package main

import (
	"os"
	"fmt"
	"net"
	"nslcd_proto"
	sd "sd_daemon"
	"sd_daemon/logger"
	_ "inotify"
	"syscall"
)

func get_socket() (socket net.Listener, err error) {
	socket = nil
	err = nil
	fds := sd.ListenFds(true);
	if (fds == nil) {
		err = fmt.Errorf("failed to aquire sockets from systemd")
		return
	}
	if (len(fds) != 1) {
		err = fmt.Errorf("wrong number of sockets from systemd: expected %d but got %d", 1, len(fds))
		return
	}
	socket, err = net.FileListener(fds[0])
	fds[0].Close()
	return
}

func getpeercred(conn *net.UnixConn) (cred *syscall.Ucred, err error) {
	cred = nil
	file, err := conn.File()
	if err != nil {
		return
	}
	defer file.Close()
	cred, err = syscall.GetsockoptUcred(int(file.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
	return
}

func handler(conn *net.UnixConn, backend nslcd_proto.Backend) {
	cred, err := getpeercred(conn)
	if err != nil {
		logger.Debug("connection from unknown client")
	} else {
		logger.Debug("connection from pid=%v uid=%v gid=%v",
			cred.Pid, cred.Uid, cred.Gid)
	}
	err = nslcd_proto.HandleRequest(backend, conn, conn, *cred)
	if err != nil {
		logger.Debug("Error while handling request: %v", err)
	}


}

func main() {
	var err error = nil
	var socket net.Listener = nil
	defer func() {
		if socket != nil {
			socket.Close()
		}
	}()

	socket, err = get_socket()
	if err != nil {
		logger.Err("%s", err.Error())
		sd.Notify(false, "STOPPING=1")
		os.Exit(1)
	}

	sd.Notify(false, "READY=1")

	for {
		conn, err := socket.Accept()
		if err != nil {
			logger.Notice("%s", err.Error())
		}
		go handler(conn.(*net.UnixConn), nil)
	}
	
	sd.Notify(false, "STOPPING=1")
	os.Exit(0)
}


// Initialize() error { func
// }