statemachine.py

   1 from libtuer import ThreadFunction, logger, fire_and_forget
   2 from actor import Actor
   3 import os, random
   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 = 8
  19 OPEN_REPEAT_NUMBER = 3
  20
  21 # StateLocking constants
  22 CLOSE_REPEAT_TIMEOUT = 8
  23 CLOSE_REPEAT_NUMBER = 3
  24
  25 # StateAboutToOpen constants
  26 ABOUTOPEN_NERVLIST = [(5, lambda : play_sound("flipswitch")), (10, lambda:play_sound("flipswitch")), (10, lambda:Logger.warning("Space open but switch not flipped for 10 seconds")),\
  27         (20, lambda:play_sound("flipswitch")), (30, lambda:play_sound("flipswitch")), (30, lambda:Logger.error("Space open but switch not flipped for 30 seconds")),\
  28         (40, lambda:play_sound("flipswitch")), (50, lambda:play_sound("flipswitch")), (56, lambda:play_sound("flipswitch")), (60, lambda:Logger.critical("Space open but switch not flipped for 60 seconds"))]
  29
  30 # StateAuf constants
  31 #  time that must pass between two bell_ringing events to buzz the door again (seconds)
  32 AUF_BELLBUZZ_REPEAT_TIME = 2
  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 LEAVE_TIMEOUT = 30
  36
  37 # play_sound constants
  38 SOUNDS_DIRECTORY = "/opt/tuer/sounds/"
  39 SOUNDS_PLAYER = "/usr/bin/mplayer"
  40
  41
  42 class Nerver():
  43         # 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.
  44         # If f returns something, that's also returned by nerv.
  45         def __init__(self, nervlist):
  46                 self.nervlist = list(nervlist)
  47                 self.last_event_time = time.time()
  48
  49         def nerv(self):
  50                 if len(self.nervlist):
  51                         (time, f) = self.nervlist[0]
  52                         now = time.time()
  53                         time_gone = now-self.last_event_time
  54                         # check if the first element is to be triggered
  55                         if time_gone >= time:
  56                                 self.nervlist = self.nervlist[1:] # "pop" the first element, but do not modify original list
  57                                 self.last_event_time = now
  58                                 return f()
  59
  60
  61 class StateMachine():
  62         # commands you can send
  63         CMD_PINS = 0
  64         CMD_BUZZ = 1
  65         CMD_UNLOCK = 2
  66         CMD_WAKEUP = 3
  67         CMD_LAST = 4
  68
  69         class State():
  70                 def __init__(self, state_machine, nervlist = None):
  71                         self.state_machine = state_machine
  72                         self._nerver = None if nervlist is None else Nerver(nervlist)
  73                 def handle_pins_event(self):
  74                         pass # one needn't implement this
  75                 def handle_buzz_event(self,arg): # this shouldn't be overwritten
  76                         self.actor.act(Actor.CMD_BUZZ)
  77                         arg("200 okay: buzz executed")
  78                 def handle_cmd_unlock_event(self,arg):
  79                         if arg is not None:
  80                                 arg("412 Precondition Failed: The current state (%s) cannot handle the OPEN event" % self.__class__.__name__)
  81                 def handle_wakeup_event(self):
  82                         if self._nerver is not None:
  83                                 return self._nerver.nerv()
  84                 def pins(self):
  85                         return self.state_machine.pins
  86                 def actor(self):
  87                         return self.state_machine.actor
  88                 def handle_event(self,ev,arg): # don't override
  89                         if arg is CMD_PINS:
  90                                 self.handle_pins_event()
  91                         elif arg is CMD_BUZZ:
  92                                 self.handle_buzz_event(arg)
  93                         elif arg is CMD_UNLOCK:
  94                                 self.handle_cmd_unlock_event(arg)
  95                         elif arg is CMD_WAKEUP:
  96                                 self.handle_wakeup_event()
  97                         else:
  98                                 raise Exception("Unknown command number: %d" % ev)
  99
 100         class StateStart(State):
 101                 def handle_pins_event(self):
 102                         super().handle_pins_event()
 103                         thepins = self.pins()
 104                         for pin in thepins:
 105                                 if pin is None:
 106                                         return None
 107                         if thepins.door_locked:
 108                                 return StateZu
 109                         else:
 110                                 return StateAuf
 111
 112         class StateZu(State):
 113                 def handle_pins_event(self):
 114                         super().handle_pins_event()
 115                         pins = self.pins()
 116                         if not pins.door_locked:
 117                                 return StateAboutToOpen(self.state_machine)
 118                 def handle_cmd_unlock_event(self,callback):
 119                         # intentionally not calling super() implementation
 120                         return StateUnlocking(callback,self.state_machine)
 121
 122         class StateUnlocking(State):
 123                 def __init__(self,callback,sm):
 124                         # construct a nervlist
 125                         nervlist = [(OPEN_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_UNLOCK)) for t in xrange(OPEN_REPEAT_NUMBER)]
 126                         nervlist += [(OPEN_REPEAT_TIMEOUT, self.could_not_open)]
 127                         super().__init__(sm,nervlist)
 128                         self.callbacks=[callback]
 129                         # FIXME: can we send "202 processing: Trying to open the door" here? Are the callbacks multi-use?
 130                         self.actor().act(Actor.CMD_UNLOCK)
 131                 def notify(self, did_it_work):
 132                         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))
 133                         for cb in self.callbacks:
 134                                 if cb is not None: # FIXME why this check? shouldn't be needed
 135                                         cb(s)
 136                 def handle_pins_event(self):
 137                         super().handle_pins_event()
 138                         pins = self.pins()
 139                         if not pins.door_locked:
 140                                 self.notify(True)
 141                                 return StateAboutToOpen(self.state_machine)
 142                 def handle_cmd_unlock_event(self,callback):
 143                         # intentionally not calling super() implementation
 144                         # FIXME: 202 notification also here if possible
 145                         self.callbacks.append(callback)
 146                 def could_not_open(self):
 147                         logger.critical("Couldn't open door after %d tries. Going back to StateZu." % OPEN_REPEAT_NUMBER)
 148                         self.notify(False)
 149                         return StateZu(self.state_machine)
 150
 151         class AbstractStateWhereOpeningIsRedundant(State):
 152                 def handle_cmd_unlock_event(self, callback):
 153                         # intentionally not calling super() implementation
 154                         callback("299 redundant: Space seems to be already open. Still processing your request tough.")
 155                         logger.warning("Received OPEN command in StateAboutToOpen. This should not be necessary.")
 156                         self.actor().act(Actor.CMD_UNLOCK)
 157
 158         class StateAboutToOpen(AbstractStateWhereOpeningIsRedundant):
 159                 def __init__(self, sm):
 160                         super().__init__(sm, ABOUTOPEN_NERVLIST)
 161                 def handle_pins_event(self):
 162                         super().handle_pins_event()
 163                         pins = self.pins()
 164                         if pins.door_locked:
 165                                 return StateZu(self.state_machine)
 166                         elif pins.space_active:
 167                                 return StateAuf(self.state_machine)
 168
 169         class StateAuf(AbstractStateWhereOpeningIsRedundant):
 170                 def __init__(self,sm):
 171                         super().__init__(sm)
 172                         self.last_buzzed = None
 173                 def handle_pins_event(self):
 174                         super().handle_pins_event()
 175                         pins = self.pins()
 176                         if pins.bell_ringing:
 177                                 now = time.time()
 178                                 if self.last_buzzed is None or now-self.last_buzzed < AUF_BELLBUZZ_REPEAT_TIME:
 179                                         logger.info("buzzing because of bell ringing in state auf")
 180                                         self.actor().act(Actor.CMD_BUZZ)
 181                                         self.last_buzzed = now
 182                         if not pins.space_active:
 183                                 logger.info("space switch off - starting leaving procedure")
 184                                 return StateAboutToLeave(self.state_machine)
 185                         if pins.door_locked:
 186                                 logger.error("door manually locked, but space switch on - going to StateZu")
 187                                 play_sound("manual_lock")
 188                                 return StateZu(self.state_machine)
 189
 190         class StateLocking(State):
 191                 # FIXME: Why does this even have callbacks?
 192                 # TODO: share code with StateUnlocking
 193                 def __init__(self,sm):
 194                         # construct a nervlist
 195                         nervlist = [(t*CLOSE_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_LOCK)) for t in range(1, CLOSE_REPEAT_NUMBER+1)]
 196                         nervlist += [((CLOSE_REPEAT_NUMBER+1)*CLOSE_REPEAT_TIMEOUT, self.could_not_close)]
 197                         super().__init__(sm, nervlist)
 198                         self.callbacks=[]
 199                         # FIXME: can we send "202 processing: Trying to close the door" here? Are the callbacks multi-use?
 200                         self.tries = 0
 201                         assert self.pins().door_closed, "Door is open while we should close it, this must not happen"
 202                         self.actor().act(Actor.CMD_LOCK)
 203                 def notify(self, did_it_work):
 204                         s = "200 okay: door closed" if did_it_work else ("500 internal server error: Couldn't close door with %d tries à %f seconds" % (CLOSE_REPEAT_NUMBER,CLOSE_REPEAT_TIMEOUT))
 205                         for cb in self.callbacks:
 206                                 if cb is not None:
 207                                         cb(s)
 208                 def handle_pins_event(self):
 209                         pins = self.pins()
 210                         if not pins.door_closed:
 211                                 # TODO play a sound? This shouldn't happen, door was opened while we are locking
 212                                 self.notify(True)
 213                                 return StateAboutToOpen(self.state_machine)
 214                         if pins.door_locked:
 215                                 return SpaceZu(self.state_machine)
 216                 def handle_cmd_unlock_event(self,callback):
 217                         callback("409 conflict: The server is currently trying to close the door. Try again later.")
 218                 def could_not_close(self):
 219                         logger.critical("Couldn't close door after %d tries. Going back to StateAboutToOpen." % CLOSE_REPEAT_NUMBER)
 220                         self.notify(False)
 221                         return StateAboutToOpen(self.state_machine)
 222
 223         class StateAboutToLeave(State):
 224                 def __init__(self, sm):
 225                         nervlist = [(LEAVE_TIMEOUT, lambda: StateLocking(self.state_machine))]
 226                         super().__init__(sm, nervlist)
 227                 def handle_pins_event(self):
 228                         if not self.pins().door_closed:
 229                                 return StateLeaving(self.state_machine)
 230                         if self.pins().door_locked:
 231                                 return StateZu(self.state_machine)
 232
 233         class StateLeaving(State):
 234                 def __init__(self, sm):
 235                         nervlist = [(LEAVE_TIMEOUT, lambda: StateAboutToOpen(self.state_machine))]
 236                         super().__init__(sm, nervlist)
 237                 def handle_pins_event(self):
 238                         if self.pins().door_closed:
 239                                 return StateLocking(self.state_machine)
 240                         if self.pins().door_locked:
 241                                 return StateZu(self.state_machine)
 242
 243         def __init__(self, actor):
 244                 self.actor = actor
 245                 self.callback = ThreadFunction(self._callback)
 246                 self.current_state = StateStart(self)
 247                 self.pins = None
 248                 self.old_pins = None
 249
 250         def stop (self):
 251                 self.callback.stop()
 252
 253         def _callback(self, cmd, arg=None):
 254                 # update pins
 255                 if cmd == StateMachine.CMD_PINS:
 256                         self.pins = arg
 257                 # handle stuff
 258                 newstate = self.current_state.handle_event(cmd,arg) # returns None or an instance of the new state
 259                 self.old_pins = self.pins # FIXME not used?
 260                 while newstate is not None:
 261                         logger.info("StateMachine: new state = %s" % newstate.__class__.__name__)
 262                         self.current_state = newstate
 263                         newstate = self.current_state.handle_event(StateMachine.CMD_PINS, self.pins)