from ScEpTIC.emulator.energy.mcu_peripheral.options import MCUPeripheralPowerStateBehaviour
from ScEpTIC.emulator.energy.voltage_drawner import VoltageDrawner
from ScEpTIC.exceptions import ConfigurationException

class MCUPeripheral(VoltageDrawner):
    """
    Generic peripheral that attaches to the MCU
    """

    def __init__(self):
        self.mcu = None
        self.power_state_behaviour = MCUPeripheralPowerStateBehaviour.ALWAYS_ON


    def set_power_state_behaviour(self, behaviour):
        """
        Sets the power-state behaviour of the peripheral
        :param behaviour: a MCUPeripheralPowerStateBehaviour enum
        """
        if not isinstance(behaviour, MCUPeripheralPowerStateBehaviour):
            raise ConfigurationException(f"{self.__class__.__name__}.set_power_state_behaviour() requires a MCUPeripheralPowerStateBehaviour but {behaviour.__class__.__name__} was given")

        self.power_state_behaviour = behaviour


    def attach_mcu(self, mcu):
        """
        Attaches the mcu to the peripheral
        :param mcu: the MCU energy model
        """

        # Smelly solution, but resolves the ciruclar import problem
        from ScEpTIC.emulator.energy.mcu import MCUEnergyModel

        if not isinstance(mcu, MCUEnergyModel):
            raise ConfigurationException(f"{self.__class__.__name__}.attach_mcu() requires a MCUEnergyModel but {mcu.__class__.__name__} was given")

        self.mcu = mcu


    def get_power_state_events(self):
        """
        :return: a list of PowerState events that are occurring
        """
        raise NotImplementedError(f"{self.__class__.__name__} must implement get_power_state_events()")


    def _follow_mcu_power_state(self):
        """
        Checks the MCU power state and updates the peripheral power state accordingly
        """
        raise NotImplementedError(f"{self.__class__.__name__} must implement check_mcu_power_state()")


    def get_drained_energy(self, t):
        """
        Calculates the energy consumed by the component and follows MCU power state.
        :param t: elapsed time
        :return: the consumed energy
        """
        if self.power_state_behaviour == MCUPeripheralPowerStateBehaviour.FOLLOW_MCU:
            self._follow_mcu_power_state()

        return self._get_drained_energy(t)


    def _get_drained_energy(self, t):
        """
        Calculates the energy consumed by the component.
        :param t: elapsed time
        :return: the consumed energy
        """
        raise NotImplementedError(f"{self.__class__.__name__} must implement _get_drained_energy()")