#!/usr/bin/env python

#

#       This program is free software; you can redistribute it and/or modify

#       it under the terms of the GNU General Public License as published by

#       the Free Software Foundation; either version 2 of the License, or

#       (at your option) any later version.

#

#       This program is distributed in the hope that it will be useful,

#       but WITHOUT ANY WARRANTY; without even the implied warranty of

#       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#       GNU General Public License for more details.



import pygame

from pygame.locals import *

from sys import exit

import random



pygame.init()



# Snippet 1

screen=pygame.display.set_mode((640,480),0,32)

pygame.display.set_caption("Pong Pong!")



# Snippet 2: Creating 2 bars, a ball and background.

back = pygame.Surface((640,480))

background = back.convert()

background.fill((0,0,0))

bar = pygame.Surface((10,50))

bar1 = bar.convert()

bar1.fill((0,0,255))

wall = pygame.Surface((11,471))

wall = wall.convert()

wall.fill((0,0,255))





# Snippet 3: Creating ball

circ_sur = pygame.Surface((15,15))

circ = pygame.draw.circle(circ_sur,(0,255,0),(7,7),7)

circle = circ_sur.convert()

circle.set_colorkey((0,0,0))



# some dimsions and start positions

bar1_x, bar1_y = 10., 215.

circle_x, circle_y = 307.5, 232.5

bar1_move = 0.

speed_x, speed_y, speed_circ = 250., 250., 250.



clock = pygame.time.Clock()



while True:



    # Snippet 4: Set keyboard events

    for event in pygame.event.get():

        if event.type == QUIT:

            exit()

        if event.type == KEYDOWN:

            if event.key == K_UP:

                bar1_move = -ai_speed

            elif event.key == K_DOWN:

                bar1_move = ai_speed

        elif event.type == KEYUP:

            if event.key == K_UP:

                bar1_move = 0.

            elif event.key == K_DOWN:

                bar1_move = 0.



    # Snippet 5: 

    screen.blit(background,(0,0))

    frame = pygame.draw.rect(screen,(255,255,255),Rect((5,5),(630,470)),2)

    screen.blit(bar1,(bar1_x,bar1_y))

    screen.blit(wall,(625,5))

    screen.blit(circle,(circle_x,circle_y))



    # Snippet 6:

    bar1_y += bar1_move

    if bar1_y < 10:

        bar1_y = 10

    if bar1_y > 420:

        bar1_y = 420



# movement of ball

    time_passed = clock.tick(30)

    time_sec = time_passed / 1000.0

    circle_x += speed_x * time_sec

    circle_y += speed_y * time_sec

    ai_speed = speed_circ * time_sec





#since we don't know anything about collision, ball hitting bars goes like this.

    if circle_x <= bar1_x + 10.:

        if circle_y >= bar1_y - 7.5 and circle_y <= bar1_y + 42.5:

            circle_x = 20.

            speed_x = -speed_x

    if circle_x < 5.:

        circle_x, circle_y = 320., 232.5

        speed_x = -speed_x

        bar1_y= 215.

    elif circle_x > 608.:

        speed_x = -speed_x

        circle_x = 608.

    if circle_y <= 10.:

        speed_y = -speed_y

        circle_y = 10.

    elif circle_y >= 457.5:

        speed_y = -speed_y

        circle_y = 457.5



    pygame.display.update()