# Snake Game with tutorial

import turtle
import time
import random

delay = 0.1

#score
score = 0
high_score = 0

# Screen Settings.
wn = turtle.Screen()
wn.title("Snake Game by EricMan")
wn.bgcolor("black")
wn.setup(width=600,  height=600)
# Turns off the screen updates
wn.tracer(0)

# Snake Head
head = turtle.Turtle()
head.speed(0)
head.shape("square")
head.color("green")
head.penup()
head.goto(0,0)
head.direction="stop"

# Snake Food
food = turtle.Turtle()
food.speed(0)
food.shape("square")
food.color("lightgreen")
food.penup()
food.goto(0,100)

#Snake body

segments = []

# Pen
pen = turtle.Turtle()
pen.speed(0)
pen.shape("square")
pen.color("white")
pen.penup()
pen.hideturtle()
pen.goto(0,260)
pen.write("Score: 0 High Score: 0", align="center", font=("Courier", 24, "normal"))

# Functions
def go_up():
    if head.direction != "down":
        head.direction = "up"

def go_down():
    if head.direction != "up":
        head.direction = "down"

def go_right():
    if head.direction != "left":
        head.direction = "right"

def go_left():
    if head.direction != "right":
        head.direction = "left"

def move():
    if head.direction == "up":
        y = head.ycor()
        head.sety(y+20)

    if head.direction == "down":
        y = head.ycor()
        head.sety(y-20)

    if head.direction == "right":
        x = head.xcor()
        head.setx(x+20)

    if head.direction == "left":
        x = head.xcor()
        head.setx(x-20)

# Keyboard Bindings
wn.listen()
wn.onkeypress(go_up, "w")
wn.onkeypress(go_down, "s")
wn.onkeypress(go_right, "d")
wn.onkeypress(go_left, "a")

# Main Game Loop
while True:
    wn.update()

    #Border collision check
    if head.xcor()>290 or head.xcor()<-290 or head.ycor()>290 or head.ycor()<-290:
        time.sleep(1)
        head.goto(0,0)
        head.direction = "stop"

        #Snake Death Thing
        for segment in segments:
            segment.goto(1000,1000)

        #clear the segments list
        segments.clear()

        # Reset Score
        score = 0

        pen.clear()
        pen.write("Score: {} High Score: {}". format(score, high_score), align="center", font=("Courier", 24, "normal"))

    # Check for body collision
    for segment in segments:
        if segment.distance(head) < 20:
            time.sleep(1)
            head.goto(0,0)
            head.direction = "stop"

            # Snake Death Thing
            for segment in segments:
                segment.goto(1000, 1000)

            # clear the segments list
            segments.clear()

            # Reset Score
            score = 0

            pen.clear()
            pen.write("Score: {} High Score: {}".format(score, high_score), align="center", font=("Courier", 24, "normal"))

    #Food Collision Check
    if head.distance(food) < 20:
        # Move the food to another random position
        x = random.randint(-290,290)
        y = random.randint(290,290)
        food.goto(x,y)

        #Add Segment
        new_segment = turtle.Turtle()
        new_segment.speed(0)
        new_segment.shape("square")
        new_segment.color("lightgreen")
        new_segment.penup()
        segments.append(new_segment)

        #score increase
        score = score + 10

        if score > high_score:
            high_score = score

        pen.clear()
        pen.write("Score: {} High Score: {}". format(score, high_score), align="center", font=("Courier", 24, "normal"))

    # Move the end segments first in reverse order?
    for index in range(len(segments) -1, 0, -1):
        x = segments[index-1] .xcor()
        y = segments[index-1] .ycor()
        segments[index] .goto(x, y)

    # Move segment 0 to where the head is
    if len(segments) > 0:
        x = head.xcor()
        y = head.ycor()
        segments[0] .goto(x,y)



    move()

    time.sleep(delay)

wn.mainloop()