#include <WiFi.h>
#include <PubSubClient.h>
#include <LiquidCrystal.h>
#include "DHT.h"


LiquidCrystal lcd(17, 16, 4, 0, 2, 15);
#define DHTPIN 26       
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
#define MQ2_PIN 32    
#define BUZZER_PIN 22


const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server ="test.mosquitto.org";

WiFiClient espClient;
PubSubClient client(espClient);

void setup_wifi() {
  WiFi.begin(ssid, password);

  lcd.clear();
  lcd.print("Connecting WiFi");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
}
void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32_Client")) {
      // Connected
    } else {
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);

  lcd.begin(16, 2);
  lcd.print("LCD Ready!");
  delay(2000);

  dht.begin();
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);

  lcd.clear();
  lcd.print("WiFi Setup...");
  setup_wifi();
  lcd.clear();
  lcd.print("WiFi Connected");

  client.setServer(mqtt_server, 1883);
  lcd.setCursor(0, 1);
  lcd.print("MQTT Ready");

  delay(1500);
}

void loop() {
  if (!client.connected()) reconnect();
  client.loop();

  float temp = dht.readTemperature();
  float hum  = dht.readHumidity();
  int gas_value = analogRead(MQ2_PIN);
  if (isnan(temp) || isnan(hum)) {
    lcd.clear();
    lcd.print("DHT Error!");
    delay(2000);
    return;
  }

  char msg[150];
sprintf(msg,
        "{\"temperature\": %.2f, \"humidity\": %.2f, \"gas\": %d}",
        temp, hum, gas_value);

client.publish("show", msg);
Serial.print("Publishing: ");
Serial.println(msg);

client.publish("show", msg);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temp);
  lcd.print("C H:");
  lcd.print(hum);

  lcd.setCursor(0, 1);
  lcd.print("Gas:");
  lcd.print(gas_value);

 if (gas_value > 2500 || temp > 35) {
    tone(BUZZER_PIN, 100);  
} else {
    noTone(BUZZER_PIN);    
}

  delay(3000);
}