<?php
namespace QWSpeedCache\Cache;

defined( 'ABSPATH' ) || exit;

/**
 * Cache purge helpers — full and targeted triggers.
 */
class Purge {

	public function __construct() {
		add_action( 'save_post', array( $this, 'on_save_post' ), 20, 3 );
		add_action( 'deleted_post', array( $this, 'on_deleted_post' ), 10, 1 );
		add_action( 'trashed_post', array( $this, 'on_deleted_post' ), 10, 1 );
		add_action( 'switch_theme', array( $this, 'purge_all' ) );
		add_action( 'wp_update_nav_menu', array( $this, 'purge_all' ) );
		add_action( 'customize_save_after', array( $this, 'purge_all' ) );
		add_action( 'edited_term', array( $this, 'on_edited_term' ), 10, 3 );
		add_action( 'delete_term', array( $this, 'purge_all' ), 10, 0 );
		add_action( 'comment_post', array( $this, 'on_comment' ), 10, 2 );
		add_action( 'edit_comment', array( $this, 'on_comment_edit' ), 10, 1 );
		add_action( 'transition_comment_status', array( $this, 'on_comment_status' ), 10, 3 );
		add_action( 'update_option_sidebars_widgets', array( $this, 'purge_all' ) );

		add_action( 'wp_ajax_qwsc_clear_cache', array( $this, 'ajax_clear_all' ) );
	}

	/**
	 * Purge QW Optimize's files and invalidate its memory-backed page cache.
	 *
	 * @return true|\WP_Error Success or a disk purge failure.
	 */
	public static function purge_all() {
		$result = \QWSpeedCache\Plugin::clear_all_cache();
		if ( is_wp_error( $result ) ) {
			return $result;
		}
		// Plugin::clear_all_cache() already invalidates memory-backed page
		// entries for every caller; do not rotate the generation twice.
		// The early cache reads this config before WordPress has loaded.
		if ( AdvancedCache::is_installed() ) {
			AdvancedCache::write_dropin_config();
		}
		do_action( 'qwsc_cache_purged_all' );
		update_option( 'qwsc_last_purge_at', time(), false );
		if ( class_exists( '\QWSpeedCache\Stats\Logger' ) ) {
			\QWSpeedCache\Stats\Logger::log( 'purge_all', 'Full page cache cleared' );
		}
		return true;
	}

	/**
	 * @param int $post_id Post ID.
	 * @return string[]
	 */
	public static function urls_for_post( $post_id ) {
		$post_id = (int) $post_id;
		$urls    = array();
		if ( $post_id <= 0 ) {
			return $urls;
		}
		if ( function_exists( 'get_permalink' ) ) {
			$permalink = get_permalink( $post_id );
			if ( $permalink ) {
				$urls[] = $permalink;
			}
		}
		if ( function_exists( 'home_url' ) ) {
			$urls[] = home_url( '/' );
		}
		if ( function_exists( 'get_post_type_archive_link' ) ) {
			$pt = get_post_type( $post_id );
			if ( $pt ) {
				$arch = get_post_type_archive_link( $pt );
				if ( $arch ) {
					$urls[] = $arch;
				}
			}
		}
		if ( function_exists( 'get_the_category' ) ) {
			foreach ( (array) get_the_category( $post_id ) as $cat ) {
				if ( ! empty( $cat->term_id ) && function_exists( 'get_category_link' ) ) {
					$link = get_category_link( $cat->term_id );
					if ( $link && ! is_wp_error( $link ) ) {
						$urls[] = $link;
					}
				}
			}
		}
		return array_values( array_unique( array_filter( $urls ) ) );
	}

	/**
	 * @param string[] $urls URLs.
	 */
	public static function purge_url( $url ) {
		$url = (string) $url;
		if ( $url ) {
			do_action( 'qwsc_cache_purged_urls', array( $url ) );
			if ( class_exists( '\QWSpeedCache\Stats\Logger' ) ) {
				\QWSpeedCache\Stats\Logger::log( 'purge_url', $url );
			}
		}
	}

	public function purge_urls( array $urls ) {
		$urls = array_values( array_filter( array_map( 'strval', $urls ) ) );
		if ( ! empty( $urls ) ) {
			/**
			 * Edge/CDN integrations (Cloudflare file purge, etc.).
			 *
			 * @param string[] $urls Absolute URLs.
			 */
			do_action( 'qwsc_cache_purged_urls', $urls );
		}
		// No local URL→file index yet: full local purge for correctness.
		$this->purge_all();
	}

	/**
	 * @param int      $post_id Post ID.
	 * @param \WP_Post $post    Post.
	 * @param bool     $update  Update.
	 */
	public function on_save_post( $post_id, $post = null, $update = true ) {
		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
			return;
		}
		$post_id = (int) $post_id;
		if ( $post_id <= 0 ) {
			return;
		}
		if ( function_exists( 'wp_is_post_revision' ) && wp_is_post_revision( $post_id ) ) {
			return;
		}
		if ( function_exists( 'wp_is_post_autosave' ) && wp_is_post_autosave( $post_id ) ) {
			return;
		}
		$status = ( $post && isset( $post->post_status ) ) ? $post->post_status : get_post_status( $post_id );
		if ( in_array( $status, array( 'auto-draft', 'inherit' ), true ) ) {
			return;
		}
		if ( in_array( $status, array( 'publish', 'private', 'future' ), true ) || $update ) {
			$this->purge_urls( self::urls_for_post( $post_id ) );
		}
	}

	/**
	 * @param int $post_id Post ID.
	 */
	public function on_deleted_post( $post_id ) {
		$this->purge_urls( self::urls_for_post( (int) $post_id ) );
	}

	/**
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    TT ID.
	 * @param string $taxonomy Taxonomy.
	 */
	public function on_edited_term( $term_id, $tt_id = 0, $taxonomy = '' ) {
		$this->purge_all();
	}

	/**
	 * @param int        $comment_id Comment ID.
	 * @param int|string $approved   Approved.
	 */
	public function on_comment( $comment_id, $approved = 1 ) {
		if ( 1 !== (int) $approved && '1' !== (string) $approved && 'approve' !== $approved ) {
			return;
		}
		$c = get_comment( $comment_id );
		if ( $c && ! empty( $c->comment_post_ID ) ) {
			$this->purge_urls( self::urls_for_post( (int) $c->comment_post_ID ) );
		}
	}

	/**
	 * @param int $comment_id Comment ID.
	 */
	public function on_comment_edit( $comment_id ) {
		$c = get_comment( $comment_id );
		if ( $c && ! empty( $c->comment_post_ID ) ) {
			$this->purge_urls( self::urls_for_post( (int) $c->comment_post_ID ) );
		}
	}

	/**
	 * @param string      $new_status New.
	 * @param string      $old_status Old.
	 * @param \WP_Comment $comment    Comment.
	 */
	public function on_comment_status( $new_status, $old_status, $comment ) {
		if ( empty( $comment->comment_post_ID ) ) {
			return;
		}
		$this->purge_urls( self::urls_for_post( (int) $comment->comment_post_ID ) );
	}

	public function ajax_clear_all() {
		check_ajax_referer( 'qwsc_clear_cache', 'nonce' );
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error();
		}
		$result = self::purge_all();
		if ( is_wp_error( $result ) ) {
			wp_send_json_error( array( 'message' => $result->get_error_message() ), 500 );
		}
		wp_send_json_success( array( 'message' => __( 'Cache cleared successfully.', 'qw-optimize' ) ) );
	}

	/**
	 * Legacy method retained for third-party calls. The actual WordPress toolbar
	 * is rendered by Admin\AdminBar so duplicate menu nodes cannot compete.
	 *
	 * @param \WP_Admin_Bar $wp_admin_bar WordPress admin bar instance.
	 */
	public function admin_bar( $wp_admin_bar ) {
		// Intentionally left blank. Admin\AdminBar owns the toolbar.
	}
}