#include "DHT.h"     
#include <PubSubClient.h>
#include <ESP8266_Lib.h>
#define DHTTYPE DHT22   

const char* ssid = "Wokwi-GUEST";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

const char* mqtt_server = "REPLACE_WITH_YOUR_RPI_IP_ADDRESS";

WiFiClient espClient;
PubSubClient client(espClient);

const int DHTPIN = 5;
const int LDRPIN = A0;

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

DHT dht(DHTPIN, DHTTYPE);

void setup_wifi() 
{
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected - ESP IP address: ");
  Serial.println(WiFi.localIP());
}

void setup() 
{
  Serial.begin(9600);
  dht.begin();
  pinMode(LDRPIN, INPUT);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() 
{
  if (!client.connected()) {
    reconnect();
  }
  if(!client.loop())
    client.connect("ESP8266Client");

  float h = dht.readHumidity();
  float t = dht.readTemperature();

  int analogValue = analogRead(LDRPIN);
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.println("%");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println("°C");
  Serial.print("Illumination: ");
  Serial.print(lux);
  Serial.println("lux");
  Serial.println("~~~~~~~~~~~~~~~~"); 
  delay(1000);
}

void reconnect() {
  while (!client.connected())
   {
     Serial.print("Attempting MQTT connection...");
     if (client.connect("ESP8266Client")) {
     Serial.println("connected");  
     client.subscribe("room/lamp");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}