1<?php
  2/**
  3 * Input validation utilities.
  4 *
  5 * @package Requests\Utilities
  6 */
  7
  8namespace WpOrg\Requests\Utility;
  9
 10use ArrayAccess;
 11use CurlHandle;
 12use Traversable;
 13
 14/**
 15 * Input validation utilities.
 16 *
 17 * @package Requests\Utilities
 18 */
 19final class InputValidator {
 20
 21	/**
 22	 * Verify that a received input parameter is of type string or is "stringable".
 23	 *
 24	 * @param mixed $input Input parameter to verify.
 25	 *
 26	 * @return bool
 27	 */
 28	public static function is_string_or_stringable($input) {
 29		return is_string($input) || self::is_stringable_object($input);
 30	}
 31
 32	/**
 33	 * Verify whether a received input parameter is usable as an integer array key.
 34	 *
 35	 * @param mixed $input Input parameter to verify.
 36	 *
 37	 * @return bool
 38	 */
 39	public static function is_numeric_array_key($input) {
 40		if (is_int($input)) {
 41			return true;
 42		}
 43
 44		if (!is_string($input)) {
 45			return false;
 46		}
 47
 48		return (bool) preg_match('`^-?[0-9]+$`', $input);
 49	}
 50
 51	/**
 52	 * Verify whether a received input parameter is "stringable".
 53	 *
 54	 * @param mixed $input Input parameter to verify.
 55	 *
 56	 * @return bool
 57	 */
 58	public static function is_stringable_object($input) {
 59		return is_object($input) && method_exists($input, '__toString');
 60	}
 61
 62	/**
 63	 * Verify whether a received input parameter is _accessible as if it were an array_.
 64	 *
 65	 * @param mixed $input Input parameter to verify.
 66	 *
 67	 * @return bool
 68	 */
 69	public static function has_array_access($input) {
 70		return is_array($input) || $input instanceof ArrayAccess;
 71	}
 72
 73	/**
 74	 * Verify whether a received input parameter is "iterable".
 75	 *
 76	 * @internal The PHP native `is_iterable()` function was only introduced in PHP 7.1
 77	 * and this library still supports PHP 5.6.
 78	 *
 79	 * @param mixed $input Input parameter to verify.
 80	 *
 81	 * @return bool
 82	 */
 83	public static function is_iterable($input) {
 84		return is_array($input) || $input instanceof Traversable;
 85	}
 86
 87	/**
 88	 * Verify whether a received input parameter is a Curl handle.
 89	 *
 90	 * The PHP Curl extension worked with resources prior to PHP 8.0 and with
 91	 * an instance of the `CurlHandle` class since PHP 8.0.
 92	 * {@link https://www.php.net/manual/en/migration80.incompatible.php#migration80.incompatible.resource2object}
 93	 *
 94	 * @param mixed $input Input parameter to verify.
 95	 *
 96	 * @return bool
 97	 */
 98	public static function is_curl_handle($input) {
 99		if (is_resource($input)) {
100			return get_resource_type($input) === 'curl';
101		}
102
103		if (is_object($input)) {
104			return $input instanceof CurlHandle;
105		}
106
107		return false;
108	}
109}
110