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

// Initialize the LCD, adjust the I2C address (0x27 is common for LCD2004)
LiquidCrystal_I2C lcd(0x27, 20, 4);

// Define DHT22 sensor settings
#define DHTPIN 13      // DHT22 data pin connected to GPIO 13
#define DHTTYPE DHT22  // DHT22 (AM2302) sensor type
DHT dht(DHTPIN, DHTTYPE);

// Initialize the DS1307 RTC
RTC_DS1307 rtc;

// Relay pin definitions
const int fanPin = 12;  // Fan relay on pin 12
const int pumpPin = 14; // Pump relay on pin 14
const int lampPin = 27; // Lamp relay on pin 27
const int buttonPin = 26; // Button pin for toggling display modes

// Thresholds
const float tempThreshold = 30.0;
const float humThreshold = 80.0;

// Variables to track button state and display mode
int displayMode = 0;
bool lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 200;  // 200 ms debounce delay

// Variables to track time using millis
unsigned long lastUpdateTime = 0;  // Tracks last time the display was updated
unsigned long updateInterval = 1000;  // 1 second update interval

void setup() {
  // Initialize the LCD
  lcd.init();
  lcd.backlight();
  
  // Initialize DHT22 sensor
  dht.begin();

  // Initialize DS1307 RTC
  if (!rtc.begin()) {
    lcd.setCursor(0, 0);
    lcd.print("Couldn't find RTC");
    while (1);  // Halt if RTC is not found
  }
  
  if (!rtc.isrunning()) {
    lcd.setCursor(0, 0);
    lcd.print("RTC is not running");
    // Uncomment the next line to set the RTC to the current time
    // rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // Initialize relays
  pinMode(fanPin, OUTPUT);
  pinMode(pumpPin, OUTPUT);
  pinMode(lampPin, OUTPUT);
  
  // Initialize button
  pinMode(buttonPin, INPUT_PULLUP);

  // Ensure relays are off at start
  digitalWrite(fanPin, LOW);  // Assume LOW turns the relay off
  digitalWrite(pumpPin, LOW);
  digitalWrite(lampPin, LOW);

  // Initial message
  lcd.setCursor(0, 0);
  lcd.print("Temp & Humidity");
  delay(2000);
}

void loop() {
  unsigned long currentMillis = millis();  // Get the current time
  
  // Button state and debouncing using millis
  bool buttonState = digitalRead(buttonPin);
  if (buttonState != lastButtonState) {
    lastDebounceTime = currentMillis;  // Reset debounce timer
  }
  if ((currentMillis - lastDebounceTime) > debounceDelay) {
    if (buttonState == LOW && lastButtonState == HIGH) {
      // Switch between display modes
      displayMode = 1;
    }
  }
  lastButtonState = buttonState;

  // Only update the LCD and relays every 1 second
  if (currentMillis - lastUpdateTime >= updateInterval) {
    lastUpdateTime = currentMillis;  // Update the last update time

    // Read temperature and humidity from DHT22
    float humidity = dht.readHumidity();
    float temperature = dht.readTemperature();

    // Check if any readings failed and exit early
    if (isnan(humidity) || isnan(temperature)) {
      lcd.setCursor(0, 0);
      lcd.print("Error reading data");
      return;
    }

    // Get current date and time from RTC
    DateTime now = rtc.now();

    // Clear LCD and display based on the current mode
    lcd.clear();
    if (displayMode == 0) {
      // Display temperature, humidity, date, and time
      lcd.setCursor(0, 0);
      lcd.print(now.day(), DEC);
      lcd.print('/');
      lcd.print(now.month(), DEC);
      lcd.print('/');
      lcd.print(now.year(), DEC);
      
      lcd.setCursor(0, 1);
      lcd.print(now.hour(), DEC);
      lcd.print(':');
      lcd.print(now.minute(), DEC);
      lcd.print(':');
      lcd.print(now.second(), DEC);

      lcd.setCursor(0, 2);
      lcd.print("Temp: ");
      lcd.print(temperature);
      lcd.print(" C");

      lcd.setCursor(0, 3);
      lcd.print("Humidity: ");
      lcd.print(humidity);
      lcd.print(" %");
    } else {
      // Display the status of fan, pump, and lamp
      lcd.setCursor(0, 0);
      lcd.print("Fan: ");
      lcd.print(digitalRead(fanPin) == HIGH ? "ON" : "OFF");

      lcd.setCursor(0, 1);
      lcd.print("Pump: ");
      lcd.print(digitalRead(pumpPin) == HIGH ? "ON" : "OFF");

      lcd.setCursor(0, 2);
      lcd.print("Lamp: ");
      lcd.print(digitalRead(lampPin) == HIGH ? "ON" : "OFF");
    }

    // Control Fan based on temperature (Active High Logic)
    if (temperature > tempThreshold) {
      digitalWrite(fanPin, HIGH);  // Turn fan ON
    } else {
      digitalWrite(fanPin, LOW);   // Turn fan OFF
    }

    // Control Pump based on humidity (Active High Logic)
    if (humidity < humThreshold) {
      digitalWrite(pumpPin, HIGH);  // Turn pump ON
    } else {
      digitalWrite(pumpPin, LOW);   // Turn pump OFF
    }

    // Control Lamp based on time (14:20 ON, 14:22 OFF)
    if (now.hour() == 14 && now.minute() == 20) {
      digitalWrite(lampPin, HIGH);  // Turn lamp ON
    } else if (now.hour() == 14 && now.minute() == 22) {
      digitalWrite(lampPin, LOW);   // Turn lamp OFF
    }
  }
}