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

#define LDR 35
const float GAMMA = 0.7;
const float RL10 = 50;

const char *ssid = "Wokwi-GUEST";
const char *password = "";


#define DEVICEID "DEV636e54ebbb3df65488"
#define TOKEN "18465f56af5e96c3" 
const char* mqtt_server = "mqtt.telkomiot.id";

WiFiClient wifiClient;
PubSubClient client(wifiClient);
int status = WL_IDLE_STATUS;
void setup()
{
  Serial.begin(9600);
  delay(10);
  pinMode(LDR, INPUT);
  Serial.print(" Connect to : ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
{
  delay(500);
  Serial.print("...");
}
Serial.print("\n");
Serial.print("IP address : ");
Serial.print(WiFi.localIP());
Serial.print("\n");
Serial.print("Connect to : ");
Serial.println(ssid);    
client.setServer( mqtt_server, 1883);
}

void loop()
{
  if ( !client.connected() ) 
  {
      reconnect();
  }
  getData();
  delay(5000);
}

void getData()
{
  int analogValue = analogRead(LDR);
  float voltage = analogValue / 4095. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  Serial.println(lux);

  String payload = "{";
  payload += "\"Intensitas Cahaya\":";payload += lux;
  payload += "}";

  char telemetry[1000];
  payload.toCharArray( telemetry, 1000 );
  client.publish("v2.0/pubs/APP636e118d6bdf765263/DEV636e54ebbb3df65488",telemetry);
  Serial.println( telemetry );   
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    status = WiFi.status();
    if ( status != WL_CONNECTED) {
      WiFi.begin(ssid, password);
      while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
      }
      Serial.println("Connected to AP");
    }
    Serial.print("Connecting to server node ...");
    if ( client.connect("DEV636e54ebbb3df65488","18465f56af5c944f", "18465f56af5e96c3")) {
      Serial.println( "[DONE]" );
    } else {
      Serial.print( "[FAILED] [ rc = " );
      Serial.println( " : retrying in 5 seconds]" );
      delay( 500 );
    }
  }
}