// SUPER ARDUINOVA (SA-12L) - Complete Implementation
// Compliant with Technical Regulations Document

// Pin Definitions
const int buttonPin = 13;        // Mode selection button
const int ledPins[] = {12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, A3}; // 12 LED pins

// Global Variables
int currentMode = 1;            // Start with Mode 1
int buttonState = 0;            // Current button state
int lastButtonState = 0;        // Previous button state
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;
unsigned long previousMillis = 0;

// Mode timing constants
const long mode2Interval = 250; // 2Hz = 500ms period, 250ms on/off
const long mode1Interval = 100; // Scanner speed
const long mode3Interval = 150; // Chase speed

void setup() {
  // Initialize all LED pins as outputs
  for (int i = 0; i < 12; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }

  // Initialize button pin with pull-down resistor
  pinMode(buttonPin, INPUT);

  // Serial.begin(9600); // Optional: for debugging
}

void loop() {
  // Handle mode selection via button
  handleModeSelection();

  // Execute current mode pattern
  switch (currentMode) {
    case 1:
      mode1Sequential();
      break;
    case 2:
      mode2Hazard();
      break;
    case 3:
      mode3Converge();
      break;
  }
}

void handleModeSelection() {
  // Read the button state with debouncing
  int reading = digitalRead(buttonPin);

  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;

      // Only change mode on button press (not release)
      if (buttonState == HIGH) {
        currentMode++;
        if (currentMode > 3) {
          currentMode = 1;
        }
        // Turn off all LEDs when changing modes
        allLEDsOff();
      }
    }
  }

  lastButtonState = reading;
}

// MODE 1: Sequential (Larson Scanner)
void mode1Sequential() {
  static int currentLED = 0;
  static bool movingForward = true;
  static unsigned long previousMode1Millis = 0;

  unsigned long currentMillis = millis();

  if (currentMillis - previousMode1Millis >= mode1Interval) {
    previousMode1Millis = currentMillis;

    // Turn off all LEDs
    allLEDsOff();

    // Turn on current LED
    digitalWrite(ledPins[currentLED], HIGH);

    // Move to next position
    if (movingForward) {
      currentLED++;
      if (currentLED >= 11) { // Changed from 12 to 11 for 0-based indexing
        movingForward = false;
      }
    } else {
      currentLED--;
      if (currentLED <= 0) {
        movingForward = true;
      }
    }
  }
}

// MODE 2: Hazard (Synchronized Flash)
void mode2Hazard() {
  static bool ledsOn = false;
  static unsigned long previousMode2Millis = 0;

  unsigned long currentMillis = millis();

  if (currentMillis - previousMode2Millis >= mode2Interval) {
    previousMode2Millis = currentMillis;

    ledsOn = !ledsOn;

    if (ledsOn) {
      allLEDsOn();
    } else {
      allLEDsOff();
    }
  }
}

// MODE 3: Converge (Inward Chase)
void mode3Converge() {
  static int position = 0;
  static unsigned long previousMode3Millis = 0;

  unsigned long currentMillis = millis();

  if (currentMillis - previousMode3Millis >= mode3Interval) {
    previousMode3Millis = currentMillis;

    // Turn off all LEDs
    allLEDsOff();

    // Light up symmetric pairs
    digitalWrite(ledPins[position], HIGH);
    digitalWrite(ledPins[11 - position], HIGH);

    // Move to next position
    position++;
    if (position > 5) { // 0-5 covers all 6 pairs (12 LEDs)
      position = 0;
    }
  }
}

// Helper functions
void allLEDsOff() {
  for (int i = 0; i < 12; i++) {
    digitalWrite(ledPins[i], LOW);
  }
}

void allLEDsOn() {
  for (int i = 0; i < 12; i++) {
    digitalWrite(ledPins[i], HIGH);
  }
}