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

// ---------------- Wi-Fi Credentials ----------------
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ---------------- MQTT Broker Settings ----------------
const char* mqtt_server = "mqtt.eclipseprojects.io";
const char* mqtt_topic = "esp32/sensor/data14";

WiFiClient espClient;
PubSubClient client(espClient);

// ---------------- Sensor Configuration ----------------
#define DHTPIN 4          // GPIO4 for DHT22 data
#define DHTTYPE DHT22     // DHT 22 (AM2302)
DHT dht(DHTPIN, DHTTYPE);

#define NTC_PIN 34        // Analog input pin for thermistor (NTC)

// ---------------- WiFi Connection Function ----------------
void connectWiFi() {
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi Connected");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// ---------------- MQTT Connection Function ----------------
void connectMQTT() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    String clientId = "ESP32Client-" + String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("MQTT connected");
      client.subscribe(mqtt_topic);  // Optional if listening
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying in 5 seconds...");
      delay(5000);
    }
  }
}

// ---------------- MQTT Callback ----------------
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Incoming message [");
  Serial.print(topic);
  Serial.print("]: ");
  for (unsigned int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

// ---------------- Setup ----------------
void setup() {
  Serial.begin(115200);
  dht.begin();

  connectWiFi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  connectMQTT();
}

// ---------------- Loop ----------------
void loop() {
  if (!client.connected()) {
    connectMQTT();
  }
  client.loop();

  // ----- Read DHT22 -----
  float temp_dht = dht.readTemperature();
  float hum_dht = dht.readHumidity();

  // Check for failed read
  if (isnan(temp_dht) || isnan(hum_dht)) {
    Serial.println("Failed to read from DHT sensor!");
  } else {
    Serial.printf("DHT22 - Temp: %.2f °C, Humidity: %.2f %%\n", temp_dht, hum_dht);
  }

  // ----- Read NTC Sensor (Thermistor) -----
  int analogValue = analogRead(NTC_PIN);
  float voltage = analogValue * (3.3 / 4095.0);  // Convert ADC to voltage
  float temp_ntc = (voltage - 0.5) * 100.0;      // Rough estimation

  Serial.printf("NTC - Analog Temp (approx): %.2f °C\n", temp_ntc);

  // ----- Publish Data -----
  String payload = "{";
  payload += "\"temp_dht\":" + String(temp_dht, 2) + ",";
  payload += "\"humidity_dht\":" + String(hum_dht, 2) + ",";
  payload += "\"temp_ntc\":" + String(temp_ntc, 2);
  payload += "}";

  client.publish(mqtt_topic, payload.c_str());
  Serial.println("Published: " + payload);

  delay(5000);  // Delay between readings
}