# Copyright (c) 2021 The Regents of the University of California
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from enum import Enum


class ExitEvent(Enum):
    """
    An enum class holding all the supported simulator exit events.

    The simulator will exit in certain conditions. The simulate package has
    been designed to categorize these into sensible states of exit, listed
    below.
    """

    EXIT = "exit"  # A standard vanilla exit.
    WORKBEGIN = "workbegin"  # An exit because a ROI has been reached.
    WORKEND = "workend"  # An exit because a ROI has ended.
    SWITCHCPU = "switchcpu"  # An exit needed to switch CPU cores.
    FAIL = "fail"  # An exit because the simulation has failed.
    CHECKPOINT = "checkpoint"  # An exit to load a checkpoint.
    MAX_TICK = "max tick" # An exit due to a maximum tick value being met.
    USER_INTERRUPT = ( # An exit due to a user interrupt (e.g., cntr + c)
        "user interupt"
    )

    @classmethod
    def translate_exit_status(cls, exit_string: str) -> "ExitEvent":
        """
        This function will translate common exit strings to their correct
        ExitEvent categorization.


        **Note:** At present, we do not guarantee this list is complete, as
        there are no bounds on what string may be returned by the simulator
        given an exit event.
        """

        if exit_string == "m5_workbegin instruction encountered":
            return ExitEvent.WORKBEGIN
        elif exit_string == "workbegin":
            return ExitEvent.WORKBEGIN
        elif exit_string == "m5_workend instruction encountered":
            return ExitEvent.WORKEND
        elif exit_string == "workend":
            return ExitEvent.WORKEND
        elif exit_string == "m5_exit instruction encountered":
            return ExitEvent.EXIT
        elif exit_string == "exiting with last active thread context":
            return ExitEvent.EXIT
        elif exit_string == "simulate() limit reached":
            return ExitEvent.MAX_TICK
        elif exit_string == "switchcpu":
            return ExitEvent.SWITCHCPU
        elif exit_string == "m5_fail instruction encountered":
            return ExitEvent.FAIL
        elif exit_string == "checkpoint":
            return ExitEvent.CHECKPOINT
        elif exit_string == "user interrupt received":
            return ExitEvent.USER_INTERRUPT
        raise NotImplementedError(
            "Exit event '{}' not implemented".format(exit_string)
        )