<?php

/*
 * This file is part of Respect/Validation.
 *
 * (c) Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
 *
 * For the full copyright and license information, please view the LICENSE file
 * that was distributed with this source code.
 */

declare(strict_types=1);

namespace Respect\Validation\Rules;

use Egulias\EmailValidator\EmailValidator;
use Egulias\EmailValidator\Validation\RFCValidation;

use function class_exists;
use function filter_var;
use function is_string;

use const FILTER_VALIDATE_EMAIL;

/**
 * Validates an email address.
 *
 * @author Andrey Kolyshkin <a.kolyshkin@semrush.com>
 * @author Eduardo Gulias Davis <me@egulias.com>
 * @author Henrique Moody <henriquemoody@gmail.com>
 * @author Paul Karikari <paulkarikari1@gmail.com>
 */
final class Email extends AbstractRule
{
    /**
     * @var EmailValidator|null
     */
    private $validator;

    /**
     * Initializes the rule assigning the EmailValidator instance.
     *
     * If the EmailValidator instance is not defined, tries to create one.
     */
    public function __construct(?EmailValidator $validator = null)
    {
        $this->validator = $validator ?: $this->createEmailValidator();
    }

    /**
     * {@inheritDoc}
     */
    public function validate($input): bool
    {
        if (!is_string($input)) {
            return false;
        }

        if ($this->validator !== null) {
            return $this->validator->isValid($input, new RFCValidation());
        }

        return (bool) filter_var($input, FILTER_VALIDATE_EMAIL);
    }

    private function createEmailValidator(): ?EmailValidator
    {
        if (class_exists(EmailValidator::class)) {
            return new EmailValidator();
        }

        return null;
    }
}