<?php

declare(strict_types=1);

namespace Doctrine\ORM\Persisters\Collection;

use BadMethodCallException;
use Doctrine\Common\Collections\Criteria;
use Doctrine\DBAL\Exception as DBALException;
use Doctrine\DBAL\Types\Type;
use Doctrine\ORM\PersistentCollection;
use Doctrine\ORM\Utility\PersisterHelper;

use function array_merge;
use function array_reverse;
use function array_values;
use function assert;
use function implode;
use function is_string;

/**
 * Persister for one-to-many collections.
 */
class OneToManyPersister extends AbstractCollectionPersister
{
    /**
     * {@inheritdoc}
     *
     * @return int|null
     */
    public function delete(PersistentCollection $collection)
    {
        // The only valid case here is when you have weak entities. In this
        // scenario, you have @OneToMany with orphanRemoval=true, and replacing
        // the entire collection with a new would trigger this operation.
        $mapping = $collection->getMapping();

        if (! $mapping['orphanRemoval']) {
            // Handling non-orphan removal should never happen, as @OneToMany
            // can only be inverse side. For owning side one to many, it is
            // required to have a join table, which would classify as a ManyToManyPersister.
            return;
        }

        $targetClass = $this->em->getClassMetadata($mapping['targetEntity']);

        return $targetClass->isInheritanceTypeJoined()
            ? $this->deleteJoinedEntityCollection($collection)
            : $this->deleteEntityCollection($collection);
    }

    /**
     * {@inheritdoc}
     */
    public function update(PersistentCollection $collection)
    {
        // This can never happen. One to many can only be inverse side.
        // For owning side one to many, it is required to have a join table,
        // then classifying it as a ManyToManyPersister.
        return;
    }

    /**
     * {@inheritdoc}
     */
    public function get(PersistentCollection $collection, $index)
    {
        $mapping = $collection->getMapping();

        if (! isset($mapping['indexBy'])) {
            throw new BadMethodCallException('Selecting a collection by index is only supported on indexed collections.');
        }

        $persister = $this->uow->getEntityPersister($mapping['targetEntity']);

        return $persister->load(
            [
                $mapping['mappedBy'] => $collection->getOwner(),
                $mapping['indexBy']  => $index,
            ],
            null,
            $mapping,
            [],
            null,
            1
        );
    }

    /**
     * {@inheritdoc}
     */
    public function count(PersistentCollection $collection)
    {
        $mapping   = $collection->getMapping();
        $persister = $this->uow->getEntityPersister($mapping['targetEntity']);

        // only works with single id identifier entities. Will throw an
        // exception in Entity Persisters if that is not the case for the
        // 'mappedBy' field.
        $criteria = new Criteria(Criteria::expr()->eq($mapping['mappedBy'], $collection->getOwner()));

        return $persister->count($criteria);
    }

    /**
     * {@inheritdoc}
     */
    public function slice(PersistentCollection $collection, $offset, $length = null)
    {
        $mapping   = $collection->getMapping();
        $persister = $this->uow->getEntityPersister($mapping['targetEntity']);

        return $persister->getOneToManyCollection($mapping, $collection->getOwner(), $offset, $length);
    }

    /**
     * {@inheritdoc}
     */
    public function containsKey(PersistentCollection $collection, $key)
    {
        $mapping = $collection->getMapping();

        if (! isset($mapping['indexBy'])) {
            throw new BadMethodCallException('Selecting a collection by index is only supported on indexed collections.');
        }

        $persister = $this->uow->getEntityPersister($mapping['targetEntity']);

        // only works with single id identifier entities. Will throw an
        // exception in Entity Persisters if that is not the case for the
        // 'mappedBy' field.
        $criteria = new Criteria();

        $criteria->andWhere(Criteria::expr()->eq($mapping['mappedBy'], $collection->getOwner()));
        $criteria->andWhere(Criteria::expr()->eq($mapping['indexBy'], $key));

        return (bool) $persister->count($criteria);
    }

     /**
      * {@inheritdoc}
      */
    public function contains(PersistentCollection $collection, $element)
    {
        if (! $this->isValidEntityState($element)) {
            return false;
        }

        $mapping   = $collection->getMapping();
        $persister = $this->uow->getEntityPersister($mapping['targetEntity']);

        // only works with single id identifier entities. Will throw an
        // exception in Entity Persisters if that is not the case for the
        // 'mappedBy' field.
        $criteria = new Criteria(Criteria::expr()->eq($mapping['mappedBy'], $collection->getOwner()));

        return $persister->exists($element, $criteria);
    }

    /**
     * {@inheritdoc}
     */
    public function loadCriteria(PersistentCollection $collection, Criteria $criteria)
    {
        throw new BadMethodCallException('Filtering a collection by Criteria is not supported by this CollectionPersister.');
    }

    /** @throws DBALException */
    private function deleteEntityCollection(PersistentCollection $collection): int
    {
        $mapping     = $collection->getMapping();
        $identifier  = $this->uow->getEntityIdentifier($collection->getOwner());
        $sourceClass = $this->em->getClassMetadata($mapping['sourceEntity']);
        $targetClass = $this->em->getClassMetadata($mapping['targetEntity']);
        $columns     = [];
        $parameters  = [];

        foreach ($targetClass->associationMappings[$mapping['mappedBy']]['joinColumns'] as $joinColumn) {
            $columns[]    = $this->quoteStrategy->getJoinColumnName($joinColumn, $targetClass, $this->platform);
            $parameters[] = $identifier[$sourceClass->getFieldForColumn($joinColumn['referencedColumnName'])];
        }

        $statement = 'DELETE FROM ' . $this->quoteStrategy->getTableName($targetClass, $this->platform)
            . ' WHERE ' . implode(' = ? AND ', $columns) . ' = ?';

        return $this->conn->executeStatement($statement, $parameters);
    }

    /**
     * Delete Class Table Inheritance entities.
     * A temporary table is needed to keep IDs to be deleted in both parent and child class' tables.
     *
     * Thanks Steve Ebersole (Hibernate) for idea on how to tackle reliably this scenario, we owe him a beer! =)
     *
     * @throws DBALException
     */
    private function deleteJoinedEntityCollection(PersistentCollection $collection): int
    {
        $mapping     = $collection->getMapping();
        $sourceClass = $this->em->getClassMetadata($mapping['sourceEntity']);
        $targetClass = $this->em->getClassMetadata($mapping['targetEntity']);
        $rootClass   = $this->em->getClassMetadata($targetClass->rootEntityName);

        // 1) Build temporary table DDL
        $tempTable         = $this->platform->getTemporaryTableName($rootClass->getTemporaryIdTableName());
        $idColumnNames     = $rootClass->getIdentifierColumnNames();
        $idColumnList      = implode(', ', $idColumnNames);
        $columnDefinitions = [];

        foreach ($idColumnNames as $idColumnName) {
            $columnDefinitions[$idColumnName] = [
                'notnull' => true,
                'type'    => Type::getType(PersisterHelper::getTypeOfColumn($idColumnName, $rootClass, $this->em)),
            ];
        }

        $statement = $this->platform->getCreateTemporaryTableSnippetSQL() . ' ' . $tempTable
            . ' (' . $this->platform->getColumnDeclarationListSQL($columnDefinitions) . ')';

        $this->conn->executeStatement($statement);

        // 2) Build insert table records into temporary table
        $query = $this->em->createQuery(
            ' SELECT t0.' . implode(', t0.', $rootClass->getIdentifierFieldNames())
            . ' FROM ' . $targetClass->name . ' t0 WHERE t0.' . $mapping['mappedBy'] . ' = :owner'
        )->setParameter('owner', $collection->getOwner());

        $sql = $query->getSQL();
        assert(is_string($sql));
        $statement  = 'INSERT INTO ' . $tempTable . ' (' . $idColumnList . ') ' . $sql;
        $parameters = array_values($sourceClass->getIdentifierValues($collection->getOwner()));
        $numDeleted = $this->conn->executeStatement($statement, $parameters);

        // 3) Delete records on each table in the hierarchy
        $classNames = array_merge($targetClass->parentClasses, [$targetClass->name], $targetClass->subClasses);

        foreach (array_reverse($classNames) as $className) {
            $tableName = $this->quoteStrategy->getTableName($this->em->getClassMetadata($className), $this->platform);
            $statement = 'DELETE FROM ' . $tableName . ' WHERE (' . $idColumnList . ')'
                . ' IN (SELECT ' . $idColumnList . ' FROM ' . $tempTable . ')';

            $this->conn->executeStatement($statement);
        }

        // 4) Drop temporary table
        $statement = $this->platform->getDropTemporaryTableSQL($tempTable);

        $this->conn->executeStatement($statement);

        return $numDeleted;
    }
}