import threading
import Queue as queue

class IllegalEventError(Exception):
	pass


class AbstractState(object):
	def __init__(self, controller):
		pass
	
	def on_registration_in_progress(self):
		raise IllegalEventError()

	def on_registration_successful(self):
		raise IllegalEventError()

	def on_gabelschalter_up(self):
		raise IllegalEventError()

	def on_gabelschalter_down(self):
		raise IllegalEventError()
	
	def on_incoming_call(self):
		raise IllegalEventError()
	
	def on_call_ended(self):
		raise IllegalEventError()
	
	def on_call_accepted(self):
		raise IllegalEventError()
	
	def on_call_ringing(self):
		raise IllegalEventError()
	
	def on_nummernschalter_input(self, num):
		raise IllegalEventError()
	
	def on_timeout(self):
		raise IllegalEventError()
		
class InitState(AbstractState):
	def on_registration_in_progress(self):
		print('registration in progress')
		return RegisteringState

class RegisteringState(AbstractState):
	def on_registration_successful(self):
		print('registration successfull')
		return IdleState

class IdleState(AbstractState):
	def on_incoming_call(self):
		print('incomfing call')
	
	def on_gabelschalter_up(self):
		print('gabel up')
		return DailingState
	
	def on_gabelschalter_down(self):
		pass

	def on_nummernschalter_input(self, x):
		pass


class SchelltState(AbstractState):
	def on_gabelschalter_up(self):
		return AcceptingState
	
	def on_call_ended(self):
		return IdleState

class AcceptingState(AbstractState):
	def on_call_accepted(self):
		return CallRunningState

class CallTerminatingState(AbstractState):
	def on_call_ended(self):
		return IdleState
	
	def on_call_accepted(self):
		return None

class ForgottenState(AbstractState):
	def on_gabelschalter_down(self):
		return IdleState

class BusyBeepingState(AbstractState):
	def on_timeout(self):
		return ForgottenState
	
	def on_gabelschalter_down(self):
		return IdleState

class CallRunningState(AbstractState):
	def on_gabelschalter_down(self):
		return CallTerminatingState
	
	def on_call_ended(self):
		return BusyBeepingState

class WecktState(AbstractState):
	def on_gabelschalter_down(self):
		return CallTerminatingState
	
	def on_call_ended(self):
		return BusyBeepingState
	
	def on_call_accepted(self):
		return CallRunningState

class ConnectingState(AbstractState):
	def on_gabelschalter_down(self):
		return CallTerminatingState
	
	def on_call_ringing(self):
		return WecktState

class DailingState(AbstractState):
	def on_gabelschalter_down(self):
		return IdleState

	def on_nummernschalter_input(self, num):
		print('nummernschalter: %d' % (num))
	
	def on_timeout(self):
		return ConnectingState



class TelefonapparatUserInterface(object):
	def __init__(self):
		pass

	def add_gabelschalter_callback(self, cb):
		pass

	def add_nummernschalter_callback(self, cb):
		pass

	def set_wecker(self, enabled):
		pass

	def set_schauzeichen(self, enabled):
		pass


class StateMachineController(object):
	def __init__(self):
		self.__state = InitState(self)

		self.__running = True
		self.__evqueue = queue.Queue()
		self.__evthread = threading.Thread(target=self.__event_dispatcher)
		self.__evthread.start()
	
	def __event_dispatcher(self):
		while self.__running:
			(evname, evargs, evkwargs) = self.__evqueue.get()
			if not evname:
				return

			print('!!! event: %s' % (evname))
			handler = getattr(self.__state, 'on_%s' % (evname))
			try:
				newstate = handler(*evargs, **evkwargs)
			except IllegalEventError:
				print('illegal event occured!!!!!!!!!!!!!!!!!!!!')
			if not newstate:
				continue

			oldstate = self.__state.__class__
			print('%s -> %s' % (oldstate.__name__, newstate.__name__))
			self.__state = newstate(self)

	
	def queue_event(self, evname, *evargs, **evkwargs):
		if not hasattr(AbstractState, 'on_%s' % (evname)):
			raise ValueError('Illegal event name: %s' % (evname))
		self.__evqueue.put((evname, evargs, evkwargs))

	def stop(self, hard=False):
		if hard:
			self.__running = False
		self.__evqueue.put((None, None, None))
	

	



if __name__ == '__main__':
	c = StateMachineController()

	c.queue_event('registration_in_progress')
	c.queue_event('registration_successful')
	c.queue_event('gabelschalter_up')
	c.queue_event('nummernschalter_input', 4)
	c.queue_event('nummernschalter_input', 2)
	#c.queue_event('gabelschalter_down')
	#c.queue_event('call_accepted')
	c.queue_event('timeout')
	c.queue_event('call_ringing')
	#c.queue_event('gabelschalter_down')
	c.queue_event('call_accepted')
	c.queue_event('call_ended')
	c.queue_event('timeout')
	c.queue_event('gabelschalter_down')

	c.stop()