// Load libraries
#include "BluetoothSerial.h"


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

// Bluetooth Serial object
BluetoothSerial SerialBT;

// GPIO where LED is connected to
const int ledPin =  4;


// Handle received and sent messages
String message = "";
char incomingChar;


void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(115200);
  // Bluetooth device name
  SerialBT.begin("ESP32");
  Serial.println("The device started, now you can pair it with bluetooth!");
}

void loop() {
 
  // Read received messages (LED control command)
  if (SerialBT.available()){
    char incomingChar = SerialBT.read();
    if (incomingChar != '\n'){
      message += String(incomingChar);
    }
    else{
      message = "";
    }
    Serial.write(incomingChar);  
  }
  // Check received message and control output accordingly
  if (message =="led_on"){
    // led on
    digitalWrite(ledPin, HIGH);
  }
  // Check received message and control output accordingly
  else if (message =="led_off"){
    // led off
    digitalWrite(ledPin, LOW);
  }
  else if (message =="led_blink"){
    // led blinking 50 times then led on
    int i=0;
    while(i<50){
    digitalWrite(ledPin, HIGH);
    delay(200);
    digitalWrite(ledPin, LOW);
    delay(200);
    i+=1;
    }
    digitalWrite(ledPin, HIGH);

  }
  delay(20);
}