<?php
require_once __DIR__ . '/../db/config.php';
session_start();

if ($_SERVER['REQUEST_METHOD'] !== 'POST' || !isset($_SESSION['user_id']) || $_SESSION['role'] !== 'admin') {
    header('Location: /login.php');
    exit;
}

$id = $_POST['id'] ?? null;
$name = $_POST['name'] ?? '';
$description = $_POST['description'] ?? '';
$price = $_POST['price'] ?? 0;
$barcode = $_POST['barcode'] ?? null;

if (empty($id) || empty($name) || !is_numeric($price)) {
    $_SESSION['error_message'] = "Invalid data provided.";
    header('Location: /dashboard.php?page=admin_products');
    exit;
}

try {
    $pdo = db();
    $stmt = $pdo->prepare("UPDATE products SET name = ?, description = ?, price = ?, barcode = ? WHERE id = ?");
    $stmt->execute([$name, $description, $price, $barcode, $id]);
    $_SESSION['success_message'] = "Product updated successfully!";
} catch (PDOException $e) {
    error_log("Product update failed: " . $e->getMessage());
    $_SESSION['error_message'] = "Failed to update product. Please try again.";
}

header('Location: /dashboard.php?page=admin_products');
exit;