<?php
require_once __DIR__ . '/../includes/app.php';
require_auth();
header('Content-Type: application/json');

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => tr('طريقة الطلب غير مدعومة.', 'Method not allowed.')]);
    exit;
}

$saleId = (int) ($_POST['sale_id'] ?? 0);
$paymentAmount = (string) ($_POST['payment_amount'] ?? '');
$completeOrder = !empty($_POST['complete_order']);

if ($saleId <= 0) {
    echo json_encode(['success' => false, 'error' => tr('الفاتورة غير صالحة.', 'Invalid invoice.')]);
    exit;
}
if ($paymentAmount === '' || !is_numeric($paymentAmount) || (float) $paymentAmount <= 0) {
    echo json_encode(['success' => false, 'error' => tr('أدخل مبلغ دفعة صحيحاً.', 'Enter a valid payment amount.')]);
    exit;
}

try {
    $sale = fetch_sale($saleId);
    if (!$sale) {
        echo json_encode(['success' => false, 'error' => tr('الفاتورة غير موجودة أو غير مصرح بها.', 'Invoice not found or not allowed.')]);
        exit;
    }

    $result = apply_sale_payment($saleId, (float) $paymentAmount, $completeOrder);

    echo json_encode([
        'success' => true,
        'message' => $result['due_amount'] <= 0.0005
            ? tr('تم سداد الفاتورة بالكامل.', 'Invoice paid in full.')
            : tr('تم تسجيل الدفعة الجزئية بنجاح.', 'Partial payment recorded successfully.'),
        'payment_status' => $result['payment_status'],
        'paid_amount' => $result['paid_amount'],
        'due_amount' => $result['due_amount'],
        'applied_amount' => $result['applied_amount'],
    ]);
} catch (Throwable $e) {
    echo json_encode(['success' => false, 'error' => tr('تعذر تسجيل الدفعة.', 'Could not record the payment.')]);
}