module.exports = function ip2long(argIP) {
  //  discuss at: https://locutus.io/php/ip2long/
  // original by: Waldo Malqui Silva (https://waldo.malqui.info)
  // improved by: Victor
  //  revised by: fearphage (https://my.opera.com/fearphage/)
  //  revised by: Theriault (https://github.com/Theriault)
  //    estarget: es2015
  //   example 1: ip2long('192.0.34.166')
  //   returns 1: 3221234342
  //   example 2: ip2long('0.0xABCDEF')
  //   returns 2: 11259375
  //   example 3: ip2long('255.255.255.256')
  //   returns 3: false

  let i = 0
  // PHP allows decimal, octal, and hexadecimal IP components.
  // PHP allows between 1 (e.g. 127) to 4 (e.g 127.0.0.1) components.

  const pattern = new RegExp(
    [
      '^([1-9]\\d*|0[0-7]*|0x[\\da-f]+)',
      '(?:\\.([1-9]\\d*|0[0-7]*|0x[\\da-f]+))?',
      '(?:\\.([1-9]\\d*|0[0-7]*|0x[\\da-f]+))?',
      '(?:\\.([1-9]\\d*|0[0-7]*|0x[\\da-f]+))?$',
    ].join(''),
    'i',
  )

  argIP = argIP.match(pattern) // Verify argIP format.
  if (!argIP) {
    // Invalid format.
    return false
  }
  // Reuse argIP variable for component counter.
  argIP[0] = 0
  for (i = 1; i < 5; i += 1) {
    argIP[0] += !!(argIP[i] || '').length
    argIP[i] = parseInt(argIP[i]) || 0
  }
  // Continue to use argIP for overflow values.
  // PHP does not allow any component to overflow.
  argIP.push(256, 256, 256, 256)
  // Recalculate overflow of last component supplied to make up for missing components.
  argIP[4 + argIP[0]] *= Math.pow(256, 4 - argIP[0])
  if (argIP[1] >= argIP[5] || argIP[2] >= argIP[6] || argIP[3] >= argIP[7] || argIP[4] >= argIP[8]) {
    return false
  }

  return (
    argIP[1] * (argIP[0] === 1 || 16777216) +
    argIP[2] * (argIP[0] <= 2 || 65536) +
    argIP[3] * (argIP[0] <= 3 || 256) +
    argIP[4] * 1
  )
}