#include <Adafruit_NeoPixel.h>

// Pin where the NeoPixel data line is connected
#define NEOPIXEL_PIN 6

// Pin where the button is connected
#define BUTTON_PIN 2

// Number of NeoPixels in your strip
#define NUM_PIXELS 4

// Create a NeoPixel object
Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

// Time intervals for normal and fast speeds
const unsigned long normalInterval = 600;
const unsigned long fastInterval = 50;
const unsigned long rampUpTime = 5000; // Time in milliseconds to reach fast interval

// Variable to store the last update time
unsigned long previousMillis = 0;
unsigned long buttonPressMillis = 0;

// Variable to keep track of the current LED and fade level
int currentLED = 0;

void setup() {
  // Initialize the NeoPixel strip
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'

  // Initialize the button pin as input with internal pull-up resistor
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  Serial.begin(9600); // Initialize serial communication for debugging
}

void loop() {
  unsigned long currentMillis = millis();
  bool buttonPressed = digitalRead(BUTTON_PIN) == LOW;

  // Handle the ramp-up mechanism
  if (buttonPressed) {
    if (buttonPressMillis == 0) {
      buttonPressMillis = currentMillis; // Start timing when button is first pressed
    }
  } else {
    buttonPressMillis = 0; // Reset timing when button is released
  }

  unsigned long interval = normalInterval;
  if (buttonPressMillis > 0) {
    unsigned long elapsed = currentMillis - buttonPressMillis;
    if (elapsed < rampUpTime) {
      // Calculate the interval based on the elapsed time for a smooth ramp-up
      interval = normalInterval - ((normalInterval - fastInterval) * elapsed / rampUpTime);
    } else {
      // Set to fast interval if ramp-up time has passed
      interval = fastInterval;
    }
  }

  // Debugging information
  Serial.print("Button Pressed: ");
  Serial.print(buttonPressed);
  Serial.print(" | Elapsed: ");
  Serial.print(currentMillis - buttonPressMillis);
  Serial.print(" | Interval: ");
  Serial.println(interval);

  // Check if it's time to update the LED
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    updateCyclotron(interval);
  }
}

void updateCyclotron(unsigned long interval) {
  // Fade out the current LED over the interval
  for (int i = 255; i >= 0; i -= (255 / (interval / 10))) {
    strip.setPixelColor(currentLED, strip.Color(i, 0, 0));
    strip.show();
    delay(interval / 255 * 10); // Adjust fade speed according to the current interval
  }

  // Move to the next LED
  currentLED = (currentLED + 1) % NUM_PIXELS;

  // Turn on the next LED at full brightness
  strip.setPixelColor(currentLED, strip.Color(255, 0, 0));
  strip.show();
}