export function validv4(ipaddress: string): boolean {
  if (
    /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(
      ipaddress,
    )
  ) {
    return true;
  }
  return false;
}

export function validv6(value: string): boolean {
  // See https://blogs.msdn.microsoft.com/oldnewthing/20060522-08/?p=31113 and
  // https://4sysops.com/archives/ipv6-tutorial-part-4-ipv6-address-syntax/
  const components = value.split(':');
  if (components.length < 2 || components.length > 8) {
    return false;
  }

  if (components[0] !== '' || components[1] !== '') {
    // Address does not begin with a zero compression ("::")
    if (!components[0].match(/^[\da-f]{1,4}/i)) {
      // Component must contain 1-4 hex characters
      return false;
    }
  }

  let numberOfZeroCompressions = 0;
  for (let i = 1; i < components.length; ++i) {
    if (components[i] === '') {
      // We're inside a zero compression ("::")
      ++numberOfZeroCompressions;
      if (numberOfZeroCompressions > 1) {
        // Zero compression can only occur once in an address
        return false;
      }
      continue;
    }
    if (!components[i].match(/^[\da-f]{1,4}/i)) {
      // Component must contain 1-4 hex characters
      return false;
    }
  }

  return true;
}