<?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 Doctrine\Common\Persistence\ManagerRegistry;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Context\ExecutionContextInterface;
use Symfony\Component\Validator\Exception\ConstraintDefinitionException;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

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

    public function __construct(ManagerRegistry $registry)
    {
        $this->registry = $registry;
    }

    /**
     * @param object     $entity
     * @param Constraint $constraint
     *
     * @throws UnexpectedTypeException
     * @throws ConstraintDefinitionException
     */
    public function validate($entity, Constraint $constraint)
    {
        if (!$constraint instanceof UniqueEntity) {
            throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\UniqueEntity');
        }

        if (!\is_array($constraint->fields) && !\is_string($constraint->fields)) {
            throw new UnexpectedTypeException($constraint->fields, 'array');
        }

        if (null !== $constraint->errorPath && !\is_string($constraint->errorPath)) {
            throw new UnexpectedTypeException($constraint->errorPath, 'string or null');
        }

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

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

        if (null === $entity) {
            return;
        }

        if ($constraint->em) {
            $em = $this->registry->getManager($constraint->em);

            if (!$em) {
                throw new ConstraintDefinitionException(sprintf('Object manager "%s" does not exist.', $constraint->em));
            }
        } else {
            $em = $this->registry->getManagerForClass(\get_class($entity));

            if (!$em) {
                throw new ConstraintDefinitionException(sprintf('Unable to find the object manager associated with an entity of class "%s".', \get_class($entity)));
            }
        }

        $class = $em->getClassMetadata(\get_class($entity));
        /* @var $class \Doctrine\Common\Persistence\Mapping\ClassMetadata */

        $criteria = array();
        $hasNullValue = false;

        foreach ($fields as $fieldName) {
            if (!$class->hasField($fieldName) && !$class->hasAssociation($fieldName)) {
                throw new ConstraintDefinitionException(sprintf('The field "%s" is not mapped by Doctrine, so it cannot be validated for uniqueness.', $fieldName));
            }

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

            if (null === $fieldValue) {
                $hasNullValue = true;
            }

            if ($constraint->ignoreNull && null === $fieldValue) {
                continue;
            }

            $criteria[$fieldName] = $fieldValue;

            if (null !== $criteria[$fieldName] && $class->hasAssociation($fieldName)) {
                /* Ensure the Proxy is initialized before using reflection to
                 * read its identifiers. This is necessary because the wrapped
                 * getter methods in the Proxy are being bypassed.
                 */
                $em->initializeObject($criteria[$fieldName]);
            }
        }

        // validation doesn't fail if one of the fields is null and if null values should be ignored
        if ($hasNullValue && $constraint->ignoreNull) {
            return;
        }

        // skip validation if there are no criteria (this can happen when the
        // "ignoreNull" option is enabled and fields to be checked are null
        if (empty($criteria)) {
            return;
        }

        $repository = $em->getRepository(\get_class($entity));
        $result = $repository->{$constraint->repositoryMethod}($criteria);

        if ($result instanceof \IteratorAggregate) {
            $result = $result->getIterator();
        }

        /* If the result is a MongoCursor, it must be advanced to the first
         * element. Rewinding should have no ill effect if $result is another
         * iterator implementation.
         */
        if ($result instanceof \Iterator) {
            $result->rewind();
            if ($result instanceof \Countable && 1 < \count($result)) {
                $result = array($result->current(), $result->current());
            } else {
                $result = $result->current();
                $result = null === $result ? array() : array($result);
            }
        } elseif (\is_array($result)) {
            reset($result);
        } else {
            $result = null === $result ? array() : array($result);
        }

        /* 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 (!$result || (1 === \count($result) && current($result) === $entity)) {
            return;
        }

        $errorPath = null !== $constraint->errorPath ? $constraint->errorPath : $fields[0];
        $invalidValue = isset($criteria[$errorPath]) ? $criteria[$errorPath] : $criteria[$fields[0]];

        if ($this->context instanceof ExecutionContextInterface) {
            $this->context->buildViolation($constraint->message)
                ->atPath($errorPath)
                ->setInvalidValue($invalidValue)
                ->setCode(UniqueEntity::NOT_UNIQUE_ERROR)
                ->addViolation();
        } else {
            $this->buildViolation($constraint->message)
                ->atPath($errorPath)
                ->setInvalidValue($invalidValue)
                ->setCode(UniqueEntity::NOT_UNIQUE_ERROR)
                ->addViolation();
        }
    }
}