import pygame


def run_game():

    ## Initialize the pygame submodules and set up the display window.

    pygame.init()

    width = 800
    height = 800
    my_win = pygame.display.set_mode((width,height))

    ## Load resources

    player_l = pygame.image.load("worm_left.gif")
    player_l = player_l.convert()
    player_r = pygame.image.load("worm_right.gif")
    player_r = player_r.convert()

    ## Initialize game objects.

    # the player
    x = 0
    y = 0
    xspeed = 0
    yspeed = 0
    w = player_r.get_width()
    h = player_r.get_height()
    player_pic = player_r

    # the obstacle (creating a rectangle at x=200, y=100 with width=200 and height=100) 
    obstacle_rect = pygame.Rect(200, 100, 200, 100)

    clock = pygame.time.Clock()

    ## GAME LOOP starts
    keepGoing = True
    while (keepGoing):

        ## handle events

        for event in pygame.event.get():
            
            if event.type == pygame.QUIT:
                keepGoing = False

            # intercept key presses and use 'wasd' to move the player
            elif event.type == pygame.KEYDOWN:
                key = pygame.key.name(event.key)
                if key == "w":
                    yspeed = -0.2
                elif key == "s":
                    yspeed = 0.2
                elif key == "a":
                    xspeed = -0.2
                elif key == "d":
                    xspeed = 0.2

            # intercept key releases to stop motion appropriately
            elif event.type == pygame.KEYUP:
                key = pygame.key.name(event.key)
                if key == "w" and yspeed < 0:
                    yspeed = 0
                elif key == "s" and yspeed > 0:
                    yspeed = 0
                elif key == "a" and xspeed < 0:
                    xspeed = 0
                elif key == "d" and xspeed > 0:
                    xspeed = 0


        ## update game objects

        dt = clock.tick()
                    
        x = x + xspeed * dt
        y = y + yspeed * dt
        if xspeed > 0:
            player_pic = player_r
        elif xspeed < 0:
            player_pic = player_l
        # otherwise, if xspeed==0 we keep the picture as it is


        # check whether player is colliding with the light green patch
        # if so move player back to beginning

        player_rect = pygame.Rect(x, y, w, h)
        
        if player_rect.colliderect(obstacle_rect): 
            x = 0
            y = 0
            xspeed = 0
            yspeed = 0
            print "Ouch!!!"


        ## draw picture and update display
        
        my_win.fill(pygame.color.Color("darkgreen"))

        pygame.draw.rect(my_win, (0, 255, 0), obstacle_rect)
        
        my_win.blit(player_pic, (x, y))

        pygame.display.update()

    ## GAME LOOP ends

    pygame.quit()


run_game()