from imutils.video import VideoStream

import argparse
import datetime
import imutils
import time
import cv2

ap = argparse.ArgumentParser()
ap.add_argument('-v', '--video', help="Path to the video file")
ap.add_argument('-a', '--min-area', type=int, default=500, help="Minimum area size")
args = vars(ap.parse_args())

if args.get('video', None) is None:
    vs = VideoStream(src=0).start()
    time.sleep(0.2)
else:
    vs = cv2.VideoCapture(args['video'])

first_frame = None
while True:
    frame = vs.read()
    frame = frame if args.get('video', None) is None else frame[1]
    text = "No motion"

    if frame is None:
        break
    
    frame = imutils.resize(frame, width=500)
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    gray = cv2.GaussianBlur(gray, (21, 21), 0)

    if first_frame is None:
        first_frame = gray
        continue

    frame_delta = cv2.absdiff(first_frame, gray)
    thresh = cv2.threshold(frame_delta, 25, 255, cv2.THRESH_BINARY)[1]

    thresh = cv2.dilate(thresh, None, iterations=2)
    cnts = cv2.findContours(thresh.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    cnts = imutils.grab_contours(cnts)

    for c in cnts:
        if cv2.contourArea(c) < args.get('min-area', 500):
            continue

        (x, y, w, h) = cv2.boundingRect(c)
        cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), thickness=2)
        text = "Motion is detected"
    
    cv2.putText(frame, "Motion status: {}".format(text), (10, 20), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), thickness=2)
    cv2.putText(frame, datetime.datetime.now().strftime('%A %d %B %Y %I:%M%S%p'), (10, frame.shape[0]-10), cv2.FONT_HERSHEY_SIMPLEX, 0.35, (0, 0, 255), thickness=1)

    cv2.imshow("Video feed", frame)
    cv2.imshow("Thresh", thresh)
    cv2.imshow("Frame delta", frame_delta)

    key = cv2.waitKey(1) & 0xFF
    if key == ord('q'):
        break

vs.stop() if args.get('video', None) is None else vs.release()
cv2.destroyAllWindows()
