<?php
session_start();

if (!isset($_SESSION['user_id'])) {
    header('Location: index.php');
    exit;
}

require_once 'db/config.php';

if (isset($_GET['id'])) {
    $id = $_GET['id'];

    try {
        $pdo = db();
        $sql = "DELETE FROM grading_scales WHERE id = ?";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([$id]);

        $_SESSION['success_message'] = 'Grade deleted successfully.';

    } catch (PDOException $e) {
        $_SESSION['error_message'] = 'Database error: ' . $e->getMessage();
    }
}

header('Location: school_settings.php');
exit;