session_start();

// connect to database
$db = mysqli_connect('localhost', 'root', '', 'multi_login');

// variable declaration
$username = "";
$email    = "";
$errors   = array();

// call the register() function if register_btn is clicked
if (isset($_POST['register_btn'])) {
	register();
}

// REGISTER USER
function register(){
	// call these variables with the global keyword to make them available in function
	global $db, $errors, $username, $email;

	// receive all input values from the form. Call the e() function
    // defined below to escape form values
	$username    =  e($_POST['username']);
	$email       =  e($_POST['email']);
	$password_1  =  e($_POST['password_1']);
	$password_2  =  e($_POST['password_2']);

	// form validation: ensure that the form is correctly filled
	if (empty($username)) {
		array_push($errors, "Username is required");
	}
	if (empty($email)) {
		array_push($errors, "Email is required");
	}
	if (empty($password_1)) {
		array_push($errors, "Password is required");
	}
	if ($password_1 != $password_2) {
		array_push($errors, "The two passwords do not match");
	}

	// register user if there are no errors in the form
	if (count($errors) == 0) {
		$password = md5($password_1);//encrypt the password before saving in the database

		if (isset($_POST['user_type'])) {
			$user_type = e($_POST['user_type']);
			$query = "INSERT INTO users (username, email, user_type, password)
					  VALUES('$username', '$email', '$user_type', '$password')";
			mysqli_query($db, $query);
			$_SESSION['success']  = "New user successfully created!!";
			header('location: home.php');
		}else{
			$query = "INSERT INTO users (username, email, user_type, password)
					  VALUES('$username', '$email', 'user', '$password')";
			mysqli_query($db, $query);

			// get id of the created user
			$logged_in_user_id = mysqli_insert_id($db);

			$_SESSION['user'] = getUserById($logged_in_user_id); // put logged in user in session
			$_SESSION['success']  = "You are now logged in";
			header('location: index.php');
		}
	}
}