import smbus
import time


class Adc:
    def __init__(self):
        # Get I2C bus
        self.bus = smbus.SMBus(1)

        # I2C address of the device
        self.ADDRESS = 0x48

        # PCF8591 Command
        self.PCF8591_CMD = 0x40  # Command

        # ADS7830 Command
        self.ADS7830_CMD = 0x84  # Single-Ended Inputs

        for i in range(3):
            aa = self.bus.read_byte_data(self.ADDRESS, 0xf4)
            if aa < 150:
                self.Index = "PCF8591"
            else:
                self.Index = "ADS7830"

    def analogReadPCF8591(self, chn):  # PCF8591 read ADC value,chn:0,1,2,3
        value = [0, 0, 0, 0, 0, 0, 0, 0, 0]
        for i in range(9):
            value[i] = self.bus.read_byte_data(self.ADDRESS, self.PCF8591_CMD + chn)
        value = sorted(value)
        return value[4]

    # TODO: bug in original code???
    #def analogWritePCF8591(self, value):  # PCF8591 write DAC value
    #    self.bus.write_byte_data(self.ADDRESS, cmd, value)

    def recvPCF8591(self, channel):  # PCF8591 write DAC value
        while (1):
            value1 = self.analogReadPCF8591(channel)  # read the ADC value of channel 0,1,2,
            value2 = self.analogReadPCF8591(channel)
            if value1 == value2:
                break;
        voltage = value1 / 256.0 * 3.3  # calculate the voltage value
        voltage = round(voltage, 2)
        return voltage

    def recvADS7830(self, channel):
        """Select the Command data from the given provided value above"""
        COMMAND_SET = self.ADS7830_CMD | ((((channel << 2) | (channel >> 1)) & 0x07) << 4)
        self.bus.write_byte(self.ADDRESS, COMMAND_SET)
        while (1):
            value1 = self.bus.read_byte(self.ADDRESS)
            value2 = self.bus.read_byte(self.ADDRESS)
            if value1 == value2:
                break;
        voltage = value1 / 255.0 * 3.3  # calculate the voltage value
        voltage = round(voltage, 2)
        return voltage

    def recvADC(self, channel):
        if self.Index == "PCF8591":
            data = self.recvPCF8591(channel)
        elif self.Index == "ADS7830":
            data = self.recvADS7830(channel)
        return data

    def i2cClose(self):
        self.bus.close()


def loop():
    adc = Adc()
    while True:
        Left_IDR = adc.recvADC(0)
        print(Left_IDR)
        Right_IDR = adc.recvADC(1)
        print(Right_IDR)
        Power = adc.recvADC(2) * 3
        print(Power)
        time.sleep(1)
        print('----')


def destroy():
    pass


# Main program logic follows:
if __name__ == '__main__':
    print('Program is starting ... ')
    try:
        loop()
    except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
        destroy()