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

// LCD setup
LiquidCrystal_I2C lcd(0x27, 20, 4); // Adjust I2C address if needed

// Rotary encoder pins
#define CLK_PIN 8
#define DT_PIN 9
#define SW_PIN 10

// LED pin
#define LED_PIN 7

// Variables for rotary encoder
int currentStateCLK;
int lastStateCLK;
int currentStateSW;
int lastStateSW = HIGH;
int menuIndex = 0;

// Menu options
const char* menuOptions[] = {
  "1. LED ON",
  "2. LED OFF"
};
const int menuSize = sizeof(menuOptions) / sizeof(menuOptions[0]);

void setup() {
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Rotary Menu Demo");

  // Initialize rotary encoder pins
  pinMode(CLK_PIN, INPUT);
  pinMode(DT_PIN, INPUT);
  pinMode(SW_PIN, INPUT_PULLUP);

  // Initialize LED pin
  pinMode(LED_PIN, OUTPUT);

  // Read initial state of CLK
  lastStateCLK = digitalRead(CLK_PIN);

  // Display initial menu
  displayMenu();
}

void loop() {
  // Handle rotary encoder rotation
  currentStateCLK = digitalRead(CLK_PIN);
  if (currentStateCLK != lastStateCLK && currentStateCLK == HIGH) {
    // Check direction
    if (digitalRead(DT_PIN) != currentStateCLK) {
      menuIndex++;
    } else {
      menuIndex--;
    }

    // Wrap around menu index
    if (menuIndex < 0) menuIndex = menuSize - 1;
    if (menuIndex >= menuSize) menuIndex = 0;

    // Update menu display
    displayMenu();
  }
  lastStateCLK = currentStateCLK;

  // Handle button press
  currentStateSW = digitalRead(SW_PIN);
  if (currentStateSW == LOW && lastStateSW == HIGH) {
    // Execute selected menu option
    executeOption(menuIndex);
  }
  lastStateSW = currentStateSW;
}

void displayMenu() {
  lcd.clear();
  for (int i = 0; i < menuSize; i++) {
    lcd.setCursor(0, i);
    if (i == menuIndex) {
      lcd.print("> "); // Highlight selected option
    } else {
      lcd.print("  ");
    }
    lcd.print(menuOptions[i]);
  }
}

void executeOption(int index) {
  switch (index) {
    case 0:
      digitalWrite(LED_PIN, HIGH); // Turn LED on
      lcd.setCursor(0, 3);
      lcd.print("LED is ON ");
      break;
    case 1:
      digitalWrite(LED_PIN, LOW); // Turn LED off
      lcd.setCursor(0, 3);
      lcd.print("LED is OFF");
      break;
  }
}