<?php

/**
 * The optimize css class.
 *
 * @since      	2.3
 */

namespace LiteSpeed;

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

class CSS extends Base
{
	const LOG_TAG = '[CSS]';

	const TYPE_GEN_CCSS = 'gen_ccss';
	const TYPE_CLEAR_Q_CCSS = 'clear_q_ccss';

	protected $_summary;
	private $_queue;
	private $_endts;

	/**
	 * Init
	 *
	 * @since  3.0
	 */
	public function __construct()
	{
		$this->_summary = self::get_summary();
	}

	/**
	 * HTML lazyload CSS
	 * @since 4.0
	 */
	public function prepare_html_lazy()
	{
		return '<style>' . implode(',', $this->conf(self::O_OPTM_HTML_LAZY)) . '{content-visibility:auto;contain-intrinsic-size:1px 1000px;}</style>';
	}

	/**
	 * Output critical css
	 *
	 * @since  1.3
	 * @access public
	 */
	public function prepare_ccss()
	{
		// Get critical css for current page
		// Note: need to consider mobile
		$rules = $this->_ccss();
		if (!$rules) {
			return null;
		}

		$error_tag = '';
		if (substr($rules, 0, 2) == '/*' && substr($rules, -2) == '*/') {
			Core::comment('QUIC.cloud CCSS bypassed due to generation error ❌');
			$error_tag = ' data-error="failed to generate"';
		}

		// Append default critical css
		$rules .= $this->conf(self::O_OPTM_CCSS_CON);

		return '<style id="litespeed-ccss"' . $error_tag . '>' . $rules . '</style>';
	}

	/**
	 * Generate CCSS url tag
	 *
	 * @since 4.0
	 */
	private function _gen_ccss_file_tag($request_url)
	{
		if (is_404()) {
			return '404';
		}

		if ($this->conf(self::O_OPTM_CCSS_PER_URL)) {
			return $request_url;
		}

		$sep_uri = $this->conf(self::O_OPTM_CCSS_SEP_URI);
		if ($sep_uri && ($hit = Utility::str_hit_array($request_url, $sep_uri))) {
			Debug2::debug('[CCSS] Separate CCSS due to separate URI setting: ' . $hit);
			return $request_url;
		}

		$pt = Utility::page_type();

		$sep_pt = $this->conf(self::O_OPTM_CCSS_SEP_POSTTYPE);
		if (in_array($pt, $sep_pt)) {
			Debug2::debug('[CCSS] Separate CCSS due to posttype setting: ' . $pt);
			return $request_url;
		}

		// Per posttype
		return $pt;
	}

	/**
	 * The critical css content of the current page
	 *
	 * @since  2.3
	 */
	private function _ccss()
	{
		global $wp;
		$request_url = home_url($wp->request);

		$filepath_prefix = $this->_build_filepath_prefix('ccss');
		$url_tag = $this->_gen_ccss_file_tag($request_url);
		$vary = $this->cls('Vary')->finalize_full_varies();
		$filename = $this->cls('Data')->load_url_file($url_tag, $vary, 'ccss');
		if ($filename) {
			$static_file = LITESPEED_STATIC_DIR . $filepath_prefix . $filename . '.css';

			if (file_exists($static_file)) {
				Debug2::debug2('[CSS] existing ccss ' . $static_file);
				Core::comment('QUIC.cloud CCSS loaded ✅ ' . $filepath_prefix . $filename . '.css');
				return File::read($static_file);
			}
		}

		$uid = get_current_user_id();

		$ua = !empty($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';

		// Store it to prepare for cron
		Core::comment('QUIC.cloud CCSS in queue');
		$this->_queue = $this->load_queue('ccss');

		if (count($this->_queue) > 500) {
			self::debug('CCSS Queue is full - 500');
			return null;
		}

		$queue_k = (strlen($vary) > 32 ? md5($vary) : $vary) . ' ' . $url_tag;
		$this->_queue[$queue_k] = array(
			'url' => apply_filters('litespeed_ccss_url', $request_url),
			'user_agent' => substr($ua, 0, 200),
			'is_mobile' => $this->_separate_mobile(),
			'is_webp' => $this->cls('Media')->webp_support() ? 1 : 0,
			'uid' => $uid,
			'vary' => $vary,
			'url_tag' => $url_tag,
		); // Current UA will be used to request
		$this->save_queue('ccss', $this->_queue);
		self::debug('Added queue_ccss [url_tag] ' . $url_tag . ' [UA] ' . $ua . ' [vary] ' . $vary . ' [uid] ' . $uid);

		// Prepare cache tag for later purge
		Tag::add('CCSS.' . md5($queue_k));

		// For v4.1- clean up
		if (isset($this->_summary['ccss_type_history']) || isset($this->_summary['ccss_history']) || isset($this->_summary['queue_ccss'])) {
			if (isset($this->_summary['ccss_type_history'])) {
				unset($this->_summary['ccss_type_history']);
			}
			if (isset($this->_summary['ccss_history'])) {
				unset($this->_summary['ccss_history']);
			}
			if (isset($this->_summary['queue_ccss'])) {
				unset($this->_summary['queue_ccss']);
			}
			self::save_summary();
		}

		return null;
	}

	/**
	 * Cron ccss generation
	 *
	 * @since  2.3
	 * @access private
	 */
	public static function cron_ccss($continue = false)
	{
		$_instance = self::cls();
		return $_instance->_cron_handler('ccss', $continue);
	}

	/**
	 * Handle UCSS/CCSS cron
	 *
	 * @since 4.2
	 */
	private function _cron_handler($type, $continue)
	{
		$this->_queue = $this->load_queue($type);

		if (empty($this->_queue)) {
			return;
		}

		$type_tag = strtoupper($type);

		// For cron, need to check request interval too
		if (!$continue) {
			if (!empty($this->_summary['curr_request_' . $type]) && time() - $this->_summary['curr_request_' . $type] < 300 && !$this->conf(self::O_DEBUG)) {
				Debug2::debug('[' . $type_tag . '] Last request not done');
				return;
			}
		}

		$i = 0;
		$timeoutLimit = ini_get('max_execution_time');
		$this->_endts = time() + $timeoutLimit;
		foreach ($this->_queue as $k => $v) {
			if (!empty($v['_status'])) {
				continue;
			}

			if (function_exists('set_time_limit')) {
				$this->_endts += 120;
				set_time_limit(120);
			}
			if ($this->_endts - time() < 10) {
				// self::debug("🚨 End loop due to timeout limit reached " . $timeoutLimit . "s");
				// return;
			}

			Debug2::debug('[' . $type_tag . '] cron job [tag] ' . $k . ' [url] ' . $v['url'] . ($v['is_mobile'] ? ' 📱 ' : '') . ' [UA] ' . $v['user_agent']);

			if ($type == 'ccss' && empty($v['url_tag'])) {
				unset($this->_queue[$k]);
				$this->save_queue($type, $this->_queue);
				Debug2::debug('[CCSS] wrong queue_ccss format');
				continue;
			}

			if (!isset($v['is_webp'])) {
				$v['is_webp'] = false;
			}

			$i++;
			$res = $this->_send_req($v['url'], $k, $v['uid'], $v['user_agent'], $v['vary'], $v['url_tag'], $type, $v['is_mobile'], $v['is_webp']);
			if (!$res) {
				// Status is wrong, drop this this->_queue
				unset($this->_queue[$k]);
				$this->save_queue($type, $this->_queue);

				if (!$continue) {
					return;
				}

				if ($i > 3) {
					GUI::print_loading(count($this->_queue), $type_tag);
					return Router::self_redirect(Router::ACTION_CSS, CSS::TYPE_GEN_CCSS);
				}

				continue;
			}

			// Exit queue if out of quota
			if ($res === 'out_of_quota') {
				return;
			}

			$this->_queue[$k]['_status'] = 'requested';
			$this->save_queue($type, $this->_queue);

			// only request first one
			if (!$continue) {
				return;
			}

			if ($i > 3) {
				GUI::print_loading(count($this->_queue), $type_tag);
				return Router::self_redirect(Router::ACTION_CSS, CSS::TYPE_GEN_CCSS);
			}
		}
	}

	/**
	 * Send to QC API to generate CCSS/UCSS
	 *
	 * @since  2.3
	 * @access private
	 */
	private function _send_req($request_url, $queue_k, $uid, $user_agent, $vary, $url_tag, $type, $is_mobile, $is_webp)
	{
		// Check if has credit to push or not
		$err = false;
		$allowance = $this->cls('Cloud')->allowance(Cloud::SVC_CCSS, $err);
		if (!$allowance) {
			Debug2::debug('[CCSS] ❌ No credit: ' . $err);
			$err && Admin_Display::error(Error::msg($err));
			return 'out_of_quota';
		}

		// Update css request status
		$this->_summary['curr_request_' . $type] = time();
		self::save_summary();

		// Gather guest HTML to send
		$html = $this->prepare_html($request_url, $user_agent, $uid);

		if (!$html) {
			return false;
		}

		// Parse HTML to gather all CSS content before requesting
		list($css, $html) = $this->prepare_css($html, $is_webp);

		if (!$css) {
			Debug2::debug('[UCSS] ❌ No combined css');
			return false;
		}

		// Generate critical css
		$data = array(
			'url' => $request_url,
			'queue_k' => $queue_k,
			'user_agent' => $user_agent,
			'is_mobile' => $is_mobile ? 1 : 0, // todo:compatible w/ tablet
			'is_webp' => $is_webp ? 1 : 0,
			'html' => $html,
			'css' => $css,
		);

		self::debug('Generating: ', $data);

		$json = Cloud::post(Cloud::SVC_CCSS, $data, 30);
		if (!is_array($json)) {
			return false;
		}

		// Old version compatibility
		if (empty($json['status'])) {
			if (!empty($json[$type])) {
				$this->_save_con($type, $json[$type], $queue_k, $is_mobile, $is_webp);
			}

			// Delete the row
			return false;
		}

		// Unknown status, remove this line
		if ($json['status'] != 'queued') {
			return false;
		}

		// Save summary data
		$this->_summary['last_spent_' . $type] = time() - $this->_summary['curr_request_' . $type];
		$this->_summary['last_request_' . $type] = $this->_summary['curr_request_' . $type];
		$this->_summary['curr_request_' . $type] = 0;
		self::save_summary();

		return true;
	}

	/**
	 * Save CCSS/UCSS content
	 *
	 * @since 4.2
	 */
	private function _save_con($type, $css, $queue_k, $mobile, $webp)
	{
		// Add filters
		$css = apply_filters('litespeed_' . $type, $css, $queue_k);
		Debug2::debug2('[CSS] con: ' . $css);

		if (substr($css, 0, 2) == '/*' && substr($css, -2) == '*/') {
			self::debug('❌ empty ' . $type . ' [content] ' . $css);
			// continue; // Save the error info too
		}

		// Write to file
		$filecon_md5 = md5($css);

		$filepath_prefix = $this->_build_filepath_prefix($type);
		$static_file = LITESPEED_STATIC_DIR . $filepath_prefix . $filecon_md5 . '.css';

		File::save($static_file, $css, true);

		$url_tag = $this->_queue[$queue_k]['url_tag'];
		$vary = $this->_queue[$queue_k]['vary'];
		Debug2::debug2("[CSS] Save URL to file [file] $static_file [vary] $vary");

		$this->cls('Data')->save_url($url_tag, $vary, $type, $filecon_md5, dirname($static_file), $mobile, $webp);

		Purge::add(strtoupper($type) . '.' . md5($queue_k));
	}

	/**
	 * Play for fun
	 *
	 * @since  3.4.3
	 */
	public function test_url($request_url)
	{
		$user_agent = $_SERVER['HTTP_USER_AGENT'];
		$html = $this->prepare_html($request_url, $user_agent);
		list($css, $html) = $this->prepare_css($html, true, true);
		// var_dump( $css );
		// 		$html = <<<EOT

		// EOT;

		// 		$css = <<<EOT

		// EOT;
		$data = array(
			'url' => $request_url,
			'ccss_type' => 'test',
			'user_agent' => $user_agent,
			'is_mobile' => 0,
			'html' => $html,
			'css' => $css,
			'type' => 'CCSS',
		);

		// self::debug( 'Generating: ', $data );

		$json = Cloud::post(Cloud::SVC_CCSS, $data, 180);

		var_dump($json);
	}

	/**
	 * Prepare HTML from URL
	 *
	 * @since  3.4.3
	 */
	public function prepare_html($request_url, $user_agent, $uid = false)
	{
		$html = $this->cls('Crawler')->self_curl(add_query_arg('LSCWP_CTRL', 'before_optm', $request_url), $user_agent, $uid);
		Debug2::debug2('[CSS] self_curl result....', $html);

		if (!$html) {
			return false;
		}

		$html = $this->cls('Optimizer')->html_min($html, true);
		// Drop <noscript>xxx</noscript>
		$html = preg_replace('#<noscript>.*</noscript>#isU', '', $html);

		return $html;
	}

	/**
	 * Prepare CSS from HTML for CCSS generation only. UCSS will used combined CSS directly.
	 * Prepare refined HTML for both CCSS and UCSS.
	 *
	 * @since  3.4.3
	 */
	public function prepare_css($html, $is_webp = false, $dryrun = false)
	{
		$css = '';
		preg_match_all('#<link ([^>]+)/?>|<style([^>]*)>([^<]+)</style>#isU', $html, $matches, PREG_SET_ORDER);
		foreach ($matches as $match) {
			$debug_info = '';
			if (strpos($match[0], '<link') === 0) {
				$attrs = Utility::parse_attr($match[1]);

				if (empty($attrs['rel'])) {
					continue;
				}

				if ($attrs['rel'] != 'stylesheet') {
					if ($attrs['rel'] != 'preload' || empty($attrs['as']) || $attrs['as'] != 'style') {
						continue;
					}
				}

				if (!empty($attrs['media']) && strpos($attrs['media'], 'print') !== false) {
					continue;
				}

				if (empty($attrs['href'])) {
					continue;
				}

				// Check Google fonts hit
				if (strpos($attrs['href'], 'fonts.googleapis.com') !== false) {
					$html = str_replace($match[0], '', $html);
					continue;
				}

				$debug_info = $attrs['href'];

				// Load CSS content
				if (!$dryrun) {
					// Dryrun will not load CSS but just drop them
					$con = $this->cls('Optimizer')->load_file($attrs['href']);
					if (!$con) {
						continue;
					}
				} else {
					$con = '';
				}
			} else {
				// Inline style
				$attrs = Utility::parse_attr($match[2]);

				if (!empty($attrs['media']) && strpos($attrs['media'], 'print') !== false) {
					continue;
				}

				Debug2::debug2('[CSS] Load inline CSS ' . substr($match[3], 0, 100) . '...', $attrs);
				$con = $match[3];

				$debug_info = '__INLINE__';
			}

			$con = Optimizer::minify_css($con);
			if ($is_webp && $this->cls('Media')->webp_support()) {
				$con = $this->cls('Media')->replace_background_webp($con);
			}

			if (!empty($attrs['media']) && $attrs['media'] !== 'all') {
				$con = '@media ' . $attrs['media'] . '{' . $con . "}\n";
			} else {
				$con = $con . "\n";
			}

			$con = '/* ' . $debug_info . ' */' . $con;
			$css .= $con;

			$html = str_replace($match[0], '', $html);
		}

		return array($css, $html);
	}

	/**
	 * Handle all request actions from main cls
	 *
	 * @since  2.3
	 * @access public
	 */
	public function handler()
	{
		$type = Router::verify_type();

		switch ($type) {
			case self::TYPE_GEN_CCSS:
				self::cron_ccss(true);
				break;

			case self::TYPE_CLEAR_Q_CCSS:
				$this->clear_q('ccss');
				break;

			default:
				break;
		}

		Admin::redirect();
	}
}