#include <Arduino.h>

#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>
#include <ArduinoJson.h>
#include <WiFi.h>
#include <HTTPClient.h>

// TODO -- BLE server name
#define bleServerName ""

bool deviceConnected = false;

// TODO --  Generate a unique UUID for your Bluetooth service
// See the following for generating UUIDs:
// https://www.uuidgenerator.net/
#define SERVICE_UUID "91bad492-b950-4226-aa2b-4ede9fa42f59"
#define CHARACTERISTIC_UUID "ca73b3ba-39f6-4ab3-91ae-186dc9577d99"

// BEGIN CHARACTERISTICS
// FOR THE FOLLOWING LINES CHANGE ONLY THE UUID of the characteristic
// Define a caracteristic with the properties: Read, Write (with response), Notify
// Use the above link for generating UUIDs
BLECharacteristic characteristic(
  CHARACTERISTIC_UUID,
  BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_WRITE | BLECharacteristic::PROPERTY_NOTIFY
);
// Define a descriptor characteristic
// IMPORTANT -- The characteristic should have the descriptor UUID 0x2902 or 0x2901
BLEDescriptor *characteristicDescriptor = new BLEDescriptor(BLEUUID((uint16_t)0x2902));

// Setup callbacks onConnect and onDisconnect (no change necessary)
class MyServerCallbacks: public BLEServerCallbacks {
  void onConnect(BLEServer* pServer) {
    deviceConnected = true;
    Serial.println("Device connected");
  };
  void onDisconnect(BLEServer* pServer) {
    deviceConnected = false;
    Serial.println("Device disconnected");
  }
};
// End setup callbacks onConnect and onDisconnect (no change necessary)

// Setup callbacks for charactristics
// IMPORTANT -- all caracteristics can use the same callbacks class 
// or you can define a different class for each characteristic containing the onWrite method
// The onWrite callback method is called when data is received by the ESP32
// This is where you will write you logic, according to the app specs
class CharacteristicsCallbacks: public BLECharacteristicCallbacks {
    void onWrite(BLECharacteristic *characteristic) {
      // Get characteristic value sent from the app, according to the specs
      std::string data = characteristic->getValue();
      Serial.println(data.c_str()); // <-- This is the message sent from the app, according to the specs

      // Possible steps:
      // 1. Deserialize data using the ArduinoJson library
      // 2. Get the action from the JSON object
      // 3. Check action and perform the corresponding operations
      // IMPORTANT -- if it is an API project, connect to WiFi when the appropriate action is requested and 
	  // make sure to set the http request timeout to 10s or more
      // IMPORTANT -- If using the ArduinoJson library, use a DynamicJsonDocument with the size of 15000
      // 5. Define the response structure, according to the app specifications
      // (Use JsonArray or JsonObject, depending on the response type)
      // IMPORTANT -- The cacapcity of the response array/object must not exceed 512B, especially for BLE
      // 6. Populate the response object according to the app specs
      // 7. Encode the response object as a JSON string
      // 8. Write value to the characteristic and notify the app
      
      // TODO -- Write your code
      

    }
};

void setup() {
  // Start serial communication 
  Serial.begin(115200);

  // BEGIN DON'T CHANGE
  // Create the BLE Device
  BLEDevice::init(bleServerName);

  // Create the BLE Server
  BLEServer *pServer = BLEDevice::createServer();
  // Set server callbacks
  pServer->setCallbacks(new MyServerCallbacks());

  // Create the BLE Service
  BLEService *bleService = pServer->createService(SERVICE_UUID);

  // Create BLE characteristics and descriptors
  bleService->addCharacteristic(&characteristic);  
  characteristic.addDescriptor(characteristicDescriptor);
  // Set chacrateristic callbacks
  characteristic.setCallbacks(new CharacteristicsCallbacks());
  
  // Start the service
  bleService->start();

  // Start advertising
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pServer->getAdvertising()->start();
  Serial.println("Waiting a client connection to notify...");
  // END DON'T CHANGE
}

void loop() {
  // possible code to be executed for the actions which run periodically 
  // (possibly conditioned by an interrupt flag)
}