statemachine.py

   1 from libtuer import ThreadFunction, logger, fire_and_forget
   2 from actor import Actor
   3 import os, random, time, threading
   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 # StateFallback constants
  26 FALLBACK_BLINK_SPEED = 0.5 # seconds
  27 FALLBACK_LEAVE_DELAY_LOCK = 5 # seconds
  28
  29 # StateAboutToOpen constants
  30 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")),\
  31         (10, lambda:play_sound("flipswitch")), (10, lambda:play_sound("flipswitch")), (0, lambda:logger.error("Space open but switch not flipped for 30 seconds")),\
  32         (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")),
  33         (59*60, lambda:logger.critical("Space open but switch not flipped for one hour"))]
  34
  35 # Timeout we wait after the switch was switched to "Closed", until we assume nobody will open the door and we just lock it
  36 # ALso the time we wait after the door was opend, till we assume something went wrong and start nerving
  37 LEAVE_TIMEOUT = 20
  38
  39 # play_sound constants
  40 SOUNDS_DIRECTORY = "/opt/tuer/sounds/"
  41 SOUNDS_PLAYER = "/usr/bin/mplayer"
  42
  43
  44 class Nerver():
  45         # 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.
  46         # If f returns something, that's also returned by nerv.
  47         def __init__(self, nervlist):
  48                 self.nervlist = list(nervlist)
  49                 self.last_event_time = time.time()
  50
  51         def nerv(self):
  52                 if len(self.nervlist):
  53                         (wait_time, f) = self.nervlist[0]
  54                         now = time.time()
  55                         time_gone = now-self.last_event_time
  56                         # check if the first element is to be triggered
  57                         if time_gone >= wait_time:
  58                                 self.nervlist = self.nervlist[1:] # "pop" the first element, but do not modify original list
  59                                 self.last_event_time = now
  60                                 return f()
  61
  62
  63 class StateMachine():
  64         # commands you can send
  65         CMD_PINS = 0
  66         CMD_BUZZ = 1
  67         CMD_UNLOCK = 2
  68         CMD_WAKEUP = 3
  69         CMD_LAST = 4
  70
  71         class State():
  72                 def __init__(self, state_machine, nervlist = None):
  73                         self.state_machine = state_machine
  74                         self._nerver = None if nervlist is None else Nerver(nervlist)
  75                 def handle_pins_event(self):
  76                         pass # one needn't implement this
  77                 def handle_buzz_event(self,arg): # this shouldn't be overwritten
  78                         self.actor().act(Actor.CMD_BUZZ)
  79                         arg("200 okay: buzz executed")
  80                 def handle_cmd_unlock_event(self,arg):
  81                         if arg is not None:
  82                                 arg("412 Precondition Failed: The current state (%s) cannot handle the UNLOCK command. Try again later." % self.__class__.__name__)
  83                 def handle_wakeup_event(self):
  84                         if self._nerver is not None:
  85                                 return self._nerver.nerv()
  86                 def on_leave(self):
  87                         pass
  88                 def pins(self):
  89                         return self.state_machine.pins
  90                 def old_pins(self):
  91                         return self.state_machine.old_pins
  92                 def actor(self):
  93                         return self.state_machine.actor
  94                 def handle_event(self,ev,arg): # don't override
  95                         if ev == StateMachine.CMD_PINS:
  96                                 return self.handle_pins_event()
  97                         elif ev == StateMachine.CMD_BUZZ:
  98                                 return self.handle_buzz_event(arg)
  99                         elif ev == StateMachine.CMD_UNLOCK:
 100                                 return self.handle_cmd_unlock_event(arg)
 101                         elif ev == StateMachine.CMD_WAKEUP:
 102                                 return self.handle_wakeup_event()
 103                         else:
 104                                 raise Exception("Unknown command number: %d" % ev)
 105
 106         class AbstractNonStartState(State):
 107                 def handle_pins_event(self):
 108                         if self.pins().door_locked != (not self.pins().space_active):
 109                                 self.actor().act(Actor.CMD_RED_ON)
 110                         else:
 111                                 self.actor().act(Actor.CMD_RED_OFF)
 112                         return super().handle_pins_event()
 113
 114         class AbstractLockedState(AbstractNonStartState):
 115                 '''A state with invariant "The space is locked", switching to StateAboutToOpen when the space becomes unlocked'''
 116                 def __init__(self, sm, nervlist = None):
 117                         super().__init__(sm, nervlist)
 118                         self.actor().act(Actor.CMD_GREEN_OFF)
 119                 def handle_pins_event(self):
 120                         if not self.pins().door_locked:
 121                                 logger.info("Door unlocked, space is about to open")
 122                                 return StateMachine.StateAboutToOpen(self.state_machine)
 123                         return super().handle_pins_event()
 124
 125         class AbstractUnlockedState(AbstractNonStartState):
 126                 '''A state with invariant "The space is unlocked", switching to StateZu when the space becomes locked'''
 127                 def __init__(self, sm, nervlist = None):
 128                         super().__init__(sm, nervlist)
 129                         self.actor().act(Actor.CMD_GREEN_ON)
 130                 def handle_pins_event(self):
 131                         if self.pins().door_locked:
 132                                 logger.info("Door locked, closing space")
 133                                 if self.pins().space_active:
 134                                         logger.warning("StateMachine: door manually locked, but space switch is still on - going to StateZu")
 135                                         play_sound("manual_lock")
 136                                 return StateMachine.StateZu(self.state_machine)
 137                         return super().handle_pins_event()
 138
 139         class StateStart(State):
 140                 def __init__(self, sm, nervlist = None, fallback=False):
 141                         super().__init__(self, sm, nervlist)
 142                         self.fallback = fallback
 143                 def handle_pins_event(self):
 144                         pins = self.pins()
 145                         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):
 146                                 if self.fallback:
 147                                         logger.info("Going to StateFallback because running in fallback mode")
 148                                         return StateMachine.StateFallback(self.state_machine)
 149                                 if pins.door_locked:
 150                                         logger.info("All sensors got a value, switching to a proper state: Space is closed")
 151                                         return StateMachine.StateZu(self.state_machine)
 152                                 else:
 153                                         logger.info("All sensors got a value, switching to a proper state: Space is (about to) open")
 154                                         return StateMachine.StateAboutToOpen(self.state_machine)
 155                         return super().handle_pins_event()
 156
 157         class StateFallback(State):
 158                 def __init__(self, sm, nervlist = None):
 159                         super().__init__(self, sm, nervlist)
 160                         self._last_blink_time = time.time()
 161                         self._red_state = False
 162                 def handle_pins_event(self):
 163                         pins = self.pins()
 164                         # buzz if open and bell rang
 165                         if pins.space_active and pins.bell_ringing and not self.old_pins().bell_ringing:
 166                                 logger.info("StateFallback: Space switch on and door bell rung => buzzing")
 167                                 self.actor().act(Actor.CMD_BUZZ)
 168                         # set green LED according to space switch
 169                         if pins.space_active:
 170                                 self.actor().act(Actor.CMD_GREEN_ON)
 171                         else:
 172                                 self.actor().act(Actor.CMD_GREEN_OFF)
 173                         # primitive leaving procedure if space switch turned off
 174                         if not pins.space_active and self.old_pins().space_active:
 175                                 def _close_after_time():
 176                                         time.sleep(FALLBACK_LEAVE_DELAY_LOCK)
 177                                         self.actor().act(Actor.CMD_LOCK)
 178                                 t = threading.Thread(target=_close_after_time)
 179                                 t.start()
 180                         # not calling superclass because we want to stay in fallback mode
 181                 def handle_wakeup_event(self):
 182                         # blink red LED
 183                         now = time.time()
 184                         if now - self._last_blink_time < FALLBACK_BLINK_SPEED:
 185                                 if self._red_state:
 186                                         self.actor().act(Actor.CMD_RED_OFF)
 187                                         self._red_state = False
 188                                 else:
 189                                         self.actor().act(Actor.CMD_RED_ON)
 190                                         self._red_state = True
 191                                 self._last_blink_time = now
 192                 def handle_cmd_unlock_event(self,arg):
 193                         if arg is not None:
 194                                 arg("298 Fallback Okay: Trying to unlock the door. The System is in fallback mode, success information is not available.")
 195                         self.actor().act(Actor.CMD_UNLOCK)
 196
 197         class StateZu(AbstractLockedState):
 198                 def handle_cmd_unlock_event(self,callback):
 199                         return StateMachine.StateUnlocking(self.state_machine, callback)
 200                 def handle_pins_event(self):
 201                         if not self.old_pins().space_active and self.pins().space_active: # first thing to check: edge detection
 202                                 logger.info("Space toggled to active while it was closed - unlocking the door")
 203                                 return StateMachine.StateUnlocking(self.state_machine)
 204                         return super().handle_pins_event()
 205
 206         class StateUnlocking(AbstractLockedState):
 207                 def __init__(self,sm,callback=None):
 208                         # construct a nervlist
 209                         nervlist = [(OPEN_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_UNLOCK)) for t in range(OPEN_REPEAT_NUMBER)]
 210                         nervlist += [(OPEN_REPEAT_TIMEOUT, self.could_not_open)]
 211                         super().__init__(sm,nervlist)
 212                         self.callbacks=[callback]
 213                         # TODO: can we send "202 processing: Trying to unlock the door" here? Are the callbacks multi-use?
 214                         self.actor().act(Actor.CMD_UNLOCK)
 215                 def notify(self, did_it_work):
 216                         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))
 217                         for cb in self.callbacks:
 218                                 if cb is not None:
 219                                         cb(s)
 220                 def on_leave(self):
 221                         self.notify(not self.pins().door_locked)
 222                 def handle_cmd_unlock_event(self,callback):
 223                         # TODO: 202 notification also here if possible
 224                         self.callbacks.append(callback)
 225                 def could_not_open(self):
 226                         logger.critical("StateMachine: Couldn't open door after %d tries. Going back to StateZu." % OPEN_REPEAT_NUMBER)
 227                         return StateMachine.StateZu(self.state_machine)
 228
 229         class AbstractStateWhereUnlockingIsRedundant(AbstractUnlockedState):
 230                 def handle_cmd_unlock_event(self, callback):
 231                         callback("299 redundant: Space seems to be already open. Still processing your request tough.")
 232                         logger.info("StateMachine: Received UNLOCK command in %s. This should not be necessary." % self.__class__.__name__)
 233                         self.actor().act(Actor.CMD_UNLOCK)
 234
 235         class StateAboutToOpen(AbstractStateWhereUnlockingIsRedundant):
 236                 def __init__(self, sm):
 237                         super().__init__(sm, ABOUTOPEN_NERVLIST)
 238                 def handle_pins_event(self):
 239                         pins = self.pins()
 240                         if pins.space_active:
 241                                 logger.info("Space activated, opening procedure completed")
 242                                 return StateMachine.StateAuf(self.state_machine)
 243                         return super().handle_pins_event()
 244
 245         class StateAuf(AbstractStateWhereUnlockingIsRedundant):
 246                 def __init__(self,sm):
 247                         nervlist = [(24*60*60, lambda: logger.critical("Space is now open for 24h. Is everything all right?"))]
 248                         super().__init__(sm, nervlist)
 249                         self.last_buzzed = None
 250                 def handle_pins_event(self):
 251                         pins = self.pins()
 252                         if pins.bell_ringing and not self.old_pins().bell_ringing: # first thing to check: edge detection
 253                                 # someone just pressed the bell
 254                                 logger.info("StateMachine: buzzing because of bell ringing in StateAuf")
 255                                 self.actor().act(Actor.CMD_BUZZ)
 256                         if not pins.space_active:
 257                                 logger.info("StateMachine: space switch turned off - starting leaving procedure")
 258                                 return StateMachine.StateAboutToLeave(self.state_machine)
 259                         return super().handle_pins_event()
 260
 261         class StateLocking(AbstractUnlockedState):
 262                 def __init__(self,sm):
 263                         # construct a nervlist
 264                         nervlist = [(CLOSE_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_LOCK)) for t in range(CLOSE_REPEAT_NUMBER)]
 265                         nervlist += [(CLOSE_REPEAT_TIMEOUT, self.could_not_close)]
 266                         super().__init__(sm, nervlist)
 267                         if self.pins().door_closed: # this should always be true, but just to be sure...
 268                                 self.actor().act(Actor.CMD_LOCK)
 269                 def handle_pins_event(self):
 270                         pins = self.pins()
 271                         if not pins.door_closed:
 272                                 # TODO play a sound? This shouldn't happen, door was opened while we are locking
 273                                 logger.warning("StateMachine: door manually opened during locking")
 274                                 return StateMachine.StateAboutToOpen(self.state_machine)
 275                         # TODO do anything here if the switch is activated now?
 276                         return super().handle_pins_event()
 277                 def handle_cmd_unlock_event(self,callback):
 278                         callback("409 conflict: The sphinx is currently trying to lock the door. Try again later.")
 279                 def could_not_close(self):
 280                         logger.critical("StateMachine: Couldn't close door after %d tries. Going back to StateAboutToOpen." % CLOSE_REPEAT_NUMBER)
 281                         return StateMachine.StateAboutToOpen(self.state_machine)
 282
 283         class StateAboutToLeave(AbstractUnlockedState):
 284                 def __init__(self, sm):
 285                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateLocking(self.state_machine))]
 286                         super().__init__(sm, nervlist)
 287                 def handle_pins_event(self):
 288                         if not self.pins().door_closed:
 289                                 return StateMachine.StateLeaving(self.state_machine)
 290                         if self.pins().space_active:
 291                                 logger.info("Space re-activated, cancelling leaving procedure")
 292                                 return StateMachine.StateAuf(self.state_machine)
 293                         return super().handle_pins_event()
 294
 295         class StateLeaving(AbstractUnlockedState):
 296                 def __init__(self, sm):
 297                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateAboutToOpen(self.state_machine))]
 298                         super().__init__(sm, nervlist)
 299                 def handle_pins_event(self):
 300                         if self.pins().door_closed:
 301                                 logger.info("The space was left, locking the door")
 302                                 return StateMachine.StateLocking(self.state_machine)
 303                         if self.pins().space_active:
 304                                 logger.info("Space re-activated, cancelling leaving procedure")
 305                                 return StateMachine.StateAuf(self.state_machine)
 306                         return super().handle_pins_event()
 307
 308         def __init__(self, actor, fallback = False):
 309                 self.actor = actor
 310                 self.callback = ThreadFunction(self._callback, name="StateMachine")
 311                 self.current_state = StateMachine.StateStart(self, fallback)
 312                 self.pins = None
 313                 self.old_pins = None
 314
 315         def stop (self):
 316                 self.callback.stop()
 317
 318         def _callback(self, cmd, arg=None):
 319                 # update pins
 320                 if cmd == StateMachine.CMD_PINS:
 321                         self.pins = arg
 322                 # handle stuff
 323                 newstate = self.current_state.handle_event(cmd,arg) # returns None or an instance of the new state
 324                 self.old_pins = self.pins
 325                 while newstate is not None:
 326                         assert isinstance(newstate, StateMachine.State), "I should get a state"
 327                         self.current_state.on_leave()
 328                         logger.debug("StateMachine: Doing state transition %s -> %s" % (self.current_state.__class__.__name__, newstate.__class__.__name__))
 329                         self.current_state = newstate
 330                         newstate = self.current_state.handle_event(StateMachine.CMD_PINS, self.pins)