// Pin variables
const int button = 3;
const int greenCrossing = 9;
const int redCrossing = 10;
const int greenLight = 11;
const int amberLight = 12;
const int redLight = 13;

// Time delay variables
long delayTime = 0;
long lastSequence = 0;

// Interrupt variables
bool buttonActive = true; // Allows for easy managing of when the button can be successfully pressed
bool awaitingSequence = false;  // Allows for the lighting sequence to run again after the delay

void setup() {
  // Setup pin modes
  pinMode(button, INPUT_PULLUP);
  pinMode(greenCrossing, OUTPUT);
  pinMode(redCrossing, OUTPUT);
  pinMode(greenLight, OUTPUT);
  pinMode(amberLight, OUTPUT);
  pinMode(redLight, OUTPUT);

  // Interrupt service, allows the ButtonPressed function to run at any point in the code
  attachInterrupt(digitalPinToInterrupt(3), buttonPressed, RISING);
}


void defaultDisplay() {
  digitalWrite(greenLight, HIGH);
  digitalWrite(redCrossing, HIGH);
}

void flashingLED(int pin1, int pin2) {
  for (int i = 1; i <= 5; i++) {
    digitalWrite(pin1, HIGH);
    digitalWrite(pin2, HIGH);
    delay(500);
    digitalWrite(pin1, LOW);
    digitalWrite(pin2, LOW);
    delay(500);
  }
}


void crossSequence() { // Lighting sequence to run when the button has been pressed and not being blocked by the 60 second delay
    digitalWrite(greenLight, LOW);
    digitalWrite(amberLight, HIGH);
    delay(3000);

    digitalWrite(amberLight, LOW);
    digitalWrite(redLight, HIGH);
    digitalWrite(redCrossing, LOW);
    digitalWrite(greenCrossing, HIGH);
    delay(10000);

    digitalWrite(redLight, LOW);
    buttonActive = true; // Allow another button press from this point onwards
    flashingLED(greenCrossing, amberLight);
    digitalWrite(greenLight, HIGH);
    digitalWrite(redCrossing, HIGH);
    lastSequence = millis(); // Log the time that the execution has finished
    delayTime = 20000;
}

void buttonPressed() { // Function to run when the interrupt is executed
  if ( buttonActive == true ) { // Button is currently accepting a press
    if ( awaitingSequence == false ) { // Has a sequence been queued already
        awaitingSequence = true; // Allow the sequence to run again at the next appropriate time [not currently running & not blocked by 60 sec delay]
        buttonActive = false;    // Prevent the button acknowledging any more presses
    }
  }
}

void loop() {
  defaultDisplay();
  if (millis() > (lastSequence + delayTime)) { // Not being blocked by the 60 second delay
    if ( awaitingSequence == true ) { // Has the button been pressed at a time where a new sequence can be `queued`
        awaitingSequence = false;
        crossSequence();
    }
  }
}