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 # 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 # 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 OPEN event" % self.__class__.__name__)
  82                 def handle_wakeup_event(self):
  83                         if self._nerver is not None:
  84                                 return self._nerver.nerv()
  85                 def pins(self):
  86                         return self.state_machine.pins
  87                 def actor(self):
  88                         return self.state_machine.actor
  89                 def handle_event(self,ev,arg): # don't override
  90                         if ev == StateMachine.CMD_PINS:
  91                                 return self.handle_pins_event()
  92                         elif ev == StateMachine.CMD_BUZZ:
  93                                 return self.handle_buzz_event(arg)
  94                         elif ev == StateMachine.CMD_UNLOCK:
  95                                 return self.handle_cmd_unlock_event(arg)
  96                         elif ev == StateMachine.CMD_WAKEUP:
  97                                 return self.handle_wakeup_event()
  98                         else:
  99                                 raise Exception("Unknown command number: %d" % ev)
 100
 101         class StateStart(State):
 102                 def handle_pins_event(self):
 103                         super().handle_pins_event()
 104                         pins = self.pins()
 105                         if pins.door_locked is None or pins.door_closed is None or pins.space_active is None or pins.bell_ringing is None:
 106                                 return None # wait till we have all sensors non-None
 107                         if pins.door_locked:
 108                                 return StateMachine.StateZu(self.state_machine)
 109                         else:
 110                                 return StateMachine.StateAuf(self.state_machine)
 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 StateMachine.StateAboutToOpen(self.state_machine)
 118                 def handle_cmd_unlock_event(self,callback):
 119                         # intentionally not calling super() implementation
 120                         return StateMachine.StateUnlocking(self.state_machine, callback)
 121
 122         class StateUnlocking(State):
 123                 def __init__(self,sm,callback=None):
 124                         # construct a nervlist
 125                         nervlist = [(OPEN_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_UNLOCK)) for t in range(OPEN_REPEAT_NUMBER)]
 126                         nervlist += [(OPEN_REPEAT_TIMEOUT, self.could_not_open)]
 127                         super().__init__(sm,nervlist)
 128                         self.callbacks=[callback]
 129                         # TODO: 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:
 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 StateMachine.StateAboutToOpen(self.state_machine)
 142                 def handle_cmd_unlock_event(self,callback):
 143                         # intentionally not calling super() implementation
 144                         # TODO: 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 StateMachine.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.info("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 StateMachine.StateZu(self.state_machine)
 166                         elif pins.space_active:
 167                                 return StateMachine.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                                 # TODO: use old_pins instead of a timer
 178                                 now = time.time()
 179                                 if self.last_buzzed is None or now-self.last_buzzed < AUF_BELLBUZZ_REPEAT_TIME:
 180                                         logger.info("buzzing because of bell ringing in state auf")
 181                                         self.actor().act(Actor.CMD_BUZZ)
 182                                         self.last_buzzed = now
 183                         if not pins.space_active:
 184                                 logger.info("space switch off - starting leaving procedure")
 185                                 return StateMachine.StateAboutToLeave(self.state_machine)
 186                         if pins.door_locked:
 187                                 logger.info("door manually locked, but space switch on - going to StateZu")
 188                                 play_sound("manual_lock")
 189                                 return StateMachine.StateZu(self.state_machine)
 190
 191         class StateLocking(State):
 192                 # TODO: share code with StateUnlocking
 193                 def __init__(self,sm):
 194                         # construct a nervlist
 195                         nervlist = [(CLOSE_REPEAT_TIMEOUT, lambda: self.actor().act(Actor.CMD_LOCK)) for t in range(CLOSE_REPEAT_NUMBER)]
 196                         nervlist += [(CLOSE_REPEAT_TIMEOUT, self.could_not_close)]
 197                         super().__init__(sm, nervlist)
 198                         if self.pins().door_closed: # this should always be true, but just to be sure...
 199                                 self.actor().act(Actor.CMD_LOCK)
 200                 def handle_pins_event(self):
 201                         pins = self.pins()
 202                         if not pins.door_closed:
 203                                 # TODO play a sound? This shouldn't happen, door was opened while we are locking
 204                                 logger.warning("door manually opened during locking")
 205                                 return StateMachine.StateAboutToOpen(self.state_machine)
 206                         if pins.door_locked:
 207                                 return StateMachine.StateZu(self.state_machine)
 208                 def handle_cmd_unlock_event(self,callback):
 209                         callback("409 conflict: The server is currently trying to lock the door. Try again later.")
 210                 def could_not_close(self):
 211                         logger.critical("Couldn't close door after %d tries. Going back to StateAboutToOpen." % CLOSE_REPEAT_NUMBER)
 212                         return StateMachine.StateAboutToOpen(self.state_machine)
 213
 214         class StateAboutToLeave(State):
 215                 def __init__(self, sm):
 216                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateLocking(self.state_machine))]
 217                         super().__init__(sm, nervlist)
 218                 def handle_pins_event(self):
 219                         if not self.pins().door_closed:
 220                                 return StateMachine.StateLeaving(self.state_machine)
 221                         if self.pins().door_locked:
 222                                 return StateMachine.StateZu(self.state_machine)
 223                         if self.pins().space_active:
 224                                 return StateMachine.StateAuf(self.state_machine)
 225
 226         class StateLeaving(State):
 227                 def __init__(self, sm):
 228                         nervlist = [(LEAVE_TIMEOUT, lambda: StateMachine.StateAboutToOpen(self.state_machine))]
 229                         super().__init__(sm, nervlist)
 230                 def handle_pins_event(self):
 231                         if self.pins().door_closed:
 232                                 return StateMachine.StateLocking(self.state_machine)
 233                         if self.pins().door_locked:
 234                                 return StateMachine.StateZu(self.state_machine)
 235                         if self.pins().space_active:
 236                                 return StateMachine.StateAuf(self.state_machine)
 237
 238         def __init__(self, actor):
 239                 self.actor = actor
 240                 self.callback = ThreadFunction(self._callback, name="StateMachine")
 241                 self.current_state = StateMachine.StateStart(self)
 242                 self.pins = None
 243                 self.old_pins = None
 244
 245         def stop (self):
 246                 self.callback.stop()
 247
 248         def _callback(self, cmd, arg=None):
 249                 # update pins
 250                 if cmd == StateMachine.CMD_PINS:
 251                         self.pins = arg
 252                 # handle stuff
 253                 newstate = self.current_state.handle_event(cmd,arg) # returns None or an instance of the new state
 254                 self.old_pins = self.pins
 255                 while newstate is not None:
 256                         logger.debug("StateMachine: new state = %s" % newstate.__class__.__name__)
 257                         self.current_state = newstate
 258                         newstate = self.current_state.handle_event(StateMachine.CMD_PINS, self.pins)