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

#define DHTPIN 2       
#define DHTTYPE DHT22   
#define LED_PIN_3 3    
#define LED_PIN_4 4    
#define LED_PIN_5 5    
#define LED_PIN_6 6    
#define LED_PIN_7 7    
#define LED_PIN_8 8    
#define RELAY_PIN 9   
#define LDR_PIN A0     

DHT dht(DHTPIN, DHTTYPE);

#define I2C_ADDR 0x27

#define LCD_COLS 20
#define LCD_ROWS 4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLS, LCD_ROWS);

const float GAMMA = 0.7;
const float RL10 = 50;

void setup() {
  Serial.begin(9600);
  dht.begin();
  lcd.init();       
  lcd.backlight();  
  lcd.clear();      
  lcd.print("Temp: ");
  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.setCursor(0, 2);
  lcd.print("Light: ");

  pinMode(LED_PIN_3, OUTPUT); 
  pinMode(LED_PIN_4, OUTPUT); 
  pinMode(LED_PIN_5, OUTPUT); 
  pinMode(LED_PIN_6, OUTPUT); 
  pinMode(LED_PIN_7, OUTPUT); 
  pinMode(LED_PIN_8, OUTPUT); 
  pinMode(RELAY_PIN, OUTPUT); 
}

void loop() {
  delay(500); 

  float temperature = dht.readTemperature();

  float humidity = dht.readHumidity();

  float lightLevel = getLightLevel();

  lcd.setCursor(6, 0);
  lcd.print(temperature);
  lcd.print(" C");

  lcd.setCursor(10, 1); 
  lcd.print(humidity);
  lcd.print(" %");

  lcd.setCursor(7, 2); 
  lcd.print("         "); 
  lcd.setCursor(7, 2);
  lcd.print(lightLevel, 2);

  if (temperature < 20) {
    digitalWrite(LED_PIN_3, HIGH); 
    digitalWrite(LED_PIN_4, LOW); 
    digitalWrite(LED_PIN_5, LOW); 
  } else if (temperature >= 20 && temperature <= 25) {
    digitalWrite(LED_PIN_3, LOW); 
    digitalWrite(LED_PIN_4, HIGH); 
    digitalWrite(LED_PIN_5, LOW); 
  } else if (temperature > 25){
    digitalWrite(LED_PIN_3, LOW); 
    digitalWrite(LED_PIN_4, LOW); 
    digitalWrite(LED_PIN_5, HIGH); 
  }

  if (humidity < 40) {
    digitalWrite(LED_PIN_6, HIGH); 
    digitalWrite(LED_PIN_7, LOW); 
    digitalWrite(LED_PIN_8, LOW); 
  } else if (humidity >= 40 && humidity <= 60) {
    digitalWrite(LED_PIN_6, LOW); 
    digitalWrite(LED_PIN_7, HIGH); 
    digitalWrite(LED_PIN_8, LOW); 
  } else if (humidity > 60){
    digitalWrite(LED_PIN_6, LOW); 
    digitalWrite(LED_PIN_7, LOW); 
    digitalWrite(LED_PIN_8, HIGH); 
  }

  if (lightLevel < 300) {
    digitalWrite(RELAY_PIN, HIGH); 
  } else {
    digitalWrite(RELAY_PIN, LOW); 
  }

  Serial.print("Температура: ");
  Serial.print(temperature);
  Serial.print("°C | Вологість: ");
  Serial.print(humidity);
  Serial.print("% | Освітленість: ");
  Serial.println(lightLevel);
}

float getLightLevel() {
  int analogValue = analogRead(LDR_PIN);
  float voltage = analogValue / 1024.0 * 5.0;
  float resistance = 2000.0 * voltage / (1.0 - voltage / 5.0);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, 1.0 / GAMMA);
  return lux;
}