#include <WiFi.h>
#include <ArduinoHttpClient.h>

#define trigpin 4
#define echopin 2

float duration;
float distance;

#define WIFI_AP "Wokwi-GUEST"
#define WIFI_PASS ""

#define TB_SERVER "eu.thingsboard.cloud"
#define TOKEN "jOT8TUDSWYezHShrXER8"

WiFiClient wifiClient;
HttpClient http(wifiClient, TB_SERVER, 80);

bool sendTelemetryHTTP(float value) {
  http.stop(); // Close previous connection, if any

  String url = "/api/v1/" + String(TOKEN) + "/telemetry";
  http.beginRequest();
  http.post(url, "application/json", "{\"UltrasonicData\":" + String(value) + "}");
  http.endRequest();

  int httpCode = http.responseStatusCode();
  if (httpCode > 0) {
    Serial.print("HTTP POST Success. Response code: ");
    Serial.println(httpCode);
    return true;
  } else {
    Serial.print("HTTP POST Error. Response code: ");
    Serial.println(httpCode);
    return false;
  }
}

void initWifi();

void setup() {
  Serial.begin(9600);
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  initWifi();
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    initWifi();
  }

  digitalWrite(trigpin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigpin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigpin, LOW);

  duration = pulseIn(echopin, HIGH);
  distance = (duration / 58.2);  

  Serial.print("Distance = ");
  Serial.print(distance);
  Serial.println(" cm");

  // Send telemetry data using HTTP
  if (sendTelemetryHTTP(distance)) {
    Serial.print("Sending Ultrasonic Data: ");
    Serial.print(distance);
    Serial.println(" cm");
    Serial.println("Telemetry data sent successfully");
  } else {
    Serial.println("Failed to send telemetry data. Try again...");
  }

  delay(1000);
}

void initWifi() {
  Serial.println("Connect WiFi");
  WiFi.begin(WIFI_AP, WIFI_PASS);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }

  Serial.println("CONNECTED");
}