/*********
  Rui Santos
  Complete instructions at https://RandomNerdTutorials.com/esp32-ble-server-client/
  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.
  The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*********/

#include "BLEDevice.h"
#include <Wire.h>

//BLE Server name (the other ESP32 name running the server sketch)
#define bleServerName "YourESP32"

/* UUID's of the service, characteristic that we want to read*/
// BLE Service
static BLEUUID bmeServiceUUID("91bad492-b950-4226-aa2b-4ede9fa42f59");

//Temperature Celsius Characteristic
static BLEUUID temperatureCharacteristicUUID("cba1d466-344c-4be3-ab3f-189f80dd7518");

//Flags stating if should begin connecting and if the connection is up
static boolean doConnect = false;
static boolean connected = false;

//Address of the peripheral device. Address will be found during scanning...
static BLEAddress* pServerAddress;

//Characteristicd that we want to read
static BLERemoteCharacteristic* temperatureCharacteristic;

//Activate notify
const uint8_t notificationOn[] = { 0x1, 0x0 };
const uint8_t notificationOff[] = { 0x0, 0x0 };

//Variables to store temperature and humidity
char* temperatureChar;

//Flags to check whether new temperature and humidity readings are available
boolean newTemperature = false;
boolean newHumidity = false;

//Connect to the BLE Server that has the name, Service, and Characteristics
bool connectToServer(BLEAddress pAddress) {
  BLEClient* pClient = BLEDevice::createClient();

  // If the flag "doConnect" is true then we have scanned for and found the desired
  // BLE Server with which we wish to connect.  Now we connect to it.  Once we are
  // connected we set the connected flag to be true.
  if (doConnect == true) {
    if (connectToServer(*pServerAddress)) {
      Serial.println("We are now connected to the BLE Server.");
      //Activate the Notify property of each Characteristic
      temperatureCharacteristic->getDescriptor(BLEUUID((uint16_t)0x2902))->writeValue((uint8_t*)notificationOn, 2, true);
      humidityCharacteristic->getDescriptor(BLEUUID((uint16_t)0x2902))->writeValue((uint8_t*)notificationOn, 2, true);
      connected = true;
    } else {
      Serial.println("We have failed to connect to the server; Restart your device to scan for nearby BLE server again.");
    }
    doConnect = false;
  }
  delay(1000);  // Delay a second between loops.
}