import sys
if sys.version_info[0] >= 3:
  import PySimpleGUI as sg
else:
  import PySimpleGUI27 as sg
import cv2
import numpy as np
from sys import exit as exit

"""
Demo program that displays a webcam using OpenCV and applies some very basic image functions

- functions from top to bottom -
none:       no processing
threshold:  simple b/w-threshold on the luma channel, slider sets the threshold value
canny:      edge finding with canny, sliders set the two threshold values for the function => edge sensitivity
contour:    colour finding in the frame, first slider sets the hue for the colour to find, second the minimum saturation
            for the object. Found objects are drawn with a red contour.
blur:       simple Gaussian blur, slider sets the sigma, i.e. the amount of blur smear
hue:        moves the image hue values by the amount selected on the slider
enhance:    applies local contrast enhancement on the luma channel to make the image fancier - slider controls fanciness.
"""
def main():

  sg.ChangeLookAndFeel('LightGreen')

  # define the window layout
  layout = [[sg.Text('OpenCV Demo', size=(40, 1), justification='center')],
            [sg.Image(filename='', key='image')],
            [sg.Radio('None', 'Radio',  True, size=(10, 1))],
            [sg.Radio('threshold', 'Radio', size=(10, 1),key='thresh'),sg.Slider((0,255),128,1,orientation='h', size=(40, 15),key='thresh_slider')],
            [sg.Radio('canny', 'Radio', size=(10, 1), key='canny'),sg.Slider((0, 255), 128, 1, orientation='h', size=(20, 15), key='canny_slider_a'),sg.Slider((0, 255), 128, 1, orientation='h', size=(20, 15), key='canny_slider_b')],
            [sg.Radio('contour', 'Radio', size=(10, 1), key='contour'),sg.Slider((0, 255), 128, 1, orientation='h', size=(20, 15), key='contour_slider'),sg.Slider((0, 255), 80, 1, orientation='h', size=(20, 15), key='base_slider')],
            [sg.Radio('blur', 'Radio', size=(10, 1),key='blur'),sg.Slider((1,11),1,1,orientation='h', size=(40, 15),key='blur_slider')],
            [sg.Radio('hue', 'Radio', size=(10, 1), key='hue'),sg.Slider((0, 225), 0, 1, orientation='h', size=(40, 15), key='hue_slider')],
            [sg.Radio('enhance', 'Radio', size=(10, 1),key='enhance'),sg.Slider((1,255),128,1,orientation='h', size=(40, 15),key='enhance_slider')],
            [sg.ReadButton('Exit', size=(10, 1))]]

  # create the window and show it without the plot
  window = sg.Window('Demo Application - OpenCV Integration',
                     location=(800,400))
  window.Layout(layout).Finalize()

  cap = cv2.VideoCapture(0)
  while True:
    event, values = window.ReadNonBlocking()
    if event == 'Exit' or values is None:
      sys.exit(0)
    ret, frame = cap.read()
    if values['thresh']:
      frame=cv2.cvtColor(frame,cv2.COLOR_BGR2LAB)[:,:,0]
      _,frame=cv2.threshold(frame,values['thresh_slider'],255,cv2.THRESH_BINARY)
    if values['canny']:
      frame=cv2.Canny(frame,values['canny_slider_a'],values['canny_slider_b'])
    if values['blur']:
      frame=cv2.GaussianBlur(frame,(21,21),values['blur_slider'])
    if values['hue']:
      frame=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
      frame[:,:,0]+=values['hue_slider']
      frame=cv2.cvtColor(frame,cv2.COLOR_HSV2BGR)
    if values['enhance']:
      enh_val=values['enhance_slider']/40
      clahe=cv2.createCLAHE(clipLimit=enh_val, tileGridSize=(8,8))
      lab=cv2.cvtColor(frame,cv2.COLOR_BGR2LAB)
      lab[:,:,0]=clahe.apply(lab[:,:,0])
      frame=cv2.cvtColor(lab,cv2.COLOR_LAB2BGR)
    if values['contour']:
      hue=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
      hue=cv2.GaussianBlur(hue,(21,21),1)
      hue=cv2.inRange(hue,np.array([values['contour_slider'],values['base_slider'],40]),np.array([values['contour_slider']+30,255,220]))
      _,cnts,_=cv2.findContours(hue,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
      cv2.drawContours(frame,cnts,-1,(0,0,255),2)
    imgbytes=cv2.imencode('.png', frame)[1].tobytes() #ditto
    window.FindElement('image').Update(data=imgbytes)

main()