t7

db/migrations/005_create_exams_table.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS exams (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255) NOT NULL,
+    created_by INT NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE CASCADE
+);

db/migrations/006_create_exam_questions_table.sql

@@ -0,0 +1,9 @@
+CREATE TABLE IF NOT EXISTS exam_questions (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    exam_id INT NOT NULL,
+    question_text TEXT NOT NULL,
+    question_type ENUM('multiple_choice', 'free_text') NOT NULL,
+    options JSON,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (exam_id) REFERENCES exams(id) ON DELETE CASCADE
+);

db/migrations/007_create_student_exams_table.sql

@@ -0,0 +1,12 @@
+CREATE TABLE IF NOT EXISTS student_exams (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    exam_id INT NOT NULL,
+    student_id INT NOT NULL,
+    status ENUM('assigned', 'in-progress', 'completed') DEFAULT 'assigned',
+    score INT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    FOREIGN KEY (exam_id) REFERENCES exams(id) ON DELETE CASCADE,
+    FOREIGN KEY (student_id) REFERENCES users(id) ON DELETE CASCADE,
+    UNIQUE KEY (exam_id, student_id)
+);

db/migrations/008_create_student_answers_table.sql

@@ -0,0 +1,10 @@
+CREATE TABLE IF NOT EXISTS student_answers (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    student_exam_id INT NOT NULL,
+    question_id INT NOT NULL,
+    answer_text TEXT,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (student_exam_id) REFERENCES student_exams(id) ON DELETE CASCADE,
+    FOREIGN KEY (question_id) REFERENCES exam_questions(id) ON DELETE CASCADE,
+    UNIQUE KEY (student_exam_id, question_id)
+);

exam_questions.php

@@ -0,0 +1,180 @@
+<?php
+session_start();
+require_once 'db/config.php';
+
+if (!isset($_SESSION['user_id'])) {
+    header('Location: login.php');
+    exit();
+}
+
+$user_id = $_SESSION['user_id'];
+$role = $_SESSION['role'];
+
+if ($role !== 'teacher') {
+    header('Location: ' . $role . '_dashboard.php');
+    exit();
+}
+
+if (!isset($_GET['exam_id'])) {
+    header('Location: exams.php');
+    exit();
+}
+
+$exam_id = $_GET['exam_id'];
+$pdo = db();
+
+// Verify the teacher owns the exam
+$stmt = $pdo->prepare('SELECT * FROM exams WHERE id = ? AND created_by = ?');
+$stmt->execute([$exam_id, $user_id]);
+$exam = $stmt->fetch();
+
+if (!$exam) {
+    echo "Exam not found or you don't have permission to edit it.";
+    exit();
+}
+
+// Handle question form submission
+if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['question_text'])) {
+    $question_text = trim($_POST['question_text']);
+    $question_type = $_POST['question_type'];
+    $options = null;
+
+    if ($question_type === 'multiple_choice') {
+        $options_raw = trim($_POST['options']);
+        if (!empty($options_raw)) {
+            $options = json_encode(array_map('trim', explode("\n", $options_raw)));
+        }
+    }
+
+    if (!empty($question_text)) {
+        if (isset($_POST['question_id']) && !empty($_POST['question_id'])) {
+            // Update question
+            $stmt = $pdo->prepare('UPDATE exam_questions SET question_text = ?, question_type = ?, options = ? WHERE id = ? AND exam_id = ?');
+            $stmt->execute([$question_text, $question_type, $options, $_POST['question_id'], $exam_id]);
+        } else {
+            // Add new question
+            $stmt = $pdo->prepare('INSERT INTO exam_questions (exam_id, question_text, question_type, options) VALUES (?, ?, ?, ?)');
+            $stmt->execute([$exam_id, $question_text, $question_type, $options]);
+        }
+    }
+    header('Location: exam_questions.php?exam_id=' . $exam_id);
+    exit();
+}
+
+// Handle question deletion
+if (isset($_GET['delete_question'])) {
+    $question_id = $_GET['delete_question'];
+    $stmt = $pdo->prepare('DELETE FROM exam_questions WHERE id = ? AND exam_id = ?');
+    $stmt->execute([$question_id, $exam_id]);
+    header('Location: exam_questions.php?exam_id=' . $exam_id);
+    exit();
+}
+
+// Fetch questions for the exam
+$stmt = $pdo->prepare('SELECT * FROM exam_questions WHERE exam_id = ? ORDER BY created_at ASC');
+$stmt->execute([$exam_id]);
+$questions = $stmt->fetchAll();
+
+// Check if we are editing a question
+$edit_question = null;
+if (isset($_GET['edit_question'])) {
+    $stmt = $pdo->prepare('SELECT * FROM exam_questions WHERE id = ? AND exam_id = ?');
+    $stmt->execute([$_GET['edit_question'], $exam_id]);
+    $edit_question = $stmt->fetch();
+}
+
+?>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Manage Questions for <?php echo htmlspecialchars($exam['name']); ?></title>
+    <link rel="stylesheet" href="assets/css/custom.css?v=<?php echo time(); ?>">
+</head>
+<body>
+    <header>
+        <h1>Manage Questions for "<?php echo htmlspecialchars($exam['name']); ?>"</h1>
+        <nav>
+            <ul>
+                <li><a href="exams.php">Back to Exams</a></li>
+                <li><a href="teacher_dashboard.php">Dashboard</a></li>
+                <li><a href="logout.php">Logout</a></li>
+            </ul>
+        </nav>
+    </header>
+    <main>
+        <section>
+            <h2><?php echo $edit_question ? 'Edit' : 'Add'; ?> Question</h2>
+            <form action="exam_questions.php?exam_id=<?php echo $exam_id; ?>" method="POST">
+                 <?php if ($edit_question): ?>
+                    <input type="hidden" name="question_id" value="<?php echo htmlspecialchars($edit_question['id']); ?>">
+                <?php endif; ?>
+                <div>
+                    <label for="question_text">Question:</label>
+                    <textarea id="question_text" name="question_text" rows="3" required><?php echo $edit_question ? htmlspecialchars($edit_question['question_text']) : ''; ?></textarea>
+                </div>
+                <div>
+                    <label for="question_type">Question Type:</label>
+                    <select id="question_type" name="question_type">
+                        <option value="free_text" <?php echo ($edit_question && $edit_question['question_type'] === 'free_text') ? 'selected' : ''; ?>>Free Text</option>
+                        <option value="multiple_choice" <?php echo ($edit_question && $edit_question['question_type'] === 'multiple_choice') ? 'selected' : ''; ?>>Multiple Choice</option>
+                    </select>
+                </div>
+                <div id="mc_options_container">
+                    <label for="options">Options (one per line):</label>
+                    <textarea id="options" name="options" rows="5"><?php echo ($edit_question && $edit_question['options']) ? htmlspecialchars(implode("\n", json_decode($edit_question['options']))) : ''; ?></textarea>
+                </div>
+                <button type="submit"><?php echo $edit_question ? 'Update' : 'Add'; ?> Question</button>
+                 <?php if ($edit_question): ?>
+                    <a href="exam_questions.php?exam_id=<?php echo $exam_id; ?>">Cancel Edit</a>
+                <?php endif; ?>
+            </form>
+        </section>
+
+        <section>
+            <h2>Questions</h2>
+            <table>
+                <thead>
+                    <tr>
+                        <th>Question</th>
+                        <th>Type</th>
+                        <th>Actions</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <?php foreach ($questions as $question):
+                    ?>
+                        <tr>
+                            <td><?php echo nl2br(htmlspecialchars($question['question_text'])); ?></td>
+                            <td><?php echo htmlspecialchars(str_replace('_', ' ', $question['question_type'])); ?></td>
+                            <td>
+                                <a href="exam_questions.php?exam_id=<?php echo $exam_id; ?>&edit_question=<?php echo $question['id']; ?>">Edit</a> | 
+                                <a href="exam_questions.php?exam_id=<?php echo $exam_id; ?>&delete_question=<?php echo $question['id']; ?>" onclick="return confirm('Are you sure you want to delete this question?');">Delete</a>
+                            </td>
+                        </tr>
+                    <?php endforeach; ?>
+                    <?php if (empty($questions)):
+                    ?>
+                         <tr>
+                            <td colspan="3">No questions have been added to this exam yet.</td>
+                        </tr>
+                    <?php endif; ?>
+                </tbody>
+            </table>
+        </section>
+    </main>
+    <script>
+        // Show/hide multiple choice options based on question type selection
+        const questionType = document.getElementById('question_type');
+        const mcOptionsContainer = document.getElementById('mc_options_container');
+
+        function toggleMcOptions() {
+            mcOptionsContainer.style.display = questionType.value === 'multiple_choice' ? 'block' : 'none';
+        }
+
+        toggleMcOptions(); // Initial check
+        questionType.addEventListener('change', toggleMcOptions);
+    </script>
+</body>
+</html>

exams.php

@@ -1,32 +1,177 @@
 <?php
 session_start();
+require_once 'db/config.php';
 
 if (!isset($_SESSION['user_id'])) {
     header('Location: login.php');
     exit();
 }
+
+$user_id = $_SESSION['user_id'];
+$role = $_SESSION['role'];
+$pdo = db();
+
+$page_title = 'Exams';
+$header_links = '<a href="' . $role . '_dashboard.php">Dashboard</a>';
+
+// Role-based logic
+if ($role === 'teacher') {
+    $page_title = 'Manage Exams';
+
+    // Handle form submissions for creating/editing exams
+    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['exam_name'])) {
+        $exam_name = trim($_POST['exam_name']);
+        if (!empty($exam_name)) {
+            if (isset($_POST['exam_id']) && !empty($_POST['exam_id'])) {
+                $stmt = $pdo->prepare('UPDATE exams SET name = ? WHERE id = ? AND created_by = ?');
+                $stmt->execute([$exam_name, $_POST['exam_id'], $user_id]);
+            } else {
+                $stmt = $pdo->prepare('INSERT INTO exams (name, created_by) VALUES (?, ?)');
+                $stmt->execute([$exam_name, $user_id]);
+            }
+        }
+        header('Location: exams.php');
+        exit();
+    }
+
+    // Handle exam deletion
+    if (isset($_GET['delete_exam'])) {
+        $stmt = $pdo->prepare('DELETE FROM exams WHERE id = ? AND created_by = ?');
+        $stmt->execute([$_GET['delete_exam'], $user_id]);
+        header('Location: exams.php');
+        exit();
+    }
+
+    // Fetch exams for the teacher view
+    $stmt = $pdo->prepare('SELECT * FROM exams WHERE created_by = ? ORDER BY created_at DESC');
+    $stmt->execute([$user_id]);
+    $exams = $stmt->fetchAll();
+
+    // Check if we are editing an exam
+    $edit_exam = null;
+    if (isset($_GET['edit_exam'])) {
+        $stmt = $pdo->prepare('SELECT * FROM exams WHERE id = ? AND created_by = ?');
+        $stmt->execute([$_GET['edit_exam'], $user_id]);
+        $edit_exam = $stmt->fetch();
+    }
+
+} elseif ($role === 'student') {
+    $page_title = 'Your Exams';
+
+    // Fetch assigned exams for the student view
+    $stmt = $pdo->prepare('
+        SELECT e.name, se.status, se.score, se.id as student_exam_id
+        FROM student_exams se
+        JOIN exams e ON se.exam_id = e.id
+        WHERE se.student_id = ?
+        ORDER BY e.created_at DESC
+    ');
+    $stmt->execute([$user_id]);
+    $assigned_exams = $stmt->fetchAll();
+
+} else {
+    // Redirect other roles to their dashboard
+    header('Location: ' . $role . '_dashboard.php');
+    exit();
+}
 ?>
 <!DOCTYPE html>
 <html lang="en">
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Exams</title>
-    <link rel="stylesheet" href="assets/css/custom.css">
+    <title><?php echo $page_title; ?></title>
+    <link rel="stylesheet" href="assets/css/custom.css?v=<?php echo time(); ?>">
 </head>
 <body>
     <header>
-        <h1>Exams</h1>
+        <h1><?php echo $page_title; ?></h1>
         <nav>
             <ul>
-                <li><a href="teacher_dashboard.php">Dashboard</a></li>
+                <li><?php echo $header_links; ?></li>
                 <li><a href="logout.php">Logout</a></li>
             </ul>
         </nav>
     </header>
     <main>
-        <h2>Exam Management</h2>
-        <p>This page will contain student exam information.</p>
+        <?php if ($role === 'teacher'): ?>
+            <section>
+                <h2><?php echo $edit_exam ? 'Edit' : 'Create'; ?> Exam</h2>
+                <form action="exams.php" method="POST">
+                    <?php if ($edit_exam): ?>
+                        <input type="hidden" name="exam_id" value="<?php echo htmlspecialchars($edit_exam['id']); ?>">
+                    <?php endif; ?>
+                    <div>
+                        <label for="exam_name">Exam Name:</label>
+                        <input type="text" id="exam_name" name="exam_name" value="<?php echo $edit_exam ? htmlspecialchars($edit_exam['name']) : ''; ?>" required>
+                    </div>
+                    <button type="submit"><?php echo $edit_exam ? 'Update' : 'Create'; ?> Exam</button>
+                    <?php if ($edit_exam): ?>
+                        <a href="exams.php">Cancel Edit</a>
+                    <?php endif; ?>
+                </form>
+            </section>
+            <section>
+                <h2>Your Exams</h2>
+                <table>
+                <thead>
+                    <tr>
+                        <th>Exam Name</th>
+                        <th>Actions</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <?php foreach ($exams as $exam): ?>
+                        <tr>
+                            <td><?php echo htmlspecialchars($exam['name']); ?></td>
+                            <td>
+                                <a href="view_submissions.php?exam_id=<?php echo $exam['id']; ?>">View Submissions</a> |
+                                <a href="exams.php?edit_exam=<?php echo $exam['id']; ?>">Edit</a> |
+                                <a href="exam_questions.php?exam_id=<?php echo $exam['id']; ?>">Manage Questions</a> |
+                                <a href="exams.php?delete_exam=<?php echo $exam['id']; ?>" onclick="return confirm('Are you sure you want to delete this exam?');">Delete</a>
+                            </td>
+                        </tr>
+                    <?php endforeach; ?>
+                     <?php if (empty($exams)): ?>
+                        <tr><td colspan="2">You have not created any exams yet.</td></tr>
+                    <?php endif; ?>
+                </tbody>
+            </table>
+            </section>
+        <?php elseif ($role === 'student'): ?>
+            <section>
+                <h2>Assigned Exams</h2>
+                 <table>
+                    <thead>
+                        <tr>
+                            <th>Exam Name</th>
+                            <th>Status</th>
+                            <th>Score</th>
+                            <th>Action</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        <?php foreach ($assigned_exams as $exam): ?>
+                            <tr>
+                                <td><?php echo htmlspecialchars($exam['name']); ?></td>
+                                <td><?php echo htmlspecialchars(ucfirst($exam['status'])); ?></td>
+                                <td><?php echo $exam['score'] !== null ? $exam['score'] . '%' : 'Not graded'; ?></td>
+                                <td>
+                                    <?php if ($exam['status'] === 'assigned' || $exam['status'] === 'in-progress'): ?>
+                                        <a href="take_exam.php?student_exam_id=<?php echo $exam['student_exam_id']; ?>">Take Exam</a>
+                                    <?php elseif ($exam['status'] === 'completed'): ?>
+                                        <a href="view_results.php?student_exam_id=<?php echo $exam['student_exam_id']; ?>">View Results</a>
+                                    <?php endif; ?>
+                                </td>
+                            </tr>
+                        <?php endforeach; ?>
+                        <?php if (empty($assigned_exams)): ?>
+                            <tr><td colspan="4">You have no assigned exams.</td></tr>
+                        <?php endif; ?>
+                    </tbody>
+                </table>
+            </section>
+        <?php endif; ?>
     </main>
 </body>
 </html>

take_exam.php

@@ -0,0 +1,133 @@
+<?php
+session_start();
+require_once 'db/config.php';
+
+if (!isset($_SESSION['user_id']) || $_SESSION['role'] !== 'student') {
+    header('Location: login.php');
+    exit();
+}
+
+$user_id = $_SESSION['user_id'];
+$pdo = db();
+
+if (!isset($_GET['student_exam_id'])) {
+    header('Location: exams.php');
+    exit();
+}
+
+$student_exam_id = $_GET['student_exam_id'];
+
+// Verify student is assigned to this exam
+$stmt = $pdo->prepare('SELECT * FROM student_exams WHERE id = ? AND student_id = ?');
+$stmt->execute([$student_exam_id, $user_id]);
+$student_exam = $stmt->fetch();
+
+if (!$student_exam) {
+    echo "You are not assigned to this exam.";
+    exit();
+}
+
+// Prevent re-taking a completed exam
+if ($student_exam['status'] === 'completed') {
+    echo "You have already completed this exam.";
+    // Maybe redirect to a results page in the future
+    echo '<br><a href="exams.php">Back to Exams</a>';
+    exit();
+}
+
+// Fetch exam details
+$stmt = $pdo->prepare('SELECT * FROM exams WHERE id = ?');
+$stmt->execute([$student_exam['exam_id']]);
+$exam = $stmt->fetch();
+
+// Fetch exam questions
+$stmt = $pdo->prepare('SELECT * FROM exam_questions WHERE exam_id = ? ORDER BY id ASC');
+$stmt->execute([$exam['id']]);
+$questions = $stmt->fetchAll();
+
+// Handle exam submission
+if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['answers'])) {
+    $answers = $_POST['answers'];
+
+    $pdo->beginTransaction();
+    try {
+        foreach ($answers as $question_id => $answer_text) {
+            // Use INSERT ... ON DUPLICATE KEY UPDATE to prevent duplicate answer submissions
+            $sql = 'INSERT INTO student_answers (student_exam_id, question_id, answer_text) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE answer_text = VALUES(answer_text)';
+            $stmt = $pdo->prepare($sql);
+            $stmt->execute([$student_exam_id, $question_id, trim($answer_text)]);
+        }
+
+        // Mark exam as completed
+        $stmt = $pdo->prepare('UPDATE student_exams SET status = \'completed\' WHERE id = ?');
+        $stmt->execute([$student_exam_id]);
+
+        $pdo->commit();
+
+        header('Location: exams.php');
+        exit();
+
+    } catch (Exception $e) {
+        $pdo->rollBack();
+        // Log error properly in a real application
+        die("An error occurred while submitting your exam. Please try again. Error: " . $e->getMessage());
+    }
+}
+
+// If student is starting the exam, mark it as 'in-progress'
+if ($student_exam['status'] === 'assigned') {
+    $stmt = $pdo->prepare('UPDATE student_exams SET status = \'in-progress\' WHERE id = ?');
+    $stmt->execute([$student_exam_id]);
+}
+
+?>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Take Exam: <?php echo htmlspecialchars($exam['name']); ?></title>
+    <link rel="stylesheet" href="assets/css/custom.css?v=<?php echo time(); ?>">
+</head>
+<body>
+    <header>
+        <h1><?php echo htmlspecialchars($exam['name']); ?></h1>
+        <nav>
+            <ul>
+                <li><a href="exams.php">Back to Exams</a></li>
+                <li><a href="logout.php">Logout</a></li>
+            </ul>
+        </nav>
+    </header>
+    <main>
+        <form action="take_exam.php?student_exam_id=<?php echo $student_exam_id; ?>" method="POST">
+            <?php foreach ($questions as $index => $q): ?>
+                <div class="question-block">
+                    <p><strong>Question <?php echo $index + 1; ?>:</strong> <?php echo nl2br(htmlspecialchars($q['question_text'])); ?></p>
+                    
+                    <?php if ($q['question_type'] === 'multiple_choice'): ?>
+                        <?php $options = json_decode($q['options']); ?>
+                        <?php if($options):
+                            foreach ($options as $option):
+                        ?>
+                                <div>
+                                    <input type="radio" id="q_<?php echo $q['id'] . '_' . htmlspecialchars($option); ?>" name="answers[<?php echo $q['id']; ?>]" value="<?php echo htmlspecialchars($option); ?>" required>
+                                    <label for="q_<?php echo $q['id'] . '_' . htmlspecialchars($option); ?>"><?php echo htmlspecialchars($option); ?></label>
+                                </div>
+                            <?php endforeach; ?>
+                        <?php endif; ?>
+                    <?php else: // free_text ?>
+                        <textarea name="answers[<?php echo $q['id']; ?>]" rows="5" required></textarea>
+                    <?php endif; ?>
+                </div>
+            <?php endforeach; ?>
+            
+            <?php if (empty($questions)): ?>
+                <p>This exam has no questions.</p>
+            <?php else: ?>
+                 <button type="submit" onclick="return confirm('Are you sure you want to submit your answers?');">Submit Exam</button>
+            <?php endif; ?>
+        </form>
+    </main>
+</body>
+</html>