<?php
declare(strict_types=1);

require_once __DIR__ . '/../../../shared/db.php';
require_once __DIR__ . '/../../../shared/auth/service.php';
require_once __DIR__ . '/../../kontakte/service.php';
require_once __DIR__ . '/../service.php';

$env = expand_env_values(parse_env_file(__DIR__ . '/../../../../.env'));

try {
    $pdo = connect_database($env);
    auth_bootstrap_session();
    $currentUser = auth_current_user($pdo);
    if ($currentUser === null) {
        json_response(401, ['ok' => false, 'error' => 'Unauthorized']);
    }

    if (($_SERVER['REQUEST_METHOD'] ?? '') !== 'POST') {
        json_response(405, ['ok' => false, 'error' => 'Method Not Allowed']);
    }

    $jsonInput = file_get_contents('php://input');
    if ($jsonInput === false || trim($jsonInput) === '') {
        json_response(400, ['ok' => false, 'error' => 'Empty payload']);
    }

    $data = json_decode($jsonInput, true, 512, JSON_THROW_ON_ERROR);
    if (!is_array($data) || !auth_validate_csrf_token($data['csrfToken'] ?? null)) {
        json_response(403, ['ok' => false, 'error' => 'Invalid security token']);
    }

    $action = trim((string) ($data['action'] ?? ''));
    if ($action === 'create_manufacturer') {
        $manufacturer = create_manufacturer(
            $pdo,
            (string) ($data['name'] ?? ''),
            isset($data['email']) ? (string) $data['email'] : null,
            isset($data['phone']) ? (string) $data['phone'] : null
        );
        json_response(201, ['ok' => true, 'manufacturer' => $manufacturer]);
    }

    if ($action === 'update_lot') {
        $manufacturerPartyId = $data['manufacturerPartyId'] ?? null;
        $manufacturerPartyId = $manufacturerPartyId === null || $manufacturerPartyId === ''
            ? null
            : (int) $manufacturerPartyId;
        $receiptQty = isset($data['receiptQty']) && $data['receiptQty'] !== '' ? (float) $data['receiptQty'] : 0.0;
        $adjustmentQty = isset($data['adjustmentQty']) && $data['adjustmentQty'] !== '' ? (float) $data['adjustmentQty'] : 0.0;
        $outQty = isset($data['outQty']) && $data['outQty'] !== '' ? (float) $data['outQty'] : 0.0;
        $updatedLot = update_stock_lot_traceability(
            $pdo,
            (int) ($data['lotId'] ?? 0),
            $manufacturerPartyId,
            isset($data['manufacturerLotNumber']) ? (string) $data['manufacturerLotNumber'] : null,
            isset($data['mfgDate']) ? (string) $data['mfgDate'] : null,
            isset($data['expiryDate']) ? (string) $data['expiryDate'] : null,
            isset($data['purchaseDate']) ? (string) $data['purchaseDate'] : null,
            (string) ($currentUser['username'] ?? $currentUser['email'] ?? 'unknown'),
            $receiptQty,
            $adjustmentQty,
            $outQty
        );
        $productId = (int) $updatedLot['product_id'];
        refresh_lager_stock_lot_forecast_for_product($pdo, $productId);
        $forecast = get_lager_product_forecast($pdo, $productId);
        json_response(200, ['ok' => true, 'productId' => $productId, 'lot' => $updatedLot, 'balance' => get_stock_lot_balance($pdo, (int) ($data['lotId'] ?? 0)), 'forecast' => $forecast]);
    }

    if ($action === 'delete_open_lot') {
        $productId = delete_open_stock_lot(
            $pdo,
            (int) ($data['lotId'] ?? 0),
            (string) ($currentUser['username'] ?? $currentUser['email'] ?? 'unknown')
        );
        sync_open_lot_activation_selection($pdo, $productId);
        json_response(200, ['ok' => true, 'productId' => $productId, 'availableQty' => get_lager_product_available_qty($pdo, $productId)]);
    }

    if ($action === 'prepare_lot') {
        $productId = (int) ($data['productId'] ?? 0);
        $lotNumber = trim((string) ($data['lotNumber'] ?? ''));
        $lotId = (int) ($data['lotId'] ?? 0);
        $manufacturerPartyId = $data['manufacturerPartyId'] ?? null;
        $manufacturerPartyId = $manufacturerPartyId === null || $manufacturerPartyId === '' ? null : (int) $manufacturerPartyId;
        $manufacturerLotNumber = trim((string) ($data['manufacturerLotNumber'] ?? ''));
        $mfgDate = trim((string) ($data['mfgDate'] ?? ''));
        $expiryDate = trim((string) ($data['expiryDate'] ?? ''));
        $purchaseDate = trim((string) ($data['purchaseDate'] ?? ''));
        $receiptQty = isset($data['receiptQty']) && $data['receiptQty'] !== '' ? (float) $data['receiptQty'] : 0.0;
        $targetQty = isset($data['targetQty']) && $data['targetQty'] !== '' ? (float) $data['targetQty'] : null;
        if ($lotId > 0) {
            $lotStmt = $pdo->prepare(
                "SELECT id
                 FROM stock_lot
                 WHERE id = :lot_id
                   AND product_id = :product_id
                   AND status = 'open'"
            );
            $lotStmt->execute([':lot_id' => $lotId, ':product_id' => $productId]);
            if ($lotStmt->fetchColumn() === false) {
                throw new InvalidArgumentException('Offene Charge nicht gefunden');
            }
        } else {
            $lotId = create_open_lot($pdo, $productId);
        }
        $preparedLot = update_stock_lot_traceability(
            $pdo,
            $lotId,
            $manufacturerPartyId,
            $manufacturerLotNumber,
            $mfgDate,
            $expiryDate,
            $purchaseDate,
            (string) ($currentUser['username'] ?? $currentUser['email'] ?? 'unknown'),
            $receiptQty,
            0.0,
            0.0,
            $lotNumber,
            $targetQty,
            $lotNumber === ''
        );
        sync_open_lot_activation_selection($pdo, $productId);
        refresh_lager_stock_lot_forecast_for_product($pdo, $productId);
        $forecast = get_lager_product_forecast($pdo, $productId);
        json_response(200, ['ok' => true, 'productId' => $productId, 'lot' => $preparedLot, 'balance' => get_stock_lot_balance($pdo, $lotId), 'availableQty' => get_lager_product_available_qty($pdo, $productId), 'forecast' => $forecast]);
    }

    if ($action === 'select_open_lot') {
        $productId = (int) ($data['productId'] ?? 0);
        $lotId = (int) ($data['lotId'] ?? 0);
        select_open_lot_for_activation($pdo, $productId, $lotId);
        json_response(200, ['ok' => true, 'productId' => $productId, 'selectedLotId' => $lotId]);
    }

    json_response(422, ['ok' => false, 'error' => 'Unsupported action']);
} catch (JsonException) {
    json_response(400, ['ok' => false, 'error' => 'Invalid JSON payload']);
} catch (InvalidArgumentException $error) {
    json_response(422, ['ok' => false, 'error' => $error->getMessage()]);
} catch (Throwable $error) {
    json_response(500, ['ok' => false, 'error' => 'Interner Serverfehler']);
}