import os
import random
import time
import numpy as np

from pynput import keyboard


class Snake:
    def __init__(self, x_bounds, y_bounds):
        self.x = int((x_bounds[1] - x_bounds[0] + 1)/4)
        self.y = int((y_bounds[1] - y_bounds[0] + 1)/4)
        self.vel = 1

        self.x_bounds = x_bounds
        self.y_bounds = y_bounds

        self.tail = [(self.x, self.y)]
        self.growing = False

    def update(self):
        if self.vel == 1:
            self.x += 1
        elif self.vel == 2:
            self.y += 1
        elif self.vel == 3:
            self.x -= 1
        elif self.vel == 0:
            self.y -= 1

        if self.x > self.x_bounds[1] or self.x < self.x_bounds[0]:
            return 1

        if self.y > self.y_bounds[1] or self.y < self.y_bounds[0]:
            return 1

        self.tail.insert(0, (self.x, self.y))
        if not self.growing:
            self.tail.pop()
        else:
            self.growing = False

        if (self.x, self.y) in self.tail[1:]:
            return 1

        return 0

    def contains(self, x, y):
        return (x, y) in self.tail

    def grow(self):
        self.growing = True


class Food:
    def __init__(self, x_bounds, y_bounds, snake):
        rand_x = snake.x
        rand_y = snake.y
        while (rand_x, rand_y) in snake.tail:
            rand_x = random.randint(x_bounds[0], x_bounds[1])
            rand_y = random.randint(y_bounds[0], y_bounds[1])

        self.x = rand_x
        self.y = rand_y


def on_release(key):
    global paused

    arrows = [keyboard.Key.up, keyboard.Key.right, keyboard.Key.down, keyboard.Key.left]
    if key == keyboard.Key.esc:
        # Stop listener
        return False
    elif key in arrows:
        new_dir = arrows.index(key)

        if (new_dir + 2) % 4 != last_dir:
            snake.vel = new_dir
    elif hasattr(key, 'char') and key.char == 'p':
        paused = not paused


x_bounds = (0, 29)
y_bounds = (0, 14)

# Collect events until released
with keyboard.Listener(
        on_press=None,
        on_release=on_release) as listener:

    snake = Snake(x_bounds, y_bounds)
    food = Food(x_bounds, y_bounds, snake)

    paused = False
    last_dir = 1
    score = 0
    with open("high_score.dat") as f:
        h_score = int(f.read().strip())

    play = True
    while play:
        os.system('cls' if os.name == 'nt' else 'clear')

        if not paused:
            play = (snake.update() == 0)
            last_dir = snake.vel

        score_str = f"Score: {score}"
        hs_str = f"High Score: {h_score}"
        print(score_str + " ".join(['']*(32 - len(score_str) - len(hs_str) + 1)) + hs_str)
        print("_".join([''] * (x_bounds[1] - x_bounds[0] + 4)))
        for i in range((y_bounds[1] - y_bounds[0]) + 1):
            print("|", end="")
            for j in range((x_bounds[1] - x_bounds[0]) + 1):
                pause_start = int(((x_bounds[1] - x_bounds[0]) + 2 - len("Paused"))/2)
                pause_range = range(pause_start, pause_start + len("Paused"))

                over_start = int(((x_bounds[1] - x_bounds[0]) + 2 - len("Game Over")) / 2)
                over_range = range(over_start, over_start + len("Game Over"))

                n_h_s_start = int(((x_bounds[1] - x_bounds[0]) + 2 - len("New High Score!")) / 2)
                n_h_s_range = range(n_h_s_start, n_h_s_start + len("New High Score!"))

                if paused and i == int((y_bounds[1] - y_bounds[0])/2) and j in pause_range:
                    print("Paused"[pause_range.index(j)], end="")
                elif not play and i == int((y_bounds[1] - y_bounds[0])/2) and j in over_range:
                    print("Game Over"[over_range.index(j)], end="")
                elif not play and score == h_score and i == int((y_bounds[1] - y_bounds[0])/2) + 2 and j in n_h_s_range:
                    print("New High Score!"[n_h_s_range.index(j)], end="")
                elif snake.contains(j, i):
                    print(u"\u2588", end="")

                    if food.x == j and food.y == i:
                        snake.grow()
                        food = Food(x_bounds, y_bounds, snake)
                        score += 1

                        if score > h_score:
                            h_score = score

                elif food.x == j and food.y == i:
                    print("o", end="")
                else:
                    print(" ", end="")
            print("|")
        print(u"\u203e".join([''] * (x_bounds[1] - x_bounds[0] + 4)))
        time.sleep(0.1)

    with open("high_score.dat", "w") as f:
        f.write(f"{h_score}\n")

    listener.stop()
    listener.join()