# Snakey (A Nibbles Clone)
# http://inventwithpython.com/blog
# By Al Sweigart al@inventwithpython.com
# Creative Commons BY-NC-SA license
# 158 lines of code


import random
import time
import pygame
import sys
from pygame.locals import *

FPS = 15
WINDOWWIDTH = 640
WINDOWHEIGHT = 480
CELLSIZE = 20
CELLWIDTH = int(WINDOWWIDTH / CELLSIZE)
CELLHEIGHT = int(WINDOWHEIGHT / CELLSIZE)

WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
DARKGREEN = (0, 155, 0)
DARKGRAY = (40, 40, 40)

BGCOLOR = BLACK

UP = 1
DOWN = 2
LEFT = 3
RIGHT = 4


def main():
    global MAINCLOCK, MAINSURF, BASICFONT

    pygame.init()
    MAINCLOCK = pygame.time.Clock()
    MAINSURF = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT))
    BASICFONT = pygame.font.Font('freesansbold.ttf', 18)
    pygame.display.set_caption('Snakey')

    showStartScreen()
    while True:
        gameLoop()
        showGameOverScreen()


def showStartScreen():
    titleFont = pygame.font.Font('freesansbold.ttf', 100)
    titleSurf1 = titleFont.render('Snakey!', True, WHITE, DARKGREEN)
    titleSurf2 = titleFont.render('Snakey!', True, GREEN)

    pressKeySurf = BASICFONT.render('Press a key to start.', True, DARKGRAY)
    pressKeyRect = pressKeySurf.get_rect()
    pressKeyRect.topleft = (WINDOWWIDTH - 200, WINDOWHEIGHT - 30)

    degrees1 = 0
    degrees2 = 0
    while True:
        MAINSURF.fill(BGCOLOR)
        rotatedSurf1 = pygame.transform.rotate(titleSurf1, degrees1)
        rotatedRect1 = rotatedSurf1.get_rect()
        rotatedRect.center = (WINDOWWIDTH / 2, WINDOWHEIGHT / 2)
        MAINSURF.blit(rotatedSurf1, rotatedRect1)

        rotatedSurf2 = pygame.transform.rotate(titleSurf2, degrees2)
        rotatedRect2 = rotatedSurf2.get_rect()
        rotatedRect2.center = (WINDOWWIDTH / 2, WINDOWHEIGHT / 2)
        MAINSURF.blit(rotatedSurf2, rotatedRect2)

        MAINSURF.blit(pressKeySurf, pressKeyRect)

        if checkForKeyPress():
            return

        pygame.display.update()
        MAINCLOCK.tick(FPS)
        degrees1 += 3
        degrees2 += 7
        if degrees1 > 360:
            degrees1 -= 360
        if degrees2 > 360:
            degrees2 -= 360


def checkForKeyPress():
    for event in pygame.event.get(QUIT):
        terminate()

    for event in pygame.event.get(KEYUP):
        if event.key == K_ESCAPE:
            terminate()
        return event.key


def terminate():
    pygame.quit()
    sys.exit()


def gameLoop():
    startx = random.randint(5, CELLWIDTH - 6)
    starty = random.randint(5, CELLHEIGHT - 6)
    snakeCoords = [(startx, starty), (startx-1, starty)]
    direction = RIGHT
    apple = (random.randint(0, CELLWIDTH - 1), random.randint(0, CELLHEIGHT - 1))
    while True:
        # get player input
        for event in pygame.event.get():
            if event.type == QUIT:
                terminate()
            elif event.type == KEYDOWN:
                if (event.key == K_LEFT or event.key == K_a) and direction != RIGHT:
                    direction = LEFT
                if (event.key == K_RIGHT or event.key == K_d) and direction != LEFT:
                    direction = RIGHT
                if (event.key == K_UP or event.key == K_w) and direction != DOWN:
                    direction = UP
                if (event.key == K_DOWN or event.key == K_s) and direction != UP:
                    direction = DOWN
                if event.key == K_ESCAPE:
                    terminate()

        # check if the snake has hit itself or the edge
        if snakeCoords[0][0] == -1 or snakeCoords[0][0] == CELLWIDTH or snakeCoords[0][1] == -1 or snakeCoords[0][1] == CELLHEIGHT:
            return
        for snakeBody in snakeCoords[1:]:
            if (snakeCoords[0][0], snakeCoords[0][1]) == snakeBody:
                return

        if snakeCoords[0][0] == apple[0] and snakeCoords[0][1] == apple[1]:
            apple = (random.randint(0, CELLWIDTH - 1), random.randint(0, CELLHEIGHT - 1))
        else:
            snakeCoords.pop()

        # move the snake
        if direction == UP:
            snakeCoords.insert(0, (snakeCoords[0][0], snakeCoords[0][1] - 1))
        elif direction == DOWN:
            snakeCoords.insert(0, (snakeCoords[0][0], snakeCoords[0][1] + 1))
        elif direction == LEFT:
            snakeCoords.insert(0, (snakeCoords[0][0] - 1, snakeCoords[0][1]))
        elif direction == RIGHT:
            snakeCoords.insert(0, (snakeCoords[0][0] + 1, snakeCoords[0][1]))

        MAINSURF.fill(BGCOLOR)
        drawSnake(snakeCoords)
        drawApple(apple)
        drawScore(len(snakeCoords))
        pygame.display.update()
        MAINCLOCK.tick(FPS)


def showGameOverScreen():
    gameOverFont = pygame.font.Font('freesansbold.ttf', 150)
    gameSurf = gameOverFont.render('Game', True, WHITE)
    overSurf = gameOverFont.render('Over', True, WHITE)
    gameRect = gameSurf.get_rect()
    overRect = overSurf.get_rect()
    gameRect.midtop = (WINDOWWIDTH / 2, 10)
    overRect.midtop = (WINDOWWIDTH / 2, gameRect.height + 10 + 25)

    MAINSURF.blit(gameSurf, gameRect)
    MAINSURF.blit(overSurf, overRect)
    pygame.display.update()
    time.sleep(0.5)
    checkForKeyPress() # clear out any key presses in the event queue made up to this point

    while True:
        if checkForKeyPress():
            return


def drawScore(score):
    scoreSurf = BASICFONT.render('Score: %s' % (score), True, WHITE)
    scoreRect = scoreSurf.get_rect()
    scoreRect.topleft = (WINDOWWIDTH - 80, 10)
    MAINSURF.blit(scoreSurf, scoreRect)
    """The drawScore() function simply displays the score"""


def drawSnake(snakeCoords):
    for coord in snakeCoords:
        x = coord[0] * CELLSIZE
        y = coord[1] * CELLSIZE
        coordRect = pygame.Rect(x, y, CELLSIZE, CELLSIZE)
        pygame.draw.rect(MAINSURF, GREEN, coordRect)


def drawApple(coord):
    x = coord[0] * CELLSIZE
    y = coord[1] * CELLSIZE
    appleRect = pygame.Rect(x, y, CELLSIZE, CELLSIZE)
    pygame.draw.rect(MAINSURF, RED, appleRect)


if __name__ == '__main__':
    main()