.-.-.-.-.-

<?php
/**
 * The plugin cache-control class for X-LiteSpeed-Cache-Control.
 *
 * Provides helpers for determining cacheability, emitting cache-control headers,
 * and honoring various LiteSpeed Cache configuration options.
 *
 * @package     LiteSpeed
 * @since       1.1.3
 */

namespace LiteSpeed;

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

/**
 * Class Control
 *
 * Handles cache-control flags, TTL calculation, redirection checks,
 * role-based exclusions, and final header output.
 */
class Control extends Root {

const LOG_TAG = '💵';

const BM_CACHEABLE        = 1;
	const BM_PRIVATE          = 2;
	const BM_SHARED           = 4;
	const BM_NO_VARY          = 8;
	const BM_FORCED_CACHEABLE = 32;
	const BM_PUBLIC_FORCED    = 64;
	const BM_STALE            = 128;
	const BM_NOTCACHEABLE     = 256;

const X_HEADER = 'X-LiteSpeed-Cache-Control';

/**
	 * Bitmask control flags for current request.
	 *
	 * @var int
	 */
	protected static $_control = 0;

/**
	 * Custom TTL for current request (seconds).
	 *
	 * @var int
	 */
	protected static $_custom_ttl = 0;

/**
	 * Mapping of HTTP status codes to custom TTLs.
	 *
	 * @var array<string,int|string>
	 */
	private $_response_header_ttls = [];

/**
	 * Init cache control.
	 *
	 * @since  1.6.2
	 * @return void
	 */
	public function init() {
		/**
		 * Add vary filter for Role Excludes.
		 *
		 * @since  1.6.2
		 */
		add_filter( 'litespeed_vary', [ $this, 'vary_add_role_exclude' ] );

// 301 redirect hook.
		add_filter( 'wp_redirect', [ $this, 'check_redirect' ], 10, 2 );

// Load response header conf.
		$this->_response_header_ttls = $this->conf( Base::O_CACHE_TTL_STATUS );
		foreach ( $this->_response_header_ttls as $k => $v ) {
			$v = explode( ' ', $v );
			if ( empty( $v[0] ) || empty( $v[1] ) ) {
				continue;
			}
			$this->_response_header_ttls[ $v[0] ] = $v[1];
		}

if ( $this->conf( Base::O_PURGE_STALE ) ) {
			$this->set_stale();
		}
	}

/**
	 * Exclude role from optimization filter.
	 *
	 * @since  1.6.2
	 * @access public
	 *
	 * @param array<string,mixed> $vary Existing vary map.
	 * @return array<string,mixed>
	 */
	public function vary_add_role_exclude( $vary ) {
		if ( $this->in_cache_exc_roles() ) {
			$vary['role_exclude_cache'] = 1;
		}

return $vary;
	}

/**
	 * Check if one user role is in exclude cache group settings.
	 *
	 * @since 1.6.2
	 * @since 3.0 Moved here from conf.cls
	 * @access public
	 *
	 * @param  string|null $role The user role.
	 * @return string|false      Comma-separated roles if set, otherwise false.
	 */
	public function in_cache_exc_roles( $role = null ) {
		// Get user role.
		if ( null === $role ) {
			$role = Router::get_role();
		}

if ( ! $role ) {
			return false;
		}

$roles = explode( ',', $role );
		$found = array_intersect( $roles, $this->conf( Base::O_CACHE_EXC_ROLES ) );

return $found ? implode( ',', $found ) : false;
	}

/**
	 * 1. Initialize cacheable status for `wp` hook
	 * 2. Hook error page tags for cacheable pages
	 *
	 * @since 1.1.3
	 * @access public
	 * @return void
	 */
	public function init_cacheable() {
		// Hook `wp` to mark default cacheable status.
		// NOTE: Any process that does NOT run into `wp` hook will not get cacheable by default.
		add_action( 'wp', [ $this, 'set_cacheable' ], 5 );

// Hook WP REST to be cacheable.
		if ( $this->conf( Base::O_CACHE_REST ) ) {
			add_action( 'rest_api_init', [ $this, 'set_cacheable' ], 5 );
		}

// AJAX cache.
		$ajax_cache = $this->conf( Base::O_CACHE_AJAX_TTL );
		foreach ( $ajax_cache as $v ) {
			$v = explode( ' ', $v );
			if ( empty( $v[0] ) || empty( $v[1] ) ) {
				continue;
			}
			add_action(
				'wp_ajax_nopriv_' . $v[0],
				function () use ( $v ) {
					self::set_custom_ttl( $v[1] );
					self::force_cacheable( 'ajax Cache setting for action ' . $v[0] );
				},
				4
			);
		}

// Check error page.
		add_filter( 'status_header', [ $this, 'check_error_codes' ], 10, 2 );
	}

/**
	 * Check if the page returns any error code.
	 *
	 * @since 1.0.13.1
	 * @access public
	 *
	 * @param string $status_header Status header.
	 * @param int    $code          HTTP status code.
	 * @return string               Original status header.
	 */
	public function check_error_codes( $status_header, $code ) {
		if ( array_key_exists( $code, $this->_response_header_ttls ) ) {
			if ( self::is_cacheable() && ! $this->_response_header_ttls[ $code ] ) {
				self::set_nocache( '[Ctrl] TTL is set to no cache [status_header] ' . $code );
			}

// Set TTL.
			self::set_custom_ttl( $this->_response_header_ttls[ $code ] );
		} elseif ( self::is_cacheable() ) {
			$first = substr( $code, 0, 1 );
			if ( '4' === $first || '5' === $first ) {
				self::set_nocache( '[Ctrl] 4xx/5xx default to no cache [status_header] ' . $code );
			}
		}

// Set cache tag.
		if ( in_array( $code, Tag::$error_code_tags, true ) ) {
			Tag::add( Tag::TYPE_HTTP . $code );
		}

// Give the default status_header back.
		return $status_header;
	}

/**
	 * Set no vary setting.
	 *
	 * @access public
	 * @since 1.1.3
	 * @return void
	 */
	public static function set_no_vary() {
		if ( self::is_no_vary() ) {
			return;
		}
		self::$_control |= self::BM_NO_VARY;
		self::debug( 'X Cache_control -> no-vary', 3 );
	}

/**
	 * Get no vary setting.
	 *
	 * @access public
	 * @since 1.1.3
	 * @return bool
	 */
	public static function is_no_vary() {
		return self::$_control & self::BM_NO_VARY;
	}

/**
	 * Set stale.
	 *
	 * @access public
	 * @since 1.1.3
	 * @return void
	 */
	public function set_stale() {
		if ( self::is_stale() ) {
			return;
		}
		self::$_control |= self::BM_STALE;
		self::debug( 'X Cache_control -> stale' );
	}

/**
	 * Get stale.
	 *
	 * @access public
	 * @since 1.1.3
	 * @return bool
	 */
	public static function is_stale() {
		return self::$_control & self::BM_STALE;
	}

/**
	 * Set cache control to shared private.
	 *
	 * @access public
	 * @since 1.1.3
	 *
	 * @param string|false $reason The reason to mark shared, or false.
	 * @return void
	 */
	public static function set_shared( $reason = false ) {
		if ( self::is_shared() ) {
			return;
		}
		self::$_control |= self::BM_SHARED;
		self::set_private();