<?php

declare(strict_types=1);

namespace Mironsoft\Event\Model\ResourceModel;

use Magento\Framework\App\ResourceConnection;

/**
 * Direct low-level access to the mironsoft_event_customer_favorite table.
 * A dedicated model/collection pair is intentionally skipped here - the
 * linkage table has no identity of its own beyond the composite key.
 */
class EventFavorite
{
    private const TABLE_NAME = 'mironsoft_event_customer_favorite';

    /**
     * @param ResourceConnection $resourceConnection Database connection provider
     */
    public function __construct(
        private readonly ResourceConnection $resourceConnection,
    ) {
    }

    /**
     * Marks the given event as a favorite for the given customer (idempotent).
     *
     * @param int $customerId
     * @param int $eventId
     * @return void
     */
    public function addFavorite(int $customerId, int $eventId): void
    {
        $connection = $this->resourceConnection->getConnection();
        $connection->insertOnDuplicate(
            $this->resourceConnection->getTableName(self::TABLE_NAME),
            ['event_id' => $eventId, 'customer_id' => $customerId]
        );
    }

    /**
     * Checks whether the given event is a favorite of the given customer.
     *
     * @param int $customerId
     * @param int $eventId
     * @return bool
     */
    public function isFavorite(int $customerId, int $eventId): bool
    {
        $connection = $this->resourceConnection->getConnection();
        $select = $connection->select()
            ->from($this->resourceConnection->getTableName(self::TABLE_NAME), ['event_id'])
            ->where('event_id = ?', $eventId)
            ->where('customer_id = ?', $customerId);

        return $connection->fetchOne($select) !== false;
    }
}

<?php

declare(strict_types=1);

namespace Mironsoft\Event\Model\Resolver;

use Magento\Authorization\Model\UserContextInterface;
use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Exception\GraphQlAuthorizationException;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use Mironsoft\Event\Api\EventRepositoryInterface;
use Mironsoft\Event\Model\ResourceModel\EventFavorite;

/**
 * Resolves the addEventToFavorites mutation field, restricted to logged-in
 * customers.
 */
class AddEventToFavorites implements ResolverInterface
{
    /**
     * @param EventRepositoryInterface $eventRepository Service contract for event access
     * @param EventFavorite $eventFavoriteResource Resource model for the favorites linkage table
     */
    public function __construct(
        private readonly EventRepositoryInterface $eventRepository,
        private readonly EventFavorite $eventFavoriteResource,
    ) {
    }

    /**
     * Adds the given event to the current customer's favorites.
     *
     * @param Field $field Resolved GraphQL field configuration
     * @param mixed $context Resolver context
     * @param ResolveInfo $info GraphQL resolve tree info
     * @param array|null $value Parent resolver's value, unused for a top-level field
     * @param array|null $args Arguments passed to the addEventToFavorites field
     * @return array<string, mixed>
     * @throws GraphQlAuthorizationException
     */
    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        ?array $value = null,
        ?array $args = null
    ): array {
        if ($context->getUserType() !== UserContextInterface::USER_TYPE_CUSTOMER
            || !$context->getExtensionAttributes()->getIsCustomer()
        ) {
            throw new GraphQlAuthorizationException(
                __('You must be logged in as a customer to favorite an event.')
            );
        }

        $eventId = (int) ($args['input']['event_id'] ?? 0);
        $customerId = (int) $context->getUserId();

        $event = $this->eventRepository->getById($eventId);
        $this->eventFavoriteResource->addFavorite($customerId, $eventId);

        return [
            'event' => [
                'event_id' => $event->getEventId(),
                'identifier' => $event->getIdentifier(),
                'title' => $event->getTitle(),
                'description' => $event->getDescription(),
                'location' => $event->getLocation(),
                'start_at' => $event->getStartAt(),
                'end_at' => $event->getEndAt(),
                'capacity' => $event->getCapacity(),
                'model' => $event,
            ],
        ];
    }
}