#include <ArduinoBLE.h>

#define MY_SERVICE_UUID             "be6d058c-9542-4d1f-9711-6eb1c06de216"
#define MY_CHARACTERISTIC_UUID      "ac7ccd7a-8c67-41d6-a248-ea66199254b0"

BLEService myService(MY_SERVICE_UUID);
BLEStringCharacteristic myCharacteristic(MY_CHARACTERISTIC_UUID, BLERead | BLEWrite | BLENotify, 8);

int myPin = 10;
String prevCharacteristicValue = "";
String characteristicValue = "";
String baseName = "Dev1";


String myName() {
  String myState = "";
  if (characteristicValue == "9") {
    myState = "ON";
  } else {
    myState = "OFF";
  }
  String dum = baseName + "_" + myState;
  return (dum);
}

void changeLocalName() {
  String dum = myName();
  BLE.stopAdvertise();
  BLE.setLocalName(dum.c_str());
  BLE.advertise();
}


void setup() {

  Serial.begin(9600);
  while (!Serial);

  pinMode(myPin, INPUT);
  digitalWrite(myPin, LOW);

  if (!BLE.begin()) {
    Serial.println("starting BLE failed!");
    while (1);
  }

  String dum = myName();
  BLE.setLocalName(dum.c_str());
  BLE.setAdvertisedService(myService);
  myService.addCharacteristic(myCharacteristic);
  BLE.addService(myService);
  myCharacteristic.writeValue("5");
  if (BLE.advertise()) {
    Serial.println("advertising...");
  }
}


unsigned prevTim = 0;

void loop() {
  BLEDevice central = BLE.central();

  unsigned tim = millis();
  if (tim - prevTim > 1000) {
    String dum = myName();
    dum = "localName of device is " + dum;
    Serial.println(dum.c_str());
    prevTim = millis();
  }

  if (false & central) {
    Serial.print("Connected to central: ");
    Serial.println(central.address());
    Serial.print(F("Disconnected from central: "));
    Serial.println(central.address());
  }

  characteristicValue = myCharacteristic.value();
  if (characteristicValue != prevCharacteristicValue) {
    prevCharacteristicValue = characteristicValue;
    if (characteristicValue == "5") {
      digitalWrite(myPin, LOW);
      changeLocalName();
      Serial.println("myPin is now set to LOW");
    }
    if (characteristicValue == "9") {
      digitalWrite(myPin, HIGH);
      changeLocalName();
      Serial.println("myPin is now set to HIGH");
    }
  }
}