from .timer import Timer


class TimersManager:
    """
    Timers manager
    For now, ScEpTIC supports timers under energy emulation mode and does not account for power off periods
    """

    def __init__(self, vmstate):
        Timer._vmstate = vmstate
        self._vmstate = vmstate
        self.timers = {}

    def check_timers(self):
        """
        Check timers expiration
        """
        for timer in self.timers.values():
            timer.check()

    def create_timer(self, name, interrupt_signal, period=0, periodic=False):
        """
        Creates a new timer
        :param name: name of the timer
        :param interrupt_signal: interrupt signal to trigger when timer expires
        :param period: period of the timer in seconds
        :param periodic: whether the timer is periodic
        """
        if name in self.timers.keys():
            raise Exception(f"Timer named \"{name}\" already exists!")

        self.timers[name] = Timer(name, interrupt_signal, period, periodic)

    def start_timer(self, name):
        """
        Starts a given timer
        :param name: name of the timer
        """
        self._get_timer(name).start()

    def stop_timer(self, name):
        """
        Stops a given timer
        :param name: name of the timer
        """
        self._get_timer(name).stop()

    def set_timer_period(self, name, period):
        """
        Sets the period of a given timer
        :param name: name of the time
        :param period: period of the timer in seconds
        """
        self._get_timer(name).set_period(period)

    def _get_timer(self, name):
        """
        Returns a timer
        :param name: name of the time
        """
        try:
            return self.timers[name]
        except KeyError:
            raise Exception(f"Timer named \"{name}\" does not exist!")