<?php
namespace Aws\Arn;
use Aws\Arn\Exception\InvalidArnException;
/**
* Amazon Resource Names (ARNs) uniquely identify AWS resources. The Arn class
* parses and stores a generic ARN object representation that can apply to any
* service resource.
*
* @internal
*/
class Arn implements ArnInterface
{
protected $data;
protected $string;
public static function parse($string)
{
$data = [
'arn' => null,
'partition' => null,
'service' => null,
'region' => null,
'account_id' => null,
'resource' => null,
];
$length = strlen($string);
$lastDelim = 0;
$numComponents = 0;
for ($i = 0; $i < $length; $i++) {
if (($numComponents < 5 && $string[$i] === ':')) {
// Split components between delimiters
$data[key($data)] = substr($string, $lastDelim, $i - $lastDelim);
// Do not include delimiter character itself
$lastDelim = $i + 1;
next($data);
$numComponents++;
}
if ($i === $length - 1) {
// Put the remainder in the last component.
if (in_array($numComponents, [5])) {
$data['resource'] = substr($string, $lastDelim);
} else {
// If there are < 5 components, put remainder in current
// component.
$data[key($data)] = substr($string, $lastDelim);
}
}
}
return $data;
}
public function __construct($data)
{
if (is_array($data)) {
$this->data = $data;
} elseif (is_string($data)) {
$this->data = static::parse($data);
} else {
throw new InvalidArnException('Constructor accepts a string or an'
. ' array as an argument.');
}
static::validate($this->data);
}
public function __toString()
{
if (!isset($this->string)) {
$components = [
$this->getPrefix(),
$this->getPartition(),
$this->getService(),
$this->getRegion(),
$this->getAccountId(),
$this->getResource(),
];
$this->string = implode(':', $components);
}
return $this->string;
}
public function getPrefix()
{
return $this->data['arn'];
}
public function getPartition()
{
return $this->data['partition'];
}
public function getService()
{
return $this->data['service'];
}
public function getRegion()
{
return $this->data['region'];
}
public function getAccountId()
{
return $this->data['account_id'];
}
public function getResource()
{
return $this->data['resource'];
}
public function toArray()
{
return $this->data;
}
/**
* Minimally restrictive generic ARN validation
*
* @param array $data
*/
protected static function validate(array $data)
{
if ($data['arn'] !== 'arn') {
throw new InvalidArnException("The 1st component of an ARN must be"
. " 'arn'.");
}
if (empty($data['partition'])) {
throw new InvalidArnException("The 2nd component of an ARN"
. " represents the partition and must not be empty.");
}
if (empty($data['service'])) {
throw new InvalidArnException("The 3rd component of an ARN"
. " represents the service and must not be empty.");
}
if (empty($data['resource'])) {
throw new InvalidArnException("The 6th component of an ARN"
. " represents the resource information and must not be empty."
. " Individual service ARNs may include additional delimiters"
. " to further qualify resources.");
}
}
protected static function validateAccountId($data, $arnName)
{
if (!self::isValidHostLabel($data['account_id'])) {
throw new InvalidArnException("The 5th component of a {$arnName}"
. " is required, represents the account ID, and"
. " must be a valid host label.");
}
}
protected static function validateRegion($data, $arnName)
{
if (empty($data['region'])) {
throw new InvalidArnException("The 4th component of a {$arnName}"
. " represents the region and must not be empty.");
}
}
/**
* Validates whether a string component is a valid host label
*
* @param $string
* @return bool
*/
protected static function isValidHostLabel($string)
{
if (empty($string) || strlen($string) > 63) {
return false;
}
if ($value = preg_match("/^[a-zA-Z0-9-]+$/", $string)) {
return true;
}
return false;
}
}