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