const int redPin = 13;
const int yellowPin = 12;
const int greenPin = 11;
// BUTTON VARIABLES
const int buttonPin = 2;

int buttonPrevState = LOW;

// added code
bool buttonPressed = false;
unsigned long buttonPressedTime = 0;

// Transitional interval
long interval = 1000;
unsigned long prevMillis = 0;

//7-segment display pin assign
int A=3;int B=4;int C=5;int D=6;int E=7;int F=8;int G=9;

//Digital map
static const uint8_t digitCodeMap[] = {
  0b01000000, // 0
  0b01111001, // 1
  0b00100100, // 2                    A
  0b00110000, // 3    GFEDCBA     F     B
  0b00011001, // 4                   G
  0b00010010, // 5                E      C
  0b00000010, // 6                   D
  0b1011000, // 7
  0b00000000, // 8
  0b00010000, // 9
};



//Pins for segment
int segmentPins[7]={A,B,C,D,E,F,G};



void setup() {
  //LEDs
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(buttonPin, INPUT);

  digitalWrite(redPin, HIGH);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, LOW);

  interval = 5000;
//Serial Output
  Serial.begin(9600);

  //Segment display
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(F, OUTPUT);
  pinMode(G, OUTPUT);



}

// Function to calculate time left before switching to the next light
unsigned long calculateTimeLeft(unsigned long currentMillis, unsigned long prevMillis, long interval) {
  return interval - (currentMillis - prevMillis);
}

void loop() {
  
  // Normal Sequence
  unsigned long currentMillis = millis(); // time elapsed since the program is run

  // button edited code
  if (isButtonPressed()) {
    buttonPressed = true;
    buttonPressedTime = currentMillis;
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, HIGH);
    digitalWrite(yellowPin, LOW);

    interval = 3000;
    Serial.print("Button Pressed\n");
  }

  // edited 
  int buttonState1 = digitalRead(buttonPin);
  if (buttonState1 == LOW) {
    if (currentMillis - prevMillis >= interval) {
      prevMillis = currentMillis;

      // Serial.print("struct");
      if (digitalRead(redPin) == HIGH) {
        digitalWrite(redPin, LOW);
        digitalWrite(yellowPin, HIGH);

        interval = 4000;
        Serial.print("Yellow\n");
      } else if (digitalRead(yellowPin) == HIGH) {
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, HIGH);

        interval = 9000;
        Serial.print("Green\n");
      } else if (digitalRead(greenPin) == HIGH) {
        digitalWrite(greenPin, LOW);
        digitalWrite(redPin, HIGH);

        interval = 9000;
        Serial.print("Red\n");
      }
    }
  }

  // Calculate time left before switching to the next light
  unsigned long timeLeft = calculateTimeLeft(currentMillis, prevMillis, interval);
  Serial.print("Time left: ");
  Serial.println(timeLeft);

  //Display timer output
  unsigned long timeInSeconds=timeLeft/1000;
  displayDigit(timeInSeconds);
  //displayDigit(9);
}

//supplementary functions


// Check button status
bool isButtonPressed() {
  static unsigned long lastButtonPressTime = 0;
  const unsigned long debounceDelay = 50; // Debounce delay in milliseconds

  int buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH && millis() - lastButtonPressTime >= debounceDelay) {
    lastButtonPressTime = millis();
    return true;
  }
  return false;
}

// switch on segments

void displayDigit(int digit) {
  for (int segment = 0; segment < 7; ++segment) {
    int segmentValue = LOW;

    if (digitCodeMap[digit] & (1 << segment)) {
      segmentValue = HIGH;
    }

    digitalWrite(segmentPins[segment], segmentValue);
  }
}