# lab1_4.py -- template for your Task #4 design file
import numpy
import matplotlib.pyplot as p
import channel
reload(channel)
import lab1
reload(lab1)
import im1d
reload(im1d)

p.ion()


def receive_8b10b(samples,samples_per_bit):
    """
    Convert an array of voltage samples transmitted by
    a 8b/10b encoder into a sequence of bits. Return the sequence of bits
    as a numpy array.
    """
    return []


# testing code.  Do it this way so we can import this file
# and use its functions without also running the test code.
if __name__ == '__main__':
    # Read in a .png image as array of greyscale values
    # with pixel values between 0.0 and 1.0
    image = im1d.im1dread("mandrils")

    # Number of pixels in the image
    num_pixels = len(image)

    # Show the image
    p.figure()
    im1d.im1dshow(image, rows=64)

    # Turn the image in to a sequence of bits
    bits = lab1.farray_to_bits(image)

    # encode 8-bit blocks
    encoded = lab1.encode_bits_8b10b(bits)

    # Convert encoded image in to samples
    # The fractional value for samples_per_bit models clock
    # drift between the transmitter and receiver.  In order to
    # work correctly, your code should resynchronize where it's
    # sampling each bit whenever it sees a transition.
    samples_per_bit=8.3
    samples = lab1.bits_to_samples(encoded,samples_per_bit)
    
    # Create channel with noise and random delay and padding
    mychannel = channel.channel(channelid='0',noise=0.1,
                                random_tails=300)

    # Send samples through channel with noise and random delay
    # and padding
    rcvd_samples = mychannel(samples)

    # Your program to receive the bit stream
    samples_per_bit=8
    rcvd_bits = receive_8b10b(rcvd_samples, samples_per_bit)

    # Turn sequence of bits into an image
    rcvd_image = lab1.bits_to_farray(rcvd_bits)

    # Show the image
    if rcvd_image != []:
        p.figure()
        im1d.im1dshow(rcvd_image,rows=64)

    # enable the following line whey you're ready to submit
    # your code to the on-line server
    #lab1.checkoff(receive_8b10b,'L1_4')