#include <Arduino.h>
#include <BluetoothSerial.h>
#include <ArduinoJson.h>
#include <WiFi.h>
#include <HTTPClient.h>

#if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BLUEDROID_ENABLED)
  #error Bluetooth is not enabled! Please run `make menuconfig` to and enable it
#endif

// TODO -- BTC server name
#define btcServerName ""

// Define the BluetoothSerial
BluetoothSerial SerialBT;

// Received data
String data = "";

// The receivedData function is called when data is available on Bluetooth (see loop function)
void receivedData() {
  // Read the data using the appropriate SerialBT functions
  // according to the app specifications
  // The data is terminated by the new line character (\n)
  while (SerialBT.available()) {
    data = SerialBT.readStringUntil('\n');
  }

  Serial.println(data); // <-- 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
  
  // Reset the received data string after processing 
  data = "";
}

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

  // No need to change the lines below
  // Initialize BTC
  SerialBT.begin(btcServerName); //Bluetooth device name
  Serial.println("The device started, now you can pair it with bluetooth!");
}

void loop() {
  // Check available Bluetooth data and perform read from the app
  if (SerialBT.available()) {
    receivedData();
  }
  // possible code to be executed for the actions which run periodically 
  // (possibly conditioned by an interrupt flag)
}