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

#define DHTPIN 2
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);
RTC_DS3231 rtc;

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int encoderPinA = 3;
const int encoderPinB = 4;
const int encoderButtonPin = 5;

int lastEncoded = 0;
int menuIndex = 0;

float lastTemperature = 0.0;
float lastHumidity = 0.0;
bool menuNeedsRedraw = false;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;

bool isMenuSelected = false;

void setup() {
  lcd.init();
  lcd.backlight();
  dht.begin();
  rtc.begin();
  
  pinMode(encoderPinA, INPUT);
  pinMode(encoderPinB, INPUT);
  pinMode(encoderButtonPin, INPUT_PULLUP);
}

void loop() {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  if (isnan(temperature) || isnan(humidity)) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Error reading DHT22");
    delay(2000);
    return;
  }

  if (!menuNeedsRedraw) {
    displayMainScreen(temperature, humidity);
    handleMenuButton();
  } else {
    if (!isMenuSelected) {
      displayMenuScreen();
      handleMenuNavigation();
    } else {
      handleSelectedMenuItem();
    }
  }
}

void displayMainScreen(float temperature, float humidity) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temperature, 1); // Display temperature with 1 decimal place
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("H:");
  lcd.print(humidity, 1); // Display humidity with 1 decimal place
  lcd.print("%");
}

void displayMenuScreen() {
  lcd.clear();
  lcd.setCursor(0, 0);
  switch (menuIndex) {
    case 0:
      lcd.print("Humidity Set");
      break;
    case 1:
      lcd.print("Time");
      break;
    case 2:
      lcd.print("Home");
      break;
  }
}

void handleMenuButton() {
  int buttonState = digitalRead(encoderButtonPin);
  if (buttonState == LOW && (millis() - lastDebounceTime) > debounceDelay) {
    menuNeedsRedraw = true;
    isMenuSelected = false;
    lastDebounceTime = millis();
    delay(200); // Debounce delay
  }
}

void handleMenuNavigation() {
  int change = readEncoder();
  if (change != 0) {
    menuIndex += change;
    if (menuIndex < 0) menuIndex = 2;
    if (menuIndex > 2) menuIndex = 0;
    lcd.clear();
    menuNeedsRedraw = true;
    delay(200); // Slow down the scroll speed
  }
}

void handleSelectedMenuItem() {
  if (menuIndex == 0) {
    // Handle Humidity Set
    // Display "Number Set" screen
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Humidity Set");
    lcd.setCursor(0, 1);
    lcd.print(">number set");
    delay(200); // Delay to stabilize display
  } else if (menuIndex == 1) {
    // Handle Time
    // Display current time
    DateTime now = rtc.now();
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Time:");
    lcd.print(now.hour(), DEC);
    lcd.print(':');
    lcd.print(now.minute(), DEC);
    lcd.print(':');
    lcd.print(now.second(), DEC);
    delay(200); // Delay to stabilize display
  } else if (menuIndex == 2) {
    // Handle Home
    menuNeedsRedraw = false;
    isMenuSelected = false;
    lcd.clear();
    delay(200); // Delay to stabilize display
  }
}

int readEncoder() {
  int MSB = digitalRead(encoderPinA);
  int LSB = digitalRead(encoderPinB);
  int encoded = (MSB << 1) | LSB;
  int sum = (lastEncoded << 2) | encoded;
  lastEncoded = encoded;

  if (sum == 0b1101 || sum == 0b0100 || sum == 0b0010 || sum == 0b1011) {
    return 1;
  }
  else if (sum == 0b1110 || sum == 0b0111 || sum == 0b0001 || sum == 0b1000) {
    return -1;
  }
  return 0;
}