"""Starter code for assignment 6.

AUTHORS:
  - YOUR NAMES HERE
  - Titus Klinge"""

from graphics import *

def display_image(img):

    """Displays the image in a window.

    PARAMETERS:
      img, an Image object

    RETURNS:
      win, the GraphWin object the image is displayed in

    POSTCONDITIONS:
      - A GraphWin window is constructed that is the same dimensions
        as the image.
      - The image is displayed and centered in the window."""

    win = GraphWin("Image Viewer", img.getWidth(), img.getHeight())

    # Below, we set the coordinates so that img is centered
    # in the window so that when drawn it takes up the full
    # space of the window
    anchor = img.getAnchor()
    x, y = anchor.getX(), anchor.getY()
    win.setCoords(x-1, y-1, x+1, y+1)

    img.draw(win)
    return win


def image_transform(img, effect):

    """Creates a new image by applying the given effect to
    every pixel in the given image.

    PARAMETERS:
      img,    an Image object
      effect, a function

    RETURNS:
      new_img, an Image object

    PRECONDITIONS:
      - The "effect" parameter is a function that takes an input
        of the form [r,g,b] and returns an input of the form [r,g,b]

    POSTCONDITIONS:
      - The new_img object returned is an exact copy of img except
        that each pixel = [r,g,b] in the original img is replaced by
        the pixel returned by effect(pixel)"""

    new_img = Image(img.getAnchor(), img.getWidth(), img.getHeight())

    # For each pixel in the old image ...
    for y in range(img.getHeight()):
        for x in range(img.getWidth()):
            pixel = img.getPixel(x, y)

            # Modify the pixel using the given effect and makes sure
            # that each component is within 0 and 255, inclusive
            new_pixel = effect(pixel)
            for i in range(len(new_pixel)):
                if new_pixel[i] < 0:
                    new_pixel[i] = 0
                elif new_pixel[i] > 255:
                    new_pixel[i] = 255
            
            # Converts the pixel into a graphics.py supported format
            new_color = color_rgb(new_pixel[0], new_pixel[1], new_pixel[2])

            # Set the pixel value in the same spot of the new image
            new_img.setPixel(x, y, new_color)

    return new_img