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

// Initialize LCD
LiquidCrystal_I2C lcd(0x27, 20, 4); // Change 0x27 to your LCD's I2C address

// Initialize Encoder
Encoder encoder(2, 3); // Pins for the rotary encoder
long oldPosition = -999;

// Define push buttons
const int buttonUp = 4;
const int buttonDown = 5;

// Menu Structure
enum MenuLevel { MAIN, SYSTEM, TIME, NETWORK };
MenuLevel currentLevel = MAIN;
int menuIndex[] = {0, 0, 0, 0}; // To track selection in each level

// Menu Items
const char* mainMenu[] = { "SYSTEM", "TIME", "NETWORK" };
const char* systemMenu[] = { "MODE", "LOGGING" };
const char* timeMenu[] = { "SET DATE", "SET TIME" };
const char* networkMenu[] = { "UPDATE RATE", "NETWORK TYPE" };

// Number of items in each menu
const int mainMenuCount = 3;
const int systemMenuCount = 2;
const int timeMenuCount = 2;
const int networkMenuCount = 2;

void setup() {
  // Setup LCD
  lcd.begin(20, 4);
  lcd.backlight();

  // Setup buttons
  pinMode(buttonUp, INPUT_PULLUP);
  pinMode(buttonDown, INPUT_PULLUP);

  // Initial display
  updateMenu();
}

void loop() {
  // Handle rotary encoder
  long newPosition = encoder.read() / 4;
  if (newPosition != oldPosition) {
    oldPosition = newPosition;
    int maxIndex = getMaxMenuIndex(currentLevel);
    menuIndex[currentLevel] = constrain(newPosition, 0, maxIndex - 1);
    updateMenu();
  }

  // Handle button presses
  if (digitalRead(buttonUp) == LOW) {
    moveUpMenuLevel();
    delay(200); // Debounce delay
    updateMenu();
  }
  if (digitalRead(buttonDown) == LOW) {
    moveDownMenuLevel();
    delay(200); // Debounce delay
    updateMenu();
  }
}

void moveUpMenuLevel() {
  if (currentLevel == MAIN) return; // Already at the top
  currentLevel = static_cast<MenuLevel>(currentLevel - 1);
  oldPosition = menuIndex[currentLevel] * 4; // Sync the encoder position with menu index
}

void moveDownMenuLevel() {
  if (currentLevel == MAIN) {
    currentLevel = static_cast<MenuLevel>(menuIndex[MAIN] + 1);
  } else {
    // Add actions for the selected menu item here
    // Example: if SYSTEM is selected, toggle mode or logging etc.
  }
  oldPosition = menuIndex[currentLevel] * 4; // Sync the encoder position with menu index
}

void updateMenu() {
  lcd.clear();
  switch (currentLevel) {
    case MAIN:
      displayMenu(mainMenu, mainMenuCount, menuIndex[MAIN]);
      break;
    case SYSTEM:
      displayMenu(systemMenu, systemMenuCount, menuIndex[SYSTEM]);
      break;
    case TIME:
      displayMenu(timeMenu, timeMenuCount, menuIndex[TIME]);
      break;
    case NETWORK:
      displayMenu(networkMenu, networkMenuCount, menuIndex[NETWORK]);
      break;
  }
}

void displayMenu(const char* menuItems[], int itemCount, int selectedIndex) {
  for (int i = 0; i < itemCount; i++) {
    lcd.setCursor(0, i);
    if (i == selectedIndex) {
      lcd.print(">"); // Indicate selection
    } else {
      lcd.print(" ");
    }
    lcd.print(menuItems[i]);
  }
}

int getMaxMenuIndex(MenuLevel level) {
  switch (level) {
    case MAIN: return mainMenuCount;
    case SYSTEM: return systemMenuCount;
    case TIME: return timeMenuCount;
    case NETWORK: return networkMenuCount;
    default: return 0;
  }
}