const path = require('path')
const TerserPlugin = require('terser-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const PrerenderSPAPlugin = require('prerender-spa-plugin')
const Renderer = PrerenderSPAPlugin.PuppeteerRenderer
const CopyPlugin = require('copy-webpack-plugin')
const { InjectManifest } = require('workbox-webpack-plugin')
const { JSDOM } = require('jsdom')
const tempy = require('tempy')
const fs = require('fs')

const magicFile = (text) => {
  const p = tempy.file()
  fs.writeFileSync(p, text)
  return p
}

// const magicAppend = (orig, text, sep = '\n') => magicFile(fs.readFileSync(orig) + sep + text)

const jsMin = {
  pure_funcs: ["F2", "F3", "F4", "F5", "F6", "F7", "F8", "F9", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "A9"],
  pure_getters: true,
  keep_fargs: false,
  unsafe_comps: true,
  unsafe: true,
  compress: true,
  mangle: true,
}

module.exports =
  {
    module: {
      rules: [{
        test: /\.elm$/,
        exclude: [/elm-stuff/, /node_modules/],
        loader: 'elm-webpack-loader'
      }],
    },
    plugins: [
      new TerserPlugin({
        terserOptions: jsMin,
      }),
      new HtmlWebpackPlugin({
        hash: true,
        meta: {
          viewport: 'width=device-width, initial-scale=1, shrink-to-fit=no'
        }
      }),
      new CopyPlugin([{ from: 'data', to: 'data' }, { from: 'wand.js', to: 'wand.js' }]),
      new PrerenderSPAPlugin({
        staticDir: path.join(__dirname, 'dist'),
        routes: ROUTES,
        minify: {
          minifyCSS: {
            compatibility: 'ie9',
            level: 2
          },
          minifyJS: jsMin,
          removeComments: true,
          collapseBooleanAttributes: true,
          collapseWhitespace: true,
          collapseInlineTagWhitespace: true,
          removeRedundantAttributes: true,
          removeScriptTypeAttributes: true,
          removeStyleLinkTypeAttributes: true,
          sortAttributes: true,
          sortClassName: true,
        },
        renderer: new Renderer(),
        postProcess(renderedRoute) {
          const dom = new JSDOM(renderedRoute.html, { runScripts: 'outside-only' })
          dom.window.eval(`
            const wandTarget = document.createElement('script')
            wandTarget.src = '/wand.js'
            document.body.appendChild(wandTarget)
          `)
          return {
            ...renderedRoute,
            html: dom.serialize(),
          }
        },
      }),
      new InjectManifest({
        importWorkboxFrom: 'local',
        swSrc: magicFile(`
          workbox.routing.registerNavigationRoute('/index.html');
          workbox.precaching.precacheAndRoute(self.__precacheManifest);
        `),
        swDest: 'sw.js',
      }),
    ]
  }