<?php
/**
 * Page Caching check.
 *
 * @package advanced-analytics
 *
 * @since 4.9.0
 */

declare(strict_types=1);

namespace ADVAN\Checks\Speed;

use ADVAN\Checks\Abstract_Check;
use ADVAN\Checks\Helpers\Cache_Detector;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'ADVAN\Checks\Speed\Page_Caching_Check' ) ) {

	/**
	 * Checks if page caching is enabled.
	 *
	 * @since 4.9.0
	 */
	class Page_Caching_Check extends Abstract_Check {

		/**
		 * Check identifier.
		 *
		 * @var string Check identifier.
		 * @since 4.9.0
		 */
		protected static string $id = 'page-caching';

		/**
		 * Check category.
		 *
		 * @var string Check category.
		 * @since 4.9.0
		 */
		protected static string $category = 'speed';

		/**
		 * Check weight (1-10).
		 *
		 * @var int Check weight.
		 * @since 4.9.0
		 */
		protected static int $weight = 10;

		/**
		 * Check title (translatable).
		 *
		 * @return string Check title.
		 *
		 * @since 4.9.0
		 */
		public static function get_title(): string {
			return \__( 'Page Caching', '0-day-analytics' );
		}

		/**
		 * Check description (translatable).
		 *
		 * @return string Check description.
		 *
		 * @since 4.9.0
		 */
		public static function get_description(): string {
			return \__( 'Checks if page caching is enabled.', '0-day-analytics' );
		}

		/**
		 * Run the check.
		 *
		 * @return array Check result.
		 *
		 * @since 4.9.0
		 */
		public static function run(): array {
			require_once __DIR__ . '/../helpers/class-cache-detector.php';

			$results = Cache_Detector::detect();

			$details = array(
				'status'         => $results['status'],
				'score'          => $results['score'],
				'plugins'        => $results['plugins'],
				'server_cache'   => $results['server_cache'],
				'cdn'            => $results['cdn'],
				'object_cache'   => $results['object_cache'],
				'advanced_cache' => $results['advanced_cache'],
				'active_test'    => $results['active_test'],
			);

			// Status: active - Caching is working.
			if ( 'active' === $results['status'] ) {
				$cache_source = static::get_cache_source( $results );
				return static::pass(
					sprintf(
					/* translators: %s: cache source */
						\__( 'Page caching is active and working using %s. Your pages are being served from cache, reducing server load and improving load times.', '0-day-analytics' ),
						$cache_source
					),
					$details
				);
			}

			// Status: inactive - Plugin installed but not working.
			if ( 'inactive' === $results['status'] ) {
				$plugin_names = static::get_installed_plugin_names( $results['plugins'] );
				$issues       = static::get_configuration_issues( $results );

				return static::fail(
					'high',
					sprintf(
					/* translators: %s: plugin names */
						\__( 'Cache plugin detected (%s) but caching is not active. Your site is not benefiting from page caching.', '0-day-analytics' ),
						$plugin_names
					),
					$issues,
					$details
				);
			}

			// Status: none - No caching detected.
			return static::fail(
				'high',
				\__( 'No page caching detected. Every visitor request requires WordPress to rebuild the entire page from scratch, significantly slowing down your site.', '0-day-analytics' ),
				\__( 'Install a caching plugin. Free options: LiteSpeed Cache (if on LiteSpeed server), WP Super Cache, or Cache Enabler. Premium option: WP Rocket. Check if your host offers built-in caching first.', '0-day-analytics' ),
				$details
			);
		}

		/**
		 * Get the active cache source name.
		 *
		 * @param array $results Detection results.
		 *
		 * @return string Cache source name.
		 *
		 * @since 4.9.0
		 */
		private static function get_cache_source( $results ) {
			// Check for active plugin first.
			foreach ( $results['plugins'] as $plugin ) {
				if ( $plugin['activated'] && ( true === $plugin['enabled'] || 'unknown' === $plugin['enabled'] ) ) {
					return $plugin['name'];
				}
			}

			// Check for server-level cache.
			foreach ( $results['server_cache'] as $cache ) {
				if ( isset( $cache['status'] ) && in_array( $cache['status'], array( 'active', 'present' ), true ) ) {
					return $cache['type'];
				}
			}

			// Check for CDN.
			if ( ! empty( $results['cdn'] ) ) {
				return $results['cdn'][0]['name'];
			}

			// Check advanced-cache.php.
			if ( ! empty( $results['advanced_cache']['created_by'] ) ) {
				return $results['advanced_cache']['created_by'];
			}

			return \__( 'Server Cache', '0-day-analytics' );
		}

		/**
		 * Get installed plugin names.
		 *
		 * @param array $plugins Plugin detection results.
		 *
		 * @return string Comma-separated plugin names.
		 *
		 * @since 4.9.0
		 */
		private static function get_installed_plugin_names( $plugins ) {
			$names = array();
			foreach ( $plugins as $plugin ) {
				if ( $plugin['installed'] || $plugin['activated'] ) {
					$names[] = $plugin['name'];
				}
			}
			return implode( ', ', $names ) ?: \__( 'Unknown', '0-day-analytics' );
		}

		/**
		 * Get specific configuration issues.
		 *
		 * @param array $results Detection results.
		 *
		 * @return string Recommendation text.
		 *
		 * @since 4.9.0
		 */
		private static function get_configuration_issues( $results ) {
			$issues = array();

			// Check WP_CACHE constant.
			if ( ! $results['advanced_cache']['wp_cache_constant'] ) {
				$issues[] = \__( "Add define('WP_CACHE', true); to your wp-config.php file.", '0-day-analytics' );
			}

			// Check advanced-cache.php.
			if ( ! $results['advanced_cache']['exists'] ) {
				$issues[] = \__( 'The advanced-cache.php drop-in is missing. Try deactivating and reactivating your cache plugin.', '0-day-analytics' );
			}

			// Check for plugins that are activated but not enabled.
			foreach ( $results['plugins'] as $plugin ) {
				if ( $plugin['activated'] && false === $plugin['enabled'] ) {
					$issues[] = sprintf(
					/* translators: %s: plugin name */
						\__( '%s is active but caching is disabled in its settings. Open the plugin settings and enable page caching.', '0-day-analytics' ),
						$plugin['name']
					);
				}
			}

			if ( empty( $issues ) ) {
				return \__( 'Check your cache plugin settings to ensure page caching is enabled. You may need to clear the cache and check file permissions.', '0-day-analytics' );
			}

			return implode( ' ', $issues );
		}
	}
}