<?php

declare(strict_types=1);

/**
 * Copyright (c) 2018-2026 Andreas Möller
 *
 * For the full copyright and license information, please view
 * the LICENSE.md file that was distributed with this source code.
 *
 * @see https://github.com/ergebnis/phpstan-rules
 */

namespace Ergebnis\PHPStan\Rules\Functions;

use Ergebnis\PHPStan\Rules\Analyzer;
use Ergebnis\PHPStan\Rules\ErrorIdentifier;
use PhpParser\Node;
use PHPStan\Analyser;
use PHPStan\Rules;

/**
 * @implements Rules\Rule<Node\Stmt\Function_>
 */
final class NoNullableReturnTypeDeclarationRule implements Rules\Rule
{
    private Analyzer $analyzer;

    public function __construct(Analyzer $analyzer)
    {
        $this->analyzer = $analyzer;
    }

    public function getNodeType(): string
    {
        return Node\Stmt\Function_::class;
    }

    public function processNode(
        Node $node,
        Analyser\Scope $scope
    ): array {
        if (!isset($node->namespacedName)) {
            return [];
        }

        if (!$this->analyzer->isNullableTypeDeclaration($node->getReturnType())) {
            return [];
        }

        $message = \sprintf(
            'Function %s() has a nullable return type declaration.',
            $node->namespacedName->toString(),
        );

        return [
            Rules\RuleErrorBuilder::message($message)
                ->identifier(ErrorIdentifier::noNullableReturnTypeDeclaration()->toString())
                ->build(),
        ];
    }
}
