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/*
    Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleWrite.cpp
    Ported to Arduino ESP32 by Evandro Copercini
*/

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>
#include "esp_wifi.h"
#include "esp_bt_main.h"


#define uS_TO_S_FACTOR 1000000ULL  /* Conversion factor for micro seconds to seconds */
#define TIME_TO_SLEEP  2   

// See the following for generating UUIDs:
// https://www.uuidgenerator.net/

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

#define LED_PIN 2
#define BTN_PIN 12

int deviceConnected = false;
int counter = 0;

class MyCallbacks: public BLECharacteristicCallbacks {
   void onConnect(BLEServer* pServer) {
      deviceConnected = true;
      Serial.println("device connected");
      BLEDevice::startAdvertising();
    };
 
    void onDisconnect(BLEServer* pServer) {
      deviceConnected = false;
      Serial.println("device disconnected");
    }
    void onWrite(BLECharacteristic *pCharacteristic) {
      std::string value = pCharacteristic->getValue();
      
      if (value.length() > 0) {
        Serial.print("*********");
        Serial.print(value.c_str());
        Serial.print("-");
        Serial.print(atoi(value.c_str()));
        Serial.print("-");
        if(atoi(value.c_str())==1)
        {
          digitalWrite(LED_PIN,HIGH);
          Serial.print("LEDON");
        }
        else
        {
          digitalWrite(LED_PIN,LOW);
          Serial.print("LEDOFF");
        }
        
        Serial.println("*********");
      }
    }
};

BLECharacteristic *pCharacteristic;

void startBluetooth() {
  BLEDevice::init("BLE_DEVICE");
  BLEServer *pServer = BLEDevice::createServer();

  BLEService *pService = pServer->createService(SERVICE_UUID);

  pCharacteristic= pService->createCharacteristic(
                                          CHARACTERISTIC_UUID,
                                          BLECharacteristic::PROPERTY_READ |
                                          BLECharacteristic::PROPERTY_WRITE |
                                          BLECharacteristic::PROPERTY_NOTIFY
                                        );

  pCharacteristic->setCallbacks(new MyCallbacks());

  pCharacteristic->setValue("Hello World");
  pService->start();

  BLEAdvertising *pAdvertising = pServer->getAdvertising();
  pAdvertising->start();
}

void setup() {
  Serial.begin(115200);
  counter = 0;
  esp_wifi_set_mode(WIFI_MODE_NULL);
  pinMode(LED_PIN,OUTPUT);
  digitalWrite(LED_PIN,LOW);
  startBluetooth();
  
}
int prevVal = LOW;
bool wasSleeping = false;
void loop() {
  // put your main code here, to run repeatedly:

  if(wasSleeping) {
    wasSleeping = false;
    startBluetooth();
    
  }
 
  int currentVal = digitalRead(BTN_PIN);
  if(currentVal!=prevVal)
  {
    prevVal=currentVal;
    if(currentVal==HIGH)
    {
      int value = 10;
      pCharacteristic->setValue((uint8_t*)&value, 4);
        pCharacteristic->notify();
    }
    else
    {
       int value = 0;
      pCharacteristic->setValue((uint8_t*)&value, 4);
        pCharacteristic->notify();
    }
  }
  // delay(100);
  // counter++;

  if(counter > 160) {  
    counter = 0;
    esp_bluedroid_disable();
    esp_bluedroid_deinit();
    btStop();
    delay(1000);

    esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
    Serial.println("Going to light sleep now");
    esp_light_sleep_start();
    esp_bluedroid_init();
    esp_bluedroid_enable();
    btStart();

  }
}