<?php 
session_start();
include 'db.php'; // ไฟล์เชื่อมต่อฐานข้อมูล

if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['status'])) {
    $statuses = $_POST['status'];
    $class_level = mysqli_real_escape_string($conn, $_POST['class_level']);
    $date = date('Y-m-d');

    // ดึง ID ครูเวรจาก session
    $duty_teacher_id = isset($_SESSION['teacher_id']) ? intval($_SESSION['teacher_id']) : 0;

    foreach ($statuses as $student_id => $status) {
        if ($status != "") {
            $student_id = intval($student_id);
            $status = mysqli_real_escape_string($conn, $status);

            // SQL แบบ Procedural
            $sql = "INSERT INTO attendance (student_id, class_level, status, date, duty_teacher_id)
                    VALUES ('$student_id', '$class_level', '$status', '$date', '$duty_teacher_id')
                    ON DUPLICATE KEY UPDATE 
                        status = VALUES(status),
                        duty_teacher_id = VALUES(duty_teacher_id)";

            if (!mysqli_query($conn, $sql)) {
                echo "Error: " . mysqli_error($conn);
                exit;
            }
        }
    }

    $_SESSION['attendance_success'] = "บันทึกเวลาเรียนสำเร็จ";
}

header("Location: dashboard.php");
exit;
?>