import path from 'path'
import { interfaces } from 'mocha'

export default function loadUI(ui: string, cwd?: string) {
  // try to load built-in ui like 'bdd'
  if (typeof interfaces[ui] !== 'undefined') {
    return ui
  }

  let loadedUI = null
  try {
    // try to load reporter from node_modules
    loadedUI = require.resolve(ui)
  } catch (e) {
    // try to load reporter from cwd
    loadedUI = require.resolve(path.resolve(cwd, ui))
  }
  return loadedUI
}