'use strict'
const fs = require('fs')
const path = require('path')

/* istanbul ignore next */
const LCHOWN = fs.lchown ? 'lchown' : 'chown'
/* istanbul ignore next */
const LCHOWNSYNC = fs.lchownSync ? 'lchownSync' : 'chownSync'

const needEISDIRHandled = fs.lchown &&
  !process.version.match(/v1[1-9]+\./) &&
  !process.version.match(/v10\.[6-9]/)

/* istanbul ignore next */
const handleEISDIR =
  needEISDIRHandled ? (path, uid, gid, cb) => er => {
    // Node prior to v10 had a very questionable implementation of
    // fs.lchown, which would always try to call fs.open on a directory
    // Fall back to fs.chown in those cases.
    if (!er || er.code !== 'EISDIR')
      cb(er)
    else
      fs.chown(path, uid, gid, cb)
  }
  : (_, __, ___, cb) => cb

/* istanbul ignore next */
const handleEISDirSync =
  needEISDIRHandled ? (path, uid, gid) => {
    try {
      return fs[LCHOWNSYNC](path, uid, gid)
    } catch (er) {
      if (er.code !== 'EISDIR')
        throw er
      fs.chownSync(path, uid, gid)
    }
  }
  : (path, uid, gid) => fs[LCHOWNSYNC](path, uid, gid)

// fs.readdir could only accept an options object as of node v6
const nodeVersion = process.version
let readdir = (path, options, cb) => fs.readdir(path, options, cb)
let readdirSync = (path, options) => fs.readdirSync(path, options)
/* istanbul ignore next */
if (/^v4\./.test(nodeVersion))
  readdir = (path, options, cb) => fs.readdir(path, cb)

const chownrKid = (p, child, uid, gid, cb) => {
  if (typeof child === 'string')
    return fs.lstat(path.resolve(p, child), (er, stats) => {
      if (er)
        return cb(er)
      stats.name = child
      chownrKid(p, stats, uid, gid, cb)
    })

  if (child.isDirectory()) {
    chownr(path.resolve(p, child.name), uid, gid, er => {
      if (er)
        return cb(er)
      const cpath = path.resolve(p, child.name)
      fs[LCHOWN](cpath, uid, gid, handleEISDIR(cpath, uid, gid, cb))
    })
  } else {
    const cpath = path.resolve(p, child.name)
    fs[LCHOWN](cpath, uid, gid, handleEISDIR(cpath, uid, gid, cb))
  }
}


const chownr = (p, uid, gid, cb) => {
  readdir(p, { withFileTypes: true }, (er, children) => {
    // any error other than ENOTDIR or ENOTSUP means it's not readable,
    // or doesn't exist.  give up.
    if (er && er.code !== 'ENOTDIR' && er.code !== 'ENOTSUP')
      return cb(er)
    if (er || !children.length)
      return fs[LCHOWN](p, uid, gid, handleEISDIR(p, uid, gid, cb))

    let len = children.length
    let errState = null
    const then = er => {
      if (errState)
        return
      if (er)
        return cb(errState = er)
      if (-- len === 0)
        return fs[LCHOWN](p, uid, gid, handleEISDIR(p, uid, gid, cb))
    }

    children.forEach(child => chownrKid(p, child, uid, gid, then))
  })
}

const chownrKidSync = (p, child, uid, gid) => {
  if (typeof child === 'string') {
    const stats = fs.lstatSync(path.resolve(p, child))
    stats.name = child
    child = stats
  }

  if (child.isDirectory())
    chownrSync(path.resolve(p, child.name), uid, gid)

  handleEISDirSync(path.resolve(p, child.name), uid, gid)
}

const chownrSync = (p, uid, gid) => {
  let children
  try {
    children = readdirSync(p, { withFileTypes: true })
  } catch (er) {
    if (er && er.code === 'ENOTDIR' && er.code !== 'ENOTSUP')
      return handleEISDirSync(p, uid, gid)
    throw er
  }

  if (children.length)
    children.forEach(child => chownrKidSync(p, child, uid, gid))

  return handleEISDirSync(p, uid, gid)
}

module.exports = chownr
chownr.sync = chownrSync