# Implementation of classic arcade game Pong

import simplegui
import random

# initialize globals - pos and vel encode vertical info for paddles
WIDTH = 600
HEIGHT = 400       
BALL_RADIUS = 20
PAD_WIDTH = 8
PAD_HEIGHT = 80
HALF_PAD_WIDTH = PAD_WIDTH / 2
HALF_PAD_HEIGHT = PAD_HEIGHT / 2
LEFT = False
RIGHT = True
ball_pos = [0,0]
ball_vel = [0,0]
score1 = 0
score2 = 0
paddle1_pos, paddle2_pos = (HEIGHT - PAD_HEIGHT)/2, (HEIGHT - PAD_HEIGHT)/2
paddle1_vel = paddle2_vel = 0
# initialize ball_pos and ball_vel for new bal in middle of table
# if direction is RIGHT, the ball's velocity is upper right, else upper left
def spawn_ball(direction):
    global ball_pos, ball_vel # these are vectors stored as lists
    ball_pos = [WIDTH / 2 , HEIGHT / 2]
    
    
    if direction:
        ball_vel[0] = -random.randrange(120, 240)/60
        ball_vel[1] = -random.randrange(60, 180)/60
    else:
        ball_vel[0] = random.randrange(120, 240)/60
        ball_vel[1] = random.randrange(60, 180)/60        

# define event handlers
def new_game():
    global paddle1_pos, paddle2_pos, paddle1_vel, paddle2_vel  # these are numbers
    global score1, score2 # these are ints
    score1 = 0
    score2 = 0
    paddle1_vel = 0.
    paddle2_vel = 0.
    spawn_ball(LEFT)

def draw(canvas):
    global score1, score2, paddle1_pos, paddle2_pos, ball_pos, ball_vel, score1, score2
 
        
    # draw mid line and gutters
    canvas.draw_line([WIDTH / 2, 0],[WIDTH / 2, HEIGHT], 1, "White")
    canvas.draw_line([PAD_WIDTH, 0],[PAD_WIDTH, HEIGHT], 1, "White")
    canvas.draw_line([WIDTH - PAD_WIDTH, 0],[WIDTH - PAD_WIDTH, HEIGHT], 1, "White")
        

        #unified code for collision and testing if the ball hits the paddle
    if ball_pos[0] <= (BALL_RADIUS + PAD_WIDTH):
        if (ball_pos[1]<= paddle1_pos + PAD_HEIGHT ) and (ball_pos[1] >= paddle1_pos):
            ball_vel[0] = - 1.1 * ball_vel[0]
        else:
            spawn_ball(RIGHT)
            score2 += 1
    if ball_pos[0] >= (-BALL_RADIUS + WIDTH - PAD_WIDTH):
        if (ball_pos[1]<= paddle2_pos + PAD_HEIGHT) and (ball_pos[1] >= paddle2_pos):
            ball_vel[0] = - 1.1 * ball_vel[0]
        else:
            spawn_ball(LEFT)
            score1 += 1     
      
    #collision conditions top bottom
    if ball_pos[1] <= BALL_RADIUS:
        ball_vel[1] = -ball_vel[1] 
    if ball_pos[1] >= (-BALL_RADIUS + HEIGHT):
        ball_vel[1] = -ball_vel[1]       
    # update ball
    ball_pos[0] = ball_pos[0] + ball_vel[0]
    ball_pos[1] = ball_pos[1] + ball_vel[1]
    
    # draw ball
    canvas.draw_circle(ball_pos, BALL_RADIUS, 0.1, "White", "White")
    

                   
    # update paddle's vertical position, keep paddle on the screen
    if 0 <= (paddle1_pos + paddle1_vel) <= HEIGHT - PAD_HEIGHT:
        paddle1_pos += paddle1_vel
        print("paddle1_pos", paddle1_pos)
    if 0 <= (paddle2_pos + paddle2_vel) <= HEIGHT - PAD_HEIGHT:
        paddle2_pos += paddle2_vel
        print("paddle2_pos", paddle2_pos)
    # draw paddles
    canvas.draw_line([PAD_WIDTH / 2, paddle1_pos], [PAD_WIDTH / 2, PAD_HEIGHT + paddle1_pos], PAD_WIDTH, "White")      
    canvas.draw_line([WIDTH - PAD_WIDTH / 2, paddle2_pos],[WIDTH- PAD_WIDTH / 2, paddle2_pos + PAD_HEIGHT], PAD_WIDTH, "White")
    # determine whether paddle and ball collide    
    
    # draw scores
    canvas.draw_text(str(score1), [250,20], 24, "Red") 
    canvas.draw_text(str(score2), [350,20], 24, "Red")  
def keydown(key):
    global paddle1_vel, paddle2_vel
    if key == simplegui.KEY_MAP["s"]:
        paddle1_vel = 2
    elif key == simplegui.KEY_MAP["w"]:
        paddle1_vel = -2
        
    elif key == simplegui.KEY_MAP["down"]:
        paddle2_vel = 2
    elif key == simplegui.KEY_MAP["up"]:
        paddle2_vel = -2
def keyup(key):
    global paddle1_vel, paddle2_vel
    if key == simplegui.KEY_MAP["s"]:
        paddle1_vel = 0
    elif key == simplegui.KEY_MAP["w"]:
        paddle1_vel = 0
        
    elif key == simplegui.KEY_MAP["up"]:
        paddle2_vel = 0
    elif key == simplegui.KEY_MAP["down"]:
        paddle2_vel = 0


# create frame
frame = simplegui.create_frame("Pong", WIDTH, HEIGHT)
frame.set_draw_handler(draw)
frame.set_keydown_handler(keydown)
frame.set_keyup_handler(keyup)
frame.add_button("restart",new_game, 100)


# start frame
new_game()
frame.start()
