import pygame
import sys
import random
import math
from pygame.math import Vector2

pygame.init()

CELL_SIZE = 30
GRID_WIDTH = 20
GRID_HEIGHT = 15
SCREEN_WIDTH = CELL_SIZE * GRID_WIDTH
SCREEN_HEIGHT = CELL_SIZE * GRID_HEIGHT
FPS = 60

BACKGROUND = (15, 15, 30)
GRID_COLOR = (30, 30, 50)
SNAKE_HEAD = (50, 205, 50)
SNAKE_BODY = (40, 180, 40)
FOOD_COLOR = (220, 60, 60)
TEXT_COLOR = (220, 220, 220)
UI_BACKGROUND = (20, 20, 40, 200)
UI_BORDER = (70, 130, 200)

screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
pygame.display.set_caption("Python貪吃蛇")
clock = pygame.time.Clock()

try:
font_large = pygame.font.Font(None, 48)
font_medium = pygame.font.Font(None, 36)
font_small = pygame.font.Font(None, 28)
except:

font_large = pygame.font.SysFont(None, 48)
font_medium = pygame.font.SysFont(None, 36)
font_small = pygame.font.SysFont(None, 28)

class Snake:
def init(self):
self.reset()

def reset(self):
    
    self.body = [Vector2(5, 7), Vector2(4, 7), Vector2(3, 7)]
    self.direction = Vector2(1, 0)
    self.new_direction = Vector2(1, 0)
    self.grow = False
    self.speed = 8  
    self.move_counter = 0
    
def update(self):
    
    if self.new_direction != -self.direction:
        self.direction = self.new_direction
    
    
    self.move_counter += self.speed / FPS
    if self.move_counter >= 1:
        self.move_counter -= 1
        
        
        head = self.body[0] + self.direction
        self.body.insert(0, head)
        
        if not self.grow:
            self.body.pop()
        else:
            self.grow = False
            
def draw(self, surface):
    
    for i, segment in enumerate(self.body):
        
        if i == 0:
            color = SNAKE_HEAD
        
        else:
            color = SNAKE_BODY
        
        
        rect = pygame.Rect(segment.x * CELL_SIZE, segment.y * CELL_SIZE, CELL_SIZE, CELL_SIZE)
        pygame.draw.rect(surface, color, rect, 0, 7)
        
        
        if i > 0:
            prev = self.body[i-1]
            
            if prev.x == segment.x:  
                if prev.y < segment.y:  
                    pygame.draw.rect(surface, color, 
                                   (segment.x * CELL_SIZE + 3, 
                                    segment.y * CELL_SIZE - 3, 
                                    CELL_SIZE - 6, 6))
                else:  
                    pygame.draw.rect(surface, color, 
                                   (segment.x * CELL_SIZE + 3, 
                                    segment.y * CELL_SIZE + CELL_SIZE - 3, 
                                    CELL_SIZE - 6, 6))
            else:  
                if prev.x < segment.x:  
                    pygame.draw.rect(surface, color, 
                                   (segment.x * CELL_SIZE - 3, 
                                    segment.y * CELL_SIZE + 3, 
                                    6, CELL_SIZE - 6))
                else:  
                    pygame.draw.rect(surface, color, 
                                   (segment.x * CELL_SIZE + CELL_SIZE - 3, 
                                    segment.y * CELL_SIZE + 3, 
                                    6, CELL_SIZE - 6))
    
    
    eye_size = CELL_SIZE // 5
    
    if self.direction == Vector2(1, 0):  
        left_eye = (self.body[0].x * CELL_SIZE + CELL_SIZE - eye_size - 2, 
                    self.body[0].y * CELL_SIZE + eye_size + 2)
        right_eye = (self.body[0].x * CELL_SIZE + CELL_SIZE - eye_size - 2, 
                     self.body[0].y * CELL_SIZE + CELL_SIZE - eye_size*2 - 2)
    elif self.direction == Vector2(-1, 0):  
        left_eye = (self.body[0].x * CELL_SIZE + 2, 
                    self.body[0].y * CELL_SIZE + eye_size + 2)
        right_eye = (self.body[0].x * CELL_SIZE + 2, 
                     self.body[0].y * CELL_SIZE + CELL_SIZE - eye_size*2 - 2)
    elif self.direction == Vector2(0, 1):  
        left_eye = (self.body[0].x * CELL_SIZE + eye_size + 2, 
                    self.body[0].y * CELL_SIZE + CELL_SIZE - eye_size - 2)
        right_eye = (self.body[0].x * CELL_SIZE + CELL_SIZE - eye_size*2 - 2, 
                     self.body[0].y * CELL_SIZE + CELL_SIZE - eye_size - 2)
    else:  
        left_eye = (self.body[0].x * CELL_SIZE + eye_size + 2, 
                    self.body[0].y * CELL_SIZE + 2)
        right_eye = (self.body[0].x * CELL_SIZE + CELL_SIZE - eye_size*2 - 2, 
                     self.body[0].y * CELL_SIZE + 2)
    
    pygame.draw.circle(surface, (0, 0, 0), left_eye, eye_size)
    pygame.draw.circle(surface, (0, 0, 0), right_eye, eye_size)

class Food:
def init(self, snake):
self.position = self.generate_position(snake)

def generate_position(self, snake):
    
    while True:
        x = random.randint(0, GRID_WIDTH - 1)
        y = random.randint(0, GRID_HEIGHT - 1)
        position = Vector2(x, y)
        
        if position not in snake.body:
            return position
            
def draw(self, surface):
    
    center = (self.position.x * CELL_SIZE + CELL_SIZE // 2,
              self.position.y * CELL_SIZE + CELL_SIZE // 2)
    radius = CELL_SIZE // 2 - 2
    
    
    pygame.draw.circle(surface, FOOD_COLOR, center, radius)
    
  
    leaf_points = [
        (center[0] - radius//2, center[1] - radius),
        (center[0] + radius//2, center[1] - radius),
        (center[0], center[1] - radius - radius//2)
    ]
    pygame.draw.polygon(surface, (50, 180, 50), leaf_points)
    
    
    pygame.draw.line(surface, (100, 70, 30), 
                     (center[0], center[1] - radius),
                     (center[0], center[1] - radius - radius//3), 2)

class Game:
def init(self):
self.snake = Snake()
self.food = Food(self.snake)
self.score = 0
self.game_over = False
self.paused = False
self.special_food_timer = 0
self.special_food = None
self.special_food_active = False

def update(self):
    if self.game_over or self.paused:
        return
        
    self.snake.update()
    
    
    if self.snake.body[0] == self.food.position:
        self.snake.grow = True
        self.food = Food(self.snake)
        self.score += 10
        
       
        if random.random() < 0.3 and self.snake.speed < 15:
            self.snake.speed += 0.5
    
    
    head = self.snake.body[0]
    if (head.x < 0 or head.x >= GRID_WIDTH or 
        head.y < 0 or head.y >= GRID_HEIGHT or 
        head in self.snake.body[1:]):
        self.game_over = True
        
    
    if self.special_food_active:
        self.special_food_timer -= 1
        if self.special_food_timer <= 0:
            self.special_food_active = False
            
        if self.snake.body[0] == self.special_food:
            self.snake.grow = True
            self.special_food_active = False
            self.score += 30
            
   
    if not self.special_food_active and random.random() < 0.005:
        self.special_food = Food(self.snake).position
        self.special_food_active = True
        self.special_food_timer = FPS * 5  
def draw(self, surface):
    
    for x in range(GRID_WIDTH):
        for y in range(GRID_HEIGHT):
            rect = pygame.Rect(x * CELL_SIZE, y * CELL_SIZE, CELL_SIZE, CELL_SIZE)
            pygame.draw.rect(surface, GRID_COLOR, rect, 1)

    
    self.food.draw(surface)
    
    
    if self.special_food_active:
        center = (self.special_food.x * CELL_SIZE + CELL_SIZE // 2,
                  self.special_food.y * CELL_SIZE + CELL_SIZE // 2)
        radius = CELL_SIZE // 3
        
        
        if pygame.time.get_ticks() % 500 < 250:
            pygame.draw.circle(surface, (255, 215, 0), center, radius)
            pygame.draw.circle(surface, (255, 255, 100), center, radius - 2)
    
    
    self.snake.draw(surface)
    
    
    score_text = font_medium.render(f"分數: {self.score}", True, TEXT_COLOR)
    surface.blit(score_text, (10, 10))
    
    
    speed_text = font_small.render(f"速度: {self.snake.speed:.1f}", True, TEXT_COLOR)
    surface.blit(speed_text, (SCREEN_WIDTH - 120, 10))
    
    
    if self.game_over:
        self.draw_game_over(surface)
        
    
    if self.paused:
        self.draw_paused(surface)

def draw_game_over(self, surface):
    
    overlay = pygame.Surface((SCREEN_WIDTH, SCREEN_HEIGHT), pygame.SRCALPHA)
    overlay.fill((0, 0, 0, 180))
    surface.blit(overlay, (0, 0))
    
    
    game_over_text = font_large.render("游戲結束!", True, (220, 60, 60))
    score_text = font_medium.render(f"最終分數: {self.score}", True, TEXT_COLOR)
    restart_text = font_small.render("按R鍵重新開始", True, TEXT_COLOR)
    
    surface.blit(game_over_text, (SCREEN_WIDTH//2 - game_over_text.get_width()//2, 
                                 SCREEN_HEIGHT//2 - 60))
    surface.blit(score_text, (SCREEN_WIDTH//2 - score_text.get_width()//2, 
                             SCREEN_HEIGHT//2))
    surface.blit(restart_text, (SCREEN_WIDTH//2 - restart_text.get_width()//2, 
                              SCREEN_HEIGHT//2 + 50))

def draw_paused(self, surface):
    
    overlay = pygame.Surface((SCREEN_WIDTH, SCREEN_HEIGHT), pygame.SRCALPHA)
    overlay.fill((0, 0, 0, 120))
    surface.blit(overlay, (0, 0))
    
    
    pause_text = font_large.render("游戲暫停", True, (70, 130, 200))
    continue_text = font_medium.render("按P鍵繼續", True, TEXT_COLOR)
    
    surface.blit(pause_text, (SCREEN_WIDTH//2 - pause_text.get_width()//2, 
                            SCREEN_HEIGHT//2 - 30))
    surface.blit(continue_text, (SCREEN_WIDTH//2 - continue_text.get_width()//2, 
                                SCREEN_HEIGHT//2 + 30))

def reset(self):
    self.snake.reset()
    self.food = Food(self.snake)
    self.score = 0
    self.game_over = False
    self.paused = False
    self.special_food_active = False

game = Game()

while True:

for event in pygame.event.get():
    if event.type == pygame.QUIT:
        pygame.quit()
        sys.exit()
        
    if event.type == pygame.KEYDOWN:
        if not game.game_over:
            
            if event.key == pygame.K_UP:
                game.snake.new_direction = Vector2(0, -1)
            elif event.key == pygame.K_DOWN:
                game.snake.new_direction = Vector2(0, 1)
            elif event.key == pygame.K_LEFT:
                game.snake.new_direction = Vector2(-1, 0)
            elif event.key == pygame.K_RIGHT:
                game.snake.new_direction = Vector2(1, 0)
                
            
            elif event.key == pygame.K_p:
                game.paused = not game.paused
        
        
        if event.key == pygame.K_r:
            game.reset()
            
        
        if event.key == pygame.K_ESCAPE:
            pygame.quit()
            sys.exit()


game.update()


screen.fill(BACKGROUND)
game.draw(screen)

pygame.draw.rect(screen, UI_BORDER, (0, 0, SCREEN_WIDTH, SCREEN_HEIGHT), 3)


title_text = font_small.render("Python貪吃蛇", True, (100, 180, 255))
screen.blit(title_text, (SCREEN_WIDTH // 2 - title_text.get_width() // 2, 
                       SCREEN_HEIGHT - 30))


if not game.game_over and not game.paused:
    controls_text = font_small.render("方向鍵移動 | P暫停 | R重開 | ESC退出", True, (180, 180, 200))
    screen.blit(controls_text, (SCREEN_WIDTH // 2 - controls_text.get_width() // 2, 
                              SCREEN_HEIGHT - 60))


pygame.display.flip()


clock.tick(FPS)