#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <RTClib.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1  // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define DHTPIN 19     // Pin connected to the DHT22 sensor
#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321
DHT dht(DHTPIN, DHTTYPE);

RTC_DS1307 rtc;

// Define button pins
#define button_up 14
#define button_down 27
#define button_enter 12

// Menu variables
int menuIndex = 0;
const int menuLength = 3; // Number of menu items
const char* menuItems[] = {"Clock", "Temp", "Humidity"};

void setup() {
  // Initialize serial communication
  Serial.begin(115200);

  // Initialize the SSD1306 display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();

  // Initialize DHT sensor
  dht.begin();

  // Initialize RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is NOT running, let's set the time!");
    // Comment out the following line once you set the correct time
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // Set button pins as input with pullup
  pinMode(button_up, INPUT_PULLUP);
  pinMode(button_down, INPUT_PULLUP);
  pinMode(button_enter, INPUT_PULLUP);

  // Display the initial menu
  displayMenu();
}

void loop() {
  // Check button presses
  if (digitalRead(button_up) == LOW) {
    menuIndex--;
    if (menuIndex < 0) menuIndex = menuLength - 1;
    displayMenu();
    delay(200); // Debounce delay
  }

  if (digitalRead(button_down) == LOW) {
    menuIndex++;
    if (menuIndex >= menuLength) menuIndex = 0;
    displayMenu();
    delay(200); // Debounce delay
  }

  if (digitalRead(button_enter) == LOW) {
    selectMenuItem();
    delay(200); // Debounce delay
  }
}

void displayMenu() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  for (int i = 0; i < menuLength; i++) {
    if (i == menuIndex) {
      display.setTextColor(SSD1306_BLACK, SSD1306_WHITE); // Highlight selected item
    } else {
      display.setTextColor(SSD1306_WHITE);
    }
    display.setCursor(0, i * 10);
    display.print(menuItems[i]);
  }

  display.display();
}

void selectMenuItem() {
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  if (menuIndex == 0) {
    // Display clock
    DateTime now = rtc.now();
    display.setCursor((SCREEN_WIDTH - 6 * 10) / 2, (SCREEN_HEIGHT - 16) / 2); // Center align
    display.printf("%02d:%02d:%02d", now.hour(), now.minute(), now.second());
  } else if (menuIndex == 1) {
    // Display temperature
    float temp = dht.readTemperature();
    display.setCursor((SCREEN_WIDTH - 7 * 6) / 2, (SCREEN_HEIGHT - 16) / 2); // Center align
    if (isnan(temp)) {
      display.print("Error");
    } else {
      display.printf("Temp: %.1fC", temp);
    }
  } else if (menuIndex == 2) {
    // Display humidity
    float humidity = dht.readHumidity();
    display.setCursor((SCREEN_WIDTH - 8 * 6) / 2, (SCREEN_HEIGHT - 16) / 2); // Center align
    if (isnan(humidity)) {
      display.print("Error");
    } else {
      display.printf("Humidity: %.1f%%", humidity);
    }
  }

  display.display();
  delay(1000); // Show the selected item for 1 second

  // After showing the selected item, return to the menu
  displayMenu();
}