import fs from 'fs'
import { join } from 'path'
import { promisify } from 'util'

const readdir = promisify(fs.readdir)
const stat = promisify(fs.stat)
const rmdir = promisify(fs.rmdir)
const unlink = promisify(fs.unlink)
const sleep = promisify(setTimeout)

const unlinkFile = async (p: string, t = 1): Promise<void> => {
  try {
    await unlink(p)
  } catch (e) {
    if ((e.code === 'EBUSY' || e.code === 'ENOTEMPTY' || e.code === 'EPERM' || e.code === 'EMFILE') && t < 3) {
      await sleep(t * 100)
      return unlinkFile(p, t++)
    }

    if (e.code === 'ENOENT') {
      return
    }

    throw e
  }
}

/**
 * Recursively delete directory contents
 * @param  {string} dir Directory to delete the contents of
 * @param  {RegExp} filter Filter for the file name, only the name part is considered, not the full path
 * @param  {boolean} ensure Esures that parameter dir exists, this is not passed recursively
 * @returns Promise void
 */
export async function recursiveDelete(dir: string, filter?: RegExp, ensure?: boolean): Promise<void> {
  let result
  try {
    result = await readdir(dir)
  } catch (e) {
    if (e.code === 'ENOENT' && !ensure) return

    throw e
  }

  await Promise.all(result.map(async (part: string) => {
    const absolutePath = join(dir, part)
    const pathStat = await stat(absolutePath).catch((e) => {
      if (e.code !== 'ENOENT') throw e
    })
    if (!pathStat) return

    if (pathStat.isDirectory()) {
      await recursiveDelete(absolutePath, filter)
      return rmdir(absolutePath)
    }

    if (!filter || filter.test(part)) {
      return unlinkFile(absolutePath)
    }
  }))
}