const int buttonPin = A5;
const int ledPin1 = 5;
const int ledPin2 = 6;

int mode = 0;
int buttonState;
int lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;

unsigned long previousMillis = 0;
unsigned long interval = 500;

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // Read the button with debouncing
  int reading = digitalRead(buttonPin);
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;
      if (buttonState == HIGH) {
        mode = (mode + 1) % 4;  // Cycle between 0, 1, 2
        Serial.print("Switched to mode: ");
        Serial.println(mode);
      }
    }
  }

  lastButtonState = reading;

  // Choose which pattern to run
  switch (mode) {
    case 0:
      patternLeftRight();
      break;
    case 1:
      patternSlowFade(); 
      break;
    case 2:
      patternCaliLight(); 
      break;
    case 3:
      pattern4(); 
      break;
  }
}

// A non-blocking version of leftRight()
void patternLeftRight() {
  static bool state = false;
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    state = !state;
    if (state) {
      analogWrite(ledPin1, 255);
      analogWrite(ledPin2, 0);
    } else {
      analogWrite(ledPin1, 0);
      analogWrite(ledPin2, 255);
    }
  }
}

void patternCaliLight() {
  static int step = 0;                      // Current step in the pattern
  static unsigned long previousMillis = 0;  // Time of last step
  const unsigned long interval = 80;        // Delay between steps (replace delay(80))

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Example caliLight logic:
    if (step < 18) {
      if (step % 2 == 0) {
        if (step < 10) {
          analogWrite(6, 255); // first 9 blinks
        } else {
          analogWrite(5, 255); // next 9 blinks
        }
      } else {
        analogWrite(5, 0);
        analogWrite(6, 0);
      }

      step++;
    } else {
      step = 0; // Reset pattern
    }
  }
}

void patternSlowFade() {
  static unsigned long previousMillis = 0;
  const unsigned long interval = 2; // Replace delay(2)
  static int brightness = 0;
  static int direction = 1; // 1 = increasing, -1 = decreasing
  static int currentLed = 5; // Start with LED on pin 5

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Write the brightness to the current LED
    analogWrite(currentLed, brightness);

    // Update brightness
    brightness += direction;

    // Reverse at limits
    if (brightness >= 50 || brightness <= 0) {
      direction = -direction;

      // If we've completed fade in + out, move to next LED
      if (brightness <= 0) {
        if (currentLed == 5) {
          currentLed = 6;
        } else {
          currentLed = 5;
        }
      }
    }
  }
}



void pattern4() {
  static bool state = false;
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    state = !state;
    if (state) {
      analogWrite(ledPin1, 255);
      analogWrite(ledPin2, 255);
    } else {
      analogWrite(ledPin1, 0);
      analogWrite(ledPin2, 0);
    }
  }
}