<?php
/**
 * Purges the page caches of posts that scheduled content changes.
 *
 * @package Yangra\Conditional
 */

namespace Yangra\Conditional\Scheduling;

use Throwable;

defined( 'ABSPATH' ) || exit;

/**
 * Purges a post's own URL in every known page cache that is active, and
 * WordPress's object cache for that post. Nothing else: it never turns caching
 * off or changes cache settings.
 *
 * Each cache's purge call was checked in that plugin's own docs or source
 * (2026-10-14):
 * - WP Rocket: `rocket_clean_files( $url )` (docs.wp-rocket.me, article 91).
 * - W3 Total Cache: `w3tc_flush_url( $url )` (w3-total-cache-api.php).
 * - LiteSpeed Cache: the `litespeed_purge_url` action (docs.litespeedtech.com/lscache/lscwp/api/).
 * - WP Super Cache: `wpsc_delete_url_cache( $url )` (inc/cache-files.php, wp-cache-phase2.php).
 * - WP Fastest Cache: `wpfc_clear_post_cache_by_id( $post_id )`, its only documented call for one
 *   post; it also clears that post's tag, category and archive caches (wpfastestcache.com tutorial).
 * - SiteGround Optimizer: `sg_cachepress_purge_cache( $url )` (helpers/helpers.php).
 *
 * Other caches can purge themselves on the `yangra_conditional_purge_post` action.
 */
class CachePurger {

	/**
	 * The known caches that are active, by key.
	 *
	 * @return array<string, array{name: string, purge: callable(int, string): void}>
	 */
	public function caches(): array {
		$caches = array();

		if ( function_exists( 'rocket_clean_files' ) ) {
			$caches['wp_rocket'] = array(
				'name'  => 'WP Rocket',
				'purge' => static function ( int $post_id, string $url ): void {
					rocket_clean_files( $url );
				},
			);
		}
		if ( function_exists( 'w3tc_flush_url' ) ) {
			$caches['w3_total_cache'] = array(
				'name'  => 'W3 Total Cache',
				'purge' => static function ( int $post_id, string $url ): void {
					w3tc_flush_url( $url );
				},
			);
		}
		if ( defined( 'LSCWP_V' ) ) {
			$caches['litespeed_cache'] = array(
				'name'  => 'LiteSpeed Cache',
				'purge' => static function ( int $post_id, string $url ): void {
					// LiteSpeed Cache's own documented action.
					do_action( 'litespeed_purge_url', $url ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
				},
			);
		}
		if ( function_exists( 'wpsc_delete_url_cache' ) ) {
			$caches['wp_super_cache'] = array(
				'name'  => 'WP Super Cache',
				'purge' => static function ( int $post_id, string $url ): void {
					wpsc_delete_url_cache( $url );
				},
			);
		}
		if ( function_exists( 'wpfc_clear_post_cache_by_id' ) ) {
			$caches['wp_fastest_cache'] = array(
				'name'  => 'WP Fastest Cache',
				'purge' => static function ( int $post_id, string $url ): void { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed -- Every purge function takes the same arguments.
					wpfc_clear_post_cache_by_id( $post_id );
				},
			);
		}
		if ( function_exists( 'sg_cachepress_purge_cache' ) ) {
			$caches['siteground_optimizer'] = array(
				'name'  => 'SiteGround Optimizer',
				'purge' => static function ( int $post_id, string $url ): void {
					sg_cachepress_purge_cache( $url );
				},
			);
		}

		/**
		 * Filters the page caches scheduled content purges.
		 *
		 * @param array<string, array{name: string, purge: callable(int, string): void}> $caches Active
		 *        known caches, by key: a name to show, and a function that purges one post (ID, URL).
		 */
		return (array) apply_filters( 'yangra_conditional_scheduled_content_caches', $caches );
	}

	/**
	 * The names of the known caches that are active.
	 *
	 * @return array<int, string>
	 */
	public function names(): array {
		return array_values( wp_list_pluck( $this->caches(), 'name' ) );
	}

	/**
	 * Purges posts from every known cache, and from WordPress's object cache.
	 *
	 * @param array<int, int> $post_ids Posts to purge.
	 * @return array{caches: array<int, string>, ok: bool} The caches that were purged, and
	 *         whether every purge worked (none of them failed with an error).
	 */
	public function purge( array $post_ids ): array {
		$caches = $this->caches();
		$ok     = true;

		foreach ( $post_ids as $post_id ) {
			$post_id = (int) $post_id;
			if ( null === get_post( $post_id ) ) {
				continue;
			}
			clean_post_cache( $post_id );

			$url = (string) get_permalink( $post_id );
			foreach ( $caches as $key => $cache ) {
				try {
					call_user_func( $cache['purge'], $post_id, $url );
				} catch ( Throwable $error ) {
					$ok = false;
					if ( defined( 'WP_DEBUG_LOG' ) && WP_DEBUG_LOG ) {
						// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- Only when WP_DEBUG_LOG is on.
						error_log( sprintf( 'Yangra Conditional: purging post %d from %s failed: %s', $post_id, $key, $error->getMessage() ) );
					}
				}
			}

			/**
			 * Fires when scheduled content purges a post, so a host or another
			 * plugin can purge its own cache.
			 *
			 * @param int $post_id Post whose page changed.
			 */
			do_action( 'yangra_conditional_purge_post', $post_id );
		}

		return array(
			'caches' => array_values( wp_list_pluck( $caches, 'name' ) ),
			'ok'     => $ok,
		);
	}
}