<?php
declare(strict_types=1);

require_once __DIR__ . '/../../../modules/shared/db.php';
require_once __DIR__ . '/../../../modules/shared/webhook_throttle.php';
require_once __DIR__ . '/../kontakte/service.php';
require_once __DIR__ . '/../bestellungen/service.php';
require_once __DIR__ . '/../artikel-mapping/service.php';
require_once __DIR__ . '/../lager/service.php';
require_once __DIR__ . '/service.php';

header('Content-Type: application/json; charset=utf-8');

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

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

$expectedSecret = env_value('N8N_WEBHOOK_SECRET', $env);
$providedSecret = (string) ($_SERVER['HTTP_X_WEBHOOK_SECRET'] ?? '');

if ($expectedSecret === '') {
    json_response(500, ['ok' => false, 'error' => 'N8N_WEBHOOK_SECRET not configured']);
}

if ($providedSecret === '' || !hash_equals($expectedSecret, $providedSecret)) {
    json_response(401, ['ok' => false, 'error' => 'Unauthorized']);
}

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

try {
    $data = json_decode($rawPayload, true, 512, JSON_THROW_ON_ERROR);
} catch (JsonException) {
    json_response(400, ['ok' => false, 'error' => 'Invalid JSON payload']);
}

if (!is_array($data)) {
    json_response(400, ['ok' => false, 'error' => 'JSON object expected']);
}

if (array_is_list($data)) {
    if (!isset($data[0]) || !is_array($data[0])) {
        json_response(400, ['ok' => false, 'error' => 'Array payload must contain one order object']);
    }
    $data = $data[0];
}

$externalRef = trim((string) ($data['BestellungNr'] ?? ''));
if ($externalRef === '') {
    json_response(422, ['ok' => false, 'error' => 'BestellungNr is required']);
}

$lineItems = $data['lineItems'] ?? [];
if (!is_array($lineItems)) {
    $lineItems = [];
}

try {
    $pdo = connect_database($env);
    ensure_required_tables_exist($pdo);
    $pdo->beginTransaction();

    $locations = get_default_location_ids($pdo);
    $existingOrderId = find_existing_order_id($pdo, $externalRef);

    $partyId = find_or_create_party($pdo, $data);
    upsert_addresses($pdo, $partyId, $data);

    $paymentMethodId = lookup_method_id($pdo, 'payment_method', map_payment_code((string) ($data['Zahlungsmethode'] ?? '')));
    $shippingMethodId = lookup_method_id($pdo, 'shipping_method', map_shipping_code((string) ($data['Liefermethode'] ?? '')));

    $orderId = upsert_sales_order($pdo, [
        ':external_ref' => $externalRef,
        ':party_id' => $partyId,
        ':order_source' => 'wix',
        ':order_status' => 'imported',
        ':payment_status' => 'paid',
        ':payment_method_id' => $paymentMethodId,
        ':shipping_method_id' => $shippingMethodId,
        ':amount_net' => parse_number($data['Netto'] ?? null),
        ':amount_shipping' => parse_number($data['Versandkosten'] ?? null),
        ':amount_tax' => parse_number($data['Mehrwertsteuer'] ?? null),
        ':amount_discount' => parse_number($data['Rabatt'] ?? null),
        ':total_amount' => parse_number($data['Gesamtsumme'] ?? null),
        ':currency' => 'CHF',
        ':webhook_payload' => json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
    ]);

    $inventoryRollback = [
        'reversedMoves' => 0,
        'reversedQty' => 0.0,
    ];
    if ($existingOrderId !== null) {
        $inventoryRollback = reverse_existing_allocations_for_order($pdo, $existingOrderId, $locations['storage']);
    }

    delete_sales_order_lines($pdo, $orderId);

    $insertedLines = 0;
    $inventory = [
        'linesMapped' => 0,
        'linesUnmapped' => 0,
        'allocationCount' => 0,
        'warnings' => [],
    ];

    foreach ($lineItems as $index => $lineItem) {
        if (!is_array($lineItem)) {
            continue;
        }

        $articleNumber = trim((string) ($lineItem['artikelnummer'] ?? ''));
        $title = trim((string) ($lineItem['titel'] ?? ''));
        $qty = parse_number($lineItem['artikelanzahl'] ?? null);
        if ($qty === null || $qty <= 0) {
            continue;
        }

        $unitPrice = parse_number($lineItem['preisEinheit'] ?? null);
        $lineTotal = $unitPrice !== null ? round($qty * $unitPrice, 2) : null;
        $sellableItemId = resolve_sellable_item_id($pdo, $articleNumber, $title);
        $lineNo = $index + 1;

        $lineId = insert_sales_order_line($pdo, [
            ':sales_order_id' => $orderId,
            ':line_no' => $lineNo,
            ':sellable_item_id' => $sellableItemId,
            ':article_number' => $articleNumber,
            ':title' => $title,
            ':qty' => $qty,
            ':unit_price' => $unitPrice,
            ':line_total' => $lineTotal,
        ]);

        $insertedLines++;

        if ($sellableItemId === null) {
            $inventory['linesUnmapped']++;
            $inventory['warnings'][] = "No sellable item mapping for line {$lineNo} (artikelnummer='{$articleNumber}', titel='{$title}')";
            continue;
        }

        $inventory['linesMapped']++;
        $allocationResult = allocate_line_inventory(
            $pdo,
            $orderId,
            $lineId,
            $lineNo,
            (float) $qty,
            $sellableItemId,
            $locations
        );

        if (($allocationResult['allocated'] ?? false) === true) {
            $inventory['allocationCount'] += (int) ($allocationResult['allocationCount'] ?? 0);
        }
    }

    $pdo->commit();

    $labelTrigger = trigger_shipping_label_flow($data, $env);
    $excelTrigger = trigger_excel_webhook($externalRef, $env);

    json_response(200, [
        'ok' => true,
        'orderId' => $orderId,
        'externalRef' => $externalRef,
        'lineItemsImported' => $insertedLines,
        'inventory' => $inventory,
        'inventoryRollback' => $inventoryRollback,
        'labelTrigger' => $labelTrigger,
        'excelTrigger' => $excelTrigger,
    ]);
} catch (Throwable $e) {
    if (isset($pdo) && $pdo instanceof PDO && $pdo->inTransaction()) {
        $pdo->rollBack();
    }

    json_response(500, [
        'ok' => false,
        'error' => 'Order import failed',
        'detail' => $e->getMessage(),
    ]);
}