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


const int trigpin=5;
const int ledpin=2;
const int echopin=18;
#define sound_speed 0.034


void callback(char*subscribetopic,byte* payload,unsigned int payloadLength);
 
 //----------Credentials of IBM accounts-----------------
#define ORG "zvvqaf"
#define Device_Type "IoT_devices"
#define Device_ID "12345"
#define Token "qagOTm?(qV+deBQ*j*"
String data3;
long duration;
float distance;

//-----------Customise the above values-----------------
char server[] = ORG ".messaging.internetofthings.ibmcloud.com";
char publishTopic[] = "iot-2/evt/Data/fmt/json";
char subscribetopic[] = "iot-2/cmd/test/fmt/String";
char authMethod[]= "use-token-auth";
char token[]=Token;
char clientId[]="d:"ORG ":" Device_Type ":" Device_ID;
//--------------------------------------------------
WiFiClient wifiClient;
PubSubClient client(server, 1883,callback ,wifiClient);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trigpin,OUTPUT);
  pinMode(ledpin,OUTPUT);
  pinMode(echopin,INPUT);
  wificonnect();
  mqttconnect();
}

void loop() {
 // put your main code here, to run repeatedly:
 digitalWrite(trigpin,LOW);
 digitalWrite(trigpin,HIGH);
 delayMicroseconds(10);
 digitalWrite(trigpin,LOW);
 duration=pulseIn(echopin,HIGH);
 distance= duration*sound_speed/2;
 PublishData(distance);
 delay(1000);
 
if(!client.loop()){
  mqttconnect();
}
}

//-----------retriving to cloud-------------
void PublishData(float distance){
  mqttconnect();

//--------creating the string in form JSon to update the data to ibm cloud-----------
String payload = "{\"Distance\":";
payload+=distance;
payload+= "}";


Serial.print("Sending payload: ");
Serial.println(payload);


if(client.publish(publishTopic,(char*)payload.c_str())){
  Serial.println("Publish ok");
}
else{
  Serial.println("Publish failed");
}
  }
void mqttconnect(){
  if(!client.connected()){
    Serial.print("Reconnecting client to ");
    Serial.println(server);
    while(!!!client.connect(clientId,authMethod,token)){
      Serial.println(".");
      delay(500);
    }
    initManageDevice();
    Serial.println();
  }
}
void wificonnect()
{
  Serial.println();
  Serial.print("Connecting to");

  WiFi.begin("Wokwi-GUEST","",6);
  while(WiFi.status() != WL_CONNECTED){
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

}
void initManageDevice(){
  if(client.subscribe(subscribetopic)){
    Serial.println((subscribetopic));
    Serial.println("subscribe to cmd OK");
  }
  else{
    Serial.println("subscribe to cmd failed");
  }
}

void callback(char* subscribetopic,byte* payload,unsigned int payloadLength)
{
  Serial.print("callback invoked for topic");
  Serial.println(subscribetopic);
  for(int i=0;i<payloadLength;i++){
    data3+=(char)payload[i];
  }
  Serial.println("data:"+data3);
  if(data3=="lighton")
  {
    Serial.println(data3);
    digitalWrite(ledpin, HIGH);
  }
  else{
    Serial.println(data3);
    digitalWrite(ledpin, LOW);

  }
  data3="";


}