<?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\Mapping\Loader;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\Constraints\Callback;
use Symfony\Component\Validator\Constraints\GroupSequence;
use Symfony\Component\Validator\Constraints\GroupSequenceProvider;
use Symfony\Component\Validator\Exception\MappingException;
use Symfony\Component\Validator\Mapping\ClassMetadata;

/**
 * Loads validation metadata using PHP attributes.
 *
 * @author Bernhard Schussek <bschussek@gmail.com>
 * @author Alexander M. Turek <me@derrabus.de>
 * @author Alexandre Daubois <alex.daubois@gmail.com>
 */
class AttributeLoader implements LoaderInterface
{
    /**
     * @param array<class-string, class-string[]> $mappedClasses
     */
    public function __construct(
        private bool $allowAnyClass = true,
        private array $mappedClasses = [],
    ) {
    }

    /**
     * @return class-string[]
     */
    public function getMappedClasses(): array
    {
        return array_keys($this->mappedClasses);
    }

    public function loadClassMetadata(ClassMetadata $metadata): bool
    {
        $className = $metadata->getClassName();

        if (!$sourceClasses = $this->mappedClasses[$className] ??= $this->allowAnyClass ? [$className] : []) {
            return false;
        }

        // When a class is the target of #[ExtendsValidationFor], its mapping only lists the
        // extension classes. The target's own constraints must still be loaded and merged,
        // so make sure the class is always part of its own source classes.
        if (!\in_array($className, $sourceClasses, true)) {
            array_unshift($sourceClasses, $className);
        }

        $success = false;
        foreach ($sourceClasses as $sourceClass) {
            $reflClass = $className === $sourceClass ? $metadata->getReflectionClass() : new \ReflectionClass($sourceClass);
            $success = $this->doLoadClassMetadata($reflClass, $metadata) || $success;
        }

        return $success;
    }

    private function doLoadClassMetadata(\ReflectionClass $reflClass, ClassMetadata $metadata): bool
    {
        $className = $reflClass->name;
        $success = false;

        foreach ($this->getAttributes($reflClass) as $constraint) {
            if ($constraint instanceof GroupSequence) {
                $metadata->setGroupSequence($constraint->groups);
            } elseif ($constraint instanceof GroupSequenceProvider) {
                $metadata->setGroupProvider($constraint->provider);
                $metadata->setGroupSequenceProvider(true);
            } elseif ($constraint instanceof Constraint) {
                $metadata->addConstraint($constraint);
            }

            $success = true;
        }

        foreach ($reflClass->getProperties() as $property) {
            if ($property->getDeclaringClass()->name === $className) {
                foreach ($this->getAttributes($property) as $constraint) {
                    if ($constraint instanceof Constraint) {
                        $metadata->addPropertyConstraint($property->name, $constraint);
                    }

                    $success = true;
                }
            }
        }

        foreach ($reflClass->getMethods() as $method) {
            if ($method->getDeclaringClass()->name === $className) {
                foreach ($this->getAttributes($method) as $constraint) {
                    if ($constraint instanceof Callback) {
                        $constraint->callback = $method->getName();

                        $metadata->addConstraint($constraint);
                    } elseif ($constraint instanceof Constraint) {
                        if (preg_match('/^(get|is|has)(.+)$/i', $method->name, $matches)) {
                            $metadata->addGetterMethodConstraint(lcfirst($matches[2]), $matches[0], $constraint);
                        } else {
                            throw new MappingException(\sprintf('The constraint on "%s::%s()" cannot be added. Constraints can only be added on methods beginning with "get", "is" or "has".', $className, $method->name));
                        }
                    }

                    $success = true;
                }
            }
        }

        return $success;
    }

    private function getAttributes(\ReflectionMethod|\ReflectionClass|\ReflectionProperty $reflection): iterable
    {
        foreach ($reflection->getAttributes(GroupSequence::class) as $attribute) {
            yield $attribute->newInstance();
        }
        foreach ($reflection->getAttributes(GroupSequenceProvider::class) as $attribute) {
            yield $attribute->newInstance();
        }
        foreach ($reflection->getAttributes(Constraint::class, \ReflectionAttribute::IS_INSTANCEOF) as $attribute) {
            yield $attribute->newInstance();
        }
    }
}