import resolve from 'resolve'
import assert from 'assert'
import slash from 'slash'
import fs from 'fs'

import { compatESModuleRequire, flatDeep } from './tools'
import type { IResolvePlugins } from './types'

/**
 * @desc Get the execution function of the plug-in, add path as the unique key value
 * @param { string } path string
 */
export function pathToRegister(path: string) {
  assert(fs.existsSync(path), `${path} not exists, pathToRegister failed`)
  return {
    path: slash(path),
    apply() {
      return compatESModuleRequire(require(path))
    }
  }
}

/**
 * @desc Get all plugins
 * @param { object } options object
 */
export default function resolvePlugins(options: IResolvePlugins) {
  const plugins = flatDeep([...options.plugins].filter(Boolean)).map((path) =>
    resolve.sync(path, {
      basedir: options.cwd,
      extensions: ['.js', '.ts']
    })
  )

  return plugins.map(pathToRegister)
}