<?php

declare(strict_types=1);

namespace Doctrine\ORM\Mapping;

use Doctrine\Common\EventManager;
use Doctrine\DBAL\Platforms;
use Doctrine\DBAL\Platforms\AbstractPlatform;
use Doctrine\Deprecations\Deprecation;
use Doctrine\ORM\EntityManagerInterface;
use Doctrine\ORM\Event\LoadClassMetadataEventArgs;
use Doctrine\ORM\Event\OnClassMetadataNotFoundEventArgs;
use Doctrine\ORM\Events;
use Doctrine\ORM\Exception\ORMException;
use Doctrine\ORM\Id\AssignedGenerator;
use Doctrine\ORM\Id\BigIntegerIdentityGenerator;
use Doctrine\ORM\Id\IdentityGenerator;
use Doctrine\ORM\Id\SequenceGenerator;
use Doctrine\ORM\Mapping\Exception\InvalidCustomGenerator;
use Doctrine\ORM\Mapping\Exception\UnknownGeneratorType;
use Doctrine\ORM\Proxy\DefaultProxyClassNameResolver;
use Doctrine\Persistence\Mapping\AbstractClassMetadataFactory;
use Doctrine\Persistence\Mapping\ClassMetadata as ClassMetadataInterface;
use Doctrine\Persistence\Mapping\Driver\MappingDriver;
use Doctrine\Persistence\Mapping\ReflectionService;
use ReflectionClass;
use ReflectionException;

use function assert;
use function class_exists;
use function count;
use function end;
use function explode;
use function in_array;
use function is_a;
use function is_subclass_of;
use function method_exists;
use function str_contains;
use function strlen;
use function strtolower;
use function substr;

/**
 * The ClassMetadataFactory is used to create ClassMetadata objects that contain all the
 * metadata mapping information of a class which describes how a class should be mapped
 * to a relational database.
 *
 * @extends AbstractClassMetadataFactory<ClassMetadata>
 */
class ClassMetadataFactory extends AbstractClassMetadataFactory
{
    private EntityManagerInterface|null $em       = null;
    private AbstractPlatform|null $targetPlatform = null;
    private MappingDriver|null $driver            = null;
    private EventManager|null $evm                = null;

    /** @var mixed[] */
    private array $embeddablesActiveNesting = [];

    private const NON_IDENTITY_DEFAULT_STRATEGY = [
        Platforms\OraclePlatform::class => ClassMetadata::GENERATOR_TYPE_SEQUENCE,
    ];

    public function setEntityManager(EntityManagerInterface $em): void
    {
        parent::setProxyClassNameResolver(new DefaultProxyClassNameResolver());

        $this->em = $em;
    }

    /**
     * @param A $maybeOwningSide
     *
     * @return (A is ManyToManyAssociationMapping ? ManyToManyOwningSideMapping : (
     *     A is OneToOneAssociationMapping ? OneToOneOwningSideMapping : (
     *     A is OneToManyAssociationMapping ? ManyToOneAssociationMapping : (
     *     A is ManyToOneAssociationMapping ? ManyToOneAssociationMapping :
     *     ManyToManyOwningSideMapping|OneToOneOwningSideMapping|ManyToOneAssociationMapping
     * ))))
     *
     * @template A of AssociationMapping
     */
    final public function getOwningSide(AssociationMapping $maybeOwningSide): OwningSideMapping
    {
        if ($maybeOwningSide instanceof OwningSideMapping) {
            assert($maybeOwningSide instanceof ManyToManyOwningSideMapping ||
                $maybeOwningSide instanceof OneToOneOwningSideMapping ||
                $maybeOwningSide instanceof ManyToOneAssociationMapping);

            return $maybeOwningSide;
        }

        assert($maybeOwningSide instanceof InverseSideMapping);

        $owningSide = $this->getMetadataFor($maybeOwningSide->targetEntity)
            ->associationMappings[$maybeOwningSide->mappedBy];

        assert($owningSide instanceof ManyToManyOwningSideMapping ||
            $owningSide instanceof OneToOneOwningSideMapping ||
            $owningSide instanceof ManyToOneAssociationMapping);

        return $owningSide;
    }

    protected function initialize(): void
    {
        $this->driver      = $this->em->getConfiguration()->getMetadataDriverImpl();
        $this->evm         = $this->em->getEventManager();
        $this->initialized = true;
    }

    protected function onNotFoundMetadata(string $className): ClassMetadata|null
    {
        if (! $this->evm->hasListeners(Events::onClassMetadataNotFound)) {
            return null;
        }

        $eventArgs = new OnClassMetadataNotFoundEventArgs($className, $this->em);

        $this->evm->dispatchEvent(Events::onClassMetadataNotFound, $eventArgs);
        $classMetadata = $eventArgs->getFoundMetadata();
        assert($classMetadata instanceof ClassMetadata || $classMetadata === null);

        return $classMetadata;
    }

    /**
     * {@inheritDoc}
     */
    protected function doLoadMetadata(
        ClassMetadataInterface $class,
        ClassMetadataInterface|null $parent,
        bool $rootEntityFound,
        array $nonSuperclassParents,
    ): void {
        if ($parent) {
            $class->setInheritanceType($parent->inheritanceType);
            $class->setDiscriminatorColumn($parent->discriminatorColumn === null ? null : clone $parent->discriminatorColumn);
            $class->setIdGeneratorType($parent->generatorType);
            $this->addInheritedFields($class, $parent);
            $this->addInheritedRelations($class, $parent);
            $this->addInheritedEmbeddedClasses($class, $parent);
            $class->setIdentifier($parent->identifier);
            $class->setVersioned($parent->isVersioned);
            $class->setVersionField($parent->versionField);
            $class->setDiscriminatorMap($parent->discriminatorMap);
            $class->addSubClasses($parent->subClasses);
            $class->setLifecycleCallbacks($parent->lifecycleCallbacks);
            $class->setChangeTrackingPolicy($parent->changeTrackingPolicy);

            if (! empty($parent->customGeneratorDefinition)) {
                $class->setCustomGeneratorDefinition($parent->customGeneratorDefinition);
            }

            if ($parent->isMappedSuperclass) {
                $class->setCustomRepositoryClass($parent->customRepositoryClassName);
            }
        }

        // Invoke driver
        try {
            $this->driver->loadMetadataForClass($class->getName(), $class);
        } catch (ReflectionException $e) {
            throw MappingException::reflectionFailure($class->getName(), $e);
        }

        // If this class has a parent the id generator strategy is inherited.
        // However this is only true if the hierarchy of parents contains the root entity,
        // if it consists of mapped superclasses these don't necessarily include the id field.
        if ($parent && $rootEntityFound) {
            $this->inheritIdGeneratorMapping($class, $parent);
        } else {
            $this->completeIdGeneratorMapping($class);
        }

        if (! $class->isMappedSuperclass) {
            if ($rootEntityFound && $class->isInheritanceTypeNone()) {
                throw MappingException::missingInheritanceTypeDeclaration(end($nonSuperclassParents), $class->name);
            }

            foreach ($class->embeddedClasses as $property => $embeddableClass) {
                if (isset($embeddableClass->inherited)) {
                    continue;
                }

                if (isset($this->embeddablesActiveNesting[$embeddableClass->class])) {
                    throw MappingException::infiniteEmbeddableNesting($class->name, $property);
                }

                $this->embeddablesActiveNesting[$class->name] = true;

                $embeddableMetadata = $this->getMetadataFor($embeddableClass->class);

                if ($embeddableMetadata->isEmbeddedClass) {
                    $this->addNestedEmbeddedClasses($embeddableMetadata, $class, $property);
                }

                $identifier = $embeddableMetadata->getIdentifier();

                if (! empty($identifier)) {
                    $this->inheritIdGeneratorMapping($class, $embeddableMetadata);
                }

                $class->inlineEmbeddable($property, $embeddableMetadata);

                unset($this->embeddablesActiveNesting[$class->name]);
            }
        }

        if ($parent) {
            if ($parent->isInheritanceTypeSingleTable()) {
                $class->setPrimaryTable($parent->table);
            }

            $this->addInheritedIndexes($class, $parent);

            if ($parent->cache) {
                $class->cache = $parent->cache;
            }

            if ($parent->containsForeignIdentifier) {
                $class->containsForeignIdentifier = true;
            }

            if ($parent->containsEnumIdentifier) {
                $class->containsEnumIdentifier = true;
            }

            if (! empty($parent->entityListeners) && empty($class->entityListeners)) {
                $class->entityListeners = $parent->entityListeners;
            }
        }

        $class->setParentClasses($nonSuperclassParents);

        if ($class->isRootEntity() && ! $class->isInheritanceTypeNone() && ! $class->discriminatorMap) {
            $this->addDefaultDiscriminatorMap($class);
        }

        // During the following event, there may also be updates to the discriminator map as per GH-1257/GH-8402.
        // So, we must not discover the missing subclasses before that.

        if ($this->evm->hasListeners(Events::loadClassMetadata)) {
            $eventArgs = new LoadClassMetadataEventArgs($class, $this->em);
            $this->evm->dispatchEvent(Events::loadClassMetadata, $eventArgs);
        }

        $this->findAbstractEntityClassesNotListedInDiscriminatorMap($class);

        $this->validateRuntimeMetadata($class, $parent);
    }

    /**
     * Validate runtime metadata is correctly defined.
     *
     * @throws MappingException
     */
    protected function validateRuntimeMetadata(ClassMetadata $class, ClassMetadataInterface|null $parent): void
    {
        if (! $class->reflClass) {
            // only validate if there is a reflection class instance
            return;
        }

        $class->validateIdentifier();
        $class->validateAssociations();
        $class->validateLifecycleCallbacks($this->getReflectionService());

        // verify inheritance
        if (! $class->isMappedSuperclass && ! $class->isInheritanceTypeNone()) {
            if (! $parent) {
                if (count($class->discriminatorMap) === 0) {
                    throw MappingException::missingDiscriminatorMap($class->name);
                }

                if (! $class->discriminatorColumn) {
                    throw MappingException::missingDiscriminatorColumn($class->name);
                }

                foreach ($class->subClasses as $subClass) {
                    if ((new ReflectionClass($subClass))->name !== $subClass) {
                        throw MappingException::invalidClassInDiscriminatorMap($subClass, $class->name);
                    }
                }
            } else {
                assert($parent instanceof ClassMetadata); // https://github.com/doctrine/orm/issues/8746
                if (
                    ! $class->reflClass->isAbstract()
                    && ! in_array($class->name, $class->discriminatorMap, true)
                ) {
                    throw MappingException::mappedClassNotPartOfDiscriminatorMap($class->name, $class->rootEntityName);
                }
            }
        } elseif ($class->isMappedSuperclass && $class->name === $class->rootEntityName && (count($class->discriminatorMap) || $class->discriminatorColumn)) {
            // second condition is necessary for mapped superclasses in the middle of an inheritance hierarchy
            throw MappingException::noInheritanceOnMappedSuperClass($class->name);
        }
    }

    protected function newClassMetadataInstance(string $className): ClassMetadata
    {
        return new ClassMetadata(
            $className,
            $this->em->getConfiguration()->getNamingStrategy(),
            $this->em->getConfiguration()->getTypedFieldMapper(),
        );
    }

    /**
     * Adds a default discriminator map if no one is given
     *
     * If an entity is of any inheritance type and does not contain a
     * discriminator map, then the map is generated automatically. This process
     * is expensive computation wise.
     *
     * The automatically generated discriminator map contains the lowercase short name of
     * each class as key.
     *
     * @throws MappingException
     */
    private function addDefaultDiscriminatorMap(ClassMetadata $class): void
    {
        $allClasses = $this->driver->getAllClassNames();
        $fqcn       = $class->getName();
        $map        = [$this->getShortName($class->name) => $fqcn];

        $duplicates = [];
        foreach ($allClasses as $subClassCandidate) {
            if (is_subclass_of($subClassCandidate, $fqcn)) {
                $shortName = $this->getShortName($subClassCandidate);

                if (isset($map[$shortName])) {
                    $duplicates[] = $shortName;
                }

                $map[$shortName] = $subClassCandidate;
            }
        }

        if ($duplicates) {
            throw MappingException::duplicateDiscriminatorEntry($class->name, $duplicates, $map);
        }

        $class->setDiscriminatorMap($map);
    }

    private function findAbstractEntityClassesNotListedInDiscriminatorMap(ClassMetadata $rootEntityClass): void
    {
        // Only root classes in inheritance hierarchies need contain a discriminator map,
        // so skip for other classes.
        if (! $rootEntityClass->isRootEntity() || $rootEntityClass->isInheritanceTypeNone()) {
            return;
        }

        $processedClasses = [$rootEntityClass->name => true];
        foreach ($rootEntityClass->subClasses as $knownSubClass) {
            $processedClasses[$knownSubClass] = true;
        }

        foreach ($rootEntityClass->discriminatorMap as $declaredClassName) {
            // This fetches non-transient parent classes only
            $parentClasses = $this->getParentClasses($declaredClassName);

            foreach ($parentClasses as $parentClass) {
                if (isset($processedClasses[$parentClass])) {
                    continue;
                }

                $processedClasses[$parentClass] = true;

                // All non-abstract entity classes must be listed in the discriminator map, and
                // this will be validated/enforced at runtime (possibly at a later time, when the
                // subclass is loaded, but anyways). Also, subclasses is about entity classes only.
                // That means we can ignore non-abstract classes here. The (expensive) driver
                // check for mapped superclasses need only be run for abstract candidate classes.
                if (! (new ReflectionClass($parentClass))->isAbstract() || $this->peekIfIsMappedSuperclass($parentClass)) {
                    continue;
                }

                // We have found a non-transient, non-mapped-superclass = an entity class (possibly abstract, but that does not matter)
                $rootEntityClass->addSubClass($parentClass);
            }
        }
    }

    /** @param class-string $className */
    private function peekIfIsMappedSuperclass(string $className): bool
    {
        $reflService = $this->getReflectionService();
        $class       = $this->newClassMetadataInstance($className);
        $this->initializeReflection($class, $reflService);

        $this->getDriver()->loadMetadataForClass($className, $class);

        return $class->isMappedSuperclass;
    }

    /**
     * Gets the lower-case short name of a class.
     *
     * @psalm-param class-string $className
     */
    private function getShortName(string $className): string
    {
        if (! str_contains($className, '\\')) {
            return strtolower($className);
        }

        $parts = explode('\\', $className);

        return strtolower(end($parts));
    }

    /**
     * Puts the `inherited` and `declared` values into mapping information for fields, associations
     * and embedded classes.
     */
    private function addMappingInheritanceInformation(
        AssociationMapping|EmbeddedClassMapping|FieldMapping $mapping,
        ClassMetadata $parentClass,
    ): void {
        if (! isset($mapping->inherited) && ! $parentClass->isMappedSuperclass) {
            $mapping->inherited = $parentClass->name;
        }

        if (! isset($mapping->declared)) {
            $mapping->declared = $parentClass->name;
        }
    }

    /**
     * Adds inherited fields to the subclass mapping.
     */
    private function addInheritedFields(ClassMetadata $subClass, ClassMetadata $parentClass): void
    {
        foreach ($parentClass->fieldMappings as $mapping) {
            $subClassMapping = clone $mapping;
            $this->addMappingInheritanceInformation($subClassMapping, $parentClass);
            $subClass->addInheritedFieldMapping($subClassMapping);
        }

        foreach ($parentClass->reflFields as $name => $field) {
            $subClass->reflFields[$name] = $field;
        }
    }

    /**
     * Adds inherited association mappings to the subclass mapping.
     *
     * @throws MappingException
     */
    private function addInheritedRelations(ClassMetadata $subClass, ClassMetadata $parentClass): void
    {
        foreach ($parentClass->associationMappings as $field => $mapping) {
            $subClassMapping = clone $mapping;
            $this->addMappingInheritanceInformation($subClassMapping, $parentClass);
            // When the class inheriting the relation ($subClass) is the first entity class since the
            // relation has been defined in a mapped superclass (or in a chain
            // of mapped superclasses) above, then declare this current entity class as the source of
            // the relationship.
            // According to the definitions given in https://github.com/doctrine/orm/pull/10396/,
            // this is the case <=> ! isset($mapping['inherited']).
            if (! isset($subClassMapping->inherited)) {
                $subClassMapping->sourceEntity = $subClass->name;
            }

            $subClass->addInheritedAssociationMapping($subClassMapping);
        }
    }

    private function addInheritedEmbeddedClasses(ClassMetadata $subClass, ClassMetadata $parentClass): void
    {
        foreach ($parentClass->embeddedClasses as $field => $embeddedClass) {
            $subClassMapping = clone $embeddedClass;
            $this->addMappingInheritanceInformation($subClassMapping, $parentClass);
            $subClass->embeddedClasses[$field] = $subClassMapping;
        }
    }

    /**
     * Adds nested embedded classes metadata to a parent class.
     *
     * @param ClassMetadata $subClass    Sub embedded class metadata to add nested embedded classes metadata from.
     * @param ClassMetadata $parentClass Parent class to add nested embedded classes metadata to.
     * @param string        $prefix      Embedded classes' prefix to use for nested embedded classes field names.
     */
    private function addNestedEmbeddedClasses(
        ClassMetadata $subClass,
        ClassMetadata $parentClass,
        string $prefix,
    ): void {
        foreach ($subClass->embeddedClasses as $property => $embeddableClass) {
            if (isset($embeddableClass->inherited)) {
                continue;
            }

            $embeddableMetadata = $this->getMetadataFor($embeddableClass->class);

            $parentClass->mapEmbedded(
                [
                    'fieldName' => $prefix . '.' . $property,
                    'class' => $embeddableMetadata->name,
                    'columnPrefix' => $embeddableClass->columnPrefix,
                    'declaredField' => $embeddableClass->declaredField
                            ? $prefix . '.' . $embeddableClass->declaredField
                            : $prefix,
                    'originalField' => $embeddableClass->originalField ?: $property,
                ],
            );
        }
    }

    /**
     * Copy the table indices from the parent class superclass to the child class
     */
    private function addInheritedIndexes(ClassMetadata $subClass, ClassMetadata $parentClass): void
    {
        if (! $parentClass->isMappedSuperclass) {
            return;
        }

        foreach (['uniqueConstraints', 'indexes'] as $indexType) {
            if (isset($parentClass->table[$indexType])) {
                foreach ($parentClass->table[$indexType] as $indexName => $index) {
                    if (isset($subClass->table[$indexType][$indexName])) {
                        continue; // Let the inheriting table override indices
                    }

                    $subClass->table[$indexType][$indexName] = $index;
                }
            }
        }
    }

    /**
     * Completes the ID generator mapping. If "auto" is specified we choose the generator
     * most appropriate for the targeted database platform.
     *
     * @throws ORMException
     */
    private function completeIdGeneratorMapping(ClassMetadata $class): void
    {
        $idGenType = $class->generatorType;
        if ($idGenType === ClassMetadata::GENERATOR_TYPE_AUTO) {
            $class->setIdGeneratorType($this->determineIdGeneratorStrategy($this->getTargetPlatform()));
        }

        // Create & assign an appropriate ID generator instance
        switch ($class->generatorType) {
            case ClassMetadata::GENERATOR_TYPE_IDENTITY:
                $sequenceName = null;
                $fieldName    = $class->identifier ? $class->getSingleIdentifierFieldName() : null;
                $platform     = $this->getTargetPlatform();

                $generator = $fieldName && $class->fieldMappings[$fieldName]->type === 'bigint'
                    ? new BigIntegerIdentityGenerator()
                    : new IdentityGenerator();

                $class->setIdGenerator($generator);

                break;

            case ClassMetadata::GENERATOR_TYPE_SEQUENCE:
                // If there is no sequence definition yet, create a default definition
                $definition = $class->sequenceGeneratorDefinition;

                if (! $definition) {
                    $fieldName    = $class->getSingleIdentifierFieldName();
                    $sequenceName = $class->getSequenceName($this->getTargetPlatform());
                    $quoted       = isset($class->fieldMappings[$fieldName]->quoted) || isset($class->table['quoted']);

                    $definition = [
                        'sequenceName'      => $this->truncateSequenceName($sequenceName),
                        'allocationSize'    => 1,
                        'initialValue'      => 1,
                    ];

                    if ($quoted) {
                        $definition['quoted'] = true;
                    }

                    $class->setSequenceGeneratorDefinition($definition);
                }

                $sequenceGenerator = new SequenceGenerator(
                    $this->em->getConfiguration()->getQuoteStrategy()->getSequenceName($definition, $class, $this->getTargetPlatform()),
                    (int) $definition['allocationSize'],
                );
                $class->setIdGenerator($sequenceGenerator);
                break;

            case ClassMetadata::GENERATOR_TYPE_NONE:
                $class->setIdGenerator(new AssignedGenerator());
                break;

            case ClassMetadata::GENERATOR_TYPE_CUSTOM:
                $definition = $class->customGeneratorDefinition;
                if ($definition === null) {
                    throw InvalidCustomGenerator::onClassNotConfigured();
                }

                if (! class_exists($definition['class'])) {
                    throw InvalidCustomGenerator::onMissingClass($definition);
                }

                $class->setIdGenerator(new $definition['class']());
                break;

            default:
                throw UnknownGeneratorType::create($class->generatorType);
        }
    }

    /** @psalm-return ClassMetadata::GENERATOR_TYPE_* */
    private function determineIdGeneratorStrategy(AbstractPlatform $platform): int
    {
        assert($this->em !== null);
        foreach ($this->em->getConfiguration()->getIdentityGenerationPreferences() as $platformFamily => $strategy) {
            if (is_a($platform, $platformFamily)) {
                return $strategy;
            }
        }

        $nonIdentityDefaultStrategy = self::NON_IDENTITY_DEFAULT_STRATEGY;

        // DBAL 3
        if (method_exists($platform, 'getIdentitySequenceName')) {
            $nonIdentityDefaultStrategy[Platforms\PostgreSQLPlatform::class] = ClassMetadata::GENERATOR_TYPE_SEQUENCE;
        }

        foreach ($nonIdentityDefaultStrategy as $platformFamily => $strategy) {
            if (is_a($platform, $platformFamily)) {
                if ($platform instanceof Platforms\PostgreSQLPlatform) {
                    Deprecation::trigger(
                        'doctrine/orm',
                        'https://github.com/doctrine/orm/issues/8893',
                        <<<'DEPRECATION'
                        Relying on non-optimal defaults for ID generation is deprecated, and IDENTITY
                        results in SERIAL, which is not recommended.
                        Instead, configure identifier generation strategies explicitly through
                        configuration.
                        We currently recommend "SEQUENCE" for "%s", when using DBAL 3,
                        and "IDENTITY" when using DBAL 4,
                        so you should use probably use the following configuration before upgrading to DBAL 4,
                        and remove it after deploying that upgrade:

                        $configuration->setIdentityGenerationPreferences([
                            "%s" => ClassMetadata::GENERATOR_TYPE_SEQUENCE,
                        ]);

                        DEPRECATION,
                        $platformFamily,
                        $platformFamily,
                    );
                }

                return $strategy;
            }
        }

        return ClassMetadata::GENERATOR_TYPE_IDENTITY;
    }

    private function truncateSequenceName(string $schemaElementName): string
    {
        $platform = $this->getTargetPlatform();
        if (! $platform instanceof Platforms\OraclePlatform) {
            return $schemaElementName;
        }

        $maxIdentifierLength = $platform->getMaxIdentifierLength();

        if (strlen($schemaElementName) > $maxIdentifierLength) {
            return substr($schemaElementName, 0, $maxIdentifierLength);
        }

        return $schemaElementName;
    }

    /**
     * Inherits the ID generator mapping from a parent class.
     */
    private function inheritIdGeneratorMapping(ClassMetadata $class, ClassMetadata $parent): void
    {
        if ($parent->isIdGeneratorSequence()) {
            $class->setSequenceGeneratorDefinition($parent->sequenceGeneratorDefinition);
        }

        if ($parent->generatorType) {
            $class->setIdGeneratorType($parent->generatorType);
        }

        if ($parent->idGenerator ?? null) {
            $class->setIdGenerator($parent->idGenerator);
        }
    }

    protected function wakeupReflection(ClassMetadataInterface $class, ReflectionService $reflService): void
    {
        $class->wakeupReflection($reflService);
    }

    protected function initializeReflection(ClassMetadataInterface $class, ReflectionService $reflService): void
    {
        $class->initializeReflection($reflService);
    }

    protected function getDriver(): MappingDriver
    {
        assert($this->driver !== null);

        return $this->driver;
    }

    protected function isEntity(ClassMetadataInterface $class): bool
    {
        return ! $class->isMappedSuperclass;
    }

    private function getTargetPlatform(): Platforms\AbstractPlatform
    {
        if (! $this->targetPlatform) {
            $this->targetPlatform = $this->em->getConnection()->getDatabasePlatform();
        }

        return $this->targetPlatform;
    }
}
