<?php
declare(strict_types=1);
header('Content-Type: application/json');
require_once '../db/config.php';

$data = json_decode(file_get_contents('php://input'), true);

if (!$data || empty($data['items'])) {
    echo json_encode(['success' => false, 'error' => 'Data permintaan tidak valid']);
    exit;
}

$db = db();
$db->beginTransaction();

try {
    $invoice_no = 'INV-' . strtoupper(bin2hex(random_bytes(4)));
    $member_id = $data['member_id'] ? (int)$data['member_id'] : null;
    $total_amount = (float)$data['total'];
    $payment_method = $data['payment_method'] ?? 'cash';
    $cash_received = (float)($data['cash_received'] ?? 0);
    $change_amount = (float)($data['change_amount'] ?? 0);
    $points_redeemed = (int)($data['points_redeemed'] ?? 0);
    $voucher_id = $data['voucher_id'] ? (int)$data['voucher_id'] : null;

    // Points calculation (1 point for every 10k spent)
    $points_earned = $member_id ? (int)floor($total_amount / 10000) : 0;

    // Insert sale
    $stmt = $db->prepare("INSERT INTO sales (invoice_no, member_id, total_amount, payment_method, cash_received, change_amount, points_earned, points_redeemed, voucher_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)");
    $stmt->execute([$invoice_no, $member_id, $total_amount, $payment_method, $cash_received, $change_amount, $points_earned, $points_redeemed, $voucher_id]);
    $sale_id = $db->lastInsertId();

    // Process items
    $stmtItem = $db->prepare("INSERT INTO sale_items (sale_id, product_id, quantity, unit_price, subtotal) VALUES (?, ?, ?, ?, ?)");
    $stmtStock = $db->prepare("UPDATE products SET stock = stock - ? WHERE id = ?");

    foreach ($data['items'] as $item) {
        $subtotal = $item['qty'] * $item['price'];
        $stmtItem->execute([$sale_id, $item['id'], $item['qty'], $item['price'], $subtotal]);
        $stmtStock->execute([$item['qty'], $item['id']]);
    }

    // Update member points
    if ($member_id) {
        $stmtMember = $db->prepare("UPDATE members SET points = points + ? - ? WHERE id = ?");
        $stmtMember->execute([$points_earned, $points_redeemed, $member_id]);
    }

    // Mark voucher as used
    if ($voucher_id) {
        $stmtVoucher = $db->prepare("UPDATE vouchers SET is_used = 1 WHERE id = ?");
        $stmtVoucher->execute([$voucher_id]);
    }

    $db->commit();
    echo json_encode(['success' => true, 'invoice_no' => $invoice_no]);

} catch (Exception $e) {
    $db->rollBack();
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}