import pygame

pygame.init()

display_width = 1200
display_height = 600

# use python style variable names (lowercase)
screen = pygame.display.set_mode((display_width, display_height))
pygame.display.set_caption('Log In')
clock = pygame.time.Clock()

# load the font only once instead of every frame
font = pygame.font.SysFont('comicsans', 20)


# class name should be singular
def _create_image(color, outline, text, rect):
    # function to create the actual surface
    # see how we can make use of Rect's virtual attributes like 'size'
    img = pygame.Surface(rect.size)
    if outline:
        # here we can make good use of Rect's functions again
        # first, fill the Surface in the outline color
        # then fill a rectangular area in the actual color
        # 'inflate' is used to 'shrink' the rect
        img.fill(outline)
        img.fill(color, rect.inflate(-4, -4))
    else:
        img.fill(color)

    # render the text once here instead of every frame
    if text != '':
        text_surf = font.render(text, 1, pygame.Color('black'))
        # again, see how easy it is to center stuff using Rect's attributes like 'center'
        text_rect = text_surf.get_rect(center=rect.center)
        img.blit(text_surf, text_rect)
    return img


class Button(pygame.sprite.Sprite):
    # 1) no need to have 4 parameters for position and size, use pygame.Rect instead
    # 2) let the Button itself handle which color it is
    # 3) give a callback function to the button so it can handle the click itself
    def __init__(self, color, color_hover, rect, callback, text='', outline=None):
        super().__init__()
        self.text = text
        # a temporary Rect to store the size of the button
        tmp_rect = pygame.Rect(0, 0, *rect.size)

        # create two Surfaces here, one the normal state, and one for the hovering state
        # we create the Surfaces here once, so we can simple blit them and dont have
        # to render the text and outline again every frame
        self.org = _create_image(color, outline, text, tmp_rect)
        self.hov = _create_image(color_hover, outline, text, tmp_rect)

        # in Sprites, the image attribute holds the Surface to be displayed...
        self.image = self.org
        # ...and the rect holds the Rect that defines it position
        self.rect = rect
        self.callback = callback

    def update(self, events):
        # here we handle all the logic of the Button
        pos = pygame.mouse.get_pos()
        hit = self.rect.collidepoint(pos)
        # if the mouse in inside the Rect (again, see how the Rect class
        # does all the calculation for use), use the 'hov' image instead of 'org'
        self.image = self.hov if hit else self.org
        for event in events:
            # the Button checks for events itself.
            # if this Button is clicked, it runs the callback function
            if event.type == pygame.MOUSEBUTTONDOWN and hit:
                self.callback(self)

run = True

# we store all Sprites in a Group, so we can easily
# call the 'update' and 'draw' functions of the Buttons
# in the main loop
sprites = pygame.sprite.Group()
sprites.add(Button(pygame.Color('green'),
                   pygame.Color('red'),
                   pygame.Rect(150, 200, 90, 100),
                   lambda b: print(f"Button '{b.text}' was clicked"),
                   'Press',
                   pygame.Color('black')))

sprites.add(Button(pygame.Color('dodgerblue'),
                   pygame.Color('lightgreen'),
                   pygame.Rect(300, 200, 90, 100),
                   lambda b: print(f"Click me again!"),
                   'Another'))

while run:
    events = pygame.event.get()
    for event in events:
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()

    # update all sprites
    # it now doesn't matter if we have one or 200 Buttons
    sprites.update(events)
    # clear the screen
    screen.fill(pygame.Color('white'))
    # draw all sprites/Buttons
    sprites.draw(screen)
    pygame.display.update()
    # limit framerate to 60 FPS
    clock.tick(60)
