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

// ================= WIFI =================
#define WIFI_AP_NAME     "Wokwi-GUEST"
#define WIFI_PASSWORD   ""

// ================= THINGSBOARD =================
#define THINGSBOARD_SERVER  "thingsboard.dmidft.com"
#define TOKEN               "Jc9COeKFBBwZMiuFVSKA"
#define MQTT_PORT           1883

// ================= DHT SENSOR =================
#define DHT_PIN 15
DHTesp dht;

// ================= MQTT =================
WiFiClient espClient;
PubSubClient client(espClient);

// ================= TIMING =================
unsigned long lastSend = 0;
const unsigned long SEND_INTERVAL = 4000;

// ================= WIFI CONNECT =================
void connectWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(WIFI_AP_NAME, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi Connected");
}

// ================= MQTT CONNECT =================
void connectMQTT() {
  client.setServer(THINGSBOARD_SERVER, MQTT_PORT);

  while (!client.connected()) {
    Serial.print("Connecting to ThingsBoard...");
    if (client.connect("ESP32Client", TOKEN, NULL)) {
      Serial.println("Connected");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying...");
      delay(2000);
    }
  }
}

// ================= SETUP =================
void setup() {
  Serial.begin(115200);

  connectWiFi();
  connectMQTT();

  dht.setup(DHT_PIN, DHTesp::DHT22);
}

// ================= LOOP =================
void loop() {

  if (WiFi.status() != WL_CONNECTED) {
    connectWiFi();
  }

  if (!client.connected()) {
    connectMQTT();
  }

  client.loop();

  if (millis() - lastSend > SEND_INTERVAL) {
    lastSend = millis();

    float temperature = dht.getTemperature();
    float humidity    = dht.getHumidity();

    if (isnan(temperature) || isnan(humidity)) {
      Serial.println("DHT sensor error!");
      return;
    }

    // --------- JSON TELEMETRY ---------
    String payload = "{";
    payload += "\"temperature\":" + String(temperature) + ",";
    payload += "\"humidity\":" + String(humidity);
    payload += "}";

    Serial.println(payload);

    client.publish("v1/devices/me/telemetry", payload.c_str());
  }
}