import { delimiter } from 'path'
import { isObj } from 'uxui-modules/exotic'
import { OverridePlugin } from '@skava/composer'
// ~/config/resolveToRoot
import { resolveToRoot } from '../../config/resolveToRoot'
import { alias } from '../../config/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']

process.env.NODE_PATH = resolveToRoot('node_modules')

/**
 * @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)

  config.resolve = {
    extensions: EXT,

    alias,

    /**
     * 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
     */
    // modules: ['node_modules', resolveToRoot('../packages')].concat(
    //   // It is guaranteed to exist because we tweak it in `env.js`
    //   process.env.NODE_PATH.split(delimiter).filter(Boolean)
    // ),

    modules: [
      resolveToRoot('../packages'),
      resolveToRoot('node_modules'),
      'node_modules',
    ],

    // @note changed with @monorepo
    // https://webpack.js.org/guides/build-performance/#resolving
    // symlinks: false,
    // symlinks: true,

    // cachePredicate: () => false,
    // unsafeCache: true,
  }

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