<?php

declare(strict_types=1);

namespace Evomedien\Vitec\Import;

use Doctrine\DBAL\ParameterType;
use TYPO3\CMS\Core\Database\ConnectionPool;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Persists one CSV-column -> DB-field mapping per import model, so editors
 * configure the mapper once and reuse it on every delivery.
 *
 * Plain table without TCA (tx_vitec_import_mapping) - the records are pure
 * tool configuration, never edited through FormEngine.
 *
 * The same row also stores record aliases (CSV identity value -> record
 * uid) for rows whose name differs slightly from the TYPO3 record, so a
 * hand-made link survives every future delivery of the same CSV.
 */
final class MappingRepository
{
    private const TABLE = 'tx_vitec_import_mapping';

    /**
     * @return array{mapping: array<string,string>, identity: string, aliases: array<string,int>}|null
     */
    public function load(string $model): ?array
    {
        $qb = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable(self::TABLE);
        $row = $qb->select('mapping', 'identity_field', 'record_aliases')->from(self::TABLE)
            ->where($qb->expr()->eq('model', $qb->createNamedParameter($model, ParameterType::STRING)))
            ->setMaxResults(1)
            ->executeQuery()->fetchAssociative();
        if (!$row) {
            return null;
        }
        // A row may exist with aliases only (saveAliases before the first
        // saveMapping) - an unparsable mapping degrades to [], not to null.
        $mapping = json_decode((string)$row['mapping'], true);
        $aliases = json_decode((string)($row['record_aliases'] ?? ''), true);
        return [
            'mapping' => is_array($mapping) ? array_map('strval', $mapping) : [],
            'identity' => (string)$row['identity_field'],
            'aliases' => is_array($aliases) ? array_map('intval', $aliases) : [],
        ];
    }

    /** @param array<string,string> $mapping */
    public function save(string $model, array $mapping, string $identity): void
    {
        $values = [
            'mapping' => (string)json_encode($mapping, JSON_UNESCAPED_UNICODE),
            'identity_field' => $identity,
            'tstamp' => time(),
        ];
        $this->upsert($model, $values);
    }

    /** @param array<string,int> $aliases */
    public function saveAliases(string $model, array $aliases): void
    {
        $this->upsert($model, [
            'record_aliases' => (string)json_encode($aliases, JSON_UNESCAPED_UNICODE),
            'tstamp' => time(),
        ]);
    }

    /** @param array<string,mixed> $values */
    private function upsert(string $model, array $values): void
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable(self::TABLE);
        $exists = $connection->count('uid', self::TABLE, ['model' => $model]) > 0;
        if ($exists) {
            $connection->update(self::TABLE, $values, ['model' => $model]);
        } else {
            $connection->insert(self::TABLE, $values + [
                'model' => $model,
                'pid' => 0,
                'crdate' => time(),
            ]);
        }
    }
}