#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 "DEV6659cf3d0616223552"  // Device ID Telkom IoT
#define KEY "18fced22c305117f" // Access Key Telkom IoT
#define TOKEN "18fced22c30b6d0a" // Access Token Telkom IoT
const char* mqtt_server = "mqtt.telkomiot.id"; // MQTT Server Telkom IoT
const char* mqtt_topic = "/v2.0/subs/APP6659cf125317f26883/DEV6659cf3d0616223552"; // MQTT Topic Telkom IoT

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, 6);
  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.telkomiot.id", 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/subs/APP6659cf125317f26883/DEV6659cf3d0616223552", telemetry);
  Serial.println( telemetry );   
  // mqtt://mqtt.telkomiot.id/v2.0/subs/APP6659c41b9794262928/DEV6659c454bbc6526032
}

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("DEV6659cf3d0616223552", "18fced22c305117f", "18fced22c30b6d0a")) {
      Serial.println( "[DONE]" );
    } else {
      Serial.print( "[FAILED] [ rc = " );
      Serial.println( " : retrying in 5 seconds]" );
      delay( 1000 );
    }
  }
}