<?php
/**
 * Re-extracts a source asynchronously whenever it changes.
 *
 * @package Unbreak
 */

namespace Unbreak\Queue;

use Unbreak\Extract\ElementorExtractor;
use Unbreak\Extract\Indexer;
use Unbreak\Extract\WidgetExtractor;
use Unbreak\Support\Settings;

defined( 'ABSPATH' ) || exit;

/**
 * Hooks content changes to background jobs. Nothing is extracted inline on save.
 */
final class ContentWatcher {

	public const HOOK_POST    = 'unbreak_index_post';
	public const HOOK_MENUS   = 'unbreak_index_menus';
	public const HOOK_WIDGETS = 'unbreak_index_widgets';
	public const HOOK_COMMENT = 'unbreak_index_comment';

	/**
	 * Indexer.
	 *
	 * @var Indexer
	 */
	private $indexer;

	/**
	 * Constructor.
	 *
	 * @param Indexer|null $indexer Indexer.
	 */
	public function __construct( ?Indexer $indexer = null ) {
		$this->indexer = $indexer ?? new Indexer();
	}

	/**
	 * Register hooks.
	 */
	public function register(): void {
		// Change detection.
		add_action( 'save_post', array( $this, 'on_save_post' ), 20, 2 );
		add_action( 'deleted_post', array( $this, 'on_post_gone' ) );
		add_action( 'trashed_post', array( $this, 'on_post_gone' ) );
		add_action( 'updated_post_meta', array( $this, 'on_meta_change' ), 10, 3 );
		add_action( 'added_post_meta', array( $this, 'on_meta_change' ), 10, 3 );
		add_action( 'wp_update_nav_menu', array( $this, 'on_menu_change' ) );
		add_action( 'wp_delete_nav_menu', array( $this, 'on_menu_change' ) );
		add_action( 'update_option_sidebars_widgets', array( $this, 'on_widgets_change' ) );
		foreach ( array_keys( WidgetExtractor::WIDGETS ) as $option ) {
			add_action( 'update_option_' . $option, array( $this, 'on_widgets_change' ) );
			add_action( 'add_option_' . $option, array( $this, 'on_widgets_change' ) );
		}
		add_action( 'wp_insert_comment', array( $this, 'on_comment_change' ) );
		add_action( 'edit_comment', array( $this, 'on_comment_change' ) );
		add_action( 'wp_set_comment_status', array( $this, 'on_comment_change' ) );
		add_action( 'deleted_comment', array( $this, 'on_comment_change' ) );

		// Background job handlers.
		add_action( self::HOOK_POST, array( $this, 'handle_post' ) );
		add_action( self::HOOK_MENUS, array( $this, 'handle_menus' ) );
		add_action( self::HOOK_WIDGETS, array( $this, 'handle_widgets' ) );
		add_action( self::HOOK_COMMENT, array( $this, 'handle_comment' ) );
	}

	/**
	 * Enqueue re-extraction for a saved post.
	 *
	 * @param int      $post_id Post ID.
	 * @param \WP_Post $post    Post.
	 */
	public function on_save_post( $post_id, $post ): void {
		if ( ! $post instanceof \WP_Post || wp_is_post_revision( $post ) || wp_is_post_autosave( $post ) ) {
			return;
		}
		if ( 'nav_menu_item' === $post->post_type ) {
			Jobs::enqueue_unique( self::HOOK_MENUS );
			return;
		}
		if ( ! in_array( $post->post_type, Indexer::post_types(), true ) ) {
			return;
		}
		// Drafts are enqueued too: the job removes instances of posts that are no longer published.
		Jobs::enqueue_unique( self::HOOK_POST, array( (int) $post_id ) );
	}

	/**
	 * Enqueue cleanup for a trashed or deleted post.
	 *
	 * @param int $post_id Post ID.
	 */
	public function on_post_gone( $post_id ): void {
		Jobs::enqueue_unique( self::HOOK_POST, array( (int) $post_id ) );
	}

	/**
	 * Elementor writes its data as post meta; re-extract when it changes.
	 *
	 * @param int    $meta_id  Meta ID.
	 * @param int    $post_id  Post ID.
	 * @param string $meta_key Meta key.
	 */
	public function on_meta_change( $meta_id, $post_id, $meta_key ): void {
		if ( ElementorExtractor::META_KEY === $meta_key || '_menu_item_url' === $meta_key ) {
			if ( '_menu_item_url' === $meta_key ) {
				Jobs::enqueue_unique( self::HOOK_MENUS );
				return;
			}
			Jobs::enqueue_unique( self::HOOK_POST, array( (int) $post_id ) );
		}
	}

	/**
	 * Enqueue menu re-extraction.
	 */
	public function on_menu_change(): void {
		Jobs::enqueue_unique( self::HOOK_MENUS );
	}

	/**
	 * Enqueue widget re-extraction.
	 */
	public function on_widgets_change(): void {
		Jobs::enqueue_unique( self::HOOK_WIDGETS );
	}

	/**
	 * Enqueue comment re-extraction (only when comment scanning is enabled).
	 *
	 * @param int $comment_id Comment ID.
	 */
	public function on_comment_change( $comment_id ): void {
		if ( Settings::source_enabled( 'comment' ) ) {
			Jobs::enqueue_unique( self::HOOK_COMMENT, array( (int) $comment_id ) );
		}
	}

	/**
	 * Job: re-extract one post.
	 *
	 * @param int $post_id Post ID.
	 */
	public function handle_post( $post_id ): void {
		$this->indexer->index_post( (int) $post_id );
	}

	/**
	 * Job: re-extract all menus.
	 */
	public function handle_menus(): void {
		$this->indexer->index_menus();
	}

	/**
	 * Job: re-extract all widgets.
	 */
	public function handle_widgets(): void {
		$this->indexer->index_widgets();
	}

	/**
	 * Job: re-extract one comment.
	 *
	 * @param int $comment_id Comment ID.
	 */
	public function handle_comment( $comment_id ): void {
		$this->indexer->index_comment( (int) $comment_id );
	}
}