import {exec} from 'child_process'
import fs from 'fs-extra'

function filewalker (dir, done) {
  let results = []

  fs.readdir(dir, function (err, list) {
    if (err) return done(err)

    let pending = list.length

    if (!pending) return done(null, results)

    list.forEach(function (file) {
      file = path.resolve(dir, file)

      fs.stat(file, function (err, stat) {
        if (err) return done(err)

        // If directory, execute a recursive call
        if (stat && stat.isDirectory()) {
          filewalker(file, function (err, res) {
            if (err) return done(err)
            results = results.concat(res)
            if (!--pending) done(null, results)
          })
        } else {
          results.push(file)

          if (!--pending) done(null, results)
        }
      })
    })
  })
}

function getFiles (dir) {
  return new Promise((resolve, reject) => {
    filewalker(dir, (err, files) => {
      if (err) return reject(err)
      resolve(files)
    })
  })
}

function promiseExec (cmd, opts) {
  return new Promise((resolve, reject) => {
    exec(cmd, opts, function (err, stdout, stderr) {
      if (err) return reject(err)
      resolve({stdout, stderr})
    })
  })
}

function askAsync (rl, q) {
  return new Promise((resolve, reject) => {
    rl.question(q, resolve)
  })
}

let a = {getFiles, promiseExec, askAsync}

export default a