import {
  HotModuleReplacementPlugin,
  WatchIgnorePlugin,
  NamedModulesPlugin,
} from 'webpack'
import { resolveToRoot } from '../../resolveToRoot'
import { Configuration, Options } from '../../typings'

const IS_WEBPACK4 = true
const IS_BABEL_CACHE_ENABLED = false
const IGNORE_SOME = process.env.BABEL_CACHE || IS_BABEL_CACHE_ENABLED

/**
 * @see https://github.com/webpack/webpack/issues/1151#issuecomment-138809417
 * @see https://github.com/insin/nwb/blob/master/docs/Configuration.md#webpack-configuration
 * @see http://stackoverflow.com/questions/32296967/webpack-dev-server-doesnt-generate-source-maps
 * @see https://webpack.github.io/docs/configuration.html#devtool
 * @see https://github.com/gaearon/react-hot-loader/blob/master/docs/Troubleshooting.md
 * @see https://github.com/glenjamin/ultimate-hot-reloading-example
 * @see https://hackernoon.com/hot-reload-all-the-things-ec0fed8ab0
 * @see https://medium.com/@rajaraodv/webpacks-hmr-react-hot-loader-the-missing-manual-232336dc0d96
 */
export default function hmr(config: Configuration, options: Options) {
  const { isDev, isServer } = options

  if (isServer) {
    // ignoring HMR on server
    return
  }

  if (isDev) {
    // webpack v4 - https://github.com/webpack/webpack/issues/6357
    config.plugins.push(new NamedModulesPlugin())

    /**
     *  @see https://github.com/gaearon/react-hot-loader/blob/master/docs/Troubleshooting.md#uncaught-rangeerror-maximum-call-stack-size-exceeded !!!!!!
     * @todo https://webpack.js.org/configuration/output/#output-hotupdatefunction
     */
    const hotModuleReplacementConfig = {
      /**
       * @see https://github.com/webpack/webpack/issues/2985
       * @see https://github.com/webpack/webpack/issues/6693
       */
      multiStep: true,
      requestTimeout: 1000000,
    }

    if (process.env.IS_HMR_ENABLED) {
      const plugin = new HotModuleReplacementPlugin(hotModuleReplacementConfig)
      config.plugins.unshift(plugin)
    }

    // @NOTE !!!!!!!!!!!!! ignoring these makes it take 1/2 the time to HMR
    const ignorePaths = [
      './modules/',
      './node_modules',
      './views/structured',
      './config',
      './scripts',
      // @todo needs more ignoring...
      './client/workers',
    ].map(resolveToRoot)

    // THIS BREAKS WHAT "HOT" does...
    if (IGNORE_SOME) {
      const ignore = new WatchIgnorePlugin(ignorePaths)
      config.plugins.push(ignore)
    }
  }
}