/**
 * @file @todo where is config.get for alias?
 */
import { isObj } from 'exotic'
// import { OverridePlugin } from '@skava/composer'
import { resolveToRoot } from '../resolveToRoot'
import { alias } from '../aliasing'
import { Configuration, Options } from '../typings'

// These extensions are tried when resolving a file.
// const EXT = ['.js', '.jsx', '.json', '.scss', '.css']
const EXT = ['.js', '.jsx', '.json', '.ts', '.tsx', '.graphql']

/**
 * @todo https://www.npmjs.com/package/directory-named-webpack-plugin
 * @see https://webpack.js.org/configuration/resolve/#resolve-mainfiles can use for theming
 * @see https://github.com/lerna/lerna/issues/1049#issuecomment-335014011
 */
export default function resolveModules(
  config: Configuration,
  options: Options
) {
  const existingResolve = config.resolve

  // const plugin = new OverridePlugin().plugin
  // config.plugins.push(plugin)

  /**
   * https://webpack.js.org/guides/build-performance/#resolving
   */
  config.resolve = {
    extensions: EXT,
    // @todo @@configurable-env ['esnext',
    mainFields: ['main'],
    alias,
  }

  if (isObj(existingResolve) === true) {
    Object.assign(config.resolve)
  }

  /**
   * This allows you to set a fallback for where Webpack should look for modules.
   * We placed these paths second because we want `node_modules` to "win"
   * if there are any conflicts. This matches Node resolution mechanism.
   * https://github.com/facebookincubator/create-react-app/issues/253
   */
  if (!process.env.PNP) {
    config.resolve.modules = [].concat([
      // resolveToRoot('./modules'),
      // resolveToRoot('./packages'),
      './node_modules',
      // 'modules',
      // 'node_modules',
      // 'scripts',
      // 'config',
    ])
    console.log('use PNP=true to use pnp')
    return
  }

  if (process.env.PNP) {
    const PnpWebpackPlugin = require('./PnpWebpackPlugin')
    const plugins = [PnpWebpackPlugin]
    config.resolve.plugins = plugins
    config.resolveLoader = {
      plugins,
    }
  }
}