# Bruce A. Maxwell
# January 2015
#
# Updated January 2022 by Bruce Maxwell for Python 3
#
# Pygame Tutorial Example 2
#
# Creates a scene with a spider and lets the broom follow the mouse.
#

####################### Setup #########################
# useful imports
import sys

# import pygame
import pygame

# initialize pygame
pygame.init()

# initialize the fonts
try:
    pygame.font.init()
except:
    print( "Fonts unavailable" )
    sys.exit()

# create a game clock
gameClock = pygame.time.Clock()


# create a screen (width, height)
screen = pygame.display.set_mode( (640, 480) )

####################### Making Content #########################

# load some images
spider = pygame.image.load( "Spider.png" ).convert_alpha()
broom = pygame.image.load( "Broom.png" ).convert_alpha()

# create a font
afont = pygame.font.SysFont( "Helvetica", 20, bold=True )

# render a surface with some text
text = afont.render( "Clean up time", True, (0, 0, 0) )


####################### Filling the Screen #########################

# A function that draws all of the static background elements
def drawBkg(screen, text, refresh, rect=None):
    # clear the screen with white
    if rect == None:
        screen.fill( (255, 255, 255) )

        # blit the text surface onto the screen
        screen.blit( text, (10, 10) )

        refresh.append( screen.get_rect() )
    else:
        screen.fill( (255, 255, 255), rect )

        # blit the text surface onto the screen if it is inside the rectangle
        screen.fill( (255, 255, 255), text.get_rect().move(10, 10).clip( rect ) )

        trect = text.get_rect().move(10, 10) # rectangle in which to
                                             # draw the text
                                             
        clippedRect = trect.clip( rect ) # intersection of the text
                                         # screen rectangle and the
                                         # area to update

        # blit the text into the area to update, the second rectangle
        # indicates which part of the text to use
        urect = screen.blit( text, clippedRect, clippedRect.move(-10,-10) )

        # refresh the rectangle
        refresh.append( rect )


############## Setting up the Broom as a sprite ################

# get the current mouse information, and make the cursor invisible if
# it is focused on the game window
pygame.event.pump()
if pygame.mouse.get_focused():
    pygame.mouse.set_visible(False)

# get the mouse position and put the broom so it is centered on the
# mouse location
tpos = pygame.mouse.get_pos()
trect = broom.get_rect()
broomRect = broom.get_rect().move( tpos[0] - trect.width/2, tpos[1] - trect.height/2 )

# blit the broom to the screen and update the display
screen.blit( broom, broomRect )

####################### Main Event Loop #########################
# set up the refresh rectangle container
refresh = []
drawBkg( screen, text, refresh )

# update the display before we start the main loop
pygame.display.update()

# reset the broom rectangle to position (0, 0) until it gets set to the mouse position in the loop
broomRect = pygame.Rect( 0, 0, broomRect.width, broomRect.height )

# respond to mouse motion events until someone clicks a mouse or hits a key
print( "Entering main loop" )
while 1:

    # handle events and erase things
    for event in pygame.event.get():
        if event.type == pygame.MOUSEMOTION:
            # erase the existing broom
            print(broomRect)
            drawBkg( screen, text, refresh, broomRect )
            
        if event.type == pygame.MOUSEBUTTONDOWN:
            sys.exit()

        if event.type == pygame.KEYDOWN:
            sys.exit()

        if event.type == pygame.QUIT:
            sys.exit()

    # draw a spider in the middle of the screen
    spiderRect = spider.get_rect().move( 320-spider.get_rect().width/2, 240 - spider.get_rect().height/2 )
    screen.fill( (255, 255, 255), spiderRect  )
    urect = screen.blit( spider, spiderRect )
    refresh.append(spiderRect)
    
    # always update the spider
    refresh.append( urect )

    # If the game is in focus, draw things
    if pygame.mouse.get_focused():
        pygame.mouse.set_visible(False)
        tpos = pygame.mouse.get_pos()

        # update the position of the cursor
        broomRect = pygame.Rect( (tpos[0] - broomRect.width/2, tpos[1] - broomRect.height/2),
                                  (broomRect.width, broomRect.height) )

        # draw the broom in the location of the mouse
        screen.blit( broom, broomRect )

        # add to the refresh list
        refresh.append( broomRect )
    else:
        pygame.mouse.set_visible(True)


    # update the parts of the screen that need it
    pygame.display.update( refresh )

    # clear out the refresh rects
    refresh = []

    # throttle the game speed to 30fps
    gameClock.tick(30)
        
# done
print( "Terminating" )