<?php
// Include database connection
require_once 'includes/db_connect.php';

// Start session if not already started
if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

// Check if user is already logged in
if (isset($_SESSION['user_id'])) {
    header('Location: index.php');
    exit;
}

$error = '';
$success = '';

// Process registration form
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // Validate inputs
    $username = $conn->real_escape_string(trim($_POST['username']));
    $email = $conn->real_escape_string(trim($_POST['email']));
    $password = trim($_POST['password']);
    $confirm_password = trim($_POST['confirm_password']);
    $user_type = $conn->real_escape_string(trim($_POST['user_type']));
    
    // Validation
    if (empty($username) || empty($email) || empty($password) || empty($confirm_password) || empty($user_type)) {
        $error = "All fields are required.";
    } elseif (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        $error = "Please enter a valid email address.";
    } elseif (strlen($password) < 6) {
        $error = "Password must be at least 6 characters long.";
    } elseif ($password !== $confirm_password) {
        $error = "Passwords do not match.";
    } elseif ($user_type !== 'student' && $user_type !== 'faculty') {
        $error = "Invalid user type.";
    } else {
        // Check if username already exists
        $check_query = "SELECT * FROM users WHERE username = ? OR email = ?";
        $check_stmt = $conn->prepare($check_query);
        $check_stmt->bind_param("ss", $username, $email);
        $check_stmt->execute();
        $check_result = $check_stmt->get_result();
        
        if ($check_result->num_rows > 0) {
            $user = $check_result->fetch_assoc();
            if ($user['username'] === $username) {
                $error = "Username already taken. Please choose another.";
            } else {
                $error = "Email already registered. Please use another email or login.";
            }
        } else {
            // Check if users table exists, create it if not
            $table_check = "SHOW TABLES LIKE 'users'";
            $table_exists = $conn->query($table_check)->num_rows > 0;
            
            if (!$table_exists) {
                $create_table = "CREATE TABLE users (
                    id INT AUTO_INCREMENT PRIMARY KEY,
                    username VARCHAR(50) NOT NULL UNIQUE,
                    email VARCHAR(100) NOT NULL UNIQUE,
                    password VARCHAR(255) NOT NULL,
                    user_type ENUM('student', 'faculty') NOT NULL,
                    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                    last_login TIMESTAMP NULL,
                    status ENUM('active', 'inactive') DEFAULT 'active'
                )";
                
                if (!$conn->query($create_table)) {
                    $error = "Error creating user table: " . $conn->error;
                }
            }
            
            if (empty($error)) {
                // Hash password
                $hashed_password = password_hash($password, PASSWORD_DEFAULT);
                
                // Insert new user
                $insert_query = "INSERT INTO users (username, email, password, user_type) VALUES (?, ?, ?, ?)";
                $insert_stmt = $conn->prepare($insert_query);
                $insert_stmt->bind_param("ssss", $username, $email, $hashed_password, $user_type);
                
                if ($insert_stmt->execute()) {
                    // Registration successful
                    $_SESSION['success_message'] = "Registration successful! Please login with your credentials.";
                    header('Location: login.php');
                    exit;
                } else {
                    $error = "Registration failed: " . $conn->error;
                }
            }
        }
    }
}

// Include header
include 'includes/header.php';
?>

<div class="row">
    <div class="col-md-12 mb-4 text-center">
        <h2>Create a New Account</h2>
        <p class="lead">Join the Domain Management System</p>
    </div>
</div>

<div class="row">
    <div class="col-md-6 offset-md-3">
        <div class="auth-form">
            <?php if (!empty($error)): ?>
                <div class="alert alert-danger alert-dismissible fade show" role="alert">
                    <i class="fas fa-exclamation-circle me-2"></i> <?php echo $error; ?>
                    <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
                </div>
            <?php endif; ?>
            
            <div class="card shadow">
                <div class="card-header bg-primary text-white text-center">
                    <h4 class="mb-0"><i class="fas fa-user-plus me-2"></i> Register</h4>
                </div>
                <div class="card-body">
                    <form method="POST" action="register.php" class="needs-validation" novalidate>
                        <div class="mb-3">
                            <label for="user_type" class="form-label">Register As</label>
                            <select class="form-select" id="user_type" name="user_type" required>
                                <option value="" selected disabled>Select user type</option>
                                <option value="student">Student</option>
                                <option value="faculty">Faculty</option>
                            </select>
                            <div class="invalid-feedback">
                                Please select a user type.
                            </div>
                        </div>
                        <div class="mb-3">
                            <label for="username" class="form-label">Username</label>
                            <div class="input-group">
                                <span class="input-group-text"><i class="fas fa-user"></i></span>
                                <input type="text" class="form-control" id="username" name="username" placeholder="Choose a username" required>
                            </div>
                            <div class="invalid-feedback">
                                Please choose a username.
                            </div>
                        </div>
                        <div class="mb-3">
                            <label for="email" class="form-label">Email</label>
                            <div class="input-group">
                                <span class="input-group-text"><i class="fas fa-envelope"></i></span>
                                <input type="email" class="form-control" id="email" name="email" placeholder="Enter your email" required>
                            </div>
                            <div class="invalid-feedback">
                                Please enter a valid email address.
                            </div>
                        </div>
                        <div class="mb-3">
                            <label for="password" class="form-label">Password</label>
                            <div class="input-group">
                                <span class="input-group-text"><i class="fas fa-lock"></i></span>
                                <input type="password" class="form-control" id="password" name="password" placeholder="Choose a password" required minlength="6">
                                <button class="btn btn-outline-secondary toggle-password" type="button" data-target="#password">
                                    <i class="fas fa-eye"></i>
                                </button>
                            </div>
                            <div class="form-text">Password must be at least 6 characters long.</div>
                            <div class="invalid-feedback">
                                Please enter a password (minimum 6 characters).
                            </div>
                        </div>
                        <div class="mb-4">
                            <label for="confirm_password" class="form-label">Confirm Password</label>
                            <div class="input-group">
                                <span class="input-group-text"><i class="fas fa-lock"></i></span>
                                <input type="password" class="form-control" id="confirm_password" name="confirm_password" placeholder="Confirm your password" required>
                                <button class="btn btn-outline-secondary toggle-password" type="button" data-target="#confirm_password">
                                    <i class="fas fa-eye"></i>
                                </button>
                            </div>
                            <div class="invalid-feedback">
                                Please confirm your password.
                            </div>
                        </div>
                        <div class="d-grid">
                            <button type="submit" class="btn btn-primary btn-lg">
                                <i class="fas fa-user-plus me-2"></i> Create Account
                            </button>
                        </div>
                    </form>
                </div>
                <div class="card-footer text-center">
                    <p class="mb-0">Already have an account? <a href="login.php">Login here</a></p>
                </div>
            </div>
        </div>
    </div>
</div>

<?php
// Include footer
include 'includes/footer.php';

// Close connection
$conn->close();
?>