import turtle
import os

# Create window
win = turtle.Screen()
win.bgcolor("black")
win.title("Space Invader")


# 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 line in range (4):
    border_pen.fd(600)
    border_pen.rt(90)
border_pen.hideturtle()


# Create main player turtle
player = turtle.Turtle()
player.color("blue")
player.shape("triangle")
player.penup()
player.speed(0)
player.setposition(0, -200)
player.setheading(90)


# Enemy
enemy = turtle.Turtle()
enemy.color("red")
enemy.shape("circle")
enemy.penup()
enemy.speed(0)
enemy.setposition(-200, 250)


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


# Variables
player_speed = 15
enemy_speed = 1.5
bullet_speed = 5

'''
Define bullet state
ready - ready to fire
fire - bullet is firing
'''
bullet_state = "ready"


# Player moving left/right
def move_left():
    left_x = player.xcor()
    left_x -= player_speed
    if left_x < -335:
        player.setx(-335)
    player.setx(left_x)


def move_right():
    right_x = player.xcor()
    right_x += player_speed
    if right_x > 335:
        player.setx(335)
    player.setx(right_x)


# Player shoots bullet
def shoot_bullet():
    global bullet_state

    bullet_x = player.xcor()
    bullet_y = player.ycor()
    bullet_y += bullet_speed
    bullet.setposition(bullet_x, bullet_y)
    bullet.showturtle()


# Create keyboard binding
win.listen()
win.onkeypress(move_left, "Left")
win.onkeypress(move_right, "Right")
win.onkeypress(shoot_bullet, "space")


# Move the enemy
while True:
    x = enemy.xcor()
    x += enemy_speed
    enemy.setx(x)

    if enemy.xcor() > 290:
        y = enemy.ycor()
        y -= 40
        enemy_speed *= -1
        enemy.sety(y)

    if enemy.xcor() < -290:
        y = enemy.ycor()
        y -= 40
        enemy_speed *= -1
        enemy.sety(y)


# Main game loop
win.mainloop()