import enum


class LcrConnException(Exception):
    """The exception thrown by LCR Connector"""

    pass


class DeviceKind(enum.IntEnum):
    """The kind of device"""

    RESISTOR = enum.auto()
    """Resistor device"""
    CAPACITOR = enum.auto()
    """Capacitor device"""
    INDUCTOR = enum.auto()
    """Inductor device"""


class JointKind(enum.IntEnum):
    """The joint type between 2 devices"""

    SERIES = enum.auto()
    """Series connection"""
    PARALLEL = enum.auto()
    """Parallel connection"""

    def flip(self) -> "JointKind":
        """
        Flip the joint kind

        Flip the joint kind from series to parallel or vice versa

        :return: The flipped joint kind
        """
        match self:
            case JointKind.SERIES:
                return JointKind.PARALLEL
            case JointKind.PARALLEL:
                return JointKind.SERIES


class SubCircuit:
    """The part of circuit composed of two devices and the joint kind"""

    __device_value: float
    """The value of the device"""
    __joint_kind: JointKind
    """The joint kind between this device and the next device"""

    def __init__(self, device_value: float, joint_kind: JointKind):
        self.__device_value = device_value
        self.__joint_kind = joint_kind

    def compute(self, value: float, device_kind: DeviceKind) -> float:
        """
        Compute the joint value

        :param value: The value computed from previous devices
        :param device_kind: The kind of the device
        :return: The joint value computed
        """
        if self.__device_value <= 0 or value <= 0:
            raise LcrConnException("Device value must be greater than 0")

        # We perform series connect for: series resistor, series inductor and parallel capacitor.
        # We perform parallel connect for: parallel resistor, parallel inductor and series capacitor.
        joint_kind = self.__joint_kind
        if device_kind == DeviceKind.CAPACITOR:
            joint_kind = joint_kind.flip()

        match joint_kind:
            case JointKind.SERIES:
                return self.__device_value + value
            case JointKind.PARALLEL:
                return (self.__device_value * value) / (self.__device_value + value)

    def get_device_value(self) -> float:
        """
        Get the device value

        :return: The device value
        """
        return self.__device_value

    def get_joint_kind(self) -> JointKind:
        """
        Get the joint kind

        :return: The joint kind
        """
        return self.__joint_kind


class CircuitDeviceCount(enum.IntEnum):
    """The number of devices in the circuit"""

    ONE = enum.auto()
    """One device"""
    TWO = enum.auto()
    """Two devices"""
    THREE = enum.auto()
    """Three devices"""

    def to_device_count(self) -> int:
        match self:
            case CircuitDeviceCount.ONE:
                return 1
            case CircuitDeviceCount.TWO:
                return 2
            case CircuitDeviceCount.THREE:
                return 3


class Circuit:
    """The circuit composed of multiple joints"""

    __first_device_value: float
    """The value of the first device"""
    __second_device_subckt: SubCircuit | None
    """The second device and its joint property"""
    __third_device_subckt: SubCircuit | None
    """The third device and its joint property"""

    def __init__(
        self,
        first_device_value: float,
        second_device_subckt: SubCircuit | None,
        third_device_subckt: SubCircuit | None,
    ):
        """
        Initialize the circuit

        :param first_device_value: The value of the first device
        :param second_device_subckt: The second device and its joint property
        :param third_device_subckt: The third device and its joint property
        """
        if second_device_subckt is None and third_device_subckt is not None:
            raise LcrConnException("Third device cannot exist without second device")

        self.__first_device_value = first_device_value
        self.__second_device_subckt = second_device_subckt
        self.__third_device_subckt = third_device_subckt

    @staticmethod
    def from_one_device(device1_value: float) -> "Circuit":
        return Circuit(device1_value, None, None)

    @staticmethod
    def from_two_devices(
        device1_value: float, device2_value: float, device2_joint: JointKind
    ) -> "Circuit":
        return Circuit(device1_value, SubCircuit(device2_value, device2_joint), None)

    @staticmethod
    def from_three_devices(
        device1_value: float,
        device2_value: float,
        device2_joint: JointKind,
        device3_value: float,
        device3_joint: JointKind,
    ) -> "Circuit":
        return Circuit(
            device1_value,
            SubCircuit(device2_value, device2_joint),
            SubCircuit(device3_value, device3_joint),
        )

    def get_device_count(self) -> CircuitDeviceCount:
        if self.__third_device_subckt is not None:
            return CircuitDeviceCount.THREE
        elif self.__second_device_subckt is not None:
            return CircuitDeviceCount.TWO
        else:
            return CircuitDeviceCount.ONE

    def get_first_device_value(self) -> float:
        """
        Get the value of the first device

        :return: The value of the first device
        """
        return self.__first_device_value

    def get_second_device_joint(self) -> JointKind:
        """
        Get the joint kind of the second device

        :return: The joint kind of the second device
        :raises LcrConnException: If there is no second device
        """
        if self.__second_device_subckt is not None:
            return self.__second_device_subckt.get_joint_kind()
        else:
            raise LcrConnException("No second device")

    def get_second_device_value(self) -> float:
        """
        Get the value of the second device

        :return: The value of the second device
        :raises LcrConnException: If there is no second device
        """
        if self.__second_device_subckt is not None:
            return self.__second_device_subckt.get_device_value()
        else:
            raise LcrConnException("No second device")

    def get_third_device_joint(self) -> JointKind:
        """
        Get the joint kind of the third device

        :return: The joint kind of the third device
        :raises LcrConnException: If there is no third device
        """
        if self.__third_device_subckt is not None:
            return self.__third_device_subckt.get_joint_kind()
        else:
            raise LcrConnException("No third device")

    def get_third_device_value(self) -> float:
        """
        Get the value of the third device

        :return: The value of the third device
        :raises LcrConnException: If there is no third device
        """
        if self.__third_device_subckt is not None:
            return self.__third_device_subckt.get_device_value()
        else:
            raise LcrConnException("No third device")

    def compute(self, device_kind: DeviceKind) -> float:
        """
        Compute the circuit value

        :param device_kind: The kind of the device
        :return: The circuit value
        """
        if self.__first_device_value <= 0:
            raise LcrConnException("Device value must be greater than 0")

        value = self.__first_device_value
        if self.__second_device_subckt is None:
            return value
        value = self.__second_device_subckt.compute(value, device_kind)
        if self.__third_device_subckt is None:
            return value
        value = self.__third_device_subckt.compute(value, device_kind)
        return value