchronous chunk.
    // We don't currently advertise code splitting but Webpack supports it.
    filename: "static/js/[name].[chunkhash:8].js",
    chunkFilename: "static/js/[name].[chunkhash:8].chunk.js",
    // We inferred the "public path" (such as / or /my-project) from homepage.
    publicPath
  },
  resolve: {
    modules: [paths.appSrc, "node_modules", paths.appContracts],
    // These are the reasonable defaults supported by the Node ecosystem.
    // We also include JSX as a common component filename extension to support
    // some tools, although we do not recommend using it, see:
    // https://github.com/facebookincubator/create-react-app/issues/290
    extensions: [".js", ".json", ".jsx"],
    alias: {
      "~": paths.appSrc,
      "#": paths.appContracts
    }
  },

  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        include: paths.appSrc,
        use: {
          loader: "babel-loader"
        }
      },
      {
        test: /\.(scss|css)$/,
        use: [
          MiniCssExtractPlugin.loader,
          {
            loader: "css-loader",
            options: {
              importLoaders: 1,
              modules: true
            }
          },
          {
            loader: "postcss-loader",
            options: {
              sourceMap: true,
              plugins: postcssPlugins
            }
          }
        ]
      },
      { test: /\.(woff|woff2)$/, loader: "url-loader?limit=100000" },
      {
        test: /\.(jpe?g|png|svg)$/i,
        exclude: /node_modules/,
        use: [
          {
            loader: "file-loader",
            options: {
              name: "img/[hash].[ext]",
              esModule: false
            }
          }
        ]
      }
    ]
  },
  plugins: [
    // Generates an `index.html` file with the <script> injected.
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
      minify: {
        removeComments: true,
        collapseWhitespace: true,
        removeRedundantAttributes: true,
        useShortDoctype: true,
        removeEmptyAttributes: true,
        removeStyleLinkTypeAttributes: true,
        keepClosingSlash: true,
        minifyJS: true,
        minifyCSS: true,
        minifyURLs: true
      }
    }),
    // Makes some environment variables available to the JS code, for example:
    // if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
    // It is absolutely essential that NODE_ENV was set to production here.
    // Otherwise React will be compiled in the very slow development mode.
    new webpack.DefinePlugin(env),
    new MiniCssExtractPlugin({
      filename: "static/css/[name].[hash:8].css",
      allChunks: "static/css/[id].[hash:8].css"
    }),
    // Generate a manifest file which contains a mapping of all asset filenames
    // to their corresponding output file so that tools can pick it up without
    // having to parse `index.html`.
    new ManifestPlugin({
      fileName: "asset-manifest.json"
    })
    // new BundleAnalyzerPlugin()
  ],
  // Some libraries import Node modules but don't use them in the browser.
  // Tell Webpack to provide empty mocks for them so importing them works.
  node: {
    fs: "empty",
    net: "empty",
    tls: "empty"
  }
}