from picamera2 import Picamera2
from gpiozero import LED
import cv2
import os


camera = Picamera2()

led = LED(17)
off = True
on_time = 100
time_left = 0

preview_config = camera.create_preview_configuration(main={'size': (640, 480)})

camera.configure(preview_config)
camera.start()

if not os.path.exists("haarcascade_frontalface_default.xml"):
    import urllib.request
    url = "https://raw.githubusercontent.com/opencv/opencv/master/data/haarcascades/haarcascade_frontalface_default.xml"
    urllib.request.urlretrieve(url, "haarcascade_frontalface_default.xml")


face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

while(1):
    frame = camera.capture_array()
    frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
    gray = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY)
    faces = face_cascade.detectMultiScale(gray, 1.3, 5)
    for (x, y, w, h) in faces:
        cv2.rectangle(frame, (x, y), (x+w, y+h), (255, 0, 0), 2)

    try:
        if faces[0][0] > 0 :
            off = False
            time_left = on_time
    except:
        off = True
        
    if not off or time_left > 0:
        led.on()
        time_left = time_left - 1
    else:
        led.off()
        time_left = 0

    print(time_left)

    cv2.imshow("Real-Time Face Detection", frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    
cv2.destroyAllWindows()