<?php
require_once __DIR__ . '/../includes/functions.php';
requireLogin();

if (isStudent()) {
    header('Location: ' . BASE_URL . '/index.php');
    exit;
}

$id = intval($_POST['id'] ?? 0);
$student_id = intval($_POST['student_id'] ?? 0);
$grade = trim($_POST['grade'] ?? '');

requireStudentAccess($student_id);

if ($id > 0) {
    $stmt = getDB()->prepare("UPDATE student_courses SET grade = ? WHERE id = ?");
    $stmt->execute([$grade, $id]);
}

header('Location: ' . BASE_URL . '/students/view.php?id=' . $student_id);
exit;