#define redLed 4
#define orangeLed 5
#define greenLed 6
#define redBtn 13
#define orangeBtn 12
#define greenBtn 11

int redLedState = LOW;
int orangeLedState = LOW;
int greenLedState = LOW;

int lastRedBtnState = LOW;
int lastOrangeBtnState = LOW;
int lastGreenBtnState = LOW;

void setup() {
  pinMode(redLed, OUTPUT);
  pinMode(orangeLed, OUTPUT);
  pinMode(greenLed, OUTPUT);

  // use plain INPUT because we have external pull-down resistors
  pinMode(redBtn, INPUT);
  pinMode(orangeBtn, INPUT);
  pinMode(greenBtn, INPUT);
}

void loop() {
  int redBtnState = digitalRead(redBtn);
  int orangeBtnState = digitalRead(orangeBtn);
  int greenBtnState = digitalRead(greenBtn);

  // if red LED and orange LED are same state, turn green LED on
  if (redLedState == orangeLedState && greenLedState == HIGH) {
    greenLedState = HIGH;
    digitalWrite(greenLed, HIGH);
  } else {
    greenLedState = LOW;
    digitalWrite(greenLed, LOW);
  }

  // red button: toggle red LED
  if (redBtnState == HIGH && lastRedBtnState == LOW) {
    redLedState = !redLedState;
    digitalWrite(redLed, redLedState);
  }

  // orange button: blink sequence
  if (orangeBtnState == HIGH && lastOrangeBtnState == LOW) {
    digitalWrite(greenLed, LOW);
    digitalWrite(redLed, LOW);
    delay(500);
    for (int i = 1; i <= 3; i++) {
      digitalWrite(redLed, HIGH);
      delay(1000);
      digitalWrite(redLed, LOW);
      delay(1000);
    }
    for (int i = 1; i <= 10; i++) {
      digitalWrite(orangeLed, HIGH);
      delay(1000);
      digitalWrite(orangeLed, LOW);
      delay(1000);
    }
    // restore LEDs to previous states
    digitalWrite(redLed, redLedState);
    digitalWrite(greenLed, greenLedState);
  }

  // green button: toggle green LED and turn off red LED
  if (greenBtnState == HIGH && lastGreenBtnState == LOW) {
    greenLedState = !greenLedState;
    digitalWrite(greenLed, greenLedState);
    redLedState = LOW;
    digitalWrite(redLed, LOW);
  }

  // save last button states
  lastRedBtnState = redBtnState;
  lastOrangeBtnState = orangeBtnState;
  lastGreenBtnState = greenBtnState;
}