#include <U8g2lib.h>
#include <Wire.h>
#include <TM1637Display.h>

#define OLED_RESET -1
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, OLED_RESET, U8X8_PIN_NONE, U8X8_PIN_NONE);

#define JOYSTICK_X A0
#define JOYSTICK_Y A1
#define JOYSTICK_BUTTON 2
#define BUZZER_PIN 3
#define TM1637_CLK 4
#define TM1637_DIO 5

TM1637Display display(TM1637_CLK, TM1637_DIO);  // Create TM1637 display object

int snakeX[50], snakeY[50];  // Snake position array
int snakeLength = 3;         // Initial length of the snake
int foodX, foodY;            // Food position
int direction = 0;           // 0: up, 1: right, 2: down, 3: left
int score = 0;               // Player's score

int screenWidth = 128;
int screenHeight = 64;
int snakeSize = 4;  // Each block of snake is 4x4 pixels

unsigned long lastMoveTime = 0;
unsigned long moveInterval = 200;  // Snake movement speed (milliseconds)

void setup() {
  // Initialize OLED display
  u8g2.begin();
  
  // Initialize joystick
  pinMode(JOYSTICK_BUTTON, INPUT_PULLUP);
  
  // Initialize buzzer
  pinMode(BUZZER_PIN, OUTPUT);
  
  // Initialize TM1637 7-segment display
  display.setBrightness(0x0f);  // Set maximum brightness
  display.showNumberDec(score); // Display the initial score (0)
  
  // Set initial snake position
  snakeX[0] = screenWidth / 2;
  snakeY[0] = screenHeight / 2;

  // Generate initial food position
  generateFood();
}

void loop() {
  u8g2.clearBuffer();  // Clear the display buffer

  // Read joystick for direction changes
  int xVal = analogRead(JOYSTICK_X);
  int yVal = analogRead(JOYSTICK_Y);
  
  // Fixing the direction inversion
  if (yVal > 600) direction = 0;  // Up
  if (xVal < 400) direction = 1;  // Right
  if (yVal < 400) direction = 2;  // Down
  if (xVal > 600) direction = 3;  // Left

  // Move the snake at regular intervals
  if (millis() - lastMoveTime > moveInterval) {
    moveSnake();
    lastMoveTime = millis();
  }

  // Draw snake
  for (int i = 0; i < snakeLength; i++) {
    u8g2.drawBox(snakeX[i], snakeY[i], snakeSize, snakeSize);
  }

  // Draw food
  u8g2.drawBox(foodX, foodY, snakeSize, snakeSize);

  // Check if snake eats the food
  if (snakeX[0] == foodX && snakeY[0] == foodY) {
    snakeLength++;
    score++;  // Increment score when food is eaten
    display.showNumberDec(score);  // Update score on TM1637 display
    generateFood();
    
    // Play sound when eating food
    playEatSound();
  }

  // Check for collisions (with self or walls)
  if (checkCollision()) {
    gameOver();
  }

  u8g2.sendBuffer();  // Send buffer to OLED
}

void moveSnake() {
  // Move snake body
  for (int i = snakeLength - 1; i > 0; i--) {
    snakeX[i] = snakeX[i - 1];
    snakeY[i] = snakeY[i - 1];
  }

  // Move snake head
  switch (direction) {
    case 0: snakeY[0] -= snakeSize; break;  // Up
    case 1: snakeX[0] += snakeSize; break;  // Right
    case 2: snakeY[0] += snakeSize; break;  // Down
    case 3: snakeX[0] -= snakeSize; break;  // Left
  }
}

void generateFood() {
  foodX = (random(screenWidth / snakeSize)) * snakeSize;
  foodY = (random(screenHeight / snakeSize)) * snakeSize;
}

bool checkCollision() {
  // Check wall collision
  if (snakeX[0] < 0 || snakeX[0] >= screenWidth || snakeY[0] < 0 || snakeY[0] >= screenHeight) {
    return true;
  }

  // Check self-collision
  for (int i = 1; i < snakeLength; i++) {
    if (snakeX[0] == snakeX[i] && snakeY[0] == snakeY[i]) {
      return true;
    }
  }
  return false;
}

void gameOver() {
  // Play game over sound
  playGameOverSound();
  
  // Display game over score (hold the score on the display)
  display.showNumberDec(score);

  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_ncenB08_tr);  // Choose a font
  u8g2.drawStr(35, 30, "Game Over!");
  u8g2.sendBuffer();
  
  delay(2000);  // Pause for 2 seconds
  
  // Reset the game
  snakeLength = 3;
  snakeX[0] = screenWidth / 2;
  snakeY[0] = screenHeight / 2;
  score = 0;  // Reset the score
  display.showNumberDec(score);  // Update the 7-segment display
  generateFood();
}

// Function to play sound when snake eats food
void playEatSound() {
  tone(BUZZER_PIN, 1000, 100);  // Play a 1kHz tone for 100ms
  delay(100);
  noTone(BUZZER_PIN);
}

// Function to play game over sound
void playGameOverSound() {
  tone(BUZZER_PIN, 400, 300);  // Play a 400Hz tone for 300ms
  delay(300);
  tone(BUZZER_PIN, 200, 300);  // Play a 200Hz tone for 300ms
  delay(300);
  noTone(BUZZER_PIN);
}