Smart dinning kiosk

  #include <Wire.h>
  #include <Adafruit_GFX.h>
  #include <Adafruit_SSD1306.h>
  #include <Bounce2.h>

  // ==========================================
  // OLED DISPLAY SETTINGS
  // ==========================================
  #define SCREEN_WIDTH 128
  #define SCREEN_HEIGHT 64
  #define OLED_RESET    -1 
  Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

  // ==========================================
  // HARDWARE PINS (UPDATED FOR 2 LEDS)
  // ==========================================
  #define JOY_X_PIN D0
  #define JOY_Y_PIN D1
  #define JOY_SW_PIN D2

  #define LED_CORRECT D3
  #define LED_WRONG D6

  Bounce2::Button joyButton = Bounce2::Button();

  // ==========================================
  // GAME STATE & VARIABLES
  // ==========================================
  enum GameState { WELCOME, FOOD_MENU, PREP_TIME, MENU, GAMES_MENU, INSTRUCTIONS, QUIZ, GAMEOVER, LEADERBOARD, REACTION_GAME, SNAKE_GAME, SNAKE_GAMEOVER, DINO_GAME, DINO_GAMEOVER };
  GameState currentState = WELCOME;

  // --- Menu Navigation ---
  int foodMenuSelection = 0;
  int mainMenuSelection = 0;     
  int gamesMenuSelection = 0;    

  // --- Food Data ---
  String foodItems[3] = {"Biriyani", "Porotta", "Mandhi"};
  int foodPrepTimes[3] = {20, 10, 25}; 
  int activePrepTime = 0;
  String activeFood = "";

  // --- Quiz Variables ---
  #define TOTAL_QUESTIONS 15
  int currentQuestion = 0;
  int quizScore = 0;
  int quizSelection = 0;
  int selectedQuestions[5]; 

  String allQuestions[TOTAL_QUESTIONS] = { 
    "What is a tomato?", "Main part of Guacamole?", "Which is a root veg?", "Sushi wrapper name?", "Not a type of pasta?",
    "What makes bread rise?", "Nut inside marzipan?", "Origin of French Fries?", "Main part of hummus?", "Tofu is made from?",
    "Spice making curry yellow", "Is a pumpkin a fruit?", "Most stolen food?", "Feta cheese is from?", "What is calamari?"
  };

  String allOptions[TOTAL_QUESTIONS][3] = { 
    {"Fruit", "Vegetable", "Meat"}, {"Tomato", "Avocado", "Lime"}, {"Spinach", "Carrot", "Celery"}, {"Nori", "Wasabi", "Mochi"}, {"Penne", "Ravioli", "Baguette"},
    {"Yeast", "Salt", "Sugar"}, {"Walnut", "Almond", "Cashew"}, {"France", "Belgium", "USA"}, {"Lentils", "Chickpeas", "Beans"}, {"Soy", "Wheat", "Milk"},
    {"Cumin", "Turmeric", "Clove"}, {"Yes", "No", "It's a root"}, {"Cheese", "Meat", "Bread"}, {"Italy", "Greece", "Spain"}, {"Squid", "Octopus", "Clam"}
  };

  int allCorrectAnswers[TOTAL_QUESTIONS] = {
    0, 1, 1, 0, 2, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0
  }; 

  // --- Reaction Game Variables ---
  unsigned long sequenceStartTime = 0;
  unsigned long waitStartTime = 0;
  unsigned long randomDelay = 0;
  unsigned long finalReactionTime = 0;
  int lightsOn = 0;
  int reactionSubState = 0; 

  // --- Snake Xenzia Variables ---
  int snakeX[64];
  int snakeY[64];
  int snakeLength = 3;
  int snakeDir = 1; 
  int foodX = 10, foodY = 10;
  unsigned long lastSnakeMove = 0;
  int snakeScore = 0;

  // --- Dino Run Variables ---
  float dinoY = 38;        
  float dinoVelocity = 0;  
  bool isJumping = false;
  int cactusX = 128;       
  int dinoScore = 0;

  // ==========================================
  // SETUP & UTILITIES
  // ==========================================
  // New function for the Welcome blinking pattern
  void playWelcomePattern() {
    for (int i = 0; i < 3; i++) {
      digitalWrite(LED_CORRECT, HIGH);
      digitalWrite(LED_WRONG, LOW);
      delay(150);
      digitalWrite(LED_CORRECT, LOW);
      digitalWrite(LED_WRONG, HIGH);
      delay(150);
    }
    digitalWrite(LED_WRONG, LOW); // Turn both off at the end
  }

  // Helper to turn off all LEDs cleanly
  void turnOffLEDs() {
    digitalWrite(LED_CORRECT, LOW);
    digitalWrite(LED_WRONG, LOW);
  }

  void setup() {
    Serial.begin(115200);
    randomSeed(analogRead(A3)); 

    pinMode(LED_CORRECT, OUTPUT);
    pinMode(LED_WRONG, OUTPUT);
    turnOffLEDs();

    joyButton.attach(JOY_SW_PIN, INPUT_PULLUP);
    joyButton.interval(15);
    joyButton.setPressedState(LOW);

    if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
      for(;;); 
    }

    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(10, 25);
    display.println("SYSTEM BOOTING...");
    display.display();
    delay(1500); 

    // Play pattern before showing the first welcome screen
    playWelcomePattern(); 
  }

  // ==========================================
  // MAIN LOOP
  // ==========================================
  void loop() {
    joyButton.update();
    int joyX = analogRead(JOY_X_PIN);
    int joyY = analogRead(JOY_Y_PIN);

    switch (currentState) {
      case WELCOME:        handleWelcome();                break;
      case FOOD_MENU:      handleFoodMenu(joyY);           break;
      case PREP_TIME:      handlePrepTime(joyX);           break;
      case MENU:           handleMainMenu(joyY);           break;
      case GAMES_MENU:     handleGamesMenu(joyY);          break;
      case INSTRUCTIONS:   handleInstructions(joyX);       break;
      case QUIZ:           handleQuiz(joyX, joyY);         break;
      case GAMEOVER:       handleGameOver();               break;
      case LEADERBOARD:    handleLeaderboard(joyX);        break;
      case REACTION_GAME:  handleReactionGame();           break;
      case SNAKE_GAME:     handleSnakeGame(joyX, joyY);    break;
      case SNAKE_GAMEOVER: handleSnakeGameOver();          break;
      case DINO_GAME:      handleDinoGame();               break;
      case DINO_GAMEOVER:  handleDinoGameOver();           break;
    }
  }

  // ==========================================
  // STATE: WELCOME SCREEN
  // ==========================================
  void handleWelcome() {
    display.clearDisplay();
    display.setTextSize(2);
    display.setCursor(20, 10);
    display.println("WELCOME");
    
    display.setTextSize(1);
    display.setCursor(15, 35);
    display.println("To The Food Hub!");
    
    display.setCursor(10, 55);
    display.println("[Press to Order]");
    display.display();

    if (joyButton.pressed()) {
      foodMenuSelection = 0;
      currentState = FOOD_MENU;
    }
  }

  // ==========================================
  // STATE: FOOD SELECTION MENU
  // ==========================================
  void handleFoodMenu(int joyY) {
    if (joyY < 1000) {
      foodMenuSelection--;
      if (foodMenuSelection < 0) foodMenuSelection = 0;
      delay(200); 
    } else if (joyY > 3000) {
      foodMenuSelection++;
      if (foodMenuSelection > 3) foodMenuSelection = 3; 
      delay(200);
    }

    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("Select Your Order:");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    for (int i = 0; i < 3; i++) {
      display.setCursor(10, 15 + (i * 12));
      if (foodMenuSelection == i) display.print(">");
      display.println(" " + foodItems[i]);
    }
    
    display.setCursor(10, 52);
    if (foodMenuSelection == 3) display.print(">");
    display.println(" <- Back");
    
    display.display();

    if (joyButton.pressed()) {
      if (foodMenuSelection == 3) {
        playWelcomePattern(); // Play pattern when returning to Welcome
        currentState = WELCOME;
      } else {
        activeFood = foodItems[foodMenuSelection];
        activePrepTime = foodPrepTimes[foodMenuSelection];
        currentState = PREP_TIME;
      }
    }
  }

  // ==========================================
  // STATE: ESTIMATED TIME SCREEN
  // ==========================================
  void handlePrepTime(int joyX) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("Order Confirmed!");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    display.setCursor(0, 20);
    display.print("Preparing: "); 
    display.println(activeFood);

    display.setTextSize(2);
    display.setCursor(0, 35);
    display.print(activePrepTime);
    display.println(" mins");
    
    display.setTextSize(1);
    display.setCursor(0, 55);
    display.println("[< Back]  [Press Next]");
    
    display.display();

    if (joyButton.pressed()) currentState = MENU;
    if (joyX < 1000) { currentState = FOOD_MENU; delay(300); }
  }

  // ==========================================
  // STATE: THE MAIN MENU
  // ==========================================
  void handleMainMenu(int joyY) {
    if (joyY < 1000) {
      mainMenuSelection--;
      if (mainMenuSelection < 0) mainMenuSelection = 0;
      delay(200); 
    } else if (joyY > 3000) {
      mainMenuSelection++;
      if (mainMenuSelection > 3) mainMenuSelection = 3; 
      delay(200);
    }

    display.clearDisplay();
    display.setCursor(0, 0);
    display.print("Wait time: ");
    display.print(activePrepTime);
    display.println(" mins");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    display.setCursor(10, 18);
    if (mainMenuSelection == 0) display.print(">"); display.println(" Games");
    
    display.setCursor(10, 30);
    if (mainMenuSelection == 1) display.print(">"); display.println(" Quizzes");
    
    display.setCursor(10, 42);
    if (mainMenuSelection == 2) display.print(">"); display.println(" Leaderboard");
    
    display.setCursor(10, 54);
    if (mainMenuSelection == 3) display.print(">"); display.println(" <- Back to Food");
    
    display.display();

    if (joyButton.pressed()) {
      if (mainMenuSelection == 0)      { gamesMenuSelection = 0; currentState = GAMES_MENU; }
      else if (mainMenuSelection == 1) currentState = INSTRUCTIONS;
      else if (mainMenuSelection == 2) currentState = LEADERBOARD;
      else if (mainMenuSelection == 3) currentState = FOOD_MENU; 
    }
  }

  // ==========================================
  // STATE: THE GAMES SUB-MENU
  // ==========================================
  void handleGamesMenu(int joyY) {
    if (joyY < 1000) {
      gamesMenuSelection--;
      if (gamesMenuSelection < 0) gamesMenuSelection = 0;
      delay(200); 
    } else if (joyY > 3000) {
      gamesMenuSelection++;
      if (gamesMenuSelection > 3) gamesMenuSelection = 3; 
      delay(200);
    }

    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("--- ARCADE ---");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    display.setCursor(10, 15);
    if (gamesMenuSelection == 0) display.print(">"); display.println(" Snake Xenzia");
    
    display.setCursor(10, 27);
    if (gamesMenuSelection == 1) display.print(">"); display.println(" Reaction Test");

    display.setCursor(10, 39);
    if (gamesMenuSelection == 2) display.print(">"); display.println(" Dino Run");
    
    display.setCursor(10, 51);
    if (gamesMenuSelection == 3) display.print(">"); display.println(" <- Back to Main");
    
    display.display();

    if (joyButton.pressed()) {
      turnOffLEDs();
      
      if (gamesMenuSelection == 0)      initSnake();
      else if (gamesMenuSelection == 1) { reactionSubState = 0; currentState = REACTION_GAME; }
      else if (gamesMenuSelection == 2) initDino();
      else if (gamesMenuSelection == 3) currentState = MENU; 
    }
  }

  // ==========================================
  // STATE: QUIZ INSTRUCTIONS
  // ==========================================
  void handleInstructions(int joyX) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("QUIZ RULES:");
    display.println("- 5 Questions");
    display.println("- 1% discount per");
    display.println("  correct answer!");
    display.setCursor(0, 50);
    display.println("[< Back] [Press Start]");
    display.display();

    if (joyButton.pressed()) {
      quizScore = 0; 
      currentQuestion = 0; 
      quizSelection = 0;
      
      for (int i = 0; i < 5; i++) {
        bool isDuplicate;
        int candidate;
        do {
          isDuplicate = false;
          candidate = random(0, TOTAL_QUESTIONS);
          for (int j = 0; j < i; j++) {
            if (selectedQuestions[j] == candidate) {
              isDuplicate = true;
              break;
            }
          }
        } while (isDuplicate);
        selectedQuestions[i] = candidate;
      }
      
      currentState = QUIZ;
    }
    
    if (joyX < 1000) { currentState = MENU; delay(300); }
  }

  // ==========================================
  // STATE: THE QUIZ LOOP
  // ==========================================
  void handleQuiz(int joyX, int joyY) {
    if (joyX < 1000) { currentState = MENU; delay(300); return; }

    if (joyY < 1000) {
      quizSelection--;
      if (quizSelection < 0) quizSelection = 0;
      delay(200);
    } else if (joyY > 3000) {
      quizSelection++;
      if (quizSelection > 2) quizSelection = 2;
      delay(200);
    }

    int actualQIndex = selectedQuestions[currentQuestion];

    display.clearDisplay();
    display.setCursor(0, 0);
    display.print("Q"); display.print(currentQuestion + 1); display.print(": ");
    display.println(allQuestions[actualQIndex]);
    display.drawLine(0, 17, 128, 17, SSD1306_WHITE);

    for (int i = 0; i < 3; i++) {
      display.setCursor(10, 25 + (i * 12));
      if (quizSelection == i) display.print(">");
      display.println(allOptions[actualQIndex][i]);
    }
    display.display();

    if (joyButton.pressed()) {
      if (quizSelection == allCorrectAnswers[actualQIndex]) {
        // Blink CORRECT LED
        digitalWrite(LED_CORRECT, HIGH); 
        delay(300); 
        digitalWrite(LED_CORRECT, LOW);
        quizScore++;
      } else {
        // Blink WRONG LED
        digitalWrite(LED_WRONG, HIGH); 
        delay(300); 
        digitalWrite(LED_WRONG, LOW);
      }
      
      currentQuestion++;
      quizSelection = 0;
      if (currentQuestion >= 5) currentState = GAMEOVER;
    }
  }

  // ==========================================
  // STATE: QUIZ RESULTS
  // ==========================================
  void handleGameOver() {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("QUIZ COMPLETE!");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    display.setTextSize(2);
    display.setCursor(0, 20);
    display.print("Score: "); display.print(quizScore); display.println("/5");
    display.setTextSize(1);
    display.setCursor(0, 45);
    display.print("You won a "); display.print(quizScore); display.println("% discount!");
    
    display.setCursor(0, 55); display.println("[Press for Leaderboard]");
    display.display();

    if (joyButton.pressed()) currentState = LEADERBOARD;
  }

  // ==========================================
  // STATE: LEADERBOARD
  // ==========================================
  void handleLeaderboard(int joyX) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("--- LEADERBOARD ---");
    display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    
    display.setCursor(10, 15); display.println("1. Table 4   - 5/5");
    display.setCursor(10, 25); display.println("2. Table 9   - 4/5");
    display.setCursor(10, 35); display.print("3. YOUR TEAM - "); display.print(quizScore); display.println("/5");
    
    display.setCursor(0, 55); display.println("[< Back] [Press Reset]");
    display.display();

    if (joyButton.pressed()) {
      turnOffLEDs();
      mainMenuSelection = 0; 
      playWelcomePattern(); // Play pattern when restarting flow
      currentState = WELCOME;
    }
    if (joyX < 1000) { currentState = MENU; delay(300); }
  }

  // ==========================================
  // ARCADE GAMES (Snake, Dino, Reaction)
  // ==========================================

  void initDino() {
    dinoY = 38; dinoVelocity = 0; isJumping = false; cactusX = 128; dinoScore = 0;
    currentState = DINO_GAME;
  }

  void handleDinoGame() {
    if (joyButton.pressed() && !isJumping) { dinoVelocity = -5.5; isJumping = true; }
    dinoVelocity += 0.6; dinoY += dinoVelocity;
    if (dinoY >= 38) { dinoY = 38; dinoVelocity = 0; isJumping = false; }
    cactusX -= 4; 
    if (cactusX < -10) {
      cactusX = 128; dinoScore++;   
      // Blink Correct LED for scoring a point
      digitalWrite(LED_CORRECT, HIGH); delay(20); digitalWrite(LED_CORRECT, LOW);
    }
    if (cactusX < 24 && cactusX > 6 && dinoY > 26) { currentState = DINO_GAMEOVER; return; }

    display.clearDisplay();
    display.setCursor(100, 0); display.print(dinoScore);
    display.drawLine(0, 50, 128, 50, SSD1306_WHITE);
    display.fillRect(cactusX, 36, 6, 14, SSD1306_WHITE); display.fillRect(cactusX - 3, 40, 3, 6, SSD1306_WHITE);
    int intY = (int)dinoY;
    display.fillRect(14, intY, 10, 8, SSD1306_WHITE); display.drawPixel(20, intY + 2, SSD1306_BLACK); display.fillRect(10, intY + 8, 12, 10, SSD1306_WHITE);  
    
    if (!isJumping && (millis() / 100) % 2 == 0) {
      display.drawLine(12, intY + 18, 12, intY + 22, SSD1306_WHITE); display.drawLine(16, intY + 18, 18, intY + 20, SSD1306_WHITE); 
    } else {
      display.drawLine(12, intY + 18, 10, intY + 20, SSD1306_WHITE); display.drawLine(18, intY + 18, 18, intY + 22, SSD1306_WHITE); 
    }
    display.display(); delay(20); 
  }

  void handleDinoGameOver() {
    display.clearDisplay(); display.setCursor(0, 0); display.println("EXTINCTION!"); display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    display.setTextSize(2); display.setCursor(0, 25); display.print("Score: "); display.println(dinoScore); display.setTextSize(1);
    display.setCursor(0, 50); display.println("[Press to Menu]"); display.display();
    if (joyButton.pressed()) { gamesMenuSelection = 0; currentState = GAMES_MENU; }
  }

  void initSnake() {
    snakeLength = 3; snakeDir = 1; snakeScore = 0;
    snakeX[0] = 16; snakeY[0] = 8; snakeX[1] = 15; snakeY[1] = 8; snakeX[2] = 14; snakeY[2] = 8;
    foodX = random(2, 30); foodY = random(2, 14); currentState = SNAKE_GAME;
  }

  void handleSnakeGame(int joyX, int joyY) {
    if (joyY < 1000 && snakeDir != 2) snakeDir = 0;      
    else if (joyX > 3000 && snakeDir != 3) snakeDir = 1; 
    else if (joyY > 3000 && snakeDir != 0) snakeDir = 2; 
    else if (joyX < 1000 && snakeDir != 1) snakeDir = 3; 

    if (millis() - lastSnakeMove > 150) { 
      lastSnakeMove = millis();
      for (int i = snakeLength - 1; i > 0; i--) { snakeX[i] = snakeX[i - 1]; snakeY[i] = snakeY[i - 1]; }
      if (snakeDir == 0) snakeY[0]--; if (snakeDir == 1) snakeX[0]++; if (snakeDir == 2) snakeY[0]++; if (snakeDir == 3) snakeX[0]--;

      if (snakeX[0] < 0 || snakeX[0] >= 32 || snakeY[0] < 0 || snakeY[0] >= 16) { currentState = SNAKE_GAMEOVER; return; }
      for (int i = 1; i < snakeLength; i++) { if (snakeX[0] == snakeX[i] && snakeY[0] == snakeY[i]) { currentState = SNAKE_GAMEOVER; return; } }
      if (snakeX[0] == foodX && snakeY[0] == foodY) {
        if (snakeLength < 64) snakeLength++; snakeScore++;
        foodX = random(1, 31); foodY = random(1, 15);
        // Blink Correct LED for eating food
        digitalWrite(LED_CORRECT, HIGH); delay(30); digitalWrite(LED_CORRECT, LOW);
      }
    }

    display.clearDisplay(); display.fillRect(foodX * 4, foodY * 4, 4, 4, SSD1306_WHITE);
    for (int i = 0; i < snakeLength; i++) { display.fillRect(snakeX[i] * 4, snakeY[i] * 4, 4, 4, SSD1306_WHITE); }
    display.display();
  }

  void handleSnakeGameOver() {
    display.clearDisplay(); display.setCursor(0, 0); display.println("SNAKE CRASHED!"); display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
    display.setTextSize(2); display.setCursor(0, 25); display.print("Apples: "); display.println(snakeScore); display.setTextSize(1);
    display.setCursor(0, 50); display.println("[Press to Menu]"); display.display();
    if (joyButton.pressed()) { gamesMenuSelection = 0; currentState = GAMES_MENU; }
  }

  void handleReactionGame() {
    switch (reactionSubState) {
      case 0: 
        display.clearDisplay(); display.setCursor(0, 0); display.println("--- LIGHTS OUT ---");
        display.println("Press the button"); display.println("the exact moment"); display.println("both LEDs go dark!");
        display.setCursor(0, 50); display.println("[Press to Ready]"); display.display();
        if (joyButton.pressed()) { reactionSubState = 1; lightsOn = 0; sequenceStartTime = millis(); }
        break;
      case 1: 
        display.clearDisplay(); display.setCursor(30, 25); display.setTextSize(2); display.println("READY"); display.setTextSize(1); display.display();
        if (millis() - sequenceStartTime > 1000) {
          if (lightsOn == 0) { 
            digitalWrite(LED_CORRECT, HIGH); lightsOn++; sequenceStartTime = millis(); 
          } 
          else if (lightsOn == 1) { 
            digitalWrite(LED_WRONG, HIGH); lightsOn++; sequenceStartTime = millis(); 
          } 
          else { 
            reactionSubState = 2; randomDelay = random(500, 3500); waitStartTime = millis(); 
          }
        }
        if (joyButton.pressed()) reactionSubState = 4; 
        break;
      case 2: 
        if (millis() - waitStartTime > randomDelay) {
          turnOffLEDs();
          sequenceStartTime = millis(); reactionSubState = 3;
        }
        if (joyButton.pressed()) reactionSubState = 4;
        break;
      case 3: 
        display.clearDisplay(); display.setCursor(50, 25); display.setTextSize(2); display.println("GO!"); display.setTextSize(1); display.display();
        if (joyButton.pressed()) { finalReactionTime = millis() - sequenceStartTime; reactionSubState = 5; }
        break;
      case 4: 
        turnOffLEDs();
        display.clearDisplay(); display.setCursor(10, 20); display.setTextSize(2); display.println("JUMP START"); display.setTextSize(1);
        display.setCursor(0, 50); display.println("[Press to Menu]"); display.display();
        if (joyButton.pressed()) currentState = GAMES_MENU;
        break;
      case 5: 
        display.clearDisplay(); display.setCursor(0, 0); display.println("REACTION TIME:"); display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
        display.setCursor(0, 25); display.setTextSize(2); display.print(finalReactionTime); display.println(" ms"); display.setTextSize(1);
        display.setCursor(0, 50); display.println("[Press to Menu]"); display.display();
        if (joyButton.pressed()) currentState = GAMES_MENU;
        break;
    }
  }