import atexit
from enum import Enum

from compLib.LogstashLogging import Logging
from compLib.MetricsLogging import MetricsLogging
from compLib.Spi import Spi, Register

MOTOR_COUNT = 4


encoder_start_values = [0] * (MOTOR_COUNT + 1)
encoder_last_raw_value = [0] * (MOTOR_COUNT + 1)

class Encoder(object):
    """Class used to read the encoders
    """

    @staticmethod
    def read_raw(port: int) -> int:
        """Read raw encoder from a specified port. Will not be reset to 0 at start.

        :param port: Port, which the motor is connected to. Between 1 and 4
        :raises: IndexError
        :return: Current encoder position
        """
        if port <= 0 or port > MOTOR_COUNT:
            raise IndexError("Invalid encoder port specified!")
        
        global encoder_last_raw_value
        raw_value = 0

        if port == 1:
            raw_value = Spi.read(Register.MOTOR_1_POS_B3, 4)
        elif port == 2:
            raw_value = Spi.read(Register.MOTOR_2_POS_B3, 4)
        elif port == 3:
            raw_value = Spi.read(Register.MOTOR_3_POS_B3, 4)
        elif port == 4:
            raw_value = Spi.read(Register.MOTOR_4_POS_B3, 4)
        
        if abs(raw_value - encoder_last_raw_value[port]) > 1000:
            encoder_last_raw_value[port] = raw_value
            return Encoder.read_raw(port)
        
        encoder_last_raw_value[port] = raw_value
        return raw_value
        
    @staticmethod
    def read(port: int) -> int:
        """Read encoder from a specified port

        :param port: Port, which the motor is connected to. Between 1 and 4
        :raises: IndexError
        :return: Current encoder position
        """
        if port <= 0 or port > MOTOR_COUNT:
            raise IndexError("Invalid encoder port specified!")

        diff = Encoder.read_raw(port) - encoder_start_values[port]
        if diff > 2 ** 31:
            diff -= 2 ** 32
        elif diff < -2 ** 31:
            diff += 2 ** 32
        
        MetricsLogging.put("Encoder", diff, port)
        return diff

    @staticmethod
    def clear(port: int):
        """Reset encoder position to 0

        :param port: Port, which the motor is connected to. Between 1 and 4
        :raises: IndexError
        """
        if port <= 0 or port > MOTOR_COUNT:
            raise IndexError("Invalid encoder port specified!")

        encoder_start_values[port] = Encoder.read_raw(port)

    @staticmethod
    def clear_all():
        """Reset all encoder positions to 0
        """

        for i in range(1, MOTOR_COUNT + 1):
            encoder_start_values[i] = Encoder.read_raw(i)