import pygame
import random

# 初始化 Pygame
pygame.init()

# 设置窗口尺寸
cell_size = 20  # 单元格大小
grid_width = 30  # 网格宽度
grid_height = 20  # 网格高度
window_width = grid_width * cell_size
window_height = grid_height * cell_size
window = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("迷宫游戏")

# 设置颜色
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)

# 设置时钟
clock = pygame.time.Clock()


# 生成随机迷宫
def generate_maze(width, height):
    # 初始化迷宫，所有单元格都是墙壁
    maze = [[1 for _ in range(width)] for _ in range(height)]

    # 确保入口和出口是通道
    maze[0][0] = 0
    maze[height - 1][width - 1] = 0

    # 使用深度优先搜索生成迷宫
    def carve_passages(x, y):
        # 随机选择方向
        directions = [(0, 2), (2, 0), (0, -2), (-2, 0)]
        random.shuffle(directions)

        for dx, dy in directions:
            nx, ny = x + dx, y + dy

            # 检查是否在边界内
            if 0 <= nx < width and 0 <= ny < height:
                # 如果目标单元格是墙壁
                if maze[ny][nx] == 1:
                    # 打通墙壁
                    maze[ny][nx] = 0
                    # 打通中间的墙壁
                    maze[y + dy // 2][x + dx // 2] = 0
                    # 递归处理下一个单元格
                    carve_passages(nx, ny)

    # 从入口开始生成迷宫
    carve_passages(0, 0)

    # 确保出口附近有通道
    maze[height - 2][width - 1] = 0
    maze[height - 1][width - 2] = 0

    return maze


# 生成迷宫
maze = generate_maze(grid_width, grid_height)


# 定义小人类
class Character:
    def __init__(self, grid_x, grid_y):
        self.grid_x = grid_x  # 小人的网格 x 坐标
        self.grid_y = grid_y  # 小人的网格 y 坐标
        self.x = grid_x * cell_size + cell_size // 2  # 小人的像素 x 坐标
        self.y = grid_y * cell_size + cell_size // 2  # 小人的像素 y 坐标
        self.radius = cell_size // 3 - 1  # 稍微减小半径，避免卡住
        self.speed = 3  # 移动速度
        self.collision_margin = 2  # 碰撞检测的边缘余量，减小这个值可以让小球更容易通过狭窄通道

    def move(self, dx, dy):
        # 计算目标位置
        new_x = self.x + dx
        new_y = self.y + dy

        # 检测是否与墙壁碰撞
        if self.will_collide(new_x, new_y):
            # 尝试单独移动 X 或 Y 方向
            if dx != 0 and not self.will_collide(new_x, self.y):
                new_y = self.y  # 只移动 X 方向
            elif dy != 0 and not self.will_collide(self.x, new_y):
                new_x = self.x  # 只移动 Y 方向
            else:
                return  # 两个方向都不能移动

        # 更新位置
        self.x = new_x
        self.y = new_y
        self.grid_x = self.x // cell_size
        self.grid_y = self.y // cell_size

    def will_collide(self, x, y):
        # 计算碰撞检测的实际半径
        collision_radius = self.radius - self.collision_margin

        # 检测小球是否会与墙壁碰撞
        # 计算小球边缘的四个点
        points = [
            (x - collision_radius, y),  # 左
            (x + collision_radius, y),  # 右
            (x, y - collision_radius),  # 上
            (x, y + collision_radius)  # 下
        ]

        # 检测每个点是否在墙壁内
        for px, py in points:
            # 计算点所在的网格位置
            grid_x = int(px // cell_size)
            grid_y = int(py // cell_size)

            # 检测是否超出边界
            if grid_x < 0 or grid_x >= grid_width or grid_y < 0 or grid_y >= grid_height:
                return True

            # 检测是否与墙壁碰撞
            if maze[grid_y][grid_x] == 1:
                return True

        return False

    def draw(self, window):
        # 绘制小人（红色小球）
        pygame.draw.circle(window, RED, (self.x, self.y), self.radius)


# 创建小人对象（初始位置在左上角）
character = Character(0, 0)

# 设置出口位置
exit_grid_x = grid_width - 1
exit_grid_y = grid_height - 1

# 主循环
running = True
while running:
    # 处理事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:  # 检测窗口关闭事件
            running = False

    # 检测键盘持续按下状态
    keys = pygame.key.get_pressed()
    if keys[pygame.K_UP]:  # 按下上箭头键
        character.move(0, -character.speed)
    if keys[pygame.K_DOWN]:  # 按下下箭头键
        character.move(0, character.speed)
    if keys[pygame.K_LEFT]:  # 按下左箭头键
        character.move(-character.speed, 0)
    if keys[pygame.K_RIGHT]:  # 按下右箭头键
        character.move(character.speed, 0)

    # 清空屏幕
    window.fill(WHITE)

    # 绘制迷宫
    for i in range(grid_height):
        for j in range(grid_width):
            if maze[i][j] == 1:  # 绘制墙壁
                pygame.draw.rect(window, BLACK, (j * cell_size, i * cell_size, cell_size, cell_size))

    # 绘制出口
    exit_x = exit_grid_x * cell_size + cell_size // 2
    exit_y = exit_grid_y * cell_size + cell_size // 2
    pygame.draw.circle(window, GREEN, (exit_x, exit_y), cell_size // 3)

    # 绘制小人
    character.draw(window)

    # 检测是否到达出口
    if abs(character.x - exit_x) < cell_size // 2 and abs(character.y - exit_y) < cell_size // 2:
        print("胜利！")
        running = False

    # 更新屏幕
    pygame.display.flip()

    # 控制帧率
    clock.tick(60)

# 退出 Pygame
pygame.quit()