// Copyright (C) 2016-2017 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.

// TODO

package sd_login

import (
	"strings"
)

// A SessionName represents a login session.
type SessionName string

func (name SessionName) isValid() bool {
	id := string(name)
	if id == "" {
		return false
	}

	return strings.TrimLeft(id, letters+digits) == ""
}

type SessionState int

const (
	// logged in, in background
	SessionOnline SessionState = iota

	// logged in, in foreground
	SessionActive

	// nominally logged out, but some processes belonging to it
	// are still around.
	SessionClosing
)

func GetSessions() ([]SessionName, error) {
	strs, err := get_files_in_directory("/run/systemd/sessions/")
	if err != nil {
		return nil, err
	}
	sessions := make([]SessionName, len(strs))
	for i := range strs {
		sessions[i] = SessionName(strs[i])
	}
	return sessions, nil
}

func (sess SessionName) IsActive() (bool, error)
func (sess SessionName) IsRemote() (bool, error)
func (sess SessionName) GetState() (SessionState, error)
func (sess SessionName) GetUser() (UserID, error)
func (sess SessionName) GetSeat() (SeatName, error)

// PAM
func (sess SessionName) GetService() (string, error)

// tty, x11, wayland, mir, unspecified
func (sess SessionName) GetType() (string, error)

// user, greeter, lock-screen
func (sess SessionName) GetClass() (string, error)

// GNOME, KDE, systemd-console
func (sess SessionName) GetDesktop() (string, error)

// X11 DISPLAY
func (sess SessionName) GetDisplay() (string, error)
func (sess SessionName) GetRemoteHost() (string, error)

// PAM
func (sess SessionName) GetRemoteUser() (string, error)
func (sess SessionName) GetTTY() (string, error)
func (sess SessionName) GetVT() (uint, error)