<?php

/**
 * The crawler class
 *
 * @since       1.1.0
 */

namespace LiteSpeed;

defined('WPINC') || exit();

class Crawler extends Root {

	const LOG_TAG = '🕸️';

	const TYPE_REFRESH_MAP     = 'refresh_map';
	const TYPE_EMPTY           = 'empty';
	const TYPE_BLACKLIST_EMPTY = 'blacklist_empty';
	const TYPE_BLACKLIST_DEL   = 'blacklist_del';
	const TYPE_BLACKLIST_ADD   = 'blacklist_add';
	const TYPE_START           = 'start';
	const TYPE_RESET           = 'reset';

	const USER_AGENT      = 'lscache_walker';
	const FAST_USER_AGENT = 'lscache_runner';
	const CHUNKS          = 10000;

	const STATUS_WAIT      = 'W';
	const STATUS_HIT       = 'H';
	const STATUS_MISS      = 'M';
	const STATUS_BLACKLIST = 'B';
	const STATUS_NOCACHE   = 'N';

	private $_sitemeta = 'meta.data';
	private $_resetfile;
	private $_end_reason;
	private $_ncpu = 1;
	private $_server_ip;

	private $_crawler_conf = array(
		'cookies' => array(),
		'headers' => array(),
		'ua' => '',
	);
	private $_crawlers     = array();
	private $_cur_threads  = -1;
	private $_max_run_time;
	private $_cur_thread_time;
	private $_map_status_list = array(
		'H' => array(),
		'M' => array(),
		'B' => array(),
		'N' => array(),
	);
	protected $_summary;

	/**
	 * Initialize crawler, assign sitemap path
	 *
	 * @since    1.1.0
	 */
	public function __construct() {
		if (is_multisite()) {
			$this->_sitemeta = 'meta' . get_current_blog_id() . '.data';
		}

		$this->_resetfile = LITESPEED_STATIC_DIR . '/crawler/' . $this->_sitemeta . '.reset';

		$this->_summary = self::get_summary();

		$this->_ncpu      = $this->_get_server_cpu();
		$this->_server_ip = $this->conf(Base::O_SERVER_IP);

		self::debug('Init w/ CPU cores=' . $this->_ncpu);
	}

	/**
	 * Try get server CPUs
	 *
	 * @since 5.2
	 */
	private function _get_server_cpu() {
		$cpuinfo_file     = '/proc/cpuinfo';
		$setting_open_dir = ini_get('open_basedir');
		if ($setting_open_dir) {
			return 1;
		} // Server has limit

		try {
			if (!@is_file($cpuinfo_file)) {
				return 1;
			}
		} catch (\Exception $e) {
			return 1;
		}

		$cpuinfo = file_get_contents($cpuinfo_file);
		preg_match_all('/^processor/m', $cpuinfo, $matches);
		return count($matches[0]) ?: 1;
	}

	/**
	 * Check whether the current crawler is active/runable/useable/enabled/want it to work or not
	 *
	 * @since  4.3
	 */
	public function is_active( $curr ) {
		$bypass_list = self::get_option('bypass_list', array());
		return !in_array($curr, $bypass_list);
	}

	/**
	 * Toggle the current crawler's activeness state, i.e., runable/useable/enabled/want it to work or not, and return the updated state
	 *
	 * @since  4.3
	 */
	public function toggle_activeness( $curr ) {
		// param type: int
		$bypass_list = self::get_option('bypass_list', array());
		if (in_array($curr, $bypass_list)) {
			// when the ith opt was off / in the bypassed list, turn it on / remove it from the list
			unset($bypass_list[array_search($curr, $bypass_list)]);
			$bypass_list = array_values($bypass_list);
			self::update_option('bypass_list', $bypass_list);
			return true;
		} else {
			// when the ith opt was on / not in the bypassed list, turn it off / add it to the list
			$bypass_list[] = (int) $curr;
			self::update_option('bypass_list', $bypass_list);
			return false;
		}
	}

	/**
	 * Clear bypassed list
	 *
	 * @since  4.3
	 * @access public
	 */
	public function clear_disabled_list() {
		self::update_option('bypass_list', array());

		$msg = __('Crawler disabled list is cleared! All crawlers are set to active! ', 'litespeed-cache');
		Admin_Display::note($msg);

		self::debug('All crawlers are set to active...... ');
	}

	/**
	 * Overwrite get_summary to init elements
	 *
	 * @since  3.0
	 * @access public
	 */
	public static function get_summary( $field = false ) {
		$_default = array(
			'list_size' => 0,
			'last_update_time' => 0,
			'curr_crawler' => 0,
			'curr_crawler_beginning_time' => 0,
			'last_pos' => 0,
			'last_count' => 0,
			'last_crawled' => 0,
			'last_start_time' => 0,
			'last_status' => '',
			'is_running' => 0,
			'end_reason' => '',
			'meta_save_time' => 0,
			'pos_reset_check' => 0,
			'done' => 0,
			'this_full_beginning_time' => 0,
			'last_full_time_cost' => 0,
			'last_crawler_total_cost' => 0,
			'crawler_stats' => array(), // this will store all crawlers hit/miss crawl status
		);

		wp_cache_delete('alloptions', 'options'); // ensure the summary is current
		$summary = parent::get_summary();
		$summary = array_merge($_default, $summary);

		if (!$field) {
			return $summary;
		}

		if (array_key_exists($field, $summary)) {
			return $summary[$field];
		}

		return null;
	}

	/**
	 * Overwrite save_summary
	 *
	 * @since  3.0
	 * @access public
	 */
	public static function save_summary( $data = false, $reload = false, $overwrite = false ) {
		$instance                             = self::cls();
		$instance->_summary['meta_save_time'] = time();

		if (!$data) {
			$data = $instance->_summary;
		}

		parent::save_summary($data, $reload, $overwrite);

		File::save(LITESPEED_STATIC_DIR . '/crawler/' . $instance->_sitemeta, \json_encode($data), true);
	}

	/**
	 * Cron start async crawling
	 *
	 * @since 5.5
	 */
	public static function start_async_cron() {
		Task::async_call('crawler');
	}

	/**
	 * Manually start async crawling
	 *
	 * @since 5.5
	 */
	public static function start_async() {
		Task::async_call('crawler_force');

		$msg = __('Started async crawling', 'litespeed-cache');
		Admin_Display::success($msg);
	}

	/**
	 * Ajax crawl handler
	 *
	 * @since 5.5
	 */
	public static function async_handler( $manually_run = false ) {
		self::debug('------------async-------------start_async_handler');
		// check_ajax_referer('async_crawler', 'nonce');
		self::start($manually_run);
	}

	/**
	 * Proceed crawling
	 *
	 * @since    1.1.0
	 * @access public
	 */
	public static function start( $manually_run = false ) {
		if (!Router::can_crawl()) {
			self::debug('......crawler is NOT allowed by the server admin......');
			return false;
		}

		if ($manually_run) {
			self::debug('......crawler manually ran......');
		}

		self::cls()->_crawl_data($manually_run);
	}

	/**
	 * Crawling start
	 *
	 * @since    1.1.0
	 * @access   private
	 */
	private function _crawl_data( $manually_run ) {
		if (!defined('LITESPEED_LANE_HASH')) {
			define('LITESPEED_LANE_HASH', Str::rrand(8));
		}
		if ($this->_check_valid_lane()) {
			$this->_take_over_lane();
		} else {
			self::debug('⚠️ lane in use');
			return;
			// if ($manually_run) {
			// self::debug('......crawler started (manually_rund)......');
			// Log pid to prevent from multi running
			// if (defined('LITESPEED_CLI')) {
			// Take over lane
			// self::debug('⚠️⚠️⚠️ Forced take over lane (CLI)');
			// $this->_take_over_lane();
			// }
			// }
		}
		self::debug('......crawler started......');

		// for the first time running
		if (!$this->_summary || !Data::cls()->tb_exist('crawler') || !Data::cls()->tb_exist('crawler_blacklist')) {
			$this->cls('Crawler_Map')->gen();
		}

		// if finished last time, regenerate sitemap
		if ($this->_summary['done'] === 'touchedEnd') {
			// check whole crawling interval
			$last_finished_at = $this->_summary['last_full_time_cost'] + $this->_summary['this_full_beginning_time'];
			if (!$manually_run && time() - $last_finished_at < $this->conf(Base::O_CRAWLER_CRAWL_INTERVAL)) {
				self::debug('Cron abort: cache warmed already.');
				// if not reach whole crawling interval, exit
				$this->Release_lane();
				return;
			}
			self::debug('TouchedEnd. regenerate sitemap....');
			$this->cls('Crawler_Map')->gen();
		}

		$this->list_crawlers();

		// Skip the crawlers that in bypassed list
		while (!$this->is_active($this->_summary['curr_crawler']) && $this->_summary['curr_crawler'] < count($this->_crawlers)) {
			self::debug('Skipped the Crawler #' . $this->_summary['curr_crawler'] . ' ......');
			++$this->_summary['curr_crawler'];
		}
		if ($this->_summary['curr_crawler'] >= count($this->_crawlers)) {
			$this->_end_reason = 'end';
			$this->_terminate_running();
			$this->Release_lane();
			return;
		}

		// In case crawlers are all done but not reload, reload it
		if (empty($this->_summary['curr_crawler']) || empty($this->_crawlers[$this->_summary['curr_crawler']])) {
			$this->_summary['curr_crawler']                                   = 0;
			$this->_summary['crawler_stats'][$this->_summary['curr_crawler']] = array();
		}

		$res = $this->load_conf();
		if (!$res) {
			self::debug('Load conf failed');
			$this->_terminate_running();
			$this->Release_lane();
			return;
		}

		try {
			$this->_engine_start();
			$this->Release_lane();
		} catch (\Exception $e) {
			self::debug('🛑 ' . $e->getMessage());
		}
	}

	/**
	 * Load conf before running crawler
	 *
	 * @since  3.0
	 * @access private
	 */
	private function load_conf() {
		$this->_crawler_conf['base'] = site_url();

		$current_crawler = $this->_crawlers[$this->_summary['curr_crawler']];

		/**
		 * Check cookie crawler
		 *
		 * @since  2.8
		 */
		foreach ($current_crawler as $k => $v) {
			if (strpos($k, 'cookie:') !== 0) {
				continue;
			}

			if ($v == '_null') {
				continue;
			}

			$this->_crawler_conf['cookies'][substr($k, 7)] = $v;
		}

		/**
		 * Set WebP simulation
		 *
		 * @since  1.9.1
		 */
		if (!empty($current_crawler['webp'])) {
			$this->_crawler_conf['headers'][] = 'Accept: image/' . ($this->conf(Base::O_IMG_OPTM_WEBP) == 2 ? 'avif' : 'webp') . ',*/*';
		}

		/**
		 * Set mobile crawler
		 *
		 * @since  2.8
		 */
		if (!empty($current_crawler['mobile'])) {
			$this->_crawler_conf['ua'] = 'Mobile iPhone';
		}

		/**
		 * Limit delay to use server setting
		 *
		 * @since 1.8.3
		 */
		$this->_crawler_conf['run_delay'] = 500; // microseconds
		if (defined('LITESPEED_CRAWLER_USLEEP') && LITESPEED_CRAWLER_USLEEP > $this->_crawler_conf['run_delay']) {
			$this->_crawler_conf['run_delay'] = LITESPEED_CRAWLER_USLEEP;
		}
		if (!empty($_SERVER[Base::ENV_CRAWLER_USLEEP]) && $_SERVER[Base::ENV_CRAWLER_USLEEP] > $this->_crawler_conf['run_delay']) {
			$this->_crawler_conf['run_delay'] = $_SERVER[Base::ENV_CRAWLER_USLEEP];
		}

		$this->_crawler_conf['run_duration'] = $this->get_crawler_duration();

		$this->_crawler_conf['load_limit'] = $this->conf(Base::O_CRAWLER_LOAD_LIMIT);
		if (!empty($_SERVER[Base::ENV_CRAWLER_LOAD_LIMIT_ENFORCE])) {
			$this->_crawler_conf['load_limit'] = $_SERVER[Base::ENV_CRAWLER_LOAD_LIMIT_ENFORCE];
		} elseif (!empty($_SERVER[Base::ENV_CRAWLER_LOAD_LIMIT]) && $_SERVER[Base::ENV_CRAWLER_LOAD_LIMIT] < $this->_crawler_conf['load_limit']) {
			$this->_crawler_conf['load_limit'] = $_SERVER[Base::ENV_CRAWLER_LOAD_LIMIT];
		}
		if ($this->_crawler_conf['load_limit'] == 0) {
			self::debug('🛑 Terminated crawler due to load limit set to 0');
			return false;
		}

		/**
		 * Set role simulation
		 *
		 * @since 1.9.1
		 */
		if (!empty($current_crawler['uid'])) {
			if (!$this->_server_ip) {
				self::debug('🛑 Terminated crawler due to Server IP not set');
				return false;
			}
			// Get role simulation vary name
			$vary_name                                  = $this->cls('Vary')->get_vary_name();
			$vary_val                                   = $this->cls('Vary')->finalize_default_vary($current_crawler['uid']);
			$this->_crawler_conf['cookies'][$vary_name] = $vary_val;
			$this->_crawler_conf['cookies']['litespeed_hash'] = Router::cls()->get_hash($current_crawler['uid']);
		}

		return true;
	}

	/**
	 * Get crawler duration allowance
	 *
	 * @since 7.0
	 */
	public function get_crawler_duration() {
		$RUN_DURATION = defined('LITESPEED_CRAWLER_DURATION') ? LITESPEED_CRAWLER_DURATION : 900;
		if ($RUN_DURATION > 900) {
			$RUN_DURATION = 900; // reset to default value if defined in conf file is higher than 900 seconds for security enhancement
		}
		return $RUN_DURATION;
	}

	/**
	 * Start crawler
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _engine_start() {
		// check if is running
		// if ($this->_summary['is_running'] && time() - $this->_summary['is_running'] < $this->_crawler_conf['run_duration']) {
		// $this->_end_reason = 'stopped';
		// self::debug('The crawler is running.');
		// return;
		// }

		// check current load
		$this->_adjust_current_threads();
		if ($this->_cur_threads == 0) {
			$this->_end_reason = 'stopped_highload';
			self::debug('Stopped due to heavy load.');
			return;
		}

		// log started time
		self::save_summary(array( 'last_start_time' => time() ));

		// set time limit
		$maxTime = (int) ini_get('max_execution_time');
		self::debug('ini_get max_execution_time=' . $maxTime);
		if ($maxTime == 0) {
			$maxTime = 300; // hardlimit
		} else {
			$maxTime -= 5;
		}
		if ($maxTime >= $this->_crawler_conf['run_duration']) {
			$maxTime = $this->_crawler_conf['run_duration'];
			self::debug('Use run_duration setting as max_execution_time=' . $maxTime);
		} elseif (ini_set('max_execution_time', $this->_crawler_conf['run_duration'] + 15) !== false) {
			$maxTime = $this->_crawler_conf['run_duration'];
			self::debug('ini_set max_execution_time=' . $maxTime);
		}
		self::debug('final max_execution_time=' . $maxTime);
		$this->_max_run_time = $maxTime + time();

		// mark running
		$this->_prepare_running();
		// run crawler
		$this->_do_running();
		$this->_terminate_running();
	}

	/**
	 * Get server load
	 *
	 * @since 5.5
	 */
	public function get_server_load() {
		/**
		 * If server is windows, exit
		 *
		 * @see  https://wordpress.org/support/topic/crawler-keeps-causing-crashes/
		 */
		if (!function_exists('sys_getloadavg')) {
			return -1;
		}

		$curload = sys_getloadavg();
		$curload = $curload[0];
		self::debug('Server load: ' . $curload);
		return $curload;
	}

	/**
	 * Adjust threads dynamically
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _adjust_current_threads() {
		$curload = $this->get_server_load();
		if ($curload == -1) {
			self::debug('set threads=0 due to func sys_getloadavg not exist!');
			$this->_cur_threads = 0;
			return;
		}

		$curload /= $this->_ncpu;
		// $curload = 1;
		$CRAWLER_THREADS = defined('LITESPEED_CRAWLER_THREADS') ? LITESPEED_CRAWLER_THREADS : 3;

		if ($this->_cur_threads == -1) {
			// init
			if ($curload > $this->_crawler_conf['load_limit']) {
				$curthreads = 0;
			} elseif ($curload >= $this->_crawler_conf['load_limit'] - 1) {
				$curthreads = 1;
			} else {
				$curthreads = intval($this->_crawler_conf['load_limit'] - $curload);
				if ($curthreads > $CRAWLER_THREADS) {
					$curthreads = $CRAWLER_THREADS;
				}
			}
		} else {
			// adjust
			$curthreads = $this->_cur_threads;
			if ($curload >= $this->_crawler_conf['load_limit'] + 1) {
				sleep(5); // sleep 5 secs
				if ($curthreads >= 1) {
					--$curthreads;
				}
			} elseif ($curload >= $this->_crawler_conf['load_limit']) {
				// if ( $curthreads > 1 ) {// if already 1, keep
				--$curthreads;
				// }
			} elseif ($curload + 1 < $this->_crawler_conf['load_limit']) {
				if ($curthreads < $CRAWLER_THREADS) {
					++$curthreads;
				}
			}
		}

		// $log = 'set current threads = ' . $curthreads . ' previous=' . $this->_cur_threads
		// . ' max_allowed=' . $CRAWLER_THREADS . ' load_limit=' . $this->_crawler_conf[ 'load_limit' ] . ' current_load=' . $curload;

		$this->_cur_threads     = $curthreads;
		$this->_cur_thread_time = time();
	}

	/**
	 * Mark running status
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _prepare_running() {
		$this->_summary['is_running']   = time();
		$this->_summary['done']         = 0; // reset done status
		$this->_summary['last_status']  = 'prepare running';
		$this->_summary['last_crawled'] = 0;

		// Current crawler starttime mark
		if ($this->_summary['last_pos'] == 0) {
			$this->_summary['curr_crawler_beginning_time'] = time();
		}

		if ($this->_summary['curr_crawler'] == 0 && $this->_summary['last_pos'] == 0) {
			$this->_summary['this_full_beginning_time'] = time();
			$this->_summary['list_size']                = $this->cls('Crawler_Map')->count_map();
		}

		if ($this->_summary['end_reason'] == 'end' && $this->_summary['last_pos'] == 0) {
			$this->_summary['crawler_stats'][$this->_summary['curr_crawler']] = array();
		}

		self::save_summary();
	}

	/**
	 * Take over lane
	 *
	 * @since 6.1
	 */
	private function _take_over_lane() {
		self::debug('Take over lane as lane is free: ' . $this->json_local_path() . '.pid');
		File::save($this->json_local_path() . '.pid', LITESPEED_LANE_HASH);
	}

	/**
	 * Update lane file
	 *
	 * @since 6.1
	 */
	private function _touch_lane() {
		touch($this->json_local_path() . '.pid');
	}

	/**
	 * Release lane file
	 *
	 * @since 6.1
	 */
	public function Release_lane() {
		$lane_file = $this->json_local_path() . '.pid';
		if (!file_exists($lane_file)) {
			return;
		}

		self::debug('Release lane');
		unlink($lane_file);
	}

	/**
	 * Check if lane is used by other crawlers
	 *
	 * @since 6.1
	 */
	private function _check_valid_lane( $strict_mode = false ) {
		// Check lane hash
		$lane_file = $this->json_local_path() . '.pid';
		if ($strict_mode) {
			if (!file_exists($lane_file)) {
				self::debug("lane file not existed, strict mode is false [file] $lane_file");
				return false;
			}
		}
		$pid = File::read($lane_file);
		if ($pid && LITESPEED_LANE_HASH != $pid) {
			// If lane file is older than 1h, ignore
			if (time() - filemtime($lane_file) > 3600) {
				self::debug('Lane file is older than 1h, releasing lane');
				$this->Release_lane();
				return true;
			}
			return false;
		}
		return true;
	}

	/**
	 * Test port for simulator
	 *
	 * @since  7.0
	 * @access private
	 * @return bool true if success and can continue crawling, false if failed and need to stop
	 */
	private function _test_port() {
		if (!$this->_server_ip) {
			self::debug('❌ Server IP not set');
			return false;
		}
		if (defined('LITESPEED_CRAWLER_LOCAL_PORT')) {
			self::debug('✅ LITESPEED_CRAWLER_LOCAL_PORT already defined');
			return true;
		}
		// Don't repeat testing in 120s
		if (!empty($this->_summary['test_port_tts']) && time() - $this->_summary['test_port_tts'] < 120) {
			if (!empty($this->_summary['test_port'])) {
				self::debug('✅ Use tested local port: ' . $this->_summary['test_port']);
				define('LITESPEED_CRAWLER_LOCAL_PORT', $this->_summary['test_port']);
				return true;
			}
			return false;
		}
		$this->_summary['test_port_tts'] = time();
		self::save_summary();

		$options = $this->_get_curl_options();
		$home    = home_url();
		File::save(LITESPEED_STATIC_DIR . '/crawler/test_port.txt', $home, true);
		$url        = LITESPEED_STATIC_URL . '/crawler/test_port.txt';
		$parsed_url = parse_url($url);
		if (empty($parsed_url['host'])) {
			self::debug('❌ Test port failed, invalid URL: ' . $url);
			return false;
		}
		$resolved                              = $parsed_url['host'] . ':443:' . $this->_server_ip;
		$options[CURLOPT_RESOLVE]              = array( $resolved );
		$options[CURLOPT_DNS_USE_GLOBAL_CACHE] = false;
		$options[CURLOPT_HEADER]               = false;
		self::debug('Test local 443 port for ' . $resolved);

		$ch = curl_init();
		curl_setopt_array($ch, $options);
		curl_setopt($ch, CURLOPT_URL, $url);
		$result      = curl_exec($ch);
		$test_result = false;
		if (curl_errno($ch) || $result !== $home) {
			if (curl_errno($ch)) {
				self::debug('❌ Test port curl error: [errNo] ' . curl_errno($ch) . ' [err] ' . curl_error($ch));
			} elseif ($result !== $home) {
				self::debug('❌ Test port response is wrong: ' . $result);
			}
			self::debug('❌ Test local 443 port failed, try port 80');

			// Try port 80
			$resolved                 = $parsed_url['host'] . ':80:' . $this->_server_ip;
			$options[CURLOPT_RESOLVE] = array( $resolved );
			$url                      = str_replace('https://', 'http://', $url);
			if (!in_array('X-Forwarded-Proto: https', $options[CURLOPT_HTTPHEADER])) {
				$options[CURLOPT_HTTPHEADER][] = 'X-Forwarded-Proto: https';
			}
			// $options[CURLOPT_HTTPHEADER][] = 'X-Forwarded-SSL: on';
			$ch = curl_init();
			curl_setopt_array($ch, $options);
			curl_setopt($ch, CURLOPT_URL, $url);
			$result = curl_exec($ch);
			if (curl_errno($ch)) {
				self::debug('❌ Test port curl error: [errNo] ' . curl_errno($ch) . ' [err] ' . curl_error($ch));
			} elseif ($result !== $home) {
				self::debug('❌ Test port response is wrong: ' . $result);
			} else {
				self::debug('✅ Test local 80 port successfully');
				define('LITESPEED_CRAWLER_LOCAL_PORT', 80);
				$this->_summary['test_port'] = 80;
				$test_result                 = true;
			}
			// self::debug('Response data: ' . $result);
			// $this->Release_lane();
			// exit($result);
		} else {
			self::debug('✅ Tested local 443 port successfully');
			define('LITESPEED_CRAWLER_LOCAL_PORT', 443);
			$this->_summary['test_port'] = 443;
			$test_result                 = true;
		}
		self::save_summary();
		curl_close($ch);
		return $test_result;
	}

	/**
	 * Run crawler
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _do_running() {
		$options = $this->_get_curl_options(true);

		// If is role simulator and not defined local port, check port once
		$test_result = $this->_test_port();
		if (!$test_result) {
			$this->_end_reason = 'port_test_failed';
			self::debug('❌ Test port failed, crawler stopped.');
			return;
		}

		while ($urlChunks = $this->cls('Crawler_Map')->list_map(self::CHUNKS, $this->_summary['last_pos'])) {
			// self::debug('$urlChunks=' . count($urlChunks) . ' $this->_cur_threads=' . $this->_cur_threads);
			// start crawling
			$urlChunks = array_chunk($urlChunks, $this->_cur_threads);
			// self::debug('$urlChunks after array_chunk: ' . count($urlChunks));
			foreach ($urlChunks as $rows) {
				if (!$this->_check_valid_lane(true)) {
					$this->_end_reason = 'lane_invalid';
					self::debug('🛑 The crawler lane is used by newer crawler.');
					throw new \Exception('invalid crawler lane');
				}
				// Update time
				$this->_touch_lane();

				// self::debug('chunk fetching count($rows)= ' . count($rows));
				// multi curl
				$rets = $this->_multi_request($rows, $options);

				// check result headers
				foreach ($rows as $row) {
					// self::debug('chunk fetching 553');
					if (empty($rets[$row['id']])) {
						// If already in blacklist, no curl happened, no corresponding record
						continue;
					}
					// self::debug('chunk fetching 557');
					// check response
					if ($rets[$row['id']]['code'] == 428) {
						// HTTP/1.1 428 Precondition Required (need to test)
						$this->_end_reason = 'crawler_disabled';
						self::debug('crawler_disabled');
						return;
					}

					$status = $this->_status_parse($rets[$row['id']]['header'], $rets[$row['id']]['code'], $row['url']); // B or H or M or N(nocache)
					self::debug('[status] ' . $this->_status2title($status) . "\t\t [url] " . $row['url']);
					$this->_map_status_list[$status][$row['id']] = array(
						'url' => $row['url'],
						'code' => $rets[$row['id']]['code'], // 201 or 200 or 404
					);
					if (empty($this->_summary['crawler_stats'][$this->_summary['curr_crawler']][$status])) {
						$this->_summary['crawler_stats'][$this->_summary['curr_crawler']][$status] = 0;
					}
					++$this->_summary['crawler_stats'][$this->_summary['curr_crawler']][$status];
				}

				// update offset position
				$_time                              = time();
				$this->_summary['last_count']       = count($rows);
				$this->_summary['last_pos']        += $this->_summary['last_count'];
				$this->_summary['last_crawled']    += $this->_summary['last_count'];
				$this->_summary['last_update_time'] = $_time;
				$this->_summary['last_status']      = 'updated position';
				// self::debug("chunk fetching 604 last_pos:{$this->_summary['last_pos']} last_count:{$this->_summary['last_count']} last_crawled:{$this->_summary['last_crawled']}");
				// check duration
				if ($this->_summary['last_update_time'] > $this->_max_run_time) {
					$this->_end_reason = 'stopped_maxtime';
					self::debug('Terminated due to maxtime');
					return;
					// return __('Stopped due to exceeding defined Maximum Run Time', 'litespeed-cache');
				}

				// make sure at least each 10s save meta & map status once
				if ($_time - $this->_summary['meta_save_time'] > 10) {
					$this->_map_status_list = $this->cls('Crawler_Map')->save_map_status($this->_map_status_list, $this->_summary['curr_crawler']);
					self::save_summary();
				}
				// self::debug('chunk fetching 597');
				// check if need to reset pos each 5s
				if ($_time > $this->_summary['pos_reset_check']) {
					$this->_summary['pos_reset_check'] = $_time + 5;
					if (file_exists($this->_resetfile) && unlink($this->_resetfile)) {
						self::debug('Terminated due to reset file');

						$this->_summary['last_pos']                                       = 0;
						$this->_summary['curr_crawler']                                   = 0;
						$this->_summary['crawler_stats'][$this->_summary['curr_crawler']] = array();
						// reset done status
						$this->_summary['done']                     = 0;
						$this->_summary['this_full_beginning_time'] = 0;
						$this->_end_reason                          = 'stopped_reset';
						return;
						// return __('Stopped due to reset meta position', 'litespeed-cache');
					}
				}
				// self::debug('chunk fetching 615');
				// check loads
				if ($this->_summary['last_update_time'] - $this->_cur_thread_time > 60) {
					$this->_adjust_current_threads();
					if ($this->_cur_threads == 0) {
						$this->_end_reason = 'stopped_highload';
						self::debug('🛑 Terminated due to highload');
						return;
						// return __('Stopped due to load over limit', 'litespeed-cache');
					}
				}

				$this->_summary['last_status'] = 'sleeping ' . $this->_crawler_conf['run_delay'] . 'ms';

				usleep($this->_crawler_conf['run_delay']);
			}
			// self::debug('chunk fetching done');
		}

		// All URLs are done for current crawler
		$this->_end_reason = 'end';
		$this->_summary['crawler_stats'][$this->_summary['curr_crawler']]['W'] = 0;
		self::debug('Crawler #' . $this->_summary['curr_crawler'] . ' touched end');
	}

	/**
	 * Send multi curl requests
	 * If res=B, bypass request and won't return
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _multi_request( $rows, $options ) {
		if (!function_exists('curl_multi_init')) {
			exit('curl_multi_init disabled');
		}
		$mh                  = curl_multi_init();
		$CRAWLER_DROP_DOMAIN = defined('LITESPEED_CRAWLER_DROP_DOMAIN') ? LITESPEED_CRAWLER_DROP_DOMAIN : false;
		$curls               = array();
		foreach ($rows as $row) {
			if (substr($row['res'], $this->_summary['curr_crawler'], 1) == self::STATUS_BLACKLIST) {
				continue;
			}
			if (substr($row['res'], $this->_summary['curr_crawler'], 1) == self::STATUS_NOCACHE) {
				continue;
			}

			if (!function_exists('curl_init')) {
				exit('curl_init disabled');
			}

			$curls[$row['id']] = curl_init();

			// Append URL
			$url = $row['url'];
			if ($CRAWLER_DROP_DOMAIN) {
				$url = $this->_crawler_conf['base'] . $row['url'];
			}

			// IP resolve
			if ((!empty($this->_crawler_conf['cookies']) && !empty($this->_crawler_conf['cookies']['litespeed_hash'])) || $this->_server_ip) {
				$parsed_url = parse_url($url);
				// self::debug('Crawl role simulator, required to use localhost for resolve');

				if (!empty($parsed_url['host'])) {
					$dom                                   = $parsed_url['host'];
					$port                                  = defined('LITESPEED_CRAWLER_LOCAL_PORT') ? LITESPEED_CRAWLER_LOCAL_PORT : '443';
					$resolved                              = $dom . ':' . $port . ':' . $this->_server_ip;
					$options[CURLOPT_RESOLVE]              = array( $resolved );
					$options[CURLOPT_DNS_USE_GLOBAL_CACHE] = false;
					// $options[CURLOPT_PORT] = $port;
					if ($port == 80) {
						$url = str_replace('https://', 'http://', $url);
						if (!in_array('X-Forwarded-Proto: https', $options[CURLOPT_HTTPHEADER])) {
							$options[CURLOPT_HTTPHEADER][] = 'X-Forwarded-Proto: https';
						}
					}
					self::debug('Resolved DNS for ' . $resolved);
				}
			}

			curl_setopt($curls[$row['id']], CURLOPT_URL, $url);
			self::debug('Crawling [url] ' . $url . ($url == $row['url'] ? '' : ' [ori] ' . $row['url']));

			curl_setopt_array($curls[$row['id']], $options);

			curl_multi_add_handle($mh, $curls[$row['id']]);
		}

		// execute curl
		if ($curls) {
			do {
				$status = curl_multi_exec($mh, $active);
				if ($active) {
					curl_multi_select($mh);
				}
			} while ($active && $status == CURLM_OK);
		}

		// curl done
		$ret = array();
		foreach ($rows as $row) {
			if (substr($row['res'], $this->_summary['curr_crawler'], 1) == self::STATUS_BLACKLIST) {
				continue;
			}
			if (substr($row['res'], $this->_summary['curr_crawler'], 1) == self::STATUS_NOCACHE) {
				continue;
			}
			// self::debug('-----debug3');
			$ch = $curls[$row['id']];

			// Parse header
			$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
			$content     = curl_multi_getcontent($ch);
			$header      = substr($content, 0, $header_size);

			$ret[$row['id']] = array(
				'header' => $header,
				'code' => curl_getinfo($ch, CURLINFO_HTTP_CODE),
			);
			// self::debug('-----debug4');
			curl_multi_remove_handle($mh, $ch);
			curl_close($ch);
		}
		// self::debug('-----debug5');
		curl_multi_close($mh);
		// self::debug('-----debug6');
		return $ret;
	}

	/**
	 * Translate the status to title
	 *
	 * @since 6.0
	 */
	private function _status2title( $status ) {
		if ($status == self::STATUS_HIT) {
			return '✅ Hit';
		}
		if ($status == self::STATUS_MISS) {
			return '😊 Miss';
		}
		if ($status == self::STATUS_BLACKLIST) {
			return '😅 Blacklisted';
		}
		if ($status == self::STATUS_NOCACHE) {
			return '😅 Blacklisted';
		}
		return '🛸 Unknown';
	}

	/**
	 * Check returned curl header to find if cached or not
	 *
	 * @since  2.0
	 * @access private
	 */
	private function _status_parse( $header, $code, $url ) {
		// self::debug('http status code: ' . $code . ' [headers]', $header);
		if ($code == 201) {
			return self::STATUS_HIT;
		}

		if (stripos($header, 'X-Litespeed-Cache-Control: no-cache') !== false) {
			// If is from DIVI, taken as miss
			if (defined('LITESPEED_CRAWLER_IGNORE_NONCACHEABLE') && LITESPEED_CRAWLER_IGNORE_NONCACHEABLE) {
				return self::STATUS_MISS;
			}

			// If blacklist is disabled
			if ((defined('LITESPEED_CRAWLER_DISABLE_BLOCKLIST') && LITESPEED_CRAWLER_DISABLE_BLOCKLIST) || apply_filters('litespeed_crawler_disable_blocklist', false, $url)) {
				return self::STATUS_MISS;
			}

			return self::STATUS_NOCACHE; // Blacklist
		}

		$_cache_headers = array( 'x-litespeed-cache', 'x-qc-cache', 'x-lsadc-cache' );

		foreach ($_cache_headers as $_header) {
			if (stripos($header, $_header) !== false) {
				if (stripos($header, $_header . ': bkn') !== false) {
					return self::STATUS_HIT; // Hit
				}
				if (stripos($header, $_header . ': miss') !== false) {
					return self::STATUS_MISS; // Miss
				}
				return self::STATUS_HIT; // Hit
			}
		}

		// If blacklist is disabled
		if ((defined('LITESPEED_CRAWLER_DISABLE_BLOCKLIST') && LITESPEED_CRAWLER_DISABLE_BLOCKLIST) || apply_filters('litespeed_crawler_disable_blocklist', false, $url)) {
			return self::STATUS_MISS;
		}

		return self::STATUS_BLACKLIST; // Blacklist
	}

	/**
	 * Get curl_options
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _get_curl_options( $crawler_only = false ) {
		$CRAWLER_TIMEOUT               = defined('LITESPEED_CRAWLER_TIMEOUT') ? LITESPEED_CRAWLER_TIMEOUT : 30;
		$options                       = array(
			CURLOPT_RETURNTRANSFER => true,
			CURLOPT_HEADER => true,
			CURLOPT_CUSTOMREQUEST => 'GET',
			CURLOPT_FOLLOWLOCATION => false,
			CURLOPT_ENCODING => 'gzip',
			CURLOPT_CONNECTTIMEOUT => 10,
			CURLOPT_TIMEOUT => $CRAWLER_TIMEOUT, // Larger timeout to avoid incorrect blacklist addition #900171
			CURLOPT_SSL_VERIFYHOST => 0,
			CURLOPT_SSL_VERIFYPEER => false,
			CURLOPT_NOBODY => false,
			CURLOPT_HTTPHEADER => $this->_crawler_conf['headers'],
		);
		$options[CURLOPT_HTTPHEADER][] = 'Cache-Control: max-age=0';

		/**
		 * Try to enable http2 connection (only available since PHP7+)
		 *
		 * @since  1.9.1
		 * @since  2.2.7 Commented due to cause no-cache issue
		 * @since  2.9.1+ Fixed wrongly usage of CURL_HTTP_VERSION_1_1 const
		 */
		$options[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_1_1;
		// $options[ CURL_HTTP_VERSION_2 ] = 1;

		// if is walker
		// $options[ CURLOPT_FRESH_CONNECT ] = true;

		// Referer
		if (isset($_SERVER['HTTP_HOST']) && isset($_SERVER['REQUEST_URI'])) {
			$options[CURLOPT_REFERER] = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
		}

		// User Agent
		if ($crawler_only) {
			if (strpos($this->_crawler_conf['ua'], self::FAST_USER_AGENT) !== 0) {
				$this->_crawler_conf['ua'] = self::FAST_USER_AGENT . ' ' . $this->_crawler_conf['ua'];
			}
		}
		$options[CURLOPT_USERAGENT] = $this->_crawler_conf['ua'];

		// Cookies
		$cookies = array();
		foreach ($this->_crawler_conf['cookies'] as $k => $v) {
			if (!$v) {
				continue;
			}
			$cookies[] = $k . '=' . urlencode($v);
		}
		if ($cookies) {
			$options[CURLOPT_COOKIE] = implode('; ', $cookies);
		}

		return $options;
	}

	/**
	 * Self curl to get HTML content
	 *
	 * @since  3.3
	 */
	public function self_curl( $url, $ua, $uid = false, $accept = false ) {
		// $accept not in use yet
		$this->_crawler_conf['base'] = site_url();
		$this->_crawler_conf['ua']   = $ua;
		if ($accept) {
			$this->_crawler_conf['headers'] = array( 'Accept: ' . $accept );
		}
		$options = $this->_get_curl_options();

		if ($uid) {
			$this->_crawler_conf['cookies']['litespeed_flash_hash'] = Router::cls()->get_flash_hash($uid);
			$parsed_url = parse_url($url);

			if (!empty($parsed_url['host'])) {
				$dom                                   = $parsed_url['host'];
				$port                                  = defined('LITESPEED_CRAWLER_LOCAL_PORT') ? LITESPEED_CRAWLER_LOCAL_PORT : '443';
				$resolved                              = $dom . ':' . $port . ':' . $this->_server_ip;
				$options[CURLOPT_RESOLVE]              = array( $resolved );
				$options[CURLOPT_DNS_USE_GLOBAL_CACHE] = false;
				$options[CURLOPT_PORT]                 = $port;
				self::debug('Resolved DNS for ' . $resolved);
			}
		}

		$options[CURLOPT_HEADER]         = false;
		$options[CURLOPT_FOLLOWLOCATION] = true;

		$ch = curl_init();
		curl_setopt_array($ch, $options);
		curl_setopt($ch, CURLOPT_URL, $url);
		$result = curl_exec($ch);
		$code   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
		curl_close($ch);

		if ($code != 200) {
			self::debug('❌ Response code is not 200 in self_curl() [code] ' . var_export($code, true));
			return false;
		}

		return $result;
	}

	/**
	 * Terminate crawling
	 *
	 * @since  1.1.0
	 * @access private
	 */
	private function _terminate_running() {
		$this->_map_status_list = $this->cls('Crawler_Map')->save_map_status($this->_map_status_list, $this->_summary['curr_crawler']);

		if ($this->_end_reason == 'end') {
			// Current crawler is fully done
			// $end_reason = sprintf( __( 'Crawler %s reached end of sitemap file.', 'litespeed-cache' ), '#' . ( $this->_summary['curr_crawler'] + 1 ) );
			++$this->_summary['curr_crawler']; // Jump to next crawler
			// $this->_summary[ 'crawler_stats' ][ $this->_summary[ 'curr_crawler' ] ] = array(); // reset this at next crawl time
			$this->_summary['last_pos']                = 0; // reset last position
			$this->_summary['last_crawler_total_cost'] = time() - $this->_summary['curr_crawler_beginning_time'];
			$count_crawlers                            = count($this->list_crawlers());
			if ($this->_summary['curr_crawler'] >= $count_crawlers) {
				self::debug('_terminate_running Touched end, whole crawled. Reload crawler!');
				$this->_summary['curr_crawler'] = 0;
				// $this->_summary[ 'crawler_stats' ][ $this->_summary[ 'curr_crawler' ] ] = array();
				$this->_summary['done']                = 'touchedEnd'; // log done status
				$this->_summary['last_full_time_cost'] = time() - $this->_summary['this_full_beginning_time'];
			}
		}
		$this->_summary['last_status'] = 'stopped';
		$this->_summary['is_running']  = 0;
		$this->_summary['end_reason']  = $this->_end_reason;
		self::save_summary();
	}

	/**
	 * List all crawlers ( tagA => [ valueA => titleA, ... ] ...)
	 *
	 * @since    1.9.1
	 * @access   public
	 */
	public function list_crawlers() {
		if ($this->_crawlers) {
			return $this->_crawlers;
		}

		$crawler_factors = array();

		// Add default Guest crawler
		$crawler_factors['uid'] = array( 0 => __('Guest', 'litespeed-cache') );

		// WebP on/off
		if ($this->conf(Base::O_IMG_OPTM_WEBP)) {
			$crawler_factors['webp'] = array( 1 => $this->cls('Media')->next_gen_image_title() );
			if (apply_filters('litespeed_crawler_webp', false)) {
				$crawler_factors['webp'][0] = '';
			}
		}

		// Guest Mode on/off
		if ($this->conf(Base::O_GUEST)) {
			$vary_name = $this->cls('Vary')->get_vary_name();
			$vary_val  = 'guest_mode:1';
			if (!defined('LSCWP_LOG')) {
				$vary_val = md5($this->conf(Base::HASH) . $vary_val);
			}
			$crawler_factors['cookie:' . $vary_name] = array(
				$vary_val => '',
				'_null' => '<font data-balloon-pos="up" aria-label="Guest Mode">👒</font>',
			);
		}

		// Mobile crawler
		if ($this->conf(Base::O_CACHE_MOBILE)) {
			$crawler_factors['mobile'] = array(
				1 => '<font data-balloon-pos="up" aria-label="Mobile">📱</font>',
				0 => '',
			);
		}

		// Get roles set
		// List all roles
		foreach ($this->conf(Base::O_CRAWLER_ROLES) as $v) {
			$role_title = '';
			$udata      = get_userdata($v);
			if (isset($udata->roles) && is_array($udata->roles)) {
				$tmp        = array_values($udata->roles);
				$role_title = array_shift($tmp);
			}
			if (!$role_title) {
				continue;
			}

			$crawler_factors['uid'][$v] = ucfirst($role_title);
		}

		// Cookie crawler
		foreach ($this->conf(Base::O_CRAWLER_COOKIES) as $v) {
			if (empty($v['name'])) {
				continue;
			}

			$this_cookie_key = 'cookie:' . $v['name'];

			$crawler_factors[$this_cookie_key] = array();

			foreach ($v['vals'] as $v2) {
				$crawler_factors[$this_cookie_key][$v2] =
					$v2 == '_null' ? '' : '<font data-balloon-pos="up" aria-label="Cookie">🍪</font>' . esc_html($v['name']) . '=' . esc_html($v2);
			}
		}

		// Crossing generate the crawler list
		$this->_crawlers = $this->_recursive_build_crawler($crawler_factors);

		return $this->_crawlers;
	}

	/**
	 * Build a crawler list recursively
	 *
	 * @since 2.8
	 * @access private
	 */
	private function _recursive_build_crawler( $crawler_factors, $group = array(), $i = 0 ) {
		$current_factor = array_keys($crawler_factors);
		$current_factor = $current_factor[$i];

		$if_touch_end = $i + 1 >= count($crawler_factors);

		$final_list = array();

		foreach ($crawler_factors[$current_factor] as $k => $v) {
			// Don't alter $group bcos of loop usage
			$item          = $group;
			$item['title'] = !empty($group['title']) ? $group['title'] : '';
			if ($v) {
				if ($item['title']) {
					$item['title'] .= ' - ';
				}
				$item['title'] .= $v;
			}
			$item[$current_factor] = $k;

			if ($if_touch_end) {
				$final_list[] = $item;
			} else {
				// Inception: next layer
				$final_list = array_merge($final_list, $this->_recursive_build_crawler($crawler_factors, $item, $i + 1));
			}
		}

		return $final_list;
	}

	/**
	 * Return crawler meta file local path
	 *
	 * @since    6.1
	 * @access public
	 */
	public function json_local_path() {
		// if (!file_exists(LITESPEED_STATIC_DIR . '/crawler/' . $this->_sitemeta)) {
		// return false;
		// }

		return LITESPEED_STATIC_DIR . '/crawler/' . $this->_sitemeta;
	}

	/**
	 * Return crawler meta file
	 *
	 * @since    1.1.0
	 * @access public
	 */
	public function json_path() {
		if (!file_exists(LITESPEED_STATIC_DIR . '/crawler/' . $this->_sitemeta)) {
			return false;
		}

		return LITESPEED_STATIC_URL . '/crawler/' . $this->_sitemeta;
	}

	/**
	 * Create reset pos file
	 *
	 * @since    1.1.0
	 * @access public
	 */
	public function reset_pos() {
		File::save($this->_resetfile, time(), true);

		self::save_summary(array( 'is_running' => 0 ));
	}

	/**
	 * Display status based by matching crawlers order
	 *
	 * @since  3.0
	 * @access public
	 */
	public function display_status( $status_row, $reason_set ) {
		if (!$status_row) {
			return '';
		}

		$_status_list = array(
			'-' => 'default',
			self::STATUS_MISS => 'primary',
			self::STATUS_HIT => 'success',
			self::STATUS_BLACKLIST => 'danger',
			self::STATUS_NOCACHE => 'warning',
		);

		$reason_set = explode(',', $reason_set);

		$status = '';
		foreach (str_split($status_row) as $k => $v) {
			$reason = $reason_set[$k];
			if ($reason == 'Man') {
				$reason = __('Manually added to blocklist', 'litespeed-cache');
			}
			if ($reason == 'Existed') {
				$reason = __('Previously existed in blocklist', 'litespeed-cache');
			}
			if ($reason) {
				$reason = 'data-balloon-pos="up" aria-label="' . $reason . '"';
			}
			$status .= '<i class="litespeed-dot litespeed-bg-' . $_status_list[$v] . '" ' . $reason . '>' . ($k + 1) . '</i>';
		}

		return $status;
	}

	/**
	 * Output info and exit
	 *
	 * @since    1.1.0
	 * @access protected
	 * @param  string $msg Error info
	 */
	protected function output( $msg ) {
		if (wp_doing_cron()) {
			echo $msg;
			// exit();
		} else {
			echo "<script>alert('" . htmlspecialchars($msg) . "');</script>";
			// exit;
		}
	}

	/**
	 * Handle all request actions from main cls
	 *
	 * @since  3.0
	 * @access public
	 */
	public function handler() {
		$type = Router::verify_type();

		switch ($type) {
			case self::TYPE_REFRESH_MAP:
            $this->cls('Crawler_Map')->gen(true);
				break;

			case self::TYPE_EMPTY:
            $this->cls('Crawler_Map')->empty_map();
				break;

			case self::TYPE_BLACKLIST_EMPTY:
            $this->cls('Crawler_Map')->blacklist_empty();
				break;

			case self::TYPE_BLACKLIST_DEL:
            if (!empty($_GET['id'])) {
					$this->cls('Crawler_Map')->blacklist_del($_GET['id']);
				}
				break;

			case self::TYPE_BLACKLIST_ADD:
            if (!empty($_GET['id'])) {
					$this->cls('Crawler_Map')->blacklist_add($_GET['id']);
				}
				break;

			case self::TYPE_START: // Handle the ajax request to proceed crawler manually by admin
            self::start_async();
				break;

			case self::TYPE_RESET:
            $this->reset_pos();
				break;

			default:
				break;
		}

		Admin::redirect();
	}
}
