<?php
declare(strict_types=1);

namespace Modules\Boersenchecker\Support;

use PDO;
use RuntimeException;

final class InstrumentRegistry
{
    public function __construct(
        private PDO $pdo,
        private string $instrumentTable,
        private string $positionTable,
        private string $quoteTable,
    ) {
    }

    public function save(array $payload): int
    {
        $currentId = (int) ($payload['id'] ?? 0);
        $data = $this->normalizePayload($payload);
        $matchingId = $this->findMatchingInstrumentId($data, $currentId);

        if ($currentId > 0 && $matchingId > 0 && $matchingId !== $currentId) {
            return $this->mergeIntoExistingInstrument($currentId, $matchingId, $data);
        }

        if ($currentId > 0) {
            $this->updateInstrument($currentId, $data);
            return $currentId;
        }

        if ($matchingId > 0) {
            $this->updateInstrument($matchingId, $data);
            return $matchingId;
        }

        return $this->insertInstrument($data);
    }

    public function findMatchingInstrumentId(array $payload, int $excludeId = 0): ?int
    {
        $data = $this->normalizePayload($payload);
        $conditions = [];
        $excludeSql = $excludeId > 0 ? ' AND id <> :exclude_id' : '';

        if ($data['isin'] !== null) {
            $conditions[] = [
                'sql' => 'SELECT id FROM ' . $this->instrumentTable . ' WHERE isin = :isin' . $excludeSql . ' LIMIT 1',
                'params' => ['isin' => $data['isin']],
            ];
        }

        if ($data['symbol'] !== null && $data['market'] !== null) {
            $conditions[] = [
                'sql' => 'SELECT id FROM ' . $this->instrumentTable . ' WHERE symbol = :symbol AND market = :market' . $excludeSql . ' LIMIT 1',
                'params' => ['symbol' => $data['symbol'], 'market' => $data['market']],
            ];
        }

        if ($data['symbol'] !== null && $data['name'] !== '') {
            $conditions[] = [
                'sql' => 'SELECT id FROM ' . $this->instrumentTable . ' WHERE symbol = :symbol AND name = :name' . $excludeSql . ' LIMIT 1',
                'params' => ['symbol' => $data['symbol'], 'name' => $data['name']],
            ];
        }

        foreach ($conditions as $condition) {
            $params = $condition['params'];
            if ($excludeId > 0) {
                $params['exclude_id'] = $excludeId;
            }

            $stmt = $this->pdo->prepare($condition['sql']);
            $stmt->execute($params);
            $id = $stmt->fetchColumn();
            if ($id !== false) {
                return (int) $id;
            }
        }

        return null;
    }

    private function normalizePayload(array $payload): array
    {
        $data = [
            'isin' => $this->normalizeUpper($payload['isin'] ?? null),
            'wkn' => $this->normalizeUpper($payload['wkn'] ?? null),
            'symbol' => $this->normalizeUpper($payload['symbol'] ?? null),
            'name' => trim((string) ($payload['name'] ?? '')),
            'quote_currency' => $this->normalizeUpper($payload['quote_currency'] ?? 'EUR', 'EUR'),
            'market' => trim((string) ($payload['market'] ?? '')) ?: null,
        ];

        if ($data['name'] === '') {
            throw new RuntimeException('Bitte mindestens einen Aktiennamen angeben.');
        }

        return $data;
    }

    private function normalizeUpper(mixed $value, string $fallback = ''): ?string
    {
        $normalized = strtoupper(trim((string) $value));
        if ($normalized !== '') {
            return $normalized;
        }

        return $fallback !== '' ? $fallback : null;
    }

    private function updateInstrument(int $instrumentId, array $data): void
    {
        $stmt = $this->pdo->prepare(
            'UPDATE ' . $this->instrumentTable . '
             SET isin = :isin,
                 wkn = :wkn,
                 symbol = :symbol,
                 name = :name,
                 quote_currency = :quote_currency,
                 market = :market,
                 updated_at = CURRENT_TIMESTAMP
             WHERE id = :id'
        );
        $stmt->execute($data + ['id' => $instrumentId]);
    }

    private function insertInstrument(array $data): int
    {
        $driver = strtolower((string) $this->pdo->getAttribute(PDO::ATTR_DRIVER_NAME));
        if ($driver === 'pgsql') {
            $stmt = $this->pdo->prepare(
                'INSERT INTO ' . $this->instrumentTable . ' (isin, wkn, symbol, name, quote_currency, market)
                 VALUES (:isin, :wkn, :symbol, :name, :quote_currency, :market)
                 RETURNING id'
            );
            $stmt->execute($data);
            return (int) $stmt->fetchColumn();
        }

        $stmt = $this->pdo->prepare(
            'INSERT INTO ' . $this->instrumentTable . ' (isin, wkn, symbol, name, quote_currency, market)
             VALUES (:isin, :wkn, :symbol, :name, :quote_currency, :market)'
        );
        $stmt->execute($data);
        return (int) $this->pdo->lastInsertId();
    }

    private function mergeIntoExistingInstrument(int $sourceId, int $targetId, array $data): int
    {
        $this->pdo->beginTransaction();
        try {
            $this->updateInstrument($targetId, $data);

            $stmt = $this->pdo->prepare(
                'UPDATE ' . $this->positionTable . '
                 SET instrument_id = :target_id, updated_at = CURRENT_TIMESTAMP
                 WHERE instrument_id = :source_id'
            );
            $stmt->execute([
                'target_id' => $targetId,
                'source_id' => $sourceId,
            ]);

            $stmt = $this->pdo->prepare(
                'UPDATE ' . $this->quoteTable . '
                 SET instrument_id = :target_id
                 WHERE instrument_id = :source_id'
            );
            $stmt->execute([
                'target_id' => $targetId,
                'source_id' => $sourceId,
            ]);

            $stmt = $this->pdo->prepare('DELETE FROM ' . $this->instrumentTable . ' WHERE id = :id');
            $stmt->execute(['id' => $sourceId]);

            $this->pdo->commit();
        } catch (\Throwable $e) {
            if ($this->pdo->inTransaction()) {
                $this->pdo->rollBack();
            }
            throw $e;
        }

        return $targetId;
    }
}