#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEScan.h>
#include <BLEAdvertisedDevice.h>
#include <string>
#include <BLEServer.h>
#include <FS.h>
#include <SD.h>
#include <SPI.h>
#include <sstream>

#define SERVICE_UUID        "635f284e-1ef9-11e9-ab14-d663bd873d93"
#define CHARACTERISTIC_UUID "635f2ace-1ef9-11e9-ab14-d663bd873d93"

int rssi = -200;
int toWrite = 1;
BLEScan* pBLEScan;
BLECharacteristic *pCharacteristic;

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

  SD.begin(5);

  // Assegna un nome ad dispositivo bluetooth
  BLEDevice::init("ESP32-Bluetooth");

  // Settaggi per il tipo di scansione BT da eseguire
  pBLEScan = BLEDevice::getScan();
  pBLEScan->setActiveScan(true);
  pBLEScan->setInterval(500);
  pBLEScan->setWindow(99);

  // Crea il server BT nel quale pubblicare il valore RSSI corrente
  BLEServer *pServer = BLEDevice::createServer();
  BLEService *pService = pServer->createService(SERVICE_UUID);
  pCharacteristic = pService->createCharacteristic(
                                         CHARACTERISTIC_UUID,
                                         BLECharacteristic::PROPERTY_READ |
                                         BLECharacteristic::PROPERTY_WRITE
                                       );

  pCharacteristic->setValue("rssi is " + rssi);
  //pService->start();

  // Effettua l'advertising del valore impostato nel passaggio precedente
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pAdvertising->setScanResponse(true);
  pAdvertising->setMinPreferred(0x06);  // functions that help with iPhone connections issue
  pAdvertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
}

void appendFile(fs::FS &fs, const char * path, const char * message){
    Serial.printf("Appending to file: %s\n", path);

    File file = fs.open(path, FILE_APPEND);
    if(!file){
        Serial.println("Failed to open file for appending");
        return;
    }
    if(file.print(message)){
        toWrite = 0;
        Serial.println("Message appended");
    } else {
        Serial.println("Append failed");
    }
    file.close();
}


void loop() {

  BLEScanResults foundDevices = pBLEScan->start(1, false);

  for (int i = 0; i < foundDevices.getCount(); i++)
  {
    BLEAdvertisedDevice app = foundDevices.getDevice(i);

    String str = app.getAddress().toString().c_str();

    if (str.equals("00:cd:ff:00:34:12") && toWrite == 1) {
      Serial.println(app.getAddress().toString().c_str());
      Serial.println(app.getRSSI());
      pCharacteristic->setValue("rssi is " + rssi);
      char str[4];
      sprintf(str, "%d\n", app.getRSSI());
      appendFile(SD, "/rssi.txt", str);
      SD.end();
    }
  }

  pBLEScan->clearResults();   // delete results fromBLEScan buffer to release memory

  delay(1000);
}