#include <DHTesp.h>         // DHT for ESP32 library
#include <WiFi.h>           // WiFi control for ESP32
#include <ThingsBoard.h>    // ThingsBoard SDK

// WiFi access point
#define WIFI_AP_NAME        "Wokwi-GUEST"
// WiFi password
#define WIFI_PASSWORD       ""

// See https://thingsboard.io/docs/getting-started-guides/helloworld/ 
// to understand how to obtain an access token
#define TOKEN               "smxJhEvGvvHkPpVw4tJg"
// ThingsBoard server instance.
#define THINGSBOARD_SERVER  "thingsboard.cloud"

// Baud rate for debug serial
#define SERIAL_DEBUG_BAUD    115200

// Initialize ThingsBoard client
WiFiClient espClient;
// Initialize ThingsBoard instance
ThingsBoard tb(espClient);
// the Wifi radio's status
int status = WL_IDLE_STATUS;

// DHT object
DHTesp dht;
// ESP32 pin used to query DHT22
#define DHT_PIN 15

// Setup an application
void setup() 
{
  // Initialize serial for debugging
  Serial.begin(SERIAL_DEBUG_BAUD);
  WiFi.begin(WIFI_AP_NAME, WIFI_PASSWORD);
  InitWiFi();

  // Initialize temperature sensor
  dht.setup(DHT_PIN, DHTesp::DHT22);
}

// Main application loop
void loop() 
{

  // Reconnect to WiFi, if needed
  if (WiFi.status() != WL_CONNECTED) 
  {
    reconnect();
    return;
  }

  // Reconnect to ThingsBoard, if needed
  if (!tb.connected()) 
  {
    // Connect to the ThingsBoard
    Serial.print("Connecting to: ");
    Serial.print(THINGSBOARD_SERVER);
    Serial.print(" with token ");
    Serial.println(TOKEN);
    if (!tb.connect(THINGSBOARD_SERVER, TOKEN)) 
    {
      Serial.println("Failed to connect");
      return;
    }
  }

  // Check if it is a time to send DHT22 temperature and humidity
  Serial.println("Sending data...");

    // Uploads new telemetry to ThingsBoard using MQTT. 
    // See https://thingsboard.io/docs/reference/mqtt-api/#telemetry-upload-api 
    // for more details

  TempAndHumidity lastValues = dht.getTempAndHumidity();    
  if (isnan(lastValues.humidity) || isnan(lastValues.temperature)) 
  {
    Serial.println("Failed to read from DHT sensor!");
  } 
  else 
  {
    tb.sendTelemetryFloat("temperature", lastValues.temperature);
    tb.sendTelemetryFloat("humidity", lastValues.humidity);
  }

  // Process messages
  tb.loop();
  delay(1000);
}

void InitWiFi()
{
  Serial.println("Connecting to AP ...");
  // attempt to connect to WiFi network

  WiFi.begin(WIFI_AP_NAME, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to AP");
}

void reconnect() 
{
  // Loop until we're reconnected
  status = WiFi.status();
  if ( status != WL_CONNECTED) 
  {
    WiFi.begin(WIFI_AP_NAME, WIFI_PASSWORD);
    while (WiFi.status() != WL_CONNECTED) 
    {
      delay(500);
      Serial.print(".");
    }
    Serial.println("Connected to AP");
  }
}