#include <Arduino.h>
//used 220 ohm resistors to limit current for LEDs

const int ledPins[] = {11, 12, 13}; //define the GPIO pins connected to LEDs
//division of the total size of LEDs array of size of a single element in the array
const int numLeds = sizeof(ledPins) / sizeof(ledPins[0]); 
const int buttonPins[] = {5, 6, 7}; //define the GPIO pins connected to push-buttons
const int numButtons = sizeof(buttonPins) / sizeof(buttonPins[0]);

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600); //serial communication
  for (int i = 0; i < numLeds; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW); //set LEDs to OFF
  }
  for (int i = 0; i < numButtons; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP); //internal pull-up resistors, pins are input
  }
}

void loop() {
  // put your main code here, to run repeatedly:
//reads the state of push-buttons
  for (int i = 0; i < numButtons; i++) {
    int buttonState = digitalRead(buttonPins[i]);
    Serial.print("Button ");
    Serial.print(i);
    Serial.print(": ");
    Serial.println(buttonState);
    delay(500);//500 ms delay for button state so we can see the button readings
}

while (Serial.available() > 0) {
    char command = Serial.read();
    if (command == '0' || command == '1' || command == '2') {
      int ledIndex = command - '0'; //converts command to integer ('0' to 0)
      //toggle LED state, negates current LED state and turn it to high or low
      digitalWrite(ledPins[ledIndex], !digitalRead(ledPins[ledIndex])); 

    } else if (command == 'A') {
      //set all LEDs simultaneously
      int newState = Serial.parseInt(); //read integer value from serial intput (1 to integer)
      for (int i = 0; i < numLeds; i++) {
        //sets state of LED associated with the pin number retrieved and turns on/off LED 
        digitalWrite(ledPins[i], newState); 
      }
    } else if (command == 'G') {
      //get all push-button states simultaneously
      for (int i = 0; i < numButtons; i++) {
        //reads the button state and GPIO pin for button and stores either high or low in button state 
        int buttonState = digitalRead(buttonPins[i]);
        Serial.print("Button ");
        Serial.print(i);
        Serial.print(": ");
        Serial.println(buttonState);
      }
    }
  }
}