<?php
if (!defined('ABSPATH')) {
	exit;//Exit if accessed directly
}

class AIOWPSecurity_Utility_IP {
	public function __construct() {
		//NOP
	}

	/**
	 * Get user IP Address.
	 *
	 * @return string User IP Address.
	 */
	public static function get_user_ip_address() {
		return AIOS_Helper::get_user_ip_address();
	}

	/**
	 * Get server suitable IP methods.
	 *
	 * @return Array array of IP methods.
	 */
	public static function get_server_suitable_ip_methods() {
		static $server_suitable_ip_methods;
		if (!isset($server_suitable_ip_methods)) {
			$server_suitable_ip_methods = array();
			foreach (AIOS_Abstracted_Ids::get_ip_retrieve_methods() as $ip_method) {
				if (isset($_SERVER[$ip_method])) {
					$server_suitable_ip_methods[] = $ip_method;
				}
			}
		}
		return $server_suitable_ip_methods;
	}

	/**
	 * Check whether all sever suitable IP address is giving same IP address or not.
	 *
	 * @return Boolean True if all server suitable IP methods gives same IP address, otherwise false.
	 */
	public static function is_server_suitable_ip_methods_give_same_ip_address() {
		$server_suitable_ip_methods = self::get_server_suitable_ip_methods();

		if (empty($server_suitable_ip_methods)) {
			return false;
		}

		if (1 === count($server_suitable_ip_methods)) {
			return true;
		}

		$ip_addresses = array();
		foreach ($server_suitable_ip_methods as $server_suitable_ip_method) {
			$ip_addresses[] = $_SERVER[$server_suitable_ip_method];
		}

		return (1 === count(array_unique($ip_addresses)));
	}
	
	/**
	 * Returns the first three octets of a sanitized IP address so it can used as an IP address range
	 *
	 * @param int $ip
	 * @return int
	 */
	public static function get_sanitized_ip_range($ip) {
		global $aio_wp_security;
		$ip_range = '';
		$valid_ip = filter_var($ip, FILTER_VALIDATE_IP); //Sanitize the IP address
		if ($valid_ip) {
			$ip_type = WP_Http::is_ip_address($ip); //returns 4 or 6 if ipv4 or ipv6 or false if invalid
			if (6 == $ip_type || false === $ip_type) return ''; // for now return empty if ipv6 or invalid IP
			$ip_range = substr($valid_ip, 0, strrpos($valid_ip, ".")); //strip last portion of address to leave an IP range
		} else {
			//Write log if the 'REMOTE_ADDR' contains something which is not an IP
			$aio_wp_security->debug_logger->log_debug("AIOWPSecurity_Utility_IP - Invalid IP received ".$ip, 4);
		}
		return $ip_range;
	}

	
	public static function create_ip_list_array_from_string_with_newline($ip_addresses) {
		$ip_list_array = preg_split("/\R/", $ip_addresses);
		return $ip_list_array;
	}
	
	/**
	 * Returns IPv6 ip address or IPv6 range if valid
	 *
	 * @param string $item possible IPv6 ip address or IPv6 range
	 * @return string|boolean $checked_ip trimmed IPv6 ip address or IPv6 range if given input is valid otherwise false.
	 */
	public static function is_ipv6_address_or_ipv6_range($item) {
		$checked_ip = false;
		$res = WP_Http::is_ip_address($item);
		if ('6' == $res && class_exists('WpOrg\Requests\Ipv6') && WpOrg\Requests\Ipv6::check_ipv6($item)) {
			$checked_ip = trim($item);
		} elseif ('6' == $res && class_exists('Requests_IPv6') && Requests_IPv6::check_ipv6($item)) {
			$checked_ip = trim($item);
		} else {
			//ipv6 - range check for valid CIDR range
			$item_ip_range = explode('/', $item);
			$ip_part_valid = filter_var($item_ip_range[0], FILTER_VALIDATE_IP, FILTER_FLAG_IPV6);
			//1 - 164 range of the IPv6 subnect masking as per CISCO propersed change from 128.
			if (2 == count($item_ip_range) && $ip_part_valid && $item_ip_range[1] >= 1 && $item_ip_range[1] <= 164) {
				$checked_ip = trim($item);
			}
		}
		return $checked_ip;
	}
	
	/**
	 * Validates IP or IP range
	 *
	 * @param array  $ip_list_array
	 * @param string $list_type
	 * @return array|WP_Error
	 */
	public static function validate_ip_list($ip_list_array, $list_type = '') {
		$errors = '';
		
		$current_user_ip = AIOWPSecurity_Utility_IP::get_user_ip_address();
		
		//validate list
		$submitted_ips = $ip_list_array;
		$list = array();
		if (!(include_once AIO_WP_SECURITY_PATH.'/vendor/mlocati/ip-lib/ip-lib.php')) {
			throw new \Exception("AIOWPSecurity_Utility_IP::validate_ip_list failed to load ip-lib.php");
		}
		if (!empty($submitted_ips)) {
			foreach ($submitted_ips as $item) {
				$item = sanitize_text_field($item);
				if (strlen($item) > 0) {
					$ip_address = \IPLib\Factory::addressFromString($item);
					$ip_address_range = \IPLib\Factory::rangeFromString($item);
					if (null == $ip_address && null == $ip_address_range) {
						$errors .= "\n" . sprintf(__('%s is not a valid IP address format.', 'all-in-one-wp-security-and-firewall'), $item);
					}
					
					if (strlen($item) > 4 && !in_array($item, $list)) {
						if ($item == $current_user_ip && 'blacklist' == $list_type) {
							//You can't ban your own IP
							$errors .= "\n".__('You cannot ban your own IP address:', 'all-in-one-wp-security-and-firewall') . ' ' . $item;
						} else {
							$list[] = trim($item);
						}
					}
				}
			}
		} else {
			//This function was called with an empty IP address array list
		}

		if (strlen($errors) > 0) {
			return new WP_Error('invalid_ips', trim($errors));
		}

		if (sizeof($list) >= 1) {
			sort($list);

			return array_unique($list, SORT_STRING);
		}

		return array();
	}

	/**
	 * If login whitelist enabled and the user IP is not whitelisted, Then forbid access.
	 *
	 * @return void
	 */
	public static function check_login_whitelist_and_forbid() {
		if (defined('AIOS_DISABLE_LOGIN_WHITELIST') && AIOS_DISABLE_LOGIN_WHITELIST) {
			return;
		}

		global $aio_wp_security;

		if ('1' != $aio_wp_security->configs->get_value('aiowps_enable_whitelisting')) {
			return;
		}

		$whitelisted_ips = $aio_wp_security->configs->get_value('aiowps_allowed_ip_addresses');
		$is_whitelisted = AIOWPSecurity_Utility_IP::is_userip_whitelisted($whitelisted_ips);

		if ($is_whitelisted) {
			return;
		}

		header('HTTP/1.1 403 Forbidden');
		exit();
	}
	
	/**
	 * Checks if user IP address matches against the specified whitelist of IP addresses or IP ranges
	 *
	 * @param type $whitelisted_ips (newline separated string of IPs)
	 * @return boolean
	 */
	public static function is_userip_whitelisted($whitelisted_ips) {
		if (empty($whitelisted_ips)) return false;
		
		$ip_list_array = AIOWPSecurity_Utility_IP::create_ip_list_array_from_string_with_newline($whitelisted_ips);
		if (empty($ip_list_array)) return false;
		
		return AIOS_Helper::is_user_ip_address_within_list($ip_list_array);
	}
}
