#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_MPU6050.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define MPU6050_ADDR 0x68
Adafruit_MPU6050 mpu;
float ax, ay, az;
float gx, gy, gz;

const int BLOCK_SIZE = 8;
const int GAME_WIDTH = 128;
const int GAME_HEIGHT = 32;
const int MAX_SNAKE_LENGTH = 20;
int snakeX[MAX_SNAKE_LENGTH] = {GAME_WIDTH / 2, GAME_WIDTH / 2, GAME_WIDTH / 2};
int snakeY[MAX_SNAKE_LENGTH] = {GAME_HEIGHT / 2 + BLOCK_SIZE, GAME_HEIGHT / 2, GAME_HEIGHT / 2 - BLOCK_SIZE};
const int INITIAL_SNAKE_LENGTH = 3;
int snakeLength = INITIAL_SNAKE_LENGTH;
int snakeDir = 0;   // 0: right, 1: down, 2: left, 3: up
int foodX = BLOCK_SIZE * (random(1, GAME_WIDTH / BLOCK_SIZE - 1));
int foodY = BLOCK_SIZE * (random(1, GAME_HEIGHT / BLOCK_SIZE - 1));
bool gameOver = false;

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.display();
  
  Serial.begin(9600);   // 初始化串口通信，波特率为 9600
  Wire.begin();
  mpu.begin(MPU6050_ADDR);
}

void loop() {
  // 读取MPU6050的加速度和角速度信息
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  ax = a.acceleration.x;
  ay = a.acceleration.y;
  az = a.acceleration.z;
  gx = g.gyro.x;
  gy = g.gyro.y;
  gz = g.gyro.z;

  // 输出数据到串口监视器
 Serial.print("ax = ");
 Serial.print(ax);
 Serial.print(", ay = ");
 Serial.print(ay);
 Serial.print(", az = ");
 Serial.print(az);
 Serial.print(", gx = ");
 Serial.print(gx);
 Serial.print(", gy = ");
 Serial.print(gy);
 Serial.print(", gz = ");
 Serial.println(gz);


  // 根据加速度信息，更新蛇的移动方向
  if (ax < -5) {
    snakeDir = 2;     // 向左
  } else if (ax > 5) {
    snakeDir = 0;     // 向右
  } else if (ay < -5) {
    snakeDir = 3;     // 向上
  } else if (ay > 5) {
    snakeDir = 1;     // 向下
  }
  
  // 执行蛇的移动操作
  moveSnake();
  
  // 检测游戏是否结束，是否吃到食物
  checkGameStatus();
  
  // 绘制游戏界面
  drawGameScreen();
}

void moveSnake() {
  // 移动蛇头
  int headX = snakeX[0];
  int headY = snakeY[0];
  if (snakeDir == 0) {   // 向右
    headX += BLOCK_SIZE;
  } else if (snakeDir == 1) {   // 向下
    headY += BLOCK_SIZE;
  } else if (snakeDir == 2) {   // 向左
    headX -= BLOCK_SIZE;
  } else if (snakeDir == 3) {   // 向上
    headY -= BLOCK_SIZE;
  }
  
  // 检测蛇是否吃到了食物
  bool eatFood = false;
  if (headX == foodX && headY == foodY) {
    eatFood = true;
    foodX = BLOCK_SIZE * (random(1, GAME_WIDTH / BLOCK_SIZE - 1));
    foodY = BLOCK_SIZE * (random(1, GAME_HEIGHT / BLOCK_SIZE - 1));
  }
  
  // 更新蛇的身体状态
  for (int i = snakeLength - 1; i > 0; i--) {
    snakeX[i] = snakeX[i-1];
    snakeY[i] = snakeY[i-1];
  }
  snakeX[0] = headX;
  snakeY[0] = headY;
  
  // 如果蛇吃到了食物，则增加蛇的长度
  if (eatFood) {
    snakeX[snakeLength] = snakeX[snakeLength - 1];
    snakeY[snakeLength] = snakeY[snakeLength - 1];
    snakeLength++;
  }
}

void checkGameStatus() {
  // 检测蛇是否碰到边界或自身
  if (snakeX[0] < 0 || snakeX[0] >= GAME_WIDTH 
      || snakeY[0] < 0 || snakeY[0] >= GAME_HEIGHT) {
    gameOver = true;
  }
  for (int i = 1; i < snakeLength; i++) {
    if (snakeX[i] == snakeX[0] && snakeY[i] == snakeY[0]) {
      gameOver = true;
    }
  }
}

void drawGameScreen() {
  // 清空屏幕
  display.clearDisplay();
  
  // 绘制蛇和食物
  display.fillCircle(snakeX[0], snakeY[0], BLOCK_SIZE / 2, SSD1306_WHITE);
  for (int i = 1; i < snakeLength; i++) {
    display.fillRect(snakeX[i] - BLOCK_SIZE / 2, snakeY[i] - BLOCK_SIZE / 2,
                     BLOCK_SIZE, BLOCK_SIZE, SSD1306_WHITE);
  }
  display.fillCircle(foodX, foodY, BLOCK_SIZE / 2, SSD1306_WHITE);
  
  // 绘制游戏结束提示
  if (gameOver) {
    display.setCursor(8, 24);
    display.println("Game Over!");
    display.display();
    delay(2000);
    
    // 重置游戏状态
    snakeDir = 0;
    snakeLength = INITIAL_SNAKE_LENGTH;
    snakeX[0] = GAME_WIDTH / 2;
    snakeY[0] = GAME_HEIGHT / 2 + BLOCK_SIZE;
    snakeX[1] = GAME_WIDTH / 2;
    snakeY[1] = GAME_HEIGHT / 2;
    snakeX[2] = GAME_WIDTH / 2;
    snakeY[2] = GAME_HEIGHT / 2 - BLOCK_SIZE;
    foodX = BLOCK_SIZE * (random(1, GAME_WIDTH / BLOCK_SIZE - 1));
    foodY = BLOCK_SIZE * (random(1, GAME_HEIGHT / BLOCK_SIZE - 1));
    gameOver = false;
  }
  
  // 显示屏幕内容
  display.display();   
}