#!/usr/bin/env python
import PySimpleGUI as sg
from PIL import Image
import cv2 as cv
import io

"""
Demo program to open and play a file using OpenCV
It's main purpose is to show you:
1. How to get a frame at a time from a video file using OpenCV
2. How to display an image in a PySimpleGUI Window

For added fun, you can reposition the video using the slider.
"""


def main():
 # ---===--- Get the filename --- #
 filename = sg.popup_get_file('Filename to play')
 if filename is None:
 return
 vidFile = cv.VideoCapture(filename)
 # ---===--- Get some Stats --- #
 num_frames = vidFile.get(cv.CAP_PROP_FRAME_COUNT)
 fps = vidFile.get(cv.CAP_PROP_FPS)

 sg.theme('Black')

 # ---===--- define the window layout --- #
 layout = [[sg.Text('OpenCV Demo', size=(15, 1), font='Helvetica 20')],
 [sg.Image(filename='', key='-image-')],
 [sg.Slider(range=(0, num_frames),
 size=(60, 10), orientation='h', key='-slider-')],
 [sg.Button('Exit', size=(7, 1), pad=((600, 0), 3), font='Helvetica 14')]]

 # create the window and show it without the plot
 window = sg.Window('Demo Application - OpenCV Integration',
 layout,
 no_titlebar=False,
 location=(0, 0))

 # locate the elements we'll be updating. Does the search only 1 time
 image_elem = window['-image-']
 slider_elem = window['-slider-']

 # ---===--- LOOP through video file by frame --- #
 cur_frame = 0
 while vidFile.isOpened():
 event, values = window.read(timeout=0)
 if event in ('Exit', None):
 break
 ret, frame = vidFile.read()
 if not ret: # if out of data stop looping
 break
 # if someone moved the slider manually, the jump to that frame
 if int(values['-slider-']) != cur_frame-1:
 cur_frame = int(values['-slider-'])
 vidFile.set(cv.CAP_PROP_POS_FRAMES, cur_frame)
 slider_elem.update(cur_frame)
 cur_frame += 1

 imgbytes = cv.imencode('.png', frame)[1].tobytes() # ditto
 image_elem.update(data=imgbytes)

 #############
 # | | #
 # | | #
 # |_| #
 # __ __ #
 # \ \ / / #
 # \ V / #
 # \_/ #
""" #############
 # This was another way updates were being done, but seems slower than the above
 img = Image.fromarray(frame) # create PIL image from frame
 bio = io.BytesIO() # a binary memory resident stream
 img.save(bio, format= 'PNG') # save image as png to it
 imgbytes = bio.getvalue() # this can be used by OpenCV hopefully
 image_elem.update(data=imgbytes)
"""

main()