<?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\Component\Validator\Constraints;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

/**
 * Provides a base class for the validation of property comparisons.
 *
 * @author Daniel Holmes <daniel@danielholmes.org>
 * @author Bernhard Schussek <bschussek@gmail.com>
 */
abstract class AbstractComparisonValidator extends ConstraintValidator
{
    /**
     * {@inheritdoc}
     */
    public function validate($value, Constraint $constraint)
    {
        if (!$constraint instanceof AbstractComparison) {
            throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\AbstractComparison');
        }

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

        $comparedValue = $constraint->value;

        // Convert strings to DateTimes if comparing another DateTime
        // This allows to compare with any date/time value supported by
        // the DateTime constructor:
        // http://php.net/manual/en/datetime.formats.php
        if (is_string($comparedValue)) {
            if ($value instanceof \DateTimeImmutable) {
                // If $value is immutable, convert the compared value to a
                // DateTimeImmutable too
                $comparedValue = new \DatetimeImmutable($comparedValue);
            } elseif ($value instanceof \DateTimeInterface) {
                // Otherwise use DateTime
                $comparedValue = new \DateTime($comparedValue);
            }
        }

        if (!$this->compareValues($value, $comparedValue)) {
            $this->context->buildViolation($constraint->message)
                ->setParameter('{{ value }}', $this->formatValue($value, self::OBJECT_TO_STRING | self::PRETTY_DATE))
                ->setParameter('{{ compared_value }}', $this->formatValue($comparedValue, self::OBJECT_TO_STRING | self::PRETTY_DATE))
                ->setParameter('{{ compared_value_type }}', $this->formatTypeOf($comparedValue))
                ->setCode($this->getErrorCode())
                ->addViolation();
        }
    }

    /**
     * Compares the two given values to find if their relationship is valid.
     *
     * @param mixed $value1 The first value to compare
     * @param mixed $value2 The second value to compare
     *
     * @return bool true if the relationship is valid, false otherwise
     */
    abstract protected function compareValues($value1, $value2);

    /**
     * Returns the error code used if the comparison fails.
     *
     * @return string|null The error code or `null` if no code should be set
     */
    protected function getErrorCode()
    {
    }
}
