#define BTN_RED 19
#define BTN_GREEN 18
#define BTN_BLUE 5
#define BTN_YELLOW 17

#define LED_RED 25
#define LED_GREEN 26

#define RED 1
#define GREEN 2
#define BLUE 3
#define YELLOW 4

#define PRESSED true

bool btn_red_state = !PRESSED;
bool btn_green_state = !PRESSED; 
bool btn_blue_state = !PRESSED;
bool btn_yellow_state = !PRESSED; 

const int combination[4] = { RED, GREEN, BLUE, YELLOW };
int input[4] = { 0, 0, 0, 0 };
int input_idx = 0;

void setup_gpios()
{
  pinMode(BTN_RED, INPUT_PULLUP);
  pinMode(BTN_GREEN, INPUT_PULLUP);
  pinMode(BTN_BLUE, INPUT_PULLUP);
  pinMode(BTN_YELLOW, INPUT_PULLUP);

  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
}

void check_btn(int btn, int color, bool *btn_state)
{
  if (LOW == digitalRead(btn))
  {
    *btn_state = PRESSED;
    delay(50);
  }
  else
  {
    if(PRESSED == *btn_state)
    {

      input[input_idx] = color;
      input_idx= (input_idx+1) % 4;

      delay(50);
      *btn_state = !PRESSED;
    }
  }
}

bool is_valid_input()
{
  for(int i=0; i < 4; i++)
  {
    if (input[i] != combination[i])
    {
      return false;
    }
  }
  return true;
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  setup_gpios();
}

void loop() {
  // put your main code here, to run repeatedly:
  //check_btn(BTN_RED, RED, &btn_red_state);
   if (LOW == digitalRead(BTN_RED))
  {
    btn_red_state = PRESSED;
    delay(50);
  }
  else
  {
    if(PRESSED == btn_red_state)
    {

      input[input_idx] = RED;
      input_idx= (input_idx+1) % 4;

      delay(50);
      btn_red_state = !PRESSED;
    }
  }
  check_btn(BTN_GREEN, GREEN, &btn_green_state);
  check_btn(BTN_BLUE, BLUE, &btn_blue_state);
  check_btn(BTN_YELLOW, YELLOW, &btn_yellow_state);


  Serial.print("USER_INPUT:");
  for (int i = 0; i < 4; i++)
  {
    Serial.print(input[i]);
    Serial.print(", ");
  }
  Serial.println("");

  if ( input_idx % 4 == 0 ) 
  {
    if (is_valid_input() )
    {
      digitalWrite(LED_GREEN, HIGH);
      digitalWrite(LED_RED, LOW);
    } 
    else 
    {
      digitalWrite(LED_GREEN, LOW);
      digitalWrite(LED_RED, HIGH);
    }
  } 
  else 
  {
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_RED, LOW);
  }

  delay(10); // this speeds up the simulation
}