from tkinter import *
import random

live = 0
seg = 0

# Globals
WIDTH = 800
HEIGHT = 600
SEG_SIZE = 20
IN_GAME = True


def esc():
    pass


def restart():
    global IN_GAME
    IN_GAME = False
    s.move()
    head_coords = c.coords(s.segments[-1].instance)
    x1, y1, x2, y2 = head_coords
    # Check for collision with gamefield edges
    if x2 > WIDTH - SEG_SIZE or x1 < 0 + SEG_SIZE or y1 < 0 + SEG_SIZE or y2 > HEIGHT - SEG_SIZE:
        IN_GAME = False

        c.create_text((WIDTH / 2) - SEG_SIZE / 8, ((HEIGHT / 2) - (HEIGHT / 4)) + SEG_SIZE * 2,
                      text="Вы наплыли на берег",
                      font="Arial 15",
                      fill="red")
    IN_GAME = True


# Helper functions
def create_block():
    """ Creates an apple to be eaten """
    global BLOCK
    posx = SEG_SIZE * random.randint(1, (WIDTH-SEG_SIZE-SEG_SIZE) / SEG_SIZE)
    posy = SEG_SIZE * random.randint(1, (HEIGHT-SEG_SIZE - SEG_SIZE) / SEG_SIZE)
    BLOCK = c.create_oval(posx, posy,
                          posx+SEG_SIZE, posy+SEG_SIZE,
                          fill="red", outline = "red")


def main():
    """ Handles game process """
    global live
    global IN_GAME
    if IN_GAME:
        s.move()
        head_coords = c.coords(s.segments[-1].instance)
        x1, y1, x2, y2 = head_coords
        # Check for collision with gamefield edges
        if x2 > WIDTH - SEG_SIZE or x1 < 0 + SEG_SIZE or y1 < 0 + SEG_SIZE or y2 > HEIGHT - SEG_SIZE:
            IN_GAME = False

            c.create_text((WIDTH / 2) - SEG_SIZE / 8, ((HEIGHT / 2) - (HEIGHT / 4)) + SEG_SIZE * 2,
                          text="Вы наплыли на берег",
                          font="Arial 15",
                          fill="red")

        # Eating apples
        elif head_coords == c.coords(BLOCK):
            s.add_segment()
            c.delete(BLOCK)
            create_block()
        # Self-eating
        else:
            for index in range(len(s.segments)-1):
                if head_coords == c.coords(s.segments[index].instance):
                    live = live + 1

                    if live == 1:
                        c.delete(live3)
                    elif live == 2:
                        c.delete(live2)
                    elif live == 3:
                        c.delete(live1)

                    if live == 3:
                        IN_GAME = False



                        c.create_text((WIDTH / 2) - SEG_SIZE / 8, ((HEIGHT / 2) - (HEIGHT / 4)) + SEG_SIZE * 2,
                                      text="Вы потратили все жизни, съев себя",
                                      font="Arial 15",
                                      fill="red")

        root.after(100, main)
    # Not IN_GAME -> stop game and print message
    else:
        c.create_text(WIDTH/2, (HEIGHT/2) - (HEIGHT/4),
                      text="GAME OVER!",
                      font="Arial 20",
                      fill="red")



class Segment(object):
    """ Single snake segment """
    def __init__(self, x, y):
        self.instance = c.create_rectangle(x, y,
                                           x+SEG_SIZE, y+SEG_SIZE,
                                           fill="#000099", outline = '#000099')


class Snake(object):
    """ Simple Snake class """
    def __init__(self, segments):
        self.segments = segments
        # possible moves
        self.mapping = {"Down": (0, 1), "Right": (1, 0),
                        "Up": (0, -1), "Left": (-1, 0)}
        # initial movement direction
        self.vector = self.mapping["Right"]

    def move(self):
        """ Moves the snake with the specified vector"""
        for index in range(len(self.segments)-1):
            segment = self.segments[index].instance
            x1, y1, x2, y2 = c.coords(self.segments[index+1].instance)
            c.coords(segment, x1, y1, x2, y2)

        x1, y1, x2, y2 = c.coords(self.segments[-2].instance)
        c.coords(self.segments[-1].instance,
                 x1+self.vector[0]*SEG_SIZE, y1+self.vector[1]*SEG_SIZE,
                 x2+self.vector[0]*SEG_SIZE, y2+self.vector[1]*SEG_SIZE)

    def add_segment(self):
        global seg
        """ Adds segment to the snake """
        last_seg = c.coords(self.segments[0].instance)
        x = last_seg[2] - SEG_SIZE
        y = last_seg[3] - SEG_SIZE
        self.segments.insert(0, Segment(x, y))
        seg = seg + 1

    def change_direction(self, event):
        """ Changes direction of snake """
        if event.keysym in self.mapping:
            self.vector = self.mapping[event.keysym]

# Setting up window
root = Tk()
root.title("Акула")


c = Canvas(root, width=WIDTH, height=HEIGHT, bg="#00ccff")
c.pack()
# catch keypressing
c.focus_set()
# creating segments and snake
segments = [Segment(SEG_SIZE, SEG_SIZE),
            Segment(SEG_SIZE*2, SEG_SIZE),
            Segment(SEG_SIZE*3, SEG_SIZE)]
s = Snake(segments)
# Reaction on keypress
c.bind("<KeyPress>", s.change_direction)

c.create_rectangle(0, 0, SEG_SIZE, HEIGHT, fill = '#ffcc66', outline = '#ffcc66')
c.create_rectangle(0, 0, WIDTH, SEG_SIZE, fill = '#ffcc66', outline = '#ffcc66')
c.create_rectangle(WIDTH, 0, WIDTH - SEG_SIZE, HEIGHT, fill = '#ffcc66', outline = '#ffcc66')
c.create_rectangle(0, HEIGHT, WIDTH, HEIGHT - SEG_SIZE, fill = '#ffcc66', outline = '#ffcc66')

live1 = c.create_oval(20, 0, 40, 20, fill = "red", outline = "red")
live2 = c.create_oval(60, 0, 80, 20, fill = "red", outline = "red")
live3 = c.create_oval(100, 0, 120, 20, fill = "red", outline = "red")

button = Button(root, width = 10, height = 3, text = "RESTART")
button.config(command = restart)
button.pack()

text = Text()

create_block()
main()
root.mainloop()