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

// WiFi
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// MQTT
const char* mqtt_server = "mqtt.eclipseprojects.io";
const char* mqtt_topic = "esp32/temperature";

WiFiClient espClient;
PubSubClient client(espClient);

// DHT22
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// Analog pin (simulate thermistor)
#define THERM_PIN 34

void setup_wifi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password, 6);  // Wokwi uses channel 6
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" connected!");
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32Client")) {
      Serial.println(" connected");
    } else {
      Serial.print(" failed, rc=");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

float convertAnalogToCelsius(int analogValue) {
  // Simulate 0–100°C from 0–4095
  return (analogValue / 4095.0) * 100.0;
}

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

  float dhtTemp = dht.readTemperature();
  int analogValue = analogRead(THERM_PIN);
  float thermTemp = convertAnalogToCelsius(analogValue);

  if (isnan(dhtTemp)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Format JSON
  StaticJsonDocument<128> doc;
  doc["dht"] = dhtTemp;
  doc["therm"] = thermTemp;

  char jsonBuffer[128];
  serializeJson(doc, jsonBuffer);

  client.publish(mqtt_topic, jsonBuffer);
  Serial.println(jsonBuffer);

  delay(5000);  // Every 5 seconds
}