# U08_Ex14_Grayscale.py
#
#  Author: Joseph Cloud
#  Course: Coding for OOP
# Section: A3
#    Date: 15 Dec 2017
#     IDE: PyCharm Community Edition
#
# Assignment Info
#   Exercise: 14
#     Source: Python Programming
#    Chapter: 8
#
# Program Description
# Converts a user entered image to grayscale
# Algorithm (pseudocode)
# Create the window
# Introduction (wait for click to undraw)
# Get filename from user
# Display the image
# Wait for the user to click
# For each row in the image
#   For each column in the image
#       Set rgb values to rgb values of current pixel converted to grayscale
#       Set the current pixels color to new rgb values
# Draw new image
# Prompt the user for a filename to save the grayscale image as

from graphics import *
from tkinter.filedialog import askopenfilename

def main():
    # Create the window
    window = GraphWin('Grayscale', 500, 500)
    # Introduction (wait for click to undraw)
    intro = Text(Point(250, 250), 'This Program Converts an Image to Grayscale (Click to Continue)')
    intro.draw(window)
    window.getMouse()
    intro.undraw()
    # Get filename from user
    fileName = askopenfilename()
    # Display the image
    pic = Image(Point(250, 250), fileName)
    pic.draw(window)
    # Wait for the user to click
    window.getMouse()
    # For each row in the image
    for y in range(pic.getHeight()):
        # For each column in the image
        for x in range(pic.getWidth()):
            # Set rgb values to rgb values of current pixel converted to grayscale
            r, g, b = pic.getPixel(x, y)
            brightness = int(round(.299 * r + .587 * g + .114 * b))
            # Set the current pixels color to new rgb values
            pic.setPixel(x, y, color_rgb(brightness, brightness, brightness))
    # Draw new image
    pic.undraw()
    pic.draw(window)
    window.getMouse()
    # Prompt the user for a filename to save the grayscale image as
    backdrop = Rectangle(Point(40, 220), Point(460, 160))
    backdrop.setFill('white')
    backdrop.setOutline('black')
    backdrop.draw(window)
    Text(Point(250, 175), 'Enter a filename to save this new image as').draw(window)
    newfilename = Entry(Point(250, 200), 40)
    newfilename.draw(window)
    window.getMouse()
    pic.save(newfilename.getText() + '.gif')


if __name__ == '__main__':
    main()