on and off button function

Question

I made two buttons for my program using pygame and OpenCV library and the intended functionality of the two buttons was to turn the camera on or off when the buttons are clicked. The first problem that I ran into was that I got a UnboundLocalError for my camera variable which I don't know where to place anywhere else in my code and the second thing was getting the functionality of the buttons to work correctly which I don't if pygame and OpenCV will correspond correctly with each other.

Here is my code:

import pygame 
import cv2
#import numpy as np

pygame.init()

# setting the width and height of the window
WIDTH, HEIGHT = 1280, 720
WINDOW = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("PANIC")

# background color 
color = ("black") 

# Webcam 
camera = cv2.VideoCapture(0) # 0 is the built in webcam
camera.set(cv2.CAP_PROP_FRAME_WIDTH, 1200) # frame width 
camera.set(cv2.CAP_PROP_FRAME_HEIGHT, 1000) # frame height

# function that will display (draw) stuff 
def draw_window():
    # background color 
    WINDOW.fill((color))
    
    #displaying the webcam 
    success, image = camera.read()
    if success:
        camera_surf = pygame.image.frombuffer(image.tobytes(), image.shape[1::-1], "BGR")
        WINDOW.blit(camera_surf, (0,0))
    
    # Buttons function
    for event in pygame.event.get():
        if event.type == pygame.MOUSEMOTION:
            # 2. put the collide check for mouse hover here for each button
            if b0.rect.collidepoint(pygame.mouse.get_pos()):
                b0.colors = "red on green"
            elif b1.rect.collidepoint(pygame.mouse.get_pos()):
                b1.colors = "red on green"
            else:
                # this will work for every buttons going back to original color after mouse goes out
                not_hover()
        if event.type == pygame.MOUSEBUTTONDOWN:
            # 3. here the interactions with the click of the mouse... done
            if b0.rect.collidepoint(pygame.mouse.get_pos()):
                camera = True
                pygame.display.update()
                print("ON") # print text of button 1
            if b1.rect.collidepoint(pygame.mouse.get_pos()):
                camera = False
                pygame.display.update()
                print("OFF") # prints text of button 2 
                
    buttons.update()
    
    buttons.draw(WINDOW)
    
    # update the display
    pygame.display.update()
    

FPS = 30
def mainWindow():
    # keeping the window open 
    run = True 
    clock = pygame.time.Clock()
    while run: 
        # capping it at the set frame rate 
        clock.tick(FPS)
        
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = False
                        
        draw_window()
        pygame.display.update()
        
    # closing the window 
    pygame.quit()
       
def not_hover():
    for x in buttons:
        x.colors = "red on yellow"
        x.update()

# button class 
buttons = pygame.sprite.Group()
class Button(pygame.sprite.Sprite):
    def __init__(self, WINDOW, position, text, size, colors="white on blue"):
        super().__init__()
        self.colors = colors
        self.fg, self.bg = self.colors.split(" on ")
        self.font = pygame.font.SysFont("Arial", size)
        self.text_render = self.font.render(text, 1, self.fg)
        self.image = self.text_render
        self.x, self.y, self.w , self.h = self.text_render.get_rect()
        self.x, self.y = position
        self.rect = pygame.Rect(self.x, self.y, self.w, self.h)
        self.position = position
        self.update()
        buttons.add(self)

    def update(self):
        self.fg, self.bg = self.colors.split(" on ")
        pygame.draw.line(WINDOW, (150, 150, 150), (self.x, self.y), (self.x + self.w , self.y), 5)
        pygame.draw.line(WINDOW, (150, 150, 150), (self.x, self.y - 2), (self.x, self.y + self.h), 5)
        pygame.draw.line(WINDOW, (50, 50, 50), (self.x, self.y + self.h), (self.x + self.w , self.y + self.h), 5)
        pygame.draw.line(WINDOW, (50, 50, 50), (self.x + self.w , self.y + self.h), [self.x + self.w , self.y], 5)
        pygame.draw.rect(WINDOW, self.bg, (self.x, self.y, self.w , self.h))

b0 = Button(WINDOW, (800, 10), "SWITCH ON", 55, "red on yellow")
b1 = Button(WINDOW, (800, 100), "SWITCH OFF", 55, "red on yellow")


# main #
mainWindow()