#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // LCD address

// Ultrasonic Sensor Pins
const int trigPin = 11;
const int echoPin = 12;

// Joystick Pins
const int joyY = A0;
const int joyBtn = 8;

// Buzzer Pin
const int buzzerPin = 3;

// Game Elements
#define DINO 'D'
#define CACTUS '#'
#define GROUND '_'

// Game Variables
int dinoPos = 1;          // 1=ground, 0=jumping
int cactusPos = 15;
int score = 0;
bool gameRunning = false;
const int jumpDistance = 15; // Distance (cm) to trigger jump

void setup() {
  lcd.init();
  lcd.backlight();
  
  // Ultrasonic Sensor
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Joystick Button
  pinMode(joyBtn, INPUT_PULLUP);
  
  // Buzzer
  pinMode(buzzerPin, OUTPUT);
  
  showStartScreen();
}

void loop() {
  if (!gameRunning && digitalRead(joyBtn) == LOW) {
    startGame();
  }

  if (gameRunning) {
    playGame();
    delay(200); // Game speed
  }
}

float getDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  long duration = pulseIn(echoPin, HIGH);
  return duration * 0.034 / 2;
}

void showStartScreen() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Wave Hand to Start");
  lcd.setCursor(0, 1);
  lcd.print("or Press Button");
}

void startGame() {
  gameRunning = true;
  score = 0;
  dinoPos = 1;
  cactusPos = 15;
  lcd.clear();
  beep(100);
}

void playGame() {
  float distance = getDistance();
  
  // Jump if hand detected OR joystick up
  if ((distance > 0 && distance < jumpDistance) || analogRead(joyY) < 300) {
    dinoPos = 0; // Jump
    beep(50);
  } else {
    dinoPos = 1; // On ground
  }

  drawGame();
  checkCollision();
  moveCactus();
}

void drawGame() {
  lcd.clear();
  
  // Draw ground
  for (int i = 0; i < 16; i++) {
    lcd.setCursor(i, 1);
    lcd.print(GROUND);
  }
  
  // Draw dino
  lcd.setCursor(1, dinoPos);
  lcd.print(DINO);
  
  // Draw cactus
  lcd.setCursor(cactusPos, 1);
  lcd.print(CACTUS);
  
  // Draw score
  lcd.setCursor(12, 0);
  lcd.print(score);
}

void checkCollision() {
  if (cactusPos == 1 && dinoPos == 1) {
    gameOver();
  }
}

void moveCactus() {
  cactusPos--;
  if (cactusPos < 0) {
    cactusPos = 15;
    score++;
    beep(50);
  }
}

void gameOver() {
  gameRunning = false;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Game Over!");
  lcd.setCursor(0, 1);
  lcd.print("Score: ");
  lcd.print(score);
  beep(300);
  delay(2000);
  showStartScreen();
}

void beep(int duration) {
  tone(buzzerPin, 1000, duration);
}