<?php
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/

namespace Magento\Framework\App\Scope;

use InvalidArgumentException;
use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Framework\App\ScopeResolverPool;
use Magento\Framework\Exception\NoSuchEntityException;
use Magento\Framework\Exception\LocalizedException;
use Magento\Framework\Phrase;

/**
* Class Validator validates scope and scope code.
*/
class Validator implements ValidatorInterface
{
/**
* @var ScopeResolverPool
*/
private $scopeResolverPool;

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

/**
* {@inheritdoc}
*/
public function isValid($scope, $scopeCode = null)
{
if ($scope === ScopeConfigInterface::SCOPE_TYPE_DEFAULT && empty($scopeCode)) {
return true;
}

if ($scope === ScopeConfigInterface::SCOPE_TYPE_DEFAULT && !empty($scopeCode)) {
throw new LocalizedException(new Phrase(
'The "%1" scope can\'t include a scope code. Try again without entering a scope code.',
[ScopeConfigInterface::SCOPE_TYPE_DEFAULT]
));
}

if (empty($scope)) {
throw new LocalizedException(new Phrase('A scope is missing. Enter a scope and try again.'));
}

$this->validateScopeCode($scopeCode);

try {
$scopeResolver = $this->scopeResolverPool->get($scope);
$scopeResolver->getScope($scopeCode)->getId();
} catch (InvalidArgumentException $e) {
throw new LocalizedException(
new Phrase('The "%1" value doesn\'t exist. Enter another value and try again.', [$scope])
);
} catch (NoSuchEntityException $e) {
throw new LocalizedException(
new Phrase('The "%1" value doesn\'t exist. Enter another value and try again.', [$scopeCode])
);
}

return true;
}

/**
* Validate scope code
* Throw exception if not valid.
*
* @param string $scopeCode
* @return void
* @throws LocalizedException if scope code is empty or has a wrong format
*/
private function validateScopeCode($scopeCode)
{
if (empty($scopeCode)) {
throw new LocalizedException(new Phrase('A scope code is missing. Enter a code and try again.'));
}

if (!preg_match('/^[a-z]+[a-z0-9_]*$/', $scopeCode)) {
throw new LocalizedException(new Phrase(
'The scope code can include only lowercase letters (a-z), numbers (0-9) and underscores (_). '
. 'Also, the first character must be a letter.'
));
}
}
}