<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Bridge\Doctrine\Validator\Constraints;

use Symfony\Bridge\Doctrine\RegistryInterface;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;
use Symfony\Component\Validator\Exception\ConstraintDefinitionException;
use Symfony\Component\Validator\ConstraintValidator;

/**
 * Unique Entity Validator checks if one or a set of fields contain unique values.
 *
 * @author Benjamin Eberlei <kontakt@beberlei.de>
 */
class UniqueEntityValidator extends ConstraintValidator
{
    /**
     * @var RegistryInterface
     */
    private $registry;

    /**
     * @param RegistryInterface $registry
     */
    public function __construct(RegistryInterface $registry)
    {
        $this->registry = $registry;
    }

    /**
     * @param object $entity
     * @param Constraint $constraint
     * @return bool
     */
    public function isValid($entity, Constraint $constraint)
    {
        if (!is_array($constraint->fields) && !is_string($constraint->fields)) {
            throw new UnexpectedTypeException($constraint->fields, 'array');
        }

        $fields = (array)$constraint->fields;

        if (count($fields) == 0) {
            throw new ConstraintDefinitionException("At least one field has to be specified.");
        }

        $em = $this->registry->getEntityManager($constraint->em);

        $className = $this->context->getCurrentClass();
        $class = $em->getClassMetadata($className);

        $criteria = array();
        foreach ($fields as $fieldName) {
            if (!isset($class->reflFields[$fieldName])) {
                throw new ConstraintDefinitionException("Only field names mapped by Doctrine can be validated for uniqueness.");
            }

            $criteria[$fieldName] = $class->reflFields[$fieldName]->getValue($entity);

            if ($criteria[$fieldName] === null) {
                return true;
            } else if (isset($class->associationMappings[$fieldName])) {
                $relatedClass = $em->getClassMetadata($class->associationMappings[$fieldName]['targetEntity']);
                $relatedId = $relatedClass->getIdentifierValues($criteria[$fieldName]);

                if (count($relatedId) > 1) {
                    throw new ConstraintDefinitionException(
                        "Associated entities are not allowed to have more than one identifier field to be " .
                        "part of a unique constraint in: " . $class->name . "#" . $fieldName
                    );
                }
                $criteria[$fieldName] = array_pop($relatedId);
            }
        }

        $repository = $em->getRepository($className);
        $result = $repository->findBy($criteria);

        /* If no entity matched the query criteria or a single entity matched,
         * which is the same as the entity being validated, the criteria is
         * unique.
         */
        if (0 == count($result) || (1 == count($result) && $entity === $result[0])) {
            return true;
        }

        $oldPath = $this->context->getPropertyPath();
        $this->context->setPropertyPath( empty($oldPath) ? $fields[0] : $oldPath.".".$fields[0]);
        $this->context->addViolation($constraint->message, array(), $criteria[$fields[0]]);
        $this->context->setPropertyPath($oldPath);

        return true; // all true, we added the violation already!
    }
}