#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

#define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

#define LDR 15

BLECharacteristic *pCharacteristic;

void setup() {
  Serial.begin(115200);

  pinMode(LDR, INPUT);
  
  Serial.println("Starting BLE work!");

  BLEDevice::init("ESP32-Pepper");
  BLEServer *pServer = BLEDevice::createServer();
  BLEService *pService = pServer->createService(SERVICE_UUID);
  pCharacteristic = pService->createCharacteristic(
                                         CHARACTERISTIC_UUID,
                                         BLECharacteristic::PROPERTY_READ |
                                         BLECharacteristic::PROPERTY_WRITE
                                       );

  pCharacteristic->setValue("Hello World");
  pService->start();
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pAdvertising->setScanResponse(true);
  pAdvertising->setMinPreferred(0x06);  
  pAdvertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
  Serial.println("Waiting a client connection to notify...");
}

void loop() {
  int ldrValue = analogRead(LDR);
  Serial.println(ldrValue);
  char ldrValueChar[50];
  sprintf(ldrValueChar, "%d", ldrValue);
  pCharacteristic->setValue(ldrValueChar);
  delay(2000);
}