#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <PubSubClient.h>

#define ONE_WIRE_BUS 14

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// Ultrasonic Sensor pins
const int trigPin = 4;
const int echoPin = 2;

long duration;
int distance;

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


// ThingsBoard parameters
const char* mqtt_server = "thingsboard.cloud";
const char* tb_token = "x4OGUSDNA5qeZT1YEE5f";

// WiFi and MQTT clients
WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  // Start serial communication
  Serial.begin(9600);
  // Start the DS18B20 sensor
  sensors.begin();

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" connected");

  // Setup MQTT
  client.setServer(mqtt_server, 1883);
  connectMQTT();
}

void loop() {
  sensors.requestTemperatures();
  // Fetch temperature in Celsius
  float temperatureC = sensors.getTempCByIndex(0);

  // Clear the trigPin by setting it LOW
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Set the trigPin HIGH for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in centimeters
  distance = duration * 0.034 / 2;

  // Print the values to the Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(temperatureC);
  Serial.println(" °C");

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

  // // Send data to ThingSpeak
  // if (WiFi.status() == WL_CONNECTED) {
  //   HTTPClient http;
  //   String url = "http://api.thingspeak.com/update?api_key=" + String(apiKey) +
  //                "&field1=" + String(temperatureC) +
  //                "&field2=" + String(distance);
    
  //   http.begin(url);
  //   int httpCode = http.GET();
  //   if (httpCode > 0) {
  //     Serial.printf("HTTP GET code: %d\n", httpCode);
  //   } else {
  //     Serial.printf("HTTP GET failed, error: %s\n", http.errorToString(httpCode).c_str());
  //   }
  //   http.end();
  // } else {
  //   Serial.println("WiFi not connected");
  // }

  // Send data to ThingsBoard
  if (!client.connected()) {
    connectMQTT();
  }
  client.loop();
  
  String payload = "{";
  payload += "\"temperature\":" + String(temperatureC) + ",";
  payload += "\"distance\":" + String(distance);
  payload += "}";

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

  delay(20000);
}

void connectMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to ThingsBoard...");
    if (client.connect("ESP32Client", tb_token, NULL)) {
      Serial.println(" connected.");
    } else {
      Serial.print(" failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}