// Define pin numbers for pedestrian signals (NS only)
const int nsweRedPin = 15;
const int nsweGreenPin = 16;

// Define pin numbers for traffic light LEDs
const int nsTrafficRedPin = 2;
const int nsTrafficYellowPin = 3;
const int nsTrafficGreenPin = 4;

const int weTrafficRedPin = 11;
const int weTrafficYellowPin = 12;
const int weTrafficGreenPin = 13;

// Define pin number for button
const int button1Pin = 17;

// Define timing constants
const unsigned long trafficGreenDuration = 5000;  // Green light duration (in milliseconds)
const unsigned long trafficYellowDuration = 2000; // Yellow light duration (in milliseconds)

bool pedestrianRequest = false;  // Flag to track if pedestrian request was made
bool buttonState = HIGH;         // Current state of the button (pressed or not)
bool lastButtonState = HIGH;     // Previous state of the button
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 50;  // Debounce delay to avoid multiple readings from one press

void setup() {
  pinMode(nsweRedPin, OUTPUT);
  pinMode(nsweGreenPin, OUTPUT);
  pinMode(nsTrafficRedPin, OUTPUT);
  pinMode(nsTrafficYellowPin, OUTPUT);
  pinMode(nsTrafficGreenPin, OUTPUT);
  pinMode(weTrafficRedPin, OUTPUT);
  pinMode(weTrafficYellowPin, OUTPUT);
  pinMode(weTrafficGreenPin, OUTPUT);
  pinMode(button1Pin, INPUT_PULLUP);  // Button with internal pull-up resistor

  Serial.begin(9600); // Start Serial Monitor for debugging
  turnOffAll();  // Initialize the system with all lights off
  digitalWrite(nsweRedPin, HIGH); // Pedestrian light should be red by default
}

void loop() {
  checkPedestrianButton();  // Check for button presses
  vehicleLightSequence();   // Run the traffic light sequence
}

void checkPedestrianButton() {
  int reading = digitalRead(button1Pin);

  // Detect if the button state has changed (debouncing)
  if (reading != lastButtonState) {
    lastDebounceTime = millis();  // Reset debounce timer
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading == LOW && buttonState == HIGH) {
      pedestrianRequest = true;  // Set pedestrian request if button is pressed
      Serial.println("Button Pressed ✅");
    }
    buttonState = reading;  // Update the current button state
  }

  lastButtonState = reading;  // Store the last button state
}

void vehicleLightSequence() {
  // NS Green, WE Red (Traffic starts with NS green, WE red)
  digitalWrite(weTrafficRedPin, HIGH);
  digitalWrite(nsTrafficRedPin, LOW);
  digitalWrite(nsTrafficGreenPin, HIGH);
  delay(trafficGreenDuration);

  // NS Yellow
  digitalWrite(nsTrafficGreenPin, LOW);
  digitalWrite(nsTrafficYellowPin, HIGH);
  delay(trafficYellowDuration);

  // WE Green, NS Red
  digitalWrite(nsTrafficYellowPin, LOW);
  digitalWrite(nsTrafficRedPin, HIGH);
  digitalWrite(weTrafficRedPin, LOW);
  digitalWrite(weTrafficGreenPin, HIGH);

  // Wait for West and East Green light to turn on (while button is pressed)
  if (pedestrianRequest) {
    blinkPedestrianGreenDuringWE();  // Activate pedestrian crossing (blink lights)
    pedestrianRequest = false;  // Reset the pedestrian request after crossing
  } else {
    delay(trafficGreenDuration);  // Regular delay for WE Green light duration
  }

  // WE Yellow
  digitalWrite(weTrafficGreenPin, LOW);
  digitalWrite(weTrafficYellowPin, HIGH);
  delay(trafficYellowDuration);

  // All Red pause (for a brief period before starting the next cycle)
  digitalWrite(weTrafficYellowPin, LOW);
  digitalWrite(weTrafficRedPin, HIGH);
  delay(1000);
}

void blinkPedestrianGreenDuringWE() {
  // Pedestrian crossing: Blink pedestrian green during WE Green light
  digitalWrite(nsweRedPin, LOW);  // Pedestrian red light off
  for (int i = 0; i < 5; i++) {
    digitalWrite(nsweGreenPin, HIGH);  // Pedestrian green on
    delay(500);  // Stay on for 500ms
    digitalWrite(nsweGreenPin, LOW);   // Pedestrian green off
    delay(500);  // Stay off for 500ms
  }
  digitalWrite(nsweRedPin, HIGH);  // After blinking, set pedestrian light back to red
}

void turnOffAll() {
  // Turn off all traffic lights and pedestrian signals
  digitalWrite(nsTrafficRedPin, LOW);
  digitalWrite(nsTrafficYellowPin, LOW);
  digitalWrite(nsTrafficGreenPin, LOW);
  digitalWrite(weTrafficRedPin, LOW);
  digitalWrite(weTrafficYellowPin, LOW);
  digitalWrite(weTrafficGreenPin, LOW);
  digitalWrite(nsweRedPin, HIGH);  // Pedestrian red light by default
  digitalWrite(nsweGreenPin, LOW);
}