# turtle_Space_Invaders.py

# turtle_Space_Invaders.py

import turtle
import os
import math
import random

#Set up the screen wn means window
wn = turtle.Screen()
wn.bgcolor('black')
wn.title('Space Invaders')
#wn.bgpic("space_invaders_background.gif")

#Register the shapes (in order to change their image)
#turtle.register_shape("invader.gif")
#turtle.register_shape("player.gif")

#Draw Border
border_pen = turtle.Turtle()
border_pen.speed(0)
border_pen.color('white')
border_pen.penup()
border_pen.setposition(-300,-300)
border_pen.pendown()
border_pen.pensize(3)
for side in range(4):
    border_pen.fd(600)
    border_pen.lt(90)
border_pen.hideturtle()

#Set the score to 0
score = 0

#Draw the score on screen
score_pen = turtle.Turtle()
score_pen.speed(0)
score_pen.color('white')
score_pen.penup()
score_pen.setposition(-250, 250)
scorestring = "Score: %s" %score
score_pen.write(scorestring, False, align="left", font=("Arial", 24, "normal"))
score_pen.hideturtle()

#Create the player turtle
player = turtle.Turtle()
player.color('blue')
player.shape('triangle')
player.penup()
player.speed(0)
player.setposition(0,-250)
player.setheading(90)

playerspeed = 15 #moves 15 pixels each time left or right

#Choose a number of enemies
number_of_enemies = 9
#Create an empty list of enemies
enemies = []

#Add enemies to the list
for i in range(number_of_enemies):
    #Create the enemy
    enemies.append(turtle.Turtle())

for enemy in enemies:
    enemy.color('red')
    enemy.shape('circle')
    enemy.penup()
    enemy.speed(0)
    x = random.randint(-200, 200)
    y = random.randint(100, 250)
    enemy.setposition(x, y)

enemyspeed = 2

#Create the player's bullet
bullet = turtle.Turtle()
bullet.color('white')
bullet.shape('triangle')
bullet.penup()
bullet.speed(0)
bullet.setheading(90)
bullet.shapesize(0.5, 0.5)
bullet.hideturtle()

bulletspeed = 20

#Define bullet state
#ready - ready to fire
#fire - bullet is firing
bulletstate = 'ready'


#Move the player left and right
def move_left():
    x = player.xcor()
    x -= playerspeed
    if x < -280:
        x = -280
    player.setx(x)

def move_right():
    x = player.xcor()
    x += playerspeed
    if x > 280:
        x = 280
    player.setx(x)


def fire_bullet():
    #Declare bulletstate as a global if it needs changed
    global bulletstate #means any change to bullet in code affects rest of code
    if bulletstate == 'ready':
        #os.system("afplay laser.wav&")
        bulletstate = 'fire'
        #Move the bullet to just above the player
        x = player.xcor()
        y = player.ycor() +10
        bullet.setposition(x, y)
        bullet.showturtle()

def isCollision(t1, t2):
    distance = math.sqrt(math.pow(t1.xcor()-t2.xcor(),2)+math.pow(t1.ycor()-t2.ycor(),2))
    if distance < 15:
        return True
    else:
        return False
#Create keyboard bindings
turtle.listen()
turtle.onkey(move_left, 'Left')
turtle.onkey(move_right, 'Right')
turtle.onkey(fire_bullet, 'space')

#Main game loop
loop = True
while loop:
    for enemy in enemies:
        #Move the enemy
        x = enemy.xcor()
        x += enemyspeed
        enemy.setx(x)

        #Move the enemy back and down
        if enemy.xcor() > 280:
            #Moves all enemies down
            for e in enemies:
                y = e.ycor()
                y -= 40
                e.sety(y)
            #Change enemy direction
            enemyspeed *= -1

        if enemy.xcor() < -280:
            #Move all enemies down
            for e in enemies:
                y = e.ycor()
                y -= 40
                e.sety(y)
            #Change enemy direction
            enemyspeed *= -1

    if enemy.ycor()-40 < player.ycor():
        player.hideturtle()
        enemy.hideturtle
        print('Game Over')
        loop = False

    #Check for a collision between the bullet and the enemy
    elif isCollision(bullet, enemy):
        #os.system("afplay explosion.wav&")
        #Reset the bullet
        bullet.hideturtle()
        bulletstate = 'ready'
        bullet.setposition(0, -400)
        #Reset the enemy
        x = random.randint(-200, 200)
        y = random.randint(100, 250)
        enemy.setposition(x, y)
        #Update the score
        score += 10
        scorestring = 'Score: %s' %score
        score_pen.clear()
        score_pen.write(scorestring, False, align="left", font=("Arial", 14, "normal"))

    #Move the bullet
    if bulletstate == 'fire':
        y = bullet.ycor()
        y += bulletspeed
        bullet.sety(y)

    #Check to see if the bullet has reached the top
    if bullet.ycor() > 275:
        bullet.hideturtle()
        bulletstate = 'ready'

turtle.done()