<?php
/**
 * Class: Validator Helper.
 *
 * Helper class used for validating data.
 *
 * @package wsal
 */

declare(strict_types=1);

namespace WSAL\Helpers;

use WSAL\Helpers\Settings_Helper;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( '\WSAL\Helpers\Validator' ) ) {
	/**
	 * Responsible for data validation
	 */
	class Validator {

		/**
		 * Validates mirror tags against rule sets
		 * Note: no short-returns here as this could be used to collect all the problems for give tag
		 *
		 * @param string $string - The string to validate.
		 *
		 * @return boolean - true - tag is valid, false - tag is not valid.
		 *
		 * @since 4.4.2.1
		 */
		public static function validate_mirror_tag( string $string ): bool {

			$valid = true;

			if ( ! self::starts_alpha_numeric( $string ) ) {
				$valid = false;
			}

			if ( ! self::is_string_less_or_equal( $string, 64 ) ) {
				$valid = false;
			}

			if ( ! self::is_string_contains_only( $string ) ) {
				$valid = false;
			}

			return $valid;
		}

		/**
		 * Checks if given string starts with a letter or number.
		 *
		 * @param string $string - The string to check.
		 *
		 * @return boolean
		 *
		 * @since 4.4.2.1
		 */
		private static function starts_alpha_numeric( string $string ): bool {
			if ( preg_match( '/^[a-zA-Z0-9]/', $string ) ) {
				return true;
			}

			return false;
		}

		/**
		 * Checks if string has less or equal number of characters.
		 *
		 * @param string  $string - The string to check.
		 * @param integer $size - The size of the string to check for.
		 *
		 * @return boolean
		 *
		 * @since 4.4.2.1
		 */
		private static function is_string_less_or_equal( string $string, int $size ): bool {
			if ( strlen( $string ) <= $size ) {
				return true;
			}

			return false;
		}

		/**
		 * Check if string contains only specific characters
		 *
		 * @param string $string - The string to check.
		 *
		 * @return boolean
		 *
		 * @since 4.4.2.1
		 */
		private static function is_string_contains_only( string $string ): bool {
			if ( preg_match( '/^[a-z\d_-]+$/i', $string ) ) {
				return true;
			}
			return false;
		}

		/**
		 * Validate IP address.
		 *
		 * @param string $ip - IP address.
		 *
		 * @return string|bool
		 */
		public static function validate_ip( $ip ) {
			$opts = FILTER_FLAG_IPV4 | FILTER_FLAG_IPV6;

			// if ( Settings_Helper::get_boolean_option_value( 'filter-internal-ip', false ) ) { .
				$opts = $opts | FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE;
			// } .

			$filtered_ip = filter_var( $ip, FILTER_VALIDATE_IP, $opts );

			if ( ! $filtered_ip || empty( $filtered_ip ) ) {
				// Regex IPV4.
				if ( preg_match( '/^(([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/', $ip ) ) {
					return $ip;
				} elseif ( preg_match( '/^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$/', $ip ) ) {
					// Regex IPV6.
					return $ip;
				}

				return false;
			} else {
				return $filtered_ip;
			}
		}

		/**
		 * Simple check for validating a URL, it must start with http:// or https://.
		 * and pass FILTER_VALIDATE_URL validation.
		 *
		 * @param string $url to check.
		 *
		 * @return bool
		 *
		 * @since 4.6.0
		 */
		public static function is_valid_url( $url ) {
			// Must start with http:// or https://.
			if ( 0 !== strpos( $url, 'http://' ) && 0 !== strpos( $url, 'https://' ) ) {
				return false;
			}

			// Must pass validation.
			if ( ! filter_var( $url, FILTER_VALIDATE_URL ) ) {
				return false;
			}

			return true;
		}

		/**
		 * Validates username
		 *
		 * @param string $username - The username to validate.
		 *
		 * @return boolean
		 *
		 * @since 5.2.1
		 */
		public static function validate_username( string $username ): bool {

			if ( preg_match( '/^[A-Za-z0-9\_\.\ \-\@]{3,}$/', $username ) ) {
				return true;
			}

			return false;
		}

		/**
		 * Check if the float is IPv4 instead.
		 *
		 * @param float $ip_address - Number to check.
		 *
		 * @return bool result validation
		 *
		 * @since 4.6.0
		 */
		public static function is_ip_address( $ip_address ) {
			return filter_var( $ip_address, FILTER_VALIDATE_IP ) !== false;
		}

		/**
		 * Checks if give string is a valid JSON
		 *
		 * @param string $json_string - The possible JSON string to validate.
		 *
		 * @return boolean
		 *
		 * @since 5.2.1
		 */
		public static function validate_json( string $json_string ): bool {
			// decode the JSON data.
			$result = json_decode( $json_string );

			// switch and check possible JSON errors.
			switch ( json_last_error() ) {
				case JSON_ERROR_NONE:
					$error = ''; // JSON is valid // No error has occurred.
					break;
				case JSON_ERROR_DEPTH:
					$error = 'The maximum stack depth has been exceeded.';
					break;
				case JSON_ERROR_STATE_MISMATCH:
					$error = 'Invalid or malformed JSON.';
					break;
				case JSON_ERROR_CTRL_CHAR:
					$error = 'Control character error, possibly incorrectly encoded.';
					break;
				case JSON_ERROR_SYNTAX:
					$error = 'Syntax error, malformed JSON.';
					break;
				// PHP >= 5.3.3.
				case JSON_ERROR_UTF8:
					$error = 'Malformed UTF-8 characters, possibly incorrectly encoded.';
					break;
				// PHP >= 5.5.0.
				case JSON_ERROR_RECURSION:
					$error = 'One or more recursive references in the value to be encoded.';
					break;
				// PHP >= 5.5.0.
				case JSON_ERROR_INF_OR_NAN:
					$error = 'One or more NAN or INF values in the value to be encoded.';
					break;
				case JSON_ERROR_UNSUPPORTED_TYPE:
					$error = 'A value of a type that cannot be encoded was given.';
					break;
				default:
					$error = 'Unknown JSON error occured.';
					break;
			}

			if ( '' !== $error ) {
				return false;
			}

			// everything is OK.
			return true;
		}
	}
}