import cv2 
import numpy as np 
import matplotlib.pyplot as plt 

def region_of_interest(img, vertices):
    mask = np.zeros_like(img)
    #channel_count = img.shape[2]
    match_mask_color = 255
    cv2.fillPoly(mask, vertices, match_mask_color)
    masked_image = cv2.bitwise_and(img, mask)
    #cv2.imshow("mask", masked_image)
    return masked_image

def draw_the_lines(img, lines):
    img = np.copy(img)
    blank_image = np.zeros((img.shape[0], img.shape[1], 3), np.uint8)

    for line in lines:
        for x1, y1, x2, y2 in line:
            cv2.line(blank_image, (x1, y1), (x2,y2), (0,255,0), thickness=3)
    
    img = cv2.addWeighted(img, 0.8, blank_image, 1, 0.0)
    return img



def process(image):
    #print(image.shape)
    height = image.shape[0]
    width = image.shape[1]

    ROI_verties = [
        #(0,height),
        #(width/2 +50, height/2 +100 ),
        #(width-50, height)

        (0,0),
        (0,height),
        (width,0),
        (width, height)

    ]

    gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    canny_image = cv2.Canny(gray_image, 100, 200)


    cropped_image = region_of_interest(canny_image, np.array([ROI_verties], np.int32))
    lines = cv2.HoughLinesP(cropped_image,
                            rho =2,
                            theta = np.pi/180,
                            threshold = 50,
                            lines=np.array([]),
                            minLineLength=40,
                            maxLineGap=25)
                    
    image_with_lines = draw_the_lines(image, lines)
    return image_with_lines
    #cv2.imshow("frame",image_with_lines)
    #cv2.waitKey(0)
    #cv2.destroyAllWindows()

cap = cv2.VideoCapture("vtest.avi")

while cap.isOpened():
    ret, frame = cap.read()

    frame = process(frame)
    cv2.imshow("frame",frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()
#image = cv2.imread('road1.jpg')
#process(image)
