statemachine.py

   1 from libtuer import ThreadFunction, logger, fire_and_forget
   2 from actor import Actor
   3 import os, random, time
   4
   5 # logger.{debug,info,warning,error,critical}
   6
   7 def play_sound (what):
   8         try:
   9                 soundfiles = os.listdir(SOUNDS_DIRECTORY+what)
  10         except FileNotFoundError:
  11                 logger.error("StateMachine: Unable to list sound files in %s" % (SOUNDS_DIRECTORY+what))
  12                 return
  13         soundfile = SOUNDS_DIRECTORY + what + '/' + random.choice(soundfiles)
  14         fire_and_forget ([SOUNDS_PLAYER,soundfile], logger.error, "StateMachine: ")
  15
  16
  17 # StateUnlocking constants
  18 OPEN_REPEAT_TIMEOUT = 7
  19 OPEN_REPEAT_NUMBER = 3
  20
  21 # StateLocking constants
  22 CLOSE_REPEAT_TIMEOUT = 7
  23 CLOSE_REPEAT_NUMBER = 3
  24
  25 # StateAboutToOpen constants
  26 ABOUTOPEN_NERVLIST = [(5, lambda : play_sound("flipswitch")), (5, lambda:play_sound("flipswitch")), (0, lambda:logger.warning("Space open but switch not flipped for 10 seconds")),\
  27         (10, lambda:play_sound("flipswitch")), (10, lambda:play_sound("flipswitch")), (0, lambda:logger.error("Space open but switch not flipped for 30 seconds")),\
  28         (10, lambda:play_sound("flipswitch")), (10, lambda:play_sound("flipswitch")), (6, lambda:play_sound("flipswitch")), (4, lambda:logger.critical("Space open but switch not flipped for 60 seconds")),
  29         (59*60, lambda:logger.critical("Space open but switch not flipped for one hour"))]
  30
  31 # Timeout we wait after the switch was switched to "Closed", until we assume nobody will open the door and we just lock it
  32 # ALso the time we wait after the door was opend, till we assume something went wrong and start nerving
  33 LEAVE_TIMEOUT = 20
  34
  35 # play_sound constants
  36 SOUNDS_DIRECTORY = "/opt/tuer/sounds/"
  37 SOUNDS_PLAYER = "/usr/bin/mplayer"
  38
  39
  40 class Nerver():
  41         # A little utility class used to run the nervlists. A nervlist is a list of (n, f) tuples where f() is run after n seconds.
  42         # If f returns something, that's also returned by nerv.
  43         def __init__(self, nervlist):
  44                 self.nervlist = list(nervlist)
  45                 self.last_event_time = time.time()
  46
  47         def nerv(self):
  48                 if len(self.nervlist):
  49                         (wait_time, f) = self.nervlist[0]
  50                         now = time.time()
  51                         time_gone = now-self.last_event_time
  52                         # check if the first element is to be triggered
  53                         if time_gone >= wait_time:
  54                                 self.nervlist = self.nervlist[1:] # "pop" the first element, but do not modify original list
  55                                 self.last_event_time = now
  56                                 return f()
  57
  58
  59 class StateMachine():
  60         # commands you can send
  61         CMD_PINS = 0
  62         CMD_BUZZ = 1
  63         CMD_UNLOCK = 2
  64         CMD_WAKEUP = 3
  65         CMD_LAST = 4
  66
  67         class State():
  68                 def __init__(self, state_machine, nervlist = None):
  69                         self.state_machine = state_machine
  70                         self._nerver = None if nervlist is None else Nerver(nervlist)
  71                 def handle_pins_event(self):
  72                         pass # one needn't implement this
  73                 def handle_buzz_event(self,arg): # this shouldn't be overwritten
  74                         self.actor().act(Actor.CMD_BUZZ)
  75                         arg("200 okay: buzz executed")
  76                 def handle_cmd_unlock_event(self,arg):
  77                         if arg is not None:
  78                                 arg("412 Precondition Failed: The current state (%s) cannot handle the UNLOCK command. Try again later." % self.__class__.__name__)
  79                 def handle_wakeup_event(self):
  80                         if self._nerver is not None:
  81                                 return self._nerver.nerv()
  82                 def pins(self):
  83                         return self.state_machine.pins
  84                 def old_pins(self):
  85                         return self.state_machine.old_pins
  86                 def actor(self):
  87                         return self.state_machine.actor
  88                 def handle_event(self,ev,arg): # don't override
  89                         if ev == StateMachine.CMD_PINS:
  90                                 return self.handle_pins_event()
  91                         elif ev == StateMachine.CMD_BUZZ:
  92                                 return self.handle_buzz_event(arg)
  93                         elif ev == StateMachine.CMD_UNLOCK:
  94                                 return self.handle_cmd_unlock_event(arg)
  95                         elif ev == StateMachine.CMD_WAKEUP:
  96                                 return self.handle_wakeup_event()
  97                         else:
  98                                 raise Exception("Unknown command number: %d" % ev)
  99
 100         class AbstractLockedState(State):
 101                 '''A state with invariant "The space is locked", switching to StateAboutToOpen when the space becomes unlocked'''
 102                 def handle_pins_event(self):
 103                         if not self.pins().door_locked:
 104                                 return StateAboutToOpen(self.state_machine)
 105                         return super().handle_pins_event
 106
 107         class AbstractUnlockedState(State):
 108                 '''A state with invariant "The space is unlocked", switching to StateZu when the space becomes locked'''
 109                 def handle_pins_event(self):
 110                         if self.pins().door_locked:
 111                                 if self.pins().space_active:
 112                                         # FIXME the same state can be reached by first locking the door, and then activating the space. What to do then?
 113                                         logger.info("StateMachine: door manually locked, but space switch is still on - going to StateZu")
 114                                         play_sound("manual_lock")
 115                                 return StateZu(self.state_machine)
 116                         return super().handle_pins_event
 117
 118         class StateStart(State):
 119                 def handle_pins_event(self):
 120                         pins = self.pins()
 121                         if not (pins.door_locked is None or pins.door_closed is None or pins.space_active is None or pins.bell_ringing is None):
 122                                 # All sensors got a value, switch to a proper state
 123                                 if pins.door_locked:
 124                                         return StateMachine.StateZu(self.state_machine)
 125                                 else:
 126                                         return StateMachine.StateAboutToOpen(self.state_machine)
 127                         return super().handle_pins_event()
 128
 129         class StateZu(AbstractLockedState):
 130                 def handle_cmd_unlock_event(self,callback):
 131                         return StateMachine.StateUnlocking(self.state_machine, callback)
 132
 133         class StateUnlocking(AbstractLockedState):
 134                 def __init__(self,sm,callback=None):
 135                         # construct a nervlist
 136                         nervlist = [(OPEN_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_UNLOCK)) for t in range(OPEN_REPEAT_NUMBER)]
 137                         nervlist += [(OPEN_REPEAT_TIMEOUT, self.could_not_open)]
 138                         super().__init__(sm,nervlist)
 139                         self.callbacks=[callback]
 140                         # TODO: can we send "202 processing: Trying to unlock the door" here? Are the callbacks multi-use?
 141                         self.actor().act(Actor.CMD_UNLOCK)
 142                 def notify(self, did_it_work):
 143                         s = "200 okay: door unlocked" if did_it_work else ("500 internal server error: Couldn't unlock door with %d tries à %f seconds" % (OPEN_REPEAT_NUMBER,OPEN_REPEAT_TIMEOUT))
 144                         for cb in self.callbacks:
 145                                 if cb is not None:
 146                                         cb(s)
 147                 def handle_pins_event(self):
 148                         # overriding superclass as we need to do notification (TODO can this be done better? on_leave?)
 149                         if not self.pins().door_locked:
 150                                 self.notify(True)
 151                                 return StateMachine.StateAboutToOpen(self.state_machine)
 152                 def handle_cmd_unlock_event(self,callback):
 153                         # TODO: 202 notification also here if possible
 154                         self.callbacks.append(callback)
 155                 def could_not_open(self):
 156                         logger.critical("StateMachine: Couldn't open door after %d tries. Going back to StateZu." % OPEN_REPEAT_NUMBER)
 157                         self.notify(False)
 158                         return StateMachine.StateZu(self.state_machine)
 159
 160         class AbstractStateWhereOpeningIsRedundant(AbstractUnlockedState):
 161                 def handle_cmd_unlock_event(self, callback):
 162                         callback("299 redundant: Space seems to be already open. Still processing your request tough.")
 163                         logger.info("StateMachine: Received UNLOCK command in %s. This should not be necessary." % self.__class__.__name__)
 164                         self.actor().act(Actor.CMD_UNLOCK)
 165
 166         class StateAboutToOpen(AbstractStateWhereOpeningIsRedundant):
 167                 def __init__(self, sm):
 168                         super().__init__(sm, ABOUTOPEN_NERVLIST)
 169                 def handle_pins_event(self):
 170                         pins = self.pins()
 171                         if pins.space_active:
 172                                 return StateMachine.StateAuf(self.state_machine)
 173                         return super().handle_pins_event()
 174
 175         class StateAuf(AbstractStateWhereOpeningIsRedundant):
 176                 def __init__(self,sm):
 177                         super().__init__(sm)
 178                         self.last_buzzed = None
 179                 def handle_pins_event(self):
 180                         pins = self.pins()
 181                         if pins.bell_ringing and not self.old_pins().bell_ringing:
 182                                 # someone just pressed the bell
 183                                 logger.info("StateMachine: buzzing because of bell ringing in StateAuf")
 184                                 self.actor().act(Actor.CMD_BUZZ)
 185                         if not pins.space_active:
 186                                 logger.info("StateMachine: space switch turned off - starting leaving procedure")
 187                                 return StateMachine.StateAboutToLeave(self.state_machine)
 188                         return super().handle_pins_event()
 189
 190         class StateLocking(AbstractUnlockedState):
 191                 def __init__(self,sm):
 192                         # construct a nervlist
 193                         nervlist = [(CLOSE_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_LOCK)) for t in range(CLOSE_REPEAT_NUMBER)]
 194                         nervlist += [(CLOSE_REPEAT_TIMEOUT, self.could_not_close)]
 195                         super().__init__(sm, nervlist)
 196                         if self.pins().door_closed: # this should always be true, but just to be sure...
 197                                 self.actor().act(Actor.CMD_LOCK)
 198                 def handle_pins_event(self):
 199                         pins = self.pins()
 200                         if not pins.door_closed:
 201                                 # TODO play a sound? This shouldn't happen, door was opened while we are locking
 202                                 logger.warning("StateMachine: door manually opened during locking")
 203                                 return StateMachine.StateAboutToOpen(self.state_machine)
 204                         # TODO do anything here if the switch is activated now?
 205                         return super().handle_pins_event()
 206                 def handle_cmd_unlock_event(self,callback):
 207                         callback("409 conflict: The sphinx is currently trying to lock the door. Try again later.")
 208                 def could_not_close(self):
 209                         logger.critical("StateMachine: Couldn't close door after %d tries. Going back to StateAboutToOpen." % CLOSE_REPEAT_NUMBER)
 210                         return StateMachine.StateAboutToOpen(self.state_machine)
 211
 212         class StateAboutToLeave(AbstractUnlockedState):
 213                 def __init__(self, sm):
 214                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateLocking(self.state_machine))]
 215                         super().__init__(sm, nervlist)
 216                 def handle_pins_event(self):
 217                         if not self.pins().door_closed:
 218                                 return StateMachine.StateLeaving(self.state_machine)
 219                         if self.pins().space_active:
 220                                 return StateMachine.StateAuf(self.state_machine)
 221                         return super().handle_pins_event()
 222
 223         class StateLeaving(AbstractUnlockedState):
 224                 def __init__(self, sm):
 225                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateAboutToOpen(self.state_machine))]
 226                         super().__init__(sm, nervlist)
 227                 def handle_pins_event(self):
 228                         if self.pins().door_closed:
 229                                 return StateMachine.StateLocking(self.state_machine)
 230                         if self.pins().space_active:
 231                                 return StateMachine.StateAuf(self.state_machine)
 232                         return super().handle_pins_event()
 233
 234         def __init__(self, actor):
 235                 self.actor = actor
 236                 self.callback = ThreadFunction(self._callback, name="StateMachine")
 237                 self.current_state = StateMachine.StateStart(self)
 238                 self.pins = None
 239                 self.old_pins = None
 240
 241         def stop (self):
 242                 self.callback.stop()
 243
 244         def _callback(self, cmd, arg=None):
 245                 # update pins
 246                 if cmd == StateMachine.CMD_PINS:
 247                         self.pins = arg
 248                 # handle stuff
 249                 newstate = self.current_state.handle_event(cmd,arg) # returns None or an instance of the new state
 250                 self.old_pins = self.pins
 251                 while newstate is not None:
 252                         logger.debug("StateMachine: Doing state transition %s -> %s" % (self.current_state.__class__.__name__, newstate.__class__.__name__))
 253                         self.current_state = newstate
 254                         newstate = self.current_state.handle_event(StateMachine.CMD_PINS, self.pins)