<?php
declare(strict_types=1);

namespace WebCalendar\WP;

defined( 'ABSPATH' ) || exit;

use WebCalendar\Core\Domain\Entity\Event;

/**
 * Injects calendar events into WordPress site search results.
 *
 * Hooks into the_posts filter on search queries to append matching
 * events from the core EventRepository as virtual WP_Post objects.
 */
class EventSearchIntegration {

	/**
	 * Hook into WordPress.
	 */
	public function init(): void {
		if ( SingleEventPage::get_mode() === 'off' ) {
			return;
		}
		add_filter( 'the_posts', [ $this, 'inject_search_results' ], 10, 2 );
		add_filter( 'post_link', [ $this, 'fix_virtual_post_permalink' ], 10, 2 );
		add_filter( 'page_link', [ $this, 'fix_virtual_post_page_link' ], 10, 2 );
	}

	/**
	 * Append matching calendar events to search results.
	 *
	 * @param array<\WP_Post> $posts Posts from the main query.
	 * @param \WP_Query       $query The query object.
	 * @return array<\WP_Post>
	 */
	public function inject_search_results( array $posts, \WP_Query $query ): array {
		if ( is_admin() || ! $query->is_main_query() || ! $query->is_search() ) {
			return $posts;
		}

		// Only inject on page 1 to avoid pagination issues
		$paged = (int) ( is_numeric( $query->get( 'paged' ) ) ? $query->get( 'paged' ) : 0 );
		if ( $paged > 1 ) {
			return $posts;
		}

		$search_term = $query->get( 's' );
		if ( ! is_string( $search_term ) || $search_term === '' ) {
			return $posts;
		}

		$event_posts = $this->search_events( sanitize_text_field( $search_term ), 10 );

		if ( ! empty( $event_posts ) ) {
			$posts               = array_merge( $posts, $event_posts );
			$query->found_posts += count( $event_posts );
		}

		return $posts;
	}

	/**
	 * Fix permalink for virtual event posts in search results.
	 *
	 * @param string   $url  The post permalink.
	 * @param \WP_Post $post The post object.
	 * @return string
	 */
	public function fix_virtual_post_permalink( string $url, \WP_Post $post ): string {
		if ( $post->ID === 0 && str_contains( $post->guid, 'webcalendar/event/' ) ) {
			return $post->guid;
		}
		return $url;
	}

	/**
	 * Fix page link for virtual event posts in search results.
	 *
	 * @param string $url     The page permalink.
	 * @param int    $post_id The post ID.
	 * @return string
	 */
	public function fix_virtual_post_page_link( string $url, int $post_id ): string {
		if ( $post_id === 0 ) {
			$post = get_post();
			if ( $post instanceof \WP_Post && str_contains( $post->guid, 'webcalendar/event/' ) ) {
				return $post->guid;
			}
		}
		return $url;
	}

	/**
	 * Search for events via the core EventRepository.
	 *
	 * @param string $search_term The search term.
	 * @param int    $limit       Maximum results.
	 * @return array<\WP_Post>
	 */
	private function search_events( string $search_term, int $limit ): array {
		$container  = Container::get_instance();
		$event_repo = $container->get_event_repository();

		$mode        = SingleEventPage::get_mode();
		$accessLevel = ( $mode === 'all' && is_user_logged_in() ) ? null : 'P';

		$events = $event_repo->search( $search_term, null, null, $accessLevel, $limit );

		$virtual_posts = [];
		foreach ( $events as $event ) {
			$virtual_posts[] = $this->event_to_virtual_post( $event );
		}

		return $virtual_posts;
	}

	/**
	 * Convert an Event entity to a virtual WP_Post.
	 *
	 * @param Event $event The event entity.
	 * @return \WP_Post
	 */
	private function event_to_virtual_post( Event $event ): \WP_Post {
		$slug = sanitize_title( $event->name() );
		$url  = home_url( 'webcalendar/event/' . $event->id()->value() . '-' . $slug . '/' );

		$description = $event->description() !== ''
		? wp_trim_words( wp_strip_all_tags( $event->description() ), 30, '...' )
		: '';

		$date = $event->start()->format( 'Y-m-d' );

		return new \WP_Post(
			(object) [
				'ID'                    => 0,
				'post_author'           => '0',
				'post_date'             => $date . ' 00:00:00',
				'post_date_gmt'         => $date . ' 00:00:00',
				'post_content'          => $description,
				'post_title'            => $event->name(),
				'post_excerpt'          => $description,
				'post_status'           => 'publish',
				'comment_status'        => 'closed',
				'ping_status'           => 'closed',
				'post_password'         => '',
				'post_name'             => $slug,
				'to_ping'               => '',
				'pinged'                => '',
				'post_modified'         => current_time( 'mysql' ),
				'post_modified_gmt'     => current_time( 'mysql', true ),
				'post_content_filtered' => '',
				'post_parent'           => 0,
				'guid'                  => $url,
				'menu_order'            => 0,
				'post_type'             => 'page',
				'post_mime_type'        => '',
				'comment_count'         => '0',
				'filter'                => 'raw',
			]
		);
	}
}