// LED pins (blue and red alternately connected to D2 ~ D9)
const int ledPins[8] = {2, 3, 4, 5, 6, 7, 8, 9};

// Button pins
const int redButton = 10;
const int blueButton = 11;
const int greenButton = 12;

// Variables to track previous button states
bool prevRedPressed = false;
bool prevBluePressed = false;
bool prevGreenPressed = false;

void setup() {
  // Set all LED pins as outputs and turn them off
  for (int i = 0; i < 8; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }

  // Set buttons as input with internal pull-up resistors
  pinMode(redButton, INPUT_PULLUP);
  pinMode(blueButton, INPUT_PULLUP);
  pinMode(greenButton, INPUT_PULLUP);

  Serial.begin(9600); // Optional: debug output
}

void loop() {
  handleRedButton();    // Play red light sequence
  handleBlueButton();   // Play blue LED flowing animation
  handleGreenButton();  // Play full pattern sequence
}

// --- Red button: Runs a 6-step light show pattern ---
void handleRedButton() {
  bool isPressed = digitalRead(redButton) == LOW;
  if (isPressed && !prevRedPressed) {
    Serial.println("Red button pressed → 6-step pattern");
    runRedSequence();
    delay(300); // Simple debounce
  }
  prevRedPressed = isPressed;
}

void runRedSequence() {
  // Step 1: All LEDs on
  setAll(HIGH);
  delay(1000);

  // Step 2: Only blue LEDs on (even indices)
  for (int i = 0; i < 8; i++)
    digitalWrite(ledPins[i], i % 2 == 0 ? HIGH : LOW);
  delay(1000);

  // Step 3: Only red LEDs on (odd indices)
  for (int i = 0; i < 8; i++)
    digitalWrite(ledPins[i], i % 2 == 1 ? HIGH : LOW);
  delay(1000);

  // Step 4: All LEDs on
  setAll(HIGH);
  delay(1000);

  // Step 5: Only blue LEDs on again
  for (int i = 0; i < 8; i++)
    digitalWrite(ledPins[i], i % 2 == 0 ? HIGH : LOW);
  delay(1000);

  // Step 6: Turn all LEDs off
  setAll(LOW);
}

// --- Blue button: Flowing LED animation, back and forth x2 ---
void handleBlueButton() {
  bool isPressed = digitalRead(blueButton) == LOW;
  if (isPressed && !prevBluePressed) {
    Serial.println("Blue button pressed → flowing animation");

    for (int round = 0; round < 2; round++) {
      // Forward flow
      for (int i = 0; i < 8; i++) {
        lightOneOnly(i);
        delay(100);
      }
      // Backward flow
      for (int i = 6; i >= 0; i--) {
        lightOneOnly(i);
        delay(100);
      }

      clearAll();
      delay(100); // Small gap between rounds
    }

    delay(300);
  }
  prevBluePressed = isPressed;
}

// Lights only one LED at the specified index
void lightOneOnly(int index) {
  for (int i = 0; i < 8; i++) {
    digitalWrite(ledPins[i], (i == index) ? HIGH : LOW);
  }
}

// --- Green button: Four full LED pattern cycles ---
void handleGreenButton() {
  bool isPressed = digitalRead(greenButton) == LOW;
  if (isPressed && !prevGreenPressed) {
    Serial.println("Green button pressed → full sequence");

    // Pattern 1: Light up and off from left to right
    for (int i = 0; i < 8; i++) {
      digitalWrite(ledPins[i], HIGH);
      delay(100);
    }
    for (int i = 0; i < 8; i++) {
      digitalWrite(ledPins[i], LOW);
      delay(100);
    }

    // Pattern 2: Right to left on and off
    for (int i = 7; i >= 0; i--) {
      digitalWrite(ledPins[i], HIGH);
      delay(100);
    }
    for (int i = 7; i >= 0; i--) {
      digitalWrite(ledPins[i], LOW);
      delay(100);
    }

    // Pattern 3: Left to right on, right to left off
    for (int i = 0; i < 8; i++) {
      digitalWrite(ledPins[i], HIGH);
      delay(100);
    }
    for (int i = 7; i >= 0; i--) {
      digitalWrite(ledPins[i], LOW);
      delay(100);
    }

    // Pattern 4: Right to left on, left to right off
    for (int i = 7; i >= 0; i--) {
      digitalWrite(ledPins[i], HIGH);
      delay(100);
    }
    for (int i = 0; i < 8; i++) {
      digitalWrite(ledPins[i], LOW);
      delay(100);
    }

    clearAll(); // Make sure all LEDs are off
    delay(300);
  }
  prevGreenPressed = isPressed;
}

// Turns all LEDs on or off
void setAll(int state) {
  for (int i = 0; i < 8; i++) {
    digitalWrite(ledPins[i], state);
  }
}

// Turns off all LEDs
void clearAll() {
  setAll(LOW);
}