Schedule Management

if (isset($_POST['day']) && isset($_POST['start_time']) && isset($_POST['grace_period'])) {
    $class_id = $_POST['class_id'];
    $day = $_POST['day'];
    $start_time = $_POST['start_time'];
    $grace_period = $_POST['grace_period'];
    
    try {
        $stmt = $pdo->prepare("
            INSERT INTO class_schedules (class_id, day_of_week, start_time, grace_period)
            VALUES (?, ?, ?, ?)
            ON DUPLICATE KEY UPDATE start_time = ?, grace_period = ?
        ");
        $stmt->execute([$class_id, $day, $start_time, $grace_period, $start_time, $grace_period]);
        $message = "Schedule updated successfully";
    } catch(PDOException $e) {
        $error = "Error updating schedule: " . $e->getMessage();
    }
}

<label>Grace Period (minutes):</label>
<input type="number" name="grace_period" min="0" max="60" value="15" required>

// Get current time
$currentTime = new DateTime();
$startTime = new DateTime($schedule['start_time']);
$graceTime = clone $startTime;
$graceTime->modify('+' . $schedule['grace_period'] . ' minutes');

// Determine status based on time
$status = $currentTime <= $graceTime ? 'on-time' : 'late';

<select name="day" required>
    <option value="1">Sunday</option>
    <option value="2">Monday</option>
    <option value="3">Tuesday</option>
    <option value="4">Wednesday</option>
    <option value="5">Thursday</option>
    <option value="6">Friday</option>
    <option value="7">Saturday</option>
</select>

$days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
foreach ($schedules as $schedule) {
    echo "<tr>";
    echo "<td>" . htmlspecialchars($days[$schedule['day_of_week'] - 1]) . "</td>";
    echo "<td>" . htmlspecialchars(date('h:i A', strtotime($schedule['start_time']))) . "</td>";
    echo "<td>" . htmlspecialchars($schedule['grace_period']) . " minutes</td>";
    echo "<td>
            <form method='post' style='display:inline;' onsubmit='return confirm(\"Are you sure you want to delete this schedule?\")' >
                <input type='hidden' name='schedule_id' value='" . $schedule['id'] . "'>
                <input type='hidden' name='class_id' value='" . $class_id . "'>
                <input type='hidden' name='action' value='delete'>
                <button type='submit' class='delete-btn'>Delete</button>
            </form>
          </td>";
    echo "</tr>";
}

// Verify the class belongs to this teacher
$class_id = $_POST['class_id'] ?? 0;
$stmt = $pdo->prepare("SELECT id FROM classes WHERE id = ? AND teacher_id = ?");
$stmt->execute([$class_id, $teacher_id]);

if ($stmt->rowCount() === 0) {
    $error = "You don't have permission to modify this class";
}

if ($class_id) {
    // Verify the class belongs to this teacher
    $stmt = $pdo->prepare("SELECT id, name FROM classes WHERE id = ? AND teacher_id = ?");
    $stmt->execute([$class_id, $teacher_id]);
    $class = $stmt->fetch(PDO::FETCH_ASSOC);
    
    if ($class) {
        $class_name = $class['name'];
        // Get schedules only if class belongs to this teacher
        $stmt = $pdo->prepare("SELECT * FROM class_schedules WHERE class_id = ?");
        $stmt->execute([$class_id]);
        $schedules = $stmt->fetchAll(PDO::FETCH_ASSOC);
    } else {
        $error = "You don't have permission to view this class schedule";
    }
}

if (isset($_POST['action']) && $_POST['action'] === 'delete') {
    $schedule_id = $_POST['schedule_id'];
    
    try {
        $stmt = $pdo->prepare("
            DELETE FROM cs 
            USING class_schedules cs 
            JOIN classes c ON cs.class_id = c.id 
            WHERE cs.id = ? AND c.teacher_id = ?
        ");
        $stmt->execute([$schedule_id, $teacher_id]);
        $message = "Schedule deleted successfully";
    } catch(PDOException $e) {
        $error = "Error deleting schedule: " . $e->getMessage();
    }
}

// Get today's schedule
$scheduleStmt = $pdo->prepare("
    SELECT cs.* 
    FROM class_schedules cs
    JOIN classes c ON cs.class_id = c.id
    WHERE c.teacher_id = ? 
    AND cs.class_id = ?
    AND cs.day_of_week = DAYOFWEEK(CURRENT_DATE())
");
$scheduleStmt->execute([$teacher_id, $student['class_id']]);
$schedule = $scheduleStmt->fetch();

if (!$schedule) {
    echo "❌ No class scheduled for today with this teacher";
    exit;
}

<?php foreach ($schedule as $day): ?>
    <div class="schedule-item">
        <div class="day-name"><?php echo htmlspecialchars($day['day_name']); ?></div>
        <div class="class-info">
            <div><strong>Class:</strong> <?php echo htmlspecialchars($class['class_name']); ?></div>
            <div><strong>Start Time:</strong> <?php echo date('h:i A', strtotime($day['start_time'])); ?></div>
            <div><strong>Late After:</strong> <?php echo date('h:i A', strtotime($day['start_time'] . ' + ' . $day['grace_period'] . ' minutes')); ?></div>
        </div>
    </div>
<?php endforeach; ?>