import functools
import random


def calculateEXOR(data):
    exoredData = functools.reduce(lambda x, y: x ^ y, data)
    return str(exoredData)


def checkError(data):
    if calculateEXOR(data) == "0":
        print("There is No error in the received data.\n")
    elif calculateEXOR(data) == "1":
        print("There is an error in the received data.\n")
    else:
        print("Invalid Input.\n")


def OneBitError(input_data, VRCbit):
    dataBits = input_data[0:len(input_data)-1]
    oneBitError = random.choice(dataBits)
    i = dataBits.index(oneBitError)
    oneBitErrorDataBits = dataBits[:i]+[1-oneBitError]+dataBits[i+1:]
    print("\n\nThe Data with one bit error is: " + str(oneBitErrorDataBits))
    oneBitErrorDataBits.append(int(VRCbit))
    print("The Received data with one bit error is: " + str(oneBitErrorDataBits))
    print("The index of the error bit is: " + str(i))
    print("Error Detection of One Bit Error is: ")
    checkError(oneBitErrorDataBits)


def TwoBitError(input_data, VRCbit):
    dataBits = input_data[0:len(input_data)-1]
    twoBitError = random.sample(dataBits, 2)
    indices = []
    for i in range(len(twoBitError)):
        indices.append(dataBits.index(i))

    for i in range(len(indices)):
        if dataBits[indices[i]] == 1:
            dataBits[indices[i]] = 0
        else:
            dataBits[indices[i]] = 1

    print("\n\nThe Data with two bit error is: " + str(dataBits))
    dataBits.append(int(VRCbit))
    print("The Received data with two bit error is: " + str(dataBits))
    print("The Index of the error bit is: " + str(indices))
    print("Error Detection of Two Bit Error is: ")
    checkError(dataBits)

input_data = input("\n\nEnter the 8 bits Binary data: ")
input_data = input_data.split()
input_data = [int(i) for i in input_data]

VRCbit = calculateEXOR(input_data)

print("\nThe VRC Parity Bit is : " + calculateEXOR(input_data))

input_data.append(int(calculateEXOR(input_data)))
print("\n\nThe Received data is: " + str(input_data))

checkError(input_data)
print("The Decoder Output is: " + str(input_data[0:len(input_data)-1]))

OneBitError(input_data, VRCbit)
TwoBitError(input_data, VRCbit)