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_cmd ([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_LEAVE_DELAY_LOCK = 5 # seconds
  27
  28 # StateAboutToOpen constants
  29 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")),\
  30         (10, lambda:play_sound("flipswitch")), (10, lambda:play_sound("flipswitch")), (0, lambda:logger.error("Space open but switch not flipped for 30 seconds")),\
  31         (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")),
  32         (59*60, lambda:logger.critical("Space open but switch not flipped for one hour"))]
  33
  34 # Timeout we wait after the switch was switched to "Closed", until we assume nobody will open the door and we just lock it
  35 # ALso the time we wait after the door was opend, till we assume something went wrong and start nerving
  36 LEAVE_TIMEOUT = 20
  37
  38 # play_sound constants
  39 SOUNDS_DIRECTORY = "/opt/tuer/sounds/"
  40 SOUNDS_PLAYER = "/usr/bin/mplayer"
  41
  42
  43 class Nerver():
  44         # 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.
  45         # If f returns something, that's also returned by nerv.
  46         def __init__(self, nervlist):
  47                 self.nervlist = list(nervlist)
  48                 self.last_event_time = time.time()
  49
  50         def nerv(self):
  51                 if len(self.nervlist):
  52                         (wait_time, f) = self.nervlist[0]
  53                         now = time.time()
  54                         time_gone = now-self.last_event_time
  55                         # check if the first element is to be triggered
  56                         if time_gone >= wait_time:
  57                                 self.nervlist = self.nervlist[1:] # "pop" the first element, but do not modify original list
  58                                 self.last_event_time = now
  59                                 return f()
  60
  61
  62 class StateMachine():
  63         # commands you can send
  64         CMD_PINS = 0
  65         CMD_BUZZ = 1
  66         CMD_UNLOCK = 2
  67         CMD_WAKEUP = 3
  68         CMD_LAST = 4
  69
  70         class State():
  71                 def __init__(self, state_machine, nervlist = None):
  72                         self.state_machine = state_machine
  73                         self._nerver = None if nervlist is None else Nerver(nervlist)
  74                 def handle_pins_event(self):
  75                         pass # one needn't implement this
  76                 def handle_buzz_event(self,arg): # this shouldn't be overwritten
  77                         self.actor().act(Actor.CMD_BUZZ)
  78                         arg("200 okay: buzz executed")
  79                 def handle_cmd_unlock_event(self,arg):
  80                         if arg is not None:
  81                                 arg("412 Precondition Failed: The current state (%s) cannot handle the UNLOCK command. Try again later." % self.__class__.__name__)
  82                 def handle_wakeup_event(self):
  83                         if self._nerver is not None:
  84                                 return self._nerver.nerv()
  85                 def on_leave(self):
  86                         pass
  87                 def pins(self):
  88                         return self.state_machine.pins
  89                 def old_pins(self):
  90                         return self.state_machine.old_pins
  91                 def actor(self):
  92                         return self.state_machine.actor
  93                 def handle_event(self,ev,arg): # don't override
  94                         if ev == StateMachine.CMD_PINS:
  95                                 return self.handle_pins_event()
  96                         elif ev == StateMachine.CMD_BUZZ:
  97                                 return self.handle_buzz_event(arg)
  98                         elif ev == StateMachine.CMD_UNLOCK:
  99                                 return self.handle_cmd_unlock_event(arg)
 100                         elif ev == StateMachine.CMD_WAKEUP:
 101                                 return self.handle_wakeup_event()
 102                         else:
 103                                 raise Exception("Unknown command number: %d" % ev)
 104
 105         class AbstractNonStartState(State):
 106                 def handle_pins_event(self):
 107                         if self.pins().door_locked != (not self.pins().space_active):
 108                                 self.actor().act(Actor.CMD_RED_ON)
 109                         else:
 110                                 self.actor().act(Actor.CMD_RED_OFF)
 111                         return super().handle_pins_event()
 112
 113         class AbstractLockedState(AbstractNonStartState):
 114                 '''A state with invariant "The space is locked", switching to StateAboutToOpen when the space becomes unlocked'''
 115                 def __init__(self, sm, nervlist = None):
 116                         super().__init__(sm, nervlist)
 117                         self.actor().act(Actor.CMD_GREEN_OFF)
 118                 def handle_pins_event(self):
 119                         if not self.pins().door_locked:
 120                                 logger.info("Door unlocked, space is about to open")
 121                                 return StateMachine.StateAboutToOpen(self.state_machine)
 122                         return super().handle_pins_event()
 123
 124         class AbstractUnlockedState(AbstractNonStartState):
 125                 '''A state with invariant "The space is unlocked", switching to StateZu when the space becomes locked'''
 126                 def __init__(self, sm, nervlist = None):
 127                         super().__init__(sm, nervlist)
 128                         self.actor().act(Actor.CMD_GREEN_ON)
 129                 def handle_pins_event(self):
 130                         if self.pins().door_locked:
 131                                 logger.info("Door locked, closing space")
 132                                 if self.pins().space_active:
 133                                         logger.warning("StateMachine: door manually locked, but space switch is still on - going to StateZu")
 134                                         play_sound("manual_lock")
 135                                 return StateMachine.StateZu(self.state_machine)
 136                         return super().handle_pins_event()
 137
 138         class StateStart(State):
 139                 def __init__(self, sm, nervlist = None, fallback=False):
 140                         super().__init__(sm, nervlist)
 141                         self.fallback = fallback
 142                 def handle_pins_event(self):
 143                         pins = self.pins()
 144                         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):
 145                                 if self.fallback:
 146                                         logger.info("Going to StateFallback because running in fallback mode")
 147                                         return StateMachine.StateFallback(self.state_machine)
 148                                 if pins.door_locked:
 149                                         logger.info("All sensors got a value, switching to a proper state: Space is closed")
 150                                         return StateMachine.StateZu(self.state_machine)
 151                                 else:
 152                                         logger.info("All sensors got a value, switching to a proper state: Space is (about to) open")
 153                                         return StateMachine.StateAboutToOpen(self.state_machine)
 154                         return super().handle_pins_event()
 155
 156         class StateFallback(State):
 157                 def __init__(self, sm, nervlist = None):
 158                         super().__init__(sm, nervlist)
 159                         self._last_blink_time = time.time()
 160                         self._red_state = False
 161                 def handle_pins_event(self):
 162                         pins = self.pins()
 163                         # buzz if open and bell rang
 164                         if pins.space_active and pins.bell_ringing and not self.old_pins().bell_ringing:
 165                                 logger.info("StateFallback: Space switch on and door bell rung => buzzing")
 166                                 self.actor().act(Actor.CMD_BUZZ)
 167                         # set green LED according to space switch
 168                         if pins.space_active:
 169                                 self.actor().act(Actor.CMD_GREEN_ON)
 170                         else:
 171                                 self.actor().act(Actor.CMD_GREEN_OFF)
 172                         # primitive leaving procedure if space switch turned off
 173                         if not pins.space_active and self.old_pins().space_active:
 174                                 def _close_after_time():
 175                                         time.sleep(FALLBACK_LEAVE_DELAY_LOCK)
 176                                         self.actor().act(Actor.CMD_LOCK)
 177                                 fire_and_forget(_close_after_time)
 178                         # not calling superclass because we want to stay in fallback mode
 179                 def handle_wakeup_event(self):
 180                         # blink red LED
 181                         now = time.time()
 182                         if self._red_state:
 183                                 self.actor().act(Actor.CMD_RED_OFF)
 184                                 self._red_state = False
 185                         else:
 186                                 self.actor().act(Actor.CMD_RED_ON)
 187                                 self._red_state = True
 188                         self._last_blink_time = now
 189                 def handle_cmd_unlock_event(self,arg):
 190                         if arg is not None:
 191                                 arg("298 Fallback Okay: Trying to unlock the door. The System is in fallback mode, success information is not available.")
 192                         self.actor().act(Actor.CMD_UNLOCK)
 193
 194         class StateZu(AbstractLockedState):
 195                 def handle_cmd_unlock_event(self,callback):
 196                         return StateMachine.StateUnlocking(self.state_machine, callback)
 197                 def handle_pins_event(self):
 198                         if not self.old_pins().space_active and self.pins().space_active: # first thing to check: edge detection
 199                                 logger.info("Space toggled to active while it was closed - unlocking the door")
 200                                 return StateMachine.StateUnlocking(self.state_machine)
 201                         return super().handle_pins_event()
 202
 203         class StateUnlocking(AbstractLockedState):
 204                 def __init__(self,sm,callback=None):
 205                         # construct a nervlist
 206                         nervlist = [(OPEN_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_UNLOCK)) for t in range(OPEN_REPEAT_NUMBER)]
 207                         nervlist += [(OPEN_REPEAT_TIMEOUT, self.could_not_open)]
 208                         super().__init__(sm,nervlist)
 209                         self.callbacks=[callback]
 210                         # TODO: can we send "202 processing: Trying to unlock the door" here? Are the callbacks multi-use?
 211                         self.actor().act(Actor.CMD_UNLOCK)
 212                 def notify(self, did_it_work):
 213                         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))
 214                         for cb in self.callbacks:
 215                                 if cb is not None:
 216                                         cb(s)
 217                 def on_leave(self):
 218                         self.notify(not self.pins().door_locked)
 219                 def handle_cmd_unlock_event(self,callback):
 220                         # TODO: 202 notification also here if possible
 221                         self.callbacks.append(callback)
 222                 def could_not_open(self):
 223                         logger.critical("StateMachine: Couldn't open door after %d tries. Going back to StateZu." % OPEN_REPEAT_NUMBER)
 224                         return StateMachine.StateZu(self.state_machine)
 225
 226         class AbstractStateWhereUnlockingIsRedundant(AbstractUnlockedState):
 227                 def handle_cmd_unlock_event(self, callback):
 228                         callback("299 redundant: Space seems to be already open. Still processing your request tough.")
 229                         logger.info("StateMachine: Received UNLOCK command in %s. This should not be necessary." % self.__class__.__name__)
 230                         self.actor().act(Actor.CMD_UNLOCK)
 231
 232         class StateAboutToOpen(AbstractStateWhereUnlockingIsRedundant):
 233                 def __init__(self, sm):
 234                         super().__init__(sm, ABOUTOPEN_NERVLIST)
 235                 def handle_pins_event(self):
 236                         pins = self.pins()
 237                         if pins.space_active:
 238                                 logger.info("Space activated, opening procedure completed")
 239                                 return StateMachine.StateAuf(self.state_machine)
 240                         return super().handle_pins_event()
 241
 242         class StateAuf(AbstractStateWhereUnlockingIsRedundant):
 243                 def __init__(self,sm):
 244                         nervlist = [(24*60*60, lambda: logger.critical("Space is now open for 24h. Is everything all right?"))]
 245                         super().__init__(sm, nervlist)
 246                         self.last_buzzed = None
 247                 def handle_pins_event(self):
 248                         pins = self.pins()
 249                         if pins.bell_ringing and not self.old_pins().bell_ringing: # first thing to check: edge detection
 250                                 # someone just pressed the bell
 251                                 logger.info("StateMachine: buzzing because of bell ringing in StateAuf")
 252                                 self.actor().act(Actor.CMD_BUZZ)
 253                         if not pins.space_active:
 254                                 logger.info("StateMachine: space switch turned off - starting leaving procedure")
 255                                 return StateMachine.StateAboutToLeave(self.state_machine)
 256                         return super().handle_pins_event()
 257
 258         class StateLocking(AbstractUnlockedState):
 259                 def __init__(self,sm):
 260                         # construct a nervlist
 261                         nervlist = [(CLOSE_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_LOCK)) for t in range(CLOSE_REPEAT_NUMBER)]
 262                         nervlist += [(CLOSE_REPEAT_TIMEOUT, self.could_not_close)]
 263                         super().__init__(sm, nervlist)
 264                         if self.pins().door_closed: # this should always be true, but just to be sure...
 265                                 self.actor().act(Actor.CMD_LOCK)
 266                 def handle_pins_event(self):
 267                         pins = self.pins()
 268                         if not pins.door_closed:
 269                                 # TODO play a sound? This shouldn't happen, door was opened while we are locking
 270                                 logger.warning("StateMachine: door manually opened during locking")
 271                                 return StateMachine.StateAboutToOpen(self.state_machine)
 272                         # TODO do anything here if the switch is activated now?
 273                         return super().handle_pins_event()
 274                 def handle_cmd_unlock_event(self,callback):
 275                         callback("409 conflict: The sphinx is currently trying to lock the door. Try again later.")
 276                 def could_not_close(self):
 277                         logger.critical("StateMachine: Couldn't close door after %d tries. Going back to StateAboutToOpen." % CLOSE_REPEAT_NUMBER)
 278                         return StateMachine.StateAboutToOpen(self.state_machine)
 279
 280         class StateAboutToLeave(AbstractUnlockedState):
 281                 def __init__(self, sm):
 282                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateLocking(self.state_machine))]
 283                         super().__init__(sm, nervlist)
 284                 def handle_pins_event(self):
 285                         if not self.pins().door_closed:
 286                                 return StateMachine.StateLeaving(self.state_machine)
 287                         if self.pins().space_active:
 288                                 logger.info("Space re-activated, cancelling leaving procedure")
 289                                 return StateMachine.StateAuf(self.state_machine)
 290                         return super().handle_pins_event()
 291
 292         class StateLeaving(AbstractUnlockedState):
 293                 def __init__(self, sm):
 294                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateAboutToOpen(self.state_machine))]
 295                         super().__init__(sm, nervlist)
 296                 def handle_pins_event(self):
 297                         if self.pins().door_closed:
 298                                 logger.info("The space was left, locking the door")
 299                                 return StateMachine.StateLocking(self.state_machine)
 300                         if self.pins().space_active:
 301                                 logger.info("Space re-activated, cancelling leaving procedure")
 302                                 return StateMachine.StateAuf(self.state_machine)
 303                         return super().handle_pins_event()
 304
 305         def __init__(self, actor, waker, fallback = False):
 306                 self.actor = actor
 307                 self.callback = ThreadFunction(self._callback, name="StateMachine")
 308                 self.current_state = StateMachine.StateStart(self, fallback=fallback)
 309                 self.pins = None
 310                 self.old_pins = None
 311                 waker.register(lambda: self.callback(StateMachine.CMD_WAKEUP), 1.0) # wake up every second
 312
 313         def stop (self):
 314                 self.callback.stop()
 315
 316         def _callback(self, cmd, arg=None):
 317                 # update pins
 318                 if cmd == StateMachine.CMD_PINS:
 319                         self.pins = arg
 320                 # handle stuff
 321                 newstate = self.current_state.handle_event(cmd,arg) # returns None or an instance of the new state
 322                 self.old_pins = self.pins
 323                 while newstate is not None:
 324                         assert isinstance(newstate, StateMachine.State), "I should get a state"
 325                         self.current_state.on_leave()
 326                         logger.debug("StateMachine: Doing state transition %s -> %s" % (self.current_state.__class__.__name__, newstate.__class__.__name__))
 327                         self.current_state = newstate
 328                         newstate = self.current_state.handle_event(StateMachine.CMD_PINS, self.pins)