<?php
include_once __DIR__ . '/../config.php';
include_once __DIR__ . '/../functions.php';
include_once __DIR__ . '/../includes/auth_check.php';
// requireRole(['admin', 'supply_manager']);

$message = '';
$message_type = 'danger'; // Default to error

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // --- Get and Sanitize Data ---
    $supply_code = isset($_POST['supply_code']) ? sanitize_input($conn, strtoupper($_POST['supply_code'])) : ''; // Convert code to uppercase
    $supply_name = isset($_POST['supply_name']) ? sanitize_input($conn, $_POST['supply_name']) : '';
    $category_id = isset($_POST['category_id']) ? intval($_POST['category_id']) : 0;
    $unit = isset($_POST['unit']) ? sanitize_input($conn, $_POST['unit']) : '';
    $min_stock_level = isset($_POST['min_stock_level']) ? intval($_POST['min_stock_level']) : 0;
    $description = isset($_POST['description']) ? sanitize_input($conn, $_POST['description']) : '';

    // --- Validate Data ---
    if (empty($supply_code) || empty($supply_name) || $category_id <= 0 || empty($unit)) {
        $message = "กรุณากรอกข้อมูลที่จำเป็นให้ครบถ้วน (รหัส, ชื่อ, หมวดหมู่, หน่วยนับ)";
    } elseif ($min_stock_level < 0) {
         $message = "จุดสั่งซื้อขั้นต่ำต้องไม่ติดลบ";
    } else {
        // --- Check if supply_code already exists ---
        $sql_check = "SELECT id FROM supplies WHERE supply_code = '$supply_code'";
        $result_check = mysqli_query($conn, $sql_check);
        if ($result_check && mysqli_num_rows($result_check) > 0) {
            $message = "รหัสพัสดุ '$supply_code' นี้มีอยู่ในระบบแล้ว กรุณาใช้รหัสอื่น";
            mysqli_free_result($result_check);
        } else {
             mysqli_free_result($result_check); // Free result even if no rows found

            // --- Prepare SQL INSERT Statement ---
            // Note: quantity_in_stock, average_unit_price, total_value default to 0 in the database schema
            $sql_insert = "INSERT INTO supplies (supply_code, supply_name, category_id, unit, min_stock_level, description, status)
                           VALUES ('$supply_code', '$supply_name', $category_id, '$unit', $min_stock_level, '$description', 'active')";

            if (mysqli_query($conn, $sql_insert)) {
                $new_supply_id = mysqli_insert_id($conn); // Get the ID of the newly inserted supply
                $message = "เพิ่มรายการพัสดุ '" . htmlspecialchars($supply_name) . "' (รหัส: $supply_code) สำเร็จแล้ว";
                $message_type = 'success';

                // Store message in session and redirect to avoid form resubmission
                $_SESSION['message'] = $message;
                $_SESSION['message_type'] = $message_type;
                mysqli_close($conn);
                redirect('index.php'); // Redirect back to the supply list

            } else {
                $message = "เกิดข้อผิดพลาดในการบันทึกข้อมูล: " . mysqli_error($conn);
                // Optional: Log the error
                // error_log("Error inserting supply: " . mysqli_error($conn));
            }
        }
    }
} else {
    // If accessed directly without POST, redirect
    redirect('supply_add.php');
}

// --- Display Error Message if Redirect Failed ---
if (!empty($message)) {
    $page_title = "ผลการบันทึก";
    include_once __DIR__ . '/../includes/header.php';
    include_once __DIR__ . '/../includes/sidebar_supply.php';
    ?>
    <div class="container-fluid">
        <h1 class="mt-4">ผลการบันทึก</h1>
        <div class="alert alert-<?php echo $message_type; ?>" role="alert">
            <?php echo $message; ?>
        </div>
        <a href="supply_add.php" class="btn btn-primary">เพิ่มรายการใหม่</a>
        <a href="index.php" class="btn btn-secondary">กลับไปรายการพัสดุ</a>
    </div>
    <?php
    include_once __DIR__ . '/../includes/footer.php';
    mysqli_close($conn); // Close connection if not closed already
}
?>