<?php

declare(strict_types=1);

/*
 * Chill is a software for social workers
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace Chill\ThirdPartyBundle\Service;

use Chill\ThirdPartyBundle\Entity\ThirdParty;
use Doctrine\DBAL\Exception;
use Doctrine\ORM\EntityManagerInterface;
use Doctrine\ORM\Mapping\ClassMetadata;

class ThirdpartyMergeService
{
    public function __construct(private readonly EntityManagerInterface $em) {}

    public function merge(ThirdParty $toKeep, ThirdParty $toDelete): void
    {
        $conn = $this->em->getConnection();
        $conn->beginTransaction();

        try {
            $queries = array_merge(
                $this->transferData($toKeep, $toDelete),
                $this->updateReferences($toKeep, $toDelete),
                $this->removeThirdparty($toDelete)
            );

            foreach ($queries as $query) {
                $conn->executeStatement($query['sql'], $query['params']);
            }

            $conn->commit();
        } catch (\Exception $e) {
            $conn->rollBack();
            throw $e;
        }
    }

    /**
     * @throws Exception
     */
    private function transferData(ThirdParty $toKeep, ThirdParty $toDelete): array
    {
        $queries = [];
        $columns = ['profession', 'firstname', 'name', 'email', 'telephone', 'comment', 'kind', 'contact_data_anonymous', 'types', 'active', 'name_company'];
        $metadata = $this->em->getClassMetadata(ThirdParty::class);

        foreach ($columns as $column) {
            $columnType = $metadata->getTypeOfField($column);
            $condition = ('string' === $columnType || 'text' === $columnType)
                ? "({$column} IS NULL OR {$column} = '')"
                : "{$column} IS NULL";

            $queries[] = [
                'sql' => "
                    UPDATE chill_3party.third_party
                    SET {$column} = COALESCE((SELECT {$column} FROM chill_3party.third_party WHERE id = :toDelete), {$column})
                    WHERE id = :toKeep AND {$condition}",
                'params' => ['toDelete' => $toDelete->getId(), 'toKeep' => $toKeep->getId()],
            ];
        }

        return $queries;
    }

    private function updateReferences(ThirdParty $toKeep, ThirdParty $toDelete): array
    {
        $queries = [];
        $allMeta = $this->em->getMetadataFactory()->getAllMetadata();

        foreach ($allMeta as $meta) {
            if ($meta->isMappedSuperclass) {
                continue;
            }

            $tableName = $meta->getTableName();
            foreach ($meta->getAssociationMappings() as $assoc) {
                if (ThirdParty::class !== $assoc['targetEntity'] && ThirdParty::class !== $assoc['sourceEntity']) {
                    continue;
                }

                if (ClassMetadata::TO_ONE === $assoc['type']) {
                    $joinColumn = $meta->getSingleAssociationJoinColumnName($assoc['fieldName']);

                    if (ThirdParty::class === $assoc['sourceEntity'] && 'parent_id' !== $joinColumn) {
                        // TODO what with 'address_id' and 'civility_id'? This condition also contains columns like updatedBy_id which we want to ignore...
                        continue;
                    }

                    $schemaPrefix = (ThirdParty::class === $assoc['sourceEntity'] && 'parent_id' === $joinColumn)
                        ? 'chill_3party.'
                        : '';

                    $queries[] = [
                        'sql' => "UPDATE {$schemaPrefix}{$tableName} SET {$joinColumn} = :toKeep WHERE {$joinColumn} = :toDelete",
                        'params' => ['toKeep' => $toKeep->getId(), 'toDelete' => $toDelete->getId()],
                    ];
                }

                if (ClassMetadata::TO_MANY === $assoc['type'] && isset($assoc['joinTable'])) {

                    $joinTable = $assoc['joinTable']['name'];
                    $joinColumn = $assoc['joinTable']['joinColumns'][0]['name'];
                    if ('thirdparty_id' === $joinColumn) {
                        $queries[] = [
                            'sql' => "DELETE FROM {$joinTable} WHERE {$joinColumn} = :toDelete",
                            'params' => ['toDelete' => $toDelete->getId()],
                        ];
                    } else {
                        $queries[] = [
                            'sql' => "UPDATE {$joinTable} SET {$joinColumn} = :toKeep WHERE {$joinColumn} = :toDelete",
                            'params' => ['toKeep' => $toKeep->getId(), 'toDelete' => $toDelete->getId()],
                        ];
                    }
                }
            }
        }

        return $queries;
    }

    public function removeThirdparty(ThirdParty $toDelete): array
    {
        return [[
            'sql' => 'DELETE FROM chill_3party.third_party WHERE id = :toDelete',
            'params' => ['toDelete' => $toDelete->getId()],
        ]];
    }
}