// Copyright (C) 2016 Luke Shumaker <lukeshu@sbcglobal.net>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package sd_login

import (
	"strconv"
)

type UserID int

func (uid UserID) isValid() bool {
	return uid >= 0
}

type UserState int

const (
	UserOffline UserState = iota
	UserLingering
	UserOnline
	UserActive
	UserClosing
)

// GetUsers returns a list of all users who currently have login
// sessions.
func GetUsers() ([]UserID, error) {
	strs, err := get_files_in_directory("/run/systemd/users/")
	if err != nil {
		return nil, err
	}
	var users []UserID
	for _, uid_str := range strs {
		uid, err := strconv.Atoi(uid_str)
		if err != nil {
			continue
		}
		users = append(users, UserID(uid))
	}
	return users, nil
}

func (uid UserID) IsOnSeat(seat SeatName, requireActive bool) bool
func (uid UserID) GetState() (UserState, error)

// primary session
func (uid UserID) GetDisplay() (SessionName, error)
func (uid UserID) GetSessions(requireActive bool) ([]SessionName, error)
func (uid UserID) GetSeats(requireActive bool) ([]SeatName, error)