fischertechnik-factory-twin/simulator/devs_models/simple_conveyor.py

from data_models.mqtt_message import MqttMessage
from pypdevs.DEVS import AtomicDEVS
from pypdevs.infinity import INFINITY
from dataclasses import dataclass
from loguru import logger

from data_models.workpiece import Workpiece
from utils.timed_phase_enum import TimedPhaseEnum


class ConveyorPhase(TimedPhaseEnum):
    """ Steps in order, along with their timings """
    IDLE = ('IDLE', INFINITY)
    RUNNING = ('RUNNING', 2.368)

@dataclass
class ConveyorState:
    delta_t: float = INFINITY
    phase: ConveyorPhase = ConveyorPhase.IDLE
    workpiece: Workpiece | None = None
    visual_update_pending: bool = False


class SimpleConveyor(AtomicDEVS):
    """ A simple conveyor belt which moves a workpiece across its belt and detects when it has reached the end """

    def __init__(self, name: str):
        super(SimpleConveyor, self).__init__(name)
        self.inp = self.addInPort("inp")
        self.out = self.addOutPort("out")

        self.mqtt_in = self.addInPort("mqtt_in") # to receive visual update requests
        self.mqtt_out = self.addOutPort("mqtt_out")

        self.state = ConveyorState()

    def change_phase(self, new_phase: ConveyorPhase):
        """ Wrapper for changing the phase and time associated with it, helps with logging """
        self.state.phase = new_phase
        self.state.delta_t = new_phase.timing
        logger.trace(f"{type(self).__name__} '{self.name}' phase changed to {new_phase}")
        self.state.visual_update_pending = True

    def get_visual_update_data(self) -> MqttMessage:
        """ Get visual update data for the animation, contains the action taken and the duration of that action left """
        message = MqttMessage()
        message.topic = "visualization/conveyor"
        duration = self.state.delta_t
        if duration == INFINITY: duration = None
        message.payload = {
            "action": self.state.phase.value,
            "duration": duration,  # should be equal to the timing of the phase
            "workpiece": self.state.workpiece.to_dict() if self.state.workpiece else None,
        }
        return message

    def extTransition(self, inputs):
        if self.mqtt_in in inputs:
            msg = inputs[self.mqtt_in][0]
            if msg.topic == "simulation/ctrl/all" and msg.payload.get("action") == "refresh":
                self.state.visual_update_pending = True
                return self.state

        if self.inp in inputs:
            new_workpiece = inputs[self.inp][0]
            logger.trace(f"{type(self).__name__} '{self.name}' received: {new_workpiece}")
            self.state.workpiece = new_workpiece
            self.change_phase(ConveyorPhase.RUNNING)

        return self.state  # important, return state

    def timeAdvance(self):
        if self.state.visual_update_pending:
            return 0.0
        return self.state.delta_t

    def outputFnc(self):
        if self.state.visual_update_pending:
            return {self.mqtt_out: [self.get_visual_update_data()]}

        logger.trace(f"{type(self).__name__} '{self.name}' outputs: {self.state.workpiece}")
        return {self.out: [self.state.workpiece]}

    def intTransition(self):
        if self.state.visual_update_pending:
            self.state.visual_update_pending = False
            return self.state

        # We have just output the workpiece, so mark it as empty again
        self.state.workpiece = None
        self.change_phase(ConveyorPhase.IDLE)
        return self.state