prepare("SELECT user_id FROM teachers WHERE id = ? AND school_id = ?");
$stmt->execute([$delete_id, $school_id]);
$user_id = $stmt->fetchColumn();
$pdo->beginTransaction();
$stmt = $pdo->prepare("DELETE FROM teachers WHERE id = ?");
$stmt->execute([$delete_id]);
if ($user_id) {
$stmt = $pdo->prepare("DELETE FROM users WHERE id = ?");
$stmt->execute([$user_id]);
}
$pdo->commit();
$message = "Teacher deleted successfully.";
} catch (PDOException $e) {
$pdo->rollBack();
if ($e->getCode() == '23000') { // Integrity constraint violation
$error = "Cannot delete this teacher because they are assigned to workloads or schedules. Please remove those associations before deleting.";
} else {
$error = "Error deleting teacher: " . $e->getMessage();
}
}
}
// Handle POST request to add or update a teacher
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['teacher_name'])) {
$teacherName = trim($_POST['teacher_name']);
$teacherEmail = trim($_POST['teacher_email']);
$password = $_POST['password'] ?? null;
$teacher_id = $_POST['teacher_id'] ?? null;
if (empty($teacherName) || empty($teacherEmail)) {
$error = 'Teacher name and email are required.';
} elseif (!filter_var($teacherEmail, FILTER_VALIDATE_EMAIL)) {
$error = 'Invalid email format.';
} elseif (!$teacher_id && empty($password)) {
$error = 'Password is required for new teachers.';
} else {
try {
$pdo->beginTransaction();
// Check for duplicate teacher name
$stmt = $pdo->prepare("SELECT id FROM teachers WHERE name = ? AND school_id = ? AND id != ?");
$stmt->execute([$teacherName, $school_id, $teacher_id ?? 0]);
if ($stmt->fetch()) {
throw new Exception("A teacher with this name already exists.");
}
if ($teacher_id) {
// Update existing teacher
$stmt = $pdo->prepare("UPDATE teachers SET name = ? WHERE id = ? AND school_id = ?");
$stmt->execute([$teacherName, $teacher_id, $school_id]);
// Also update user email
$stmt = $pdo->prepare("SELECT user_id FROM teachers WHERE id = ?");
$stmt->execute([$teacher_id]);
$user_id = $stmt->fetchColumn();
if ($user_id) {
$sql = "UPDATE users SET email = ?, username = ?";
$params = [$teacherEmail, $teacherEmail];
if (!empty($password)) {
$sql .= ", password = ?";
$params[] = password_hash($password, PASSWORD_DEFAULT);
}
$sql .= " WHERE id = ?";
$params[] = $user_id;
$stmt = $pdo->prepare($sql);
$stmt->execute($params);
}
$message = "Teacher updated successfully!";
} else {
// Check for duplicate email in users table
$stmt = $pdo->prepare("SELECT id FROM users WHERE email = ?");
$stmt->execute([$teacherEmail]);
if ($stmt->fetch()) {
throw new Exception("A user with this email already exists.");
}
// Insert new user
$hashed_password = password_hash($password, PASSWORD_DEFAULT);
$stmt = $pdo->prepare("INSERT INTO users (school_id, username, email, password, role) VALUES (?, ?, ?, ?, 'teacher')");
$stmt->execute([$school_id, $teacherEmail, $teacherEmail, $hashed_password]);
$user_id = $pdo->lastInsertId();
// Insert new teacher
$stmt = $pdo->prepare("INSERT INTO teachers (name, school_id, user_id) VALUES (?, ?, ?)");
$stmt->execute([$teacherName, $school_id, $user_id]);
$message = "Teacher created successfully!";
}
$pdo->commit();
} catch (Exception $e) {
if ($pdo->inTransaction()) {
$pdo->rollBack();
}
$error = $e->getMessage();
}
}
}
// Handle Edit request
if (isset($_GET['edit_id'])) {
try {
$edit_id = $_GET['edit_id'];
$stmt = $pdo->prepare("SELECT t.*, u.email FROM teachers t LEFT JOIN users u ON t.user_id = u.id WHERE t.id = ? AND t.school_id = ?");
$stmt->execute([$edit_id, $school_id]);
$editing_teacher = $stmt->fetch(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
$error = "Error fetching teacher: " . $e->getMessage();
}
}
// Fetch all teachers to display
$teachers = [];
try {
$teachers_stmt = $pdo->prepare("SELECT t.*, u.email FROM teachers t LEFT JOIN users u ON t.user_id = u.id WHERE t.school_id = ? ORDER BY t.name ASC");
$teachers_stmt->execute([$school_id]);
$teachers = $teachers_stmt->fetchAll(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
$error = 'Database error: ' . $e->getMessage();
}
// Check for teachers with no user account linked
$unlinked_teachers = [];
foreach ($teachers as $teacher) {
if (empty($teacher['user_id'])) {
$unlinked_teachers[] = $teacher['name'];
}
}
if (!empty($unlinked_teachers)) {
$unlinked_list = '
';
foreach ($unlinked_teachers as $name) {
$unlinked_list .= '
' . htmlspecialchars($name) . '
';
}
$unlinked_list .= '
';
$error .= '
Data Inconsistency Found: The following teachers are not linked to a user account and will not be able to log in or see their timetables: ' . $unlinked_list . ' To fix this, please delete these teachers and create them again. This will create a linked user account for them.