import bluetooth
import time
import os
import commands


def esta_screensaver():
    salida = commands.getoutput('ps afx | grep xscreensaver | grep -v grep')
    resultado = False

    if (salida != ""):
        resultado = True

    return resultado




def presencia():
    
    MAC  = '00:1B:59:44:63:0A'
    
    activado = False
    commands.getoutput('killall xscreensaver')

    
    while 1:
        
        lista = bluetooth.discover_devices(duration=3)
        
        if (not MAC in lista):
            
            if (not activado):
                os.spawnvpe(os.P_NOWAIT, 'xscreensaver', ['xscreensaver'], os.environ)
                print "Xscreensaver activado"
                time.sleep(3)
                commands.getoutput('xscreensaver-command -lock')
                activado=True
                
        else:

            if (activado):
                commands.getoutput('killall xscreensaver')
                print "Xscreensaver desactivado"
                activado=False
                
                
                    
        time.sleep(1)
                



presencia()