from ScEpTIC.emulator.energy import energy_utils
from ScEpTIC.emulator.energy.system_energy_model import SystemEnergyModel
from ScEpTIC.exceptions import ConfigurationException


class ChangePointDetector:
    """
    Base model of the FBTC Changepoint Detector.
    """

    def __init__(self, R1, R2, system_model):
        """
        :param R1: R1 of the changepoint detector's voltage divider
        :param R2: R2 of the changepoint detector's voltage divider
        :param system_model: the SystemEnergyModel
        """

        if not isinstance(system_model, SystemEnergyModel):
            raise ConfigurationException(f"{system_model.__class__.__name__} is not a valid SystemEnergyModel for {self.__class__.__name__}")

        self.system_model = system_model

        self.R1 = energy_utils.str_to_float(R1)
        self.R2 = energy_utils.str_to_float(R2)
        self.partition = self.R2 / (self.R1 + self.R2)


    def output(self):
        """
        Outputs the logical value of the Changepoint Detector
        :return: a changepoint is reached
        """
        raise Exception(f"{self.__class__.__name__} must implement output()")


    def _get_output_charge_detector(self):
        """
        Outputs the logical value of the Changepoint Detector configured to detect charge
        :return: a charge changepoint is reached
        """
        v_buff = self.system_model.energy_buffer.get_voltage() * self.partition
        v_sup = self.system_model.voltage_regulator.get_voltage()

        #print(f"Charge state: v_buff = {v_buff}V; v_sup = {v_sup}V; {v_buff > v_sup}")

        return v_buff > v_sup


    def _get_output_discharge_detector(self):
        """
        Outputs the logical value of the Changepoint Detector configured to detect discharge
        :return: a discharge changepoint is reached
        """
        v_buff = self.system_model.energy_buffer.get_voltage() * self.partition
        v_sup = self.system_model.voltage_regulator.get_voltage()

        #print(f"Discharge state: v_buff = {v_buff}V; v_sup = {v_sup}V; {v_buff < v_sup}")

        return v_buff < v_sup


class ChangepointChargeDetector(ChangePointDetector):
    """
    Model of the FBTC Changepoint Charge Detector.
    It consists in an OpAmp that outputs if the voltage of the energy buffer is higher than a certain threshold w.r.t.
    the voltage of the voltage regulator.
    """

    def output(self):
        """
        Outputs the logical value of the Changepoint Charge Detector
        :return: a charge changepoint is reached
        """
        return self._get_output_charge_detector()


class ChangepointDischargeDetector(ChangePointDetector):
    """
    Model of the FBTC Changepoint Discharge Detector.
    It consists in an OpAmp that outputs if the voltage of the energy buffer is lower than a certain threshold w.r.t.
    the voltage of the voltage regulator.
    """
    
    def output(self):
        """
        Outputs the logical value of the Changepoint Discharge Detector
        :return: a discharge changepoint is reached
        """
        return self._get_output_discharge_detector()