from Cimpl import *
import math
file = choose_file()

image = load_image(file)

def grayscale(image: Image) -> Image:
    """Return a grayscale copy of image.

    >>> image = load_image(choose_file())
    >>> gray_image = grayscale(image)
    >>> show(gray_image)
    """
    new_image = copy(image)
    for x, y, (r, g, b) in image:

        # Use the pixel's brightness as the value of RGB components for the
        # shade of gray. These means that the pixel's original colour and the
        # corresponding gray shade will have approximately the same brightness.

        brightness = (r + g + b) // 3

        # or, brightness = (r + g + b) / 3
        # create_color will convert an argument of type float to an int

        gray = create_color(brightness, brightness, brightness)
        set_color(new_image, x, y, gray)
    #show (new_image)
    return new_image


def Sepia_channel():

    """
    The funcion returns the selected image in a sepia filter, however it does not alter the original image.

    Ahmed Shakir - 101143951

    """
    sepia_picture = grayscale(image)

    for x, y, (r,g,b) in sepia_picture:
        if g < 63:
            b*=0.9
            r*=1.1
            b= round (b)
            r = round (r)
        elif 63 <= g <= 191:
            r*=1.15
            b *= 0.85
            r = round (r)
            b = round (b)
        elif g > 191 :
            b*= 0.93
            r*=1.08
            b = round (b)
            r= round (r)
        sepia = create_color( r, g, b)
        set_color(sepia_picture, x, y, sepia)

    show(sepia_picture)
    return sepia_picture



def test_filter_grayscale (image):
    gray_picture = grayscale (image)

    for x,y, (r,g,b) in gray_picture:

        r, g, b = get_color (gray_picture, x, y)
        red, green, blue = get_color (image, x, y)
        brightness = (red + green + blue)// 3
        if brightness== r and brightness == g and brightness == b:
            continue
        else:
            return False
    return True


def test_filter_sepia (image):

    filtered_picture = Sepia_channel()
    graypic = grayscale (image)


    graytest = test_filter_grayscale (image)

    if graytest == False:
        return False

    for x,y, (r,g,b) in filtered_picture:

        r,g,b = get_color (filtered_picture, x, y)
        red, green, blue = get_color (graypic, x, y)
        if red< 63 and r== round(red*1.1) :
            continue
        elif (red >= 63 and red<=191) and r == round(red*1.15):
            continue
        elif red>191 and r == round(red*1.08):
            continue
        else:
            return False

        if blue< 63 and b== round(blue*0.9) :
            continue
        elif (blue >= 63 and blue<=191) and b == round(blue*0.85):
            continue
        elif blue>191 and b == round(blue*0.93):
            continue
        else:
            return False
    return True