<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Argus_GeoIP_RIR {

	const SOURCES = array(
		'arin'    => 'https://ftp.arin.net/pub/stats/arin/delegated-arin-extended-latest',
		'ripencc' => 'https://ftp.ripe.net/pub/stats/ripencc/delegated-ripencc-extended-latest',
		'apnic'   => 'https://ftp.apnic.net/stats/apnic/delegated-apnic-extended-latest',
		'lacnic'  => 'https://ftp.lacnic.net/pub/stats/lacnic/delegated-lacnic-extended-latest',
		'afrinic' => 'https://ftp.afrinic.net/pub/stats/afrinic/delegated-afrinic-extended-latest',
	);

	const TIME_BUDGET_SECONDS = 40;

	const CURSOR_OPTION       = 'argus_wpd_geoip_cursor';
	const BUILD_PATH_OPTION   = 'argus_wpd_geoip_build_path';
	const LAST_REFRESH_OPTION = 'argus_wpd_geoip_last_refresh';
	const RANGE_COUNT_OPTION  = 'argus_wpd_geoip_range_count';
	const LAST_ERROR_OPTION   = 'argus_wpd_geoip_last_error';
	const CORRUPT_OPTION      = 'argus_wpd_geoip_corrupt_detected';

	const HEADER_MAGIC   = 'AWG1';
	const HEADER_LEN     = 16;
	const FORMAT_VERSION = 1;

	protected static $file_cache = null;

	public static function init() {
		add_filter( 'argus_wpd_resolve_country', array( __CLASS__, 'resolve' ), 10, 2 );
	}

	public static function resolve( $result, $ip ) {
		if ( null !== $result ) {
			return $result; 
		}
		if ( ! Argus_Settings::get( 'geoip_rir_enabled', true ) ) {
			return null;
		}
		$code = self::lookup_ipv4( $ip );
		if ( ! $code ) {
			return null;
		}
		return array( 'label' => self::country_name( $code ), 'code' => $code );
	}

	public static function lookup_ipv4( $ip ) {
		$n = self::ipv4_to_uint( $ip );
		if ( false === $n ) {
			return null; 
		}

		if ( null === self::$file_cache ) {
			self::$file_cache = self::read_and_verify();
		}
		if ( '' === self::$file_cache ) {
			return null; 
		}

		$count = (int) ( strlen( self::$file_cache ) / 10 );
		$lo    = 0;
		$hi    = $count - 1;

		while ( $lo <= $hi ) {
			$mid = intdiv( $lo + $hi, 2 );
			$rec = unpack( 'Nstart/Nend/a2cc', substr( self::$file_cache, $mid * 10, 10 ) );
			if ( $n < $rec['start'] ) {
				$hi = $mid - 1;
			} elseif ( $n > $rec['end'] ) {
				$lo = $mid + 1;
			} else {
				return $rec['cc'];
			}
		}
		return null;
	}

	protected static function read_and_verify() {
		$path = self::compiled_file();
		if ( ! file_exists( $path ) ) {
			return '';
		}
		$raw = file_get_contents( $path ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( false === $raw || '' === $raw ) {
			return '';
		}

		if ( strlen( $raw ) < self::HEADER_LEN || self::HEADER_MAGIC !== substr( $raw, 0, 4 ) ) {
			return $raw; 
		}

		$header = unpack( 'a4magic/Cversion/Ncount/Ncrc', substr( $raw, 0, self::HEADER_LEN ) );
		$records = substr( $raw, self::HEADER_LEN );

		if ( (int) $header['count'] !== (int) ( strlen( $records ) / 10 ) || (int) $header['crc'] !== crc32( $records ) ) {

			if ( ! get_option( self::CORRUPT_OPTION ) ) {
				update_option( self::CORRUPT_OPTION, true, false );
				Argus_Events::record( 'geoip_corrupt', 'medium', 'GeoIP database file failed its integrity check and was ignored until the next scheduled refresh.', array() );
			}
			return '';
		}

		if ( get_option( self::CORRUPT_OPTION ) ) {
			delete_option( self::CORRUPT_OPTION );
		}

		return $records;
	}

	public static function run_daily_refresh() {
		$started = microtime( true );
		$sources = array_keys( self::SOURCES );
		$cursor  = (int) get_option( self::CURSOR_OPTION, 0 );

		$build_path = get_option( self::BUILD_PATH_OPTION, '' );
		if ( 0 === $cursor || '' === $build_path || ! file_exists( $build_path ) ) {

			foreach ( glob( trailingslashit( self::data_dir() ) . 'geoip-build-*.raw' ) ?: array() as $stray ) {
				@unlink( $stray ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
			}
			$build_path = trailingslashit( self::data_dir() ) . 'geoip-build-' . wp_generate_password( 8, false ) . '.raw';
			update_option( self::BUILD_PATH_OPTION, $build_path, false );
			$cursor = 0;
		}

		$handle = fopen( $build_path, 'ab' ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( ! $handle ) {
			self::record_outcome( false, __( 'Could not open a working file in uploads to build the GeoIP database.', 'argus-wordpress-defence' ) );
			return;
		}

		$any_failure = false;
		while ( $cursor < count( $sources ) ) {
			if ( microtime( true ) - $started > self::TIME_BUDGET_SECONDS ) {
				break; 
			}
			$key = $sources[ $cursor ];
			if ( ! self::fetch_and_append( $key, self::SOURCES[ $key ], $handle ) ) {
				$any_failure = true;
			}
			$cursor++;
			update_option( self::CURSOR_OPTION, $cursor, false );
		}

		fclose( $handle ); // phpcs:ignore WordPress.WP.AlternativeFunctions

		if ( $cursor < count( $sources ) ) {
			return; 
		}

		$swap_result = self::compile_and_swap( $build_path, $any_failure );
		@unlink( $build_path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors

		update_option( self::BUILD_PATH_OPTION, '', false );
		update_option( self::CURSOR_OPTION, 0, false );
		update_option( self::RANGE_COUNT_OPTION, $swap_result['count'], false );

		if ( $swap_result['swapped'] ) {

			update_option( self::LAST_REFRESH_OPTION, current_time( 'mysql', true ), false );
		}

		if ( $any_failure && ! $swap_result['swapped'] ) {

			self::record_outcome(
				false,
				sprintf(
					
					__( 'One or more RIR sources could not be reached this cycle. Kept the existing %d-range database rather than replacing it with an incomplete one; will retry on the next scheduled refresh.', 'argus-wordpress-defence' ),
					$swap_result['count']
				)
			);
		} else {
			self::record_outcome(
				! $any_failure,
				$any_failure
					? sprintf(
						
						__( 'GeoIP database refreshed with %d IPv4 ranges, but one or more RIR sources could not be reached this cycle -- those ranges are missing until a future refresh succeeds.', 'argus-wordpress-defence' ),
						$swap_result['count']
					)
					: sprintf(
						
						__( 'GeoIP database refreshed: %d IPv4 ranges loaded from 5 RIR sources.', 'argus-wordpress-defence' ),
						$swap_result['count']
					)
			);
		}

		self::$file_cache = null; 
	}

	protected static function fetch_and_append( $source_key, $url, $handle ) {

		$tmp = tempnam( sys_get_temp_dir(), 'argus-geoip-' . $source_key . '-' );
		if ( ! $tmp ) {
			return false;
		}

		$response = wp_remote_get( $url, array( 'timeout' => 30, 'stream' => true, 'filename' => $tmp ) );
		if ( is_wp_error( $response ) || 200 !== (int) wp_remote_retrieve_response_code( $response ) ) {
			@unlink( $tmp ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
			return false;
		}

		$fh = fopen( $tmp, 'r' ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( ! $fh ) {
			@unlink( $tmp ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
			return false;
		}

		while ( false !== ( $line = fgets( $fh ) ) ) { // phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition
			$line = trim( $line );
			if ( '' === $line || '#' === $line[0] ) {
				continue;
			}
			
			$parts = explode( '|', $line );
			if ( count( $parts ) < 7 ) {
				continue;
			}
			if ( 'ipv4' !== $parts[2] ) {
				continue; 
			}
			if ( ! in_array( $parts[6], array( 'allocated', 'assigned' ), true ) ) {
				continue; 
			}
			$cc = strtoupper( $parts[1] );
			if ( 2 !== strlen( $cc ) || ! ctype_alpha( $cc ) ) {
				continue; 
			}
			$start = self::ipv4_to_uint( $parts[3] );
			$count = (int) $parts[4];
			if ( false === $start || $count <= 0 ) {
				continue;
			}
			$end = min( $start + $count - 1, 4294967295 );

			fwrite( $handle, pack( 'NNa2', $start, $end, $cc ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		}

		fclose( $fh ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		@unlink( $tmp ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
		return true;
	}

	protected static function compile_and_swap( $build_path, $any_failure = false ) {
		$data = file_get_contents( $build_path ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( false === $data || '' === $data ) {
			return array( 'count' => self::count_from_file( self::compiled_file() ), 'swapped' => false );
		}

		$existing_file = self::compiled_file();
		if ( $any_failure && file_exists( $existing_file ) ) {
			return array( 'count' => self::count_from_file( $existing_file ), 'swapped' => false );
		}

		$records = str_split( $data, 10 );
		usort(
			$records,
			function ( $a, $b ) {
				return substr_compare( $a, $b, 0, 4 );
			}
		);

		$record_bytes = implode( '', $records );

		$header = pack( 'a4CNNa3', self::HEADER_MAGIC, self::FORMAT_VERSION, count( $records ), crc32( $record_bytes ), '' );

		$tmp_final = trailingslashit( self::data_dir() ) . 'geoip-v4.bin.tmp';
		file_put_contents( $tmp_final, $header . $record_bytes ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		rename( $tmp_final, $existing_file ); // phpcs:ignore WordPress.WP.AlternativeFunctions

		delete_option( self::CORRUPT_OPTION );

		return array( 'count' => count( $records ), 'swapped' => true );
	}

	protected static function count_from_file( $path ) {
		if ( ! file_exists( $path ) ) {
			return 0;
		}
		$head = file_get_contents( $path, false, null, 0, self::HEADER_LEN ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( is_string( $head ) && strlen( $head ) === self::HEADER_LEN && self::HEADER_MAGIC === substr( $head, 0, 4 ) ) {
			$header = unpack( 'a4magic/Cversion/Ncount', $head );
			return (int) $header['count'];
		}
		return (int) ( filesize( $path ) / 10 );
	}

	protected static function record_outcome( $success, $message ) {
		update_option( self::LAST_ERROR_OPTION, $success ? '' : $message, false );
		Argus_Events::record( 'geoip_refresh', $success ? 'info' : 'medium', $message, array( 'success' => $success ) );
	}

	protected static function data_dir() {
		$uploads = wp_get_upload_dir();
		$dir     = trailingslashit( $uploads['basedir'] ) . 'argus-wpd-data';
		if ( ! is_dir( $dir ) ) {
			wp_mkdir_p( $dir );
		}
		return $dir;
	}

	protected static function compiled_file() {
		return trailingslashit( self::data_dir() ) . 'geoip-v4.bin';
	}

	public static function ipv4_to_uint( $ip ) {
		if ( ! filter_var( $ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 ) ) {
			return false;
		}
		$parts = explode( '.', $ip );
		if ( 4 !== count( $parts ) ) {
			return false;
		}
		return ( (int) $parts[0] << 24 ) + ( (int) $parts[1] << 16 ) + ( (int) $parts[2] << 8 ) + (int) $parts[3];
	}

	public static function status() {
		return array(
			'last_refresh' => get_option( self::LAST_REFRESH_OPTION, '' ) ?: null,
			'range_count'  => (int) get_option( self::RANGE_COUNT_OPTION, 0 ),
			'last_error'   => get_option( self::LAST_ERROR_OPTION, '' ),
			'cursor'       => (int) get_option( self::CURSOR_OPTION, 0 ),
		);
	}

	public static function country_name( $code ) {
		static $names = null;
		if ( null === $names ) {
			$names = array(
				'AL' => 'Albania', 'AD' => 'Andorra', 'AT' => 'Austria', 'BY' => 'Belarus', 'BE' => 'Belgium',
				'BA' => 'Bosnia and Herzegovina', 'BG' => 'Bulgaria', 'HR' => 'Croatia', 'CY' => 'Cyprus', 'CZ' => 'Czech Republic',
				'DK' => 'Denmark', 'EE' => 'Estonia', 'FI' => 'Finland', 'FR' => 'France', 'DE' => 'Germany',
				'GR' => 'Greece', 'HU' => 'Hungary', 'IS' => 'Iceland', 'IE' => 'Ireland', 'IT' => 'Italy',
				'XK' => 'Kosovo', 'LV' => 'Latvia', 'LI' => 'Liechtenstein', 'LT' => 'Lithuania', 'LU' => 'Luxembourg',
				'MT' => 'Malta', 'MD' => 'Moldova', 'MC' => 'Monaco', 'ME' => 'Montenegro', 'NL' => 'Netherlands',
				'MK' => 'North Macedonia', 'NO' => 'Norway', 'PL' => 'Poland', 'PT' => 'Portugal', 'RO' => 'Romania',
				'RU' => 'Russia', 'SM' => 'San Marino', 'RS' => 'Serbia', 'SK' => 'Slovakia', 'SI' => 'Slovenia',
				'ES' => 'Spain', 'SE' => 'Sweden', 'CH' => 'Switzerland', 'UA' => 'Ukraine', 'GB' => 'United Kingdom',
				'VA' => 'Vatican City', 'AF' => 'Afghanistan', 'AM' => 'Armenia', 'AZ' => 'Azerbaijan', 'BH' => 'Bahrain',
				'BD' => 'Bangladesh', 'BT' => 'Bhutan', 'BN' => 'Brunei', 'KH' => 'Cambodia', 'CN' => 'China',
				'GE' => 'Georgia', 'IN' => 'India', 'ID' => 'Indonesia', 'IR' => 'Iran', 'IQ' => 'Iraq',
				'IL' => 'Israel', 'JP' => 'Japan', 'JO' => 'Jordan', 'KZ' => 'Kazakhstan', 'KW' => 'Kuwait',
				'KG' => 'Kyrgyzstan', 'LA' => 'Laos', 'LB' => 'Lebanon', 'MY' => 'Malaysia', 'MV' => 'Maldives',
				'MN' => 'Mongolia', 'MM' => 'Myanmar', 'NP' => 'Nepal', 'KP' => 'North Korea', 'OM' => 'Oman',
				'PK' => 'Pakistan', 'PS' => 'Palestine', 'PH' => 'Philippines', 'QA' => 'Qatar', 'SA' => 'Saudi Arabia',
				'SG' => 'Singapore', 'KR' => 'South Korea', 'LK' => 'Sri Lanka', 'SY' => 'Syria', 'TW' => 'Taiwan',
				'TJ' => 'Tajikistan', 'TH' => 'Thailand', 'TL' => 'Timor-Leste', 'TR' => 'Turkey', 'TM' => 'Turkmenistan',
				'AE' => 'United Arab Emirates', 'UZ' => 'Uzbekistan', 'VN' => 'Vietnam', 'YE' => 'Yemen', 'AG' => 'Antigua and Barbuda',
				'AR' => 'Argentina', 'BS' => 'Bahamas', 'BB' => 'Barbados', 'BZ' => 'Belize', 'BO' => 'Bolivia',
				'BR' => 'Brazil', 'CA' => 'Canada', 'CL' => 'Chile', 'CO' => 'Colombia', 'CR' => 'Costa Rica',
				'CU' => 'Cuba', 'DM' => 'Dominica', 'DO' => 'Dominican Republic', 'EC' => 'Ecuador', 'SV' => 'El Salvador',
				'GD' => 'Grenada', 'GT' => 'Guatemala', 'GY' => 'Guyana', 'HT' => 'Haiti', 'HN' => 'Honduras',
				'JM' => 'Jamaica', 'MX' => 'Mexico', 'NI' => 'Nicaragua', 'PA' => 'Panama', 'PY' => 'Paraguay',
				'PE' => 'Peru', 'KN' => 'Saint Kitts and Nevis', 'LC' => 'Saint Lucia', 'VC' => 'Saint Vincent and the Grenadines', 'SR' => 'Suriname',
				'TT' => 'Trinidad and Tobago', 'US' => 'United States', 'UY' => 'Uruguay', 'VE' => 'Venezuela', 'DZ' => 'Algeria',
				'AO' => 'Angola', 'BJ' => 'Benin', 'BW' => 'Botswana', 'BF' => 'Burkina Faso', 'BI' => 'Burundi',
				'CM' => 'Cameroon', 'CV' => 'Cape Verde', 'CF' => 'Central African Republic', 'TD' => 'Chad', 'KM' => 'Comoros',
				'CG' => 'Republic of the Congo', 'CD' => 'Democratic Republic of the Congo', 'CI' => 'Ivory Coast', 'DJ' => 'Djibouti', 'EG' => 'Egypt',
				'GQ' => 'Equatorial Guinea', 'ER' => 'Eritrea', 'ET' => 'Ethiopia', 'GA' => 'Gabon', 'GM' => 'Gambia',
				'GH' => 'Ghana', 'GN' => 'Guinea', 'GW' => 'Guinea-Bissau', 'KE' => 'Kenya', 'LS' => 'Lesotho',
				'LR' => 'Liberia', 'LY' => 'Libya', 'MG' => 'Madagascar', 'MW' => 'Malawi', 'ML' => 'Mali',
				'MR' => 'Mauritania', 'MU' => 'Mauritius', 'MA' => 'Morocco', 'MZ' => 'Mozambique', 'NA' => 'Namibia',
				'NE' => 'Niger', 'NG' => 'Nigeria', 'RW' => 'Rwanda', 'ST' => 'Sao Tome and Principe', 'SN' => 'Senegal',
				'SL' => 'Sierra Leone', 'SO' => 'Somalia', 'ZA' => 'South Africa', 'SS' => 'South Sudan', 'SD' => 'Sudan',
				'SZ' => 'Eswatini', 'TZ' => 'Tanzania', 'TG' => 'Togo', 'TN' => 'Tunisia', 'UG' => 'Uganda',
				'ZM' => 'Zambia', 'ZW' => 'Zimbabwe', 'AU' => 'Australia', 'FJ' => 'Fiji', 'KI' => 'Kiribati',
				'MH' => 'Marshall Islands', 'FM' => 'Micronesia', 'NR' => 'Nauru', 'NZ' => 'New Zealand', 'PW' => 'Palau',
				'PG' => 'Papua New Guinea', 'WS' => 'Samoa', 'SB' => 'Solomon Islands', 'TO' => 'Tonga', 'TV' => 'Tuvalu',
				'VU' => 'Vanuatu',
			);
		}
		return $names[ $code ] ?? $code;
	}
}