#include <Wire.h>                 // Include the Wire library for I2C communication
#include <LiquidCrystal_I2C.h>     // Include the LCD library
#include <RTClib.h>                // Include the RTC library
#include <DHT.h>                   // Include the DHT sensor library

#define DHTPIN 10                  // Define DHT22 data pin
#define DHTTYPE DHT22              // Define the type of DHT sensor

// Define relay pins
#define FAN_RELAY_PIN 5            // Relay connected to control fan
#define PUMP_RELAY_PIN 6           // Relay connected to control pump
#define LIGHT_RELAY_PIN 7          // Relay connected to control light

LiquidCrystal_I2C lcd(0x27, 20, 4); // Set the LCD I2C address to 0x27, with 20 columns and 4 rows
RTC_DS1307 rtc;                     // Create an RTC object
DHT dht(DHTPIN, DHTTYPE);           // Create a DHT object

void setup() {
  Wire.begin();            // Initialize I2C communication
  lcd.init();              // Initialize the LCD
  lcd.backlight();         // Turn on the LCD backlight
  
  dht.begin();             // Initialize the DHT sensor
  
  pinMode(FAN_RELAY_PIN, OUTPUT);   // Set fan relay pin as output
  pinMode(PUMP_RELAY_PIN, OUTPUT);  // Set pump relay pin as output
  pinMode(LIGHT_RELAY_PIN, OUTPUT); // Set light relay pin as output
  
  // Initially turn off all relays
  digitalWrite(FAN_RELAY_PIN, HIGH);   
  digitalWrite(PUMP_RELAY_PIN, HIGH);  
  digitalWrite(LIGHT_RELAY_PIN, HIGH); 
  
  if (!rtc.begin()) {
    lcd.setCursor(0, 0);   // Set cursor to the first column, first row
    lcd.print("Couldn't find RTC");
    while (1);
  }

  if (!rtc.isrunning()) {
    lcd.setCursor(0, 0);   // Set cursor to the first column, first row
    lcd.print("RTC is NOT running!");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Set the RTC to the date & time this sketch was compiled
  }
}

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

  displayTime(now);          // Display the time
  displayTempHumidity();     // Display temperature and humidity
  controlRelays(now);        // Control the relays based on sensor readings and time
  
  delay(1000);               // Update every second
}

// Function to display the current time
void displayTime(DateTime now) {
  lcd.setCursor(0, 0);     // Set cursor to the first column, first row
  lcd.print("TIME: ");     // Display "TIME: "
  
  lcd.setCursor(6, 0);     // Set cursor position for time display
  if (now.hour() < 10) lcd.print('0');  // Add leading zero if needed
  lcd.print(now.hour());
  lcd.print(':');
  
  if (now.minute() < 10) lcd.print('0'); // Add leading zero if needed
  lcd.print(now.minute());
  lcd.print(':');
  
  if (now.second() < 10) lcd.print('0'); // Add leading zero if needed
  lcd.print(now.second());
}

// Function to display temperature and humidity
void displayTempHumidity() {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  lcd.setCursor(0, 1);     // Set cursor to the first column, second row
  lcd.print("TEMP: ");     // Display "TEMP: "
  
  if (isnan(temperature)) {
    lcd.print("Err");      // Display error if reading fails
  } else {
    lcd.print((int)temperature); // Display temperature as an integer
    lcd.print((char)223);   // Display the degree symbol (°)
    lcd.print("C ");
  }

  lcd.print("HIM: ");      // Display "HIM: "
  if (isnan(humidity)) {
    lcd.print("Err");      // Display error if reading fails
  } else {
    lcd.print((int)humidity); // Display humidity as an integer
    lcd.print("%");
  }
}

// Function to control relays based on sensor readings and time
void controlRelays(DateTime now) {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  
  // Control the fan based on temperature
  if (temperature > 30) {
    digitalWrite(FAN_RELAY_PIN, HIGH);   // Turn on the fan
    lcd.setCursor(0, 2);     // Set cursor to the first column, third row
    lcd.print("Fan: ON     "); // Display "Fan: ON"
  } else {
    digitalWrite(FAN_RELAY_PIN, LOW);    // Turn off the fan
    lcd.setCursor(0, 2);     // Set cursor to the first column, third row
    lcd.print("Fan: OFF    "); // Display "Fan: OFF"
  }

  // Control the pump based on humidity
  if (humidity < 80) {
    digitalWrite(PUMP_RELAY_PIN, HIGH);  // Turn on the pump
    lcd.setCursor(10, 2);     // Set cursor to the 11th column, third row
    lcd.print("Pump: ON ");   // Display "Pump: ON"
  } else {
    digitalWrite(PUMP_RELAY_PIN, LOW);   // Turn off the pump
    lcd.setCursor(10, 2);     // Set cursor to the 11th column, third row
    lcd.print("Pump: OFF");   // Display "Pump: OFF"
  }

  // Control the light based on the specified time range (14:44 to 14:45)
  if (now.hour() == 9 && now.minute() >= 41 && now.minute() <= 42) {
    digitalWrite(LIGHT_RELAY_PIN, HIGH);  // Turn on the light
  } else {
    digitalWrite(LIGHT_RELAY_PIN, LOW); // Turn off the light
  }
}