<?php
/**
 * Serializes bookings and booking configuration across public and admin entry points.
 *
 * @package Abientot
 */

namespace Abientot\Repositories;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class BookingLock {
	private static bool $held = false;

	public static function is_held(): bool {
		return self::$held;
	}

	public static function name(): string {
		global $wpdb;
		return 'abientot_booking_' . md5( DB_NAME . '|' . $wpdb->prefix );
	}

	public static function acquire(): bool {
		global $wpdb;
		if ( self::$held ) {
			return true;
		}
		self::$held = '1' === (string) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 5)', self::name() ) );
		if ( self::$held ) {
			// wp_send_json/wp_die/redirect exits do not execute PHP finally blocks.
			register_shutdown_function( array( self::class, 'release' ) );
			// Bootstrap may have cached options before another request finished saving.
			// Refresh only when entering the critical section, never on re-entry.
			wp_cache_delete( 'alloptions', 'options' );
			wp_cache_delete( 'notoptions', 'options' );
			wp_cache_delete( 'abientot_settings', 'options' );
			wp_cache_delete( 'abientot_location_weekly_schedule', 'options' );
		}
		return self::$held;
	}

	/** Hold through the complete configuration operation; shutdown releases on exits. */
	public static function require_configuration_lock(): void {
		if ( self::acquire() ) {
			return;
		}
		wp_die(
			esc_html__( 'Another booking is being saved. Please try again.', 'abientot' ),
			'',
			array(
				'response'  => 409,
				'back_link' => true
			)
		);
	}

	public static function release(): void {
		global $wpdb;
		if ( self::$held ) {
			$suppressed = $wpdb->suppress_errors( true );
			try {
				$released = $wpdb->get_var( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', self::name() ) );
			} catch ( \Throwable $error ) {
				return;
			} finally {
					$wpdb->suppress_errors( $suppressed );
			}
				// Retain ownership and queued callbacks when release is unconfirmed.
				// Shutdown retries; a persisted booking is never reported as a rollback.
			if ( '1' !== (string) $released ) {
				return;
			}
				self::$held = false;
			try {
				do_action( 'abientot_booking_lock_released' );
			} catch ( \Throwable $error ) {
			}
		}
	}
}