#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <DHT.h>
#include <Wire.h>
#include <RTClib.h>

#define TFT_CS     10
#define TFT_RST    9
#define TFT_DC     8

#define DHT_PIN_1    7
#define DHT_PIN_2    6
#define DHT_TYPE   DHT22

#define ROTARY_CLK  3
#define ROTARY_DT   4
#define ROTARY_SW   5

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
DHT dht1(DHT_PIN_1, DHT_TYPE);
DHT dht2(DHT_PIN_2, DHT_TYPE);
RTC_DS3231 rtc;

volatile int rotaryPosition = 0;
bool isCelsius = true;
bool showSettings = false;

DateTime lastDisplayUpdate;

void setup() {
  Serial.begin(9600);
  tft.begin();
  dht1.begin();
  dht2.begin();
  if (!rtc.begin()) {
    tft.setTextSize(2);
    tft.setTextColor(ILI9341_WHITE);
    tft.setCursor(0, 0);
    tft.println("Clock is lost");
    tft.setTextSize(1);
    tft.println("Do you want to continue?");
    tft.println("Rotate encoder to select");
    tft.println("Press to confirm");

    pinMode(ROTARY_CLK, INPUT_PULLUP);
    pinMode(ROTARY_DT, INPUT_PULLUP);
    pinMode(ROTARY_SW, INPUT_PULLUP);

    attachInterrupt(digitalPinToInterrupt(ROTARY_CLK), handleEncoder, CHANGE);
    attachInterrupt(digitalPinToInterrupt(ROTARY_DT), handleEncoder, CHANGE);

    while (digitalRead(ROTARY_SW) == HIGH) {
      delay(50);
    }

    if (rotaryPosition == 0) {
      while (rtc.lostPower()) {
        delay(500);
      }
    }
  }

  lastDisplayUpdate = rtc.now();
}

void loop() {
  DateTime now = rtc.now();

  if (showSettings) {
    handleSettings();
    return;
  }

  // Update display every 5 seconds
  if (now.second() % 5 == 0 && now != lastDisplayUpdate) {
    lastDisplayUpdate = now;

    float temperature1, temperature2;
    float humidity1, humidity2;

    // Read temperature and humidity from first DHT22
    humidity1 = dht1.readHumidity();
    temperature1 = dht1.readTemperature();

    // Read temperature and humidity from second DHT22
    humidity2 = dht2.readHumidity();
    temperature2 = dht2.readTemperature();

    // If temperature or humidity reading failed, display an error message
    if (isnan(humidity1) || isnan(temperature1) || isnan(humidity2) || isnan(temperature2)) {
      tft.fillScreen(ILI9341_BLACK);
      tft.setTextSize(2);
      tft.setTextColor(ILI9341_RED);
      tft.setCursor(0, 0);
      if (isnan(humidity1) || isnan(temperature1)) {
        tft.println("Error reading sensor 1!");
      } else {
        tft.println("Error reading sensor 2!");
      }
      return;
    }

    // Convert temperature to Fahrenheit if needed
    if (!isCelsius) {
      temperature1 = temperature1 * 9.0 / 5.0 + 32.0;
      temperature2 = temperature2 * 9.0 / 5.0 + 32.0;
    }

    // Display date and time
    tft.fillScreen(ILI9341_BLACK);
    tft.setCursor(0, 0);
    tft.setTextSize(1);
    tft.setTextColor(ILI9341_WHITE);
    tft.print(now.year(), DEC);
    tft.print('/');
    tft.print(now.month(), DEC);
    tft.print('/');
    tft.print(now.day(), DEC);
    tft.print(" ");
    int hour = now.hour();
    bool isPM = false;
    if (hour > 12) {
      hour -= 12;
      isPM = true;
    }
    tft.print(hour);
    tft.print(":");
    if (now.minute() < 10) tft.print("0");
    tft.print(now.minute(), DEC);
    if (isPM) {
      tft.print(" PM");
    } else {
      tft.print(" AM");
    }
    
    // Display temperature and humidity on TFT display
    tft.setCursor(0, 20);
    tft.print("Temp 1: ");
    tft.println(temperature1, 1);
    tft.print("Humidity 1: ");
    tft.println(humidity1, 1);
    tft.print("Temp 2: ");
    tft.println(temperature2, 1);
    tft.print("Humidity 2: ");
    tft.println(humidity2, 1);

    // Display unit indication
    tft.setCursor(0, 220);
    tft.setTextSize(1);
    tft.setTextColor(ILI9341_WHITE);
    if (isCelsius) {
      tft.println("Unit: Celsius");
    } else {
      tft.println("Unit: Fahrenheit");
    }
  }

  // If the RTC is lost, keep taking readings every 20 seconds
  if (rtc.lostPower()) {
    delay(20000);
    return;
  }

  delay(1000); // Delay before next iteration
}

void handleEncoder() {
  static unsigned long lastRotaryTime = 0;
  unsigned long currentRotaryTime = millis();

  if (currentRotaryTime - lastRotaryTime > 4) {
    int CLK = digitalRead(ROTARY_CLK);
    int DT = digitalRead(ROTARY_DT);

    if (CLK == HIGH) {
      if (DT == LOW) {
        rotaryPosition++;
      } else {
        rotaryPosition--;
      }
    } else {
      if (DT == HIGH) {
        rotaryPosition++;
      } else {
        rotaryPosition--;
      }
    }

    if (rotaryPosition > 3) {
      rotaryPosition = 3;
    } else if (rotaryPosition < 0) {
      rotaryPosition = 0;
    }

    lastRotaryTime = currentRotaryTime;
  }
}

void handleSettings() {
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextSize(2);
  tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(0, 0);
  tft.println("Settings");
  tft.setTextSize(1);
  tft.setTextColor(ILI9341_YELLOW);
  tft.println("Use encoder to scroll options:");
  tft.setTextColor(ILI9341_WHITE);
  tft.println("1. Show all readings");
  tft.println("2. Convert to Celsius/Fahrenheit");
  tft.println("3. Calculate average");
  tft.println("4. Back to main screen");

  switch (rotaryPosition) {
    case 0:
      tft.fillRect(0, 88, 320, 12, ILI9341_GREEN); // Highlight selected option
      break;
    case 1:
      tft.fillRect(0, 100, 320, 12, ILI9341_GREEN);
      break;
    case 2:
      tft.fillRect(0, 112, 320, 12, ILI9341_GREEN);
      break;
    case 3:
      tft.fillRect(0, 124, 320, 12, ILI9341_GREEN);
      break;
  }

  if (digitalRead(ROTARY_SW) == LOW) {
    delay(200); // debounce
    switch (rotaryPosition) {
      case 0:
        showSettings = false;
        break;
      case 1:
        showAllReadings();
        break;
      case 2:
        toggleTemperatureUnit();
        break;
      case 3:
        showAverage();
        break;
    }
  }
}

void showAllReadings() {
  showSettings = false; // Exit settings
}

void toggleTemperatureUnit() {
  isCelsius = !isCelsius;
}

void showAverage() {
  float temperature1 = dht1.readTemperature();
  float temperature2 = dht2.readTemperature();
  float humidity1 = dht1.readHumidity();
  float humidity2 = dht2.readHumidity();

  float averageTemperature = (temperature1 + temperature2) / 2;
  float averageHumidity = (humidity1 + humidity2) / 2;

  tft.fillScreen(ILI9341_BLACK);
  tft.setTextSize(2);
  tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(0, 0);
  tft.println("Average:");
  tft.setTextSize(1);
  tft.setTextColor(ILI9341_YELLOW);
  tft.println("Temperature: ");
  tft.setTextColor(ILI9341_WHITE);
  tft.print(averageTemperature);
  tft.println(isCelsius ? "°C" : "°F");
  tft.setTextColor(ILI9341_YELLOW);
  tft.println("Humidity: ");
  tft.setTextColor(ILI9341_WHITE);
  tft.print(averageHumidity);
  tft.println("%");
  delay(5000);
}