<?php

declare(strict_types=1);

namespace FlexatechTableReservations\Support;

use FlexatechTableReservations\Blocks\BlockRegistry;

defined( 'ABSPATH' ) || exit;

/**
 * The page that holds the manage-reservation block, where the link in a
 * reservation email lands. The home page has no block to read the token, so
 * a link to it would do nothing.
 *
 * The plugin uses a page with the block on it, and creates "Your
 * reservation" once when there is none. If that page is later removed,
 * another page with the block takes its place; with none, links are left
 * out rather than sent to a page that cannot use them.
 */
final class ReservationPage {

	public const OPTION = 'fxtr_reservation_page';

	public const BLOCK = 'fxtr/manage-reservation';

	/** The page URL, or '' when there is no page to send a guest to. */
	public static function url(): string {
		$id = (int) get_option( self::OPTION, 0 );
		if ( $id < 1 || 'publish' !== get_post_status( $id ) ) {
			// The stored page is gone: any published page with the block will do.
			$id = self::find();
			if ( $id < 1 ) {
				return '';
			}
			update_option( self::OPTION, $id );
		}

		return (string) get_permalink( $id );
	}

	/**
	 * Finds or creates the page, once. Runs on activation and on the first
	 * admin load after an update, so sites set up before this existed get
	 * one too.
	 */
	public static function ensure(): void {
		// A page was found or made before: if the owner removed it since,
		// that was on purpose.
		if ( (int) get_option( self::OPTION, 0 ) > 0 ) {
			return;
		}

		$id = self::find();
		if ( $id < 1 ) {
			$id = wp_insert_post(
				[
					'post_type'    => 'page',
					'post_status'  => 'publish',
					'post_title'   => __( 'Your reservation', 'flexatech-table-reservations' ),
					'post_content' => '<!-- wp:' . self::BLOCK . ' /-->',
				]
			); // 0 when the insert fails.
		}

		update_option( self::OPTION, $id );
	}

	/** A published page with the block or its shortcode on it, or 0. */
	private static function find(): int {
		return BlockRegistry::page_with( self::BLOCK );
	}
}