// https://forum.arduino.cc/t/color-changing-neopixel-with-button-ending-with2-white-leds/987308


#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif


#define BUTTON_PIN   2

#define PIXEL_PIN    6  // Digital IO pin connected to the NeoPixels.

#define PIXEL_COUNT 12  // Number of NeoPixels
unsigned long interval = 1000;
unsigned long previousMillis=0;

#define INTERVAL_LENGTH1 5000

unsigned long time_1 = 0;
unsigned long time_2 = time_1;
unsigned long time_3 = time_2;
unsigned long time_4 = time_3;



// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(PIXEL_COUNT, PIXEL_PIN, NEO_GRB + NEO_KHZ800);

boolean oldState = HIGH;
int     mode     = 0;    // Currently-active animation mode, 0-9

void setup() {
 
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  strip.begin(); // Initialize NeoPixel strip object (REQUIRED)
  strip.show();  // Initialize all pixels to 'off'
}

void loop() {
  unsigned long currentMillis = millis(); //grab current time    
  // Get current button state.
  boolean newState = digitalRead(BUTTON_PIN);
  // Check if state changed from high to low (button press).
  if((newState == LOW) && (oldState == HIGH)) {
    // Short delay to debounce button.
    delay(20);
    // Check if button is still low after debounce.
    newState = digitalRead(BUTTON_PIN);
    if(newState == LOW) {      // Yes, still low
      if(++mode > 2) mode = 0; // Advance to next mode, wrap around after #1
     
      switch(mode) {           // Start the new animation...
        case 0: 
        colorWipe(strip.Color(  0,   0,   0), 0);    // Black/off
        delay(0)  ;
        break;
        case 1:
        
        colorWipe(strip.Color(255,  0,   0), 50);    // Red        


        // check if 'interval' time has passed (1000 milliseconds)
        if (currentMillis - previousMillis >= interval)  { // we've waited "interval" lamount of time, so lets do something       
          colorWipe(strip.Color(255,  40,   0), 50); // Orange across all pixels
          // save the "current" time
          previousMillis = currentMillis;
        }
            else {
            }
        break;
        case 2:
        strip.clear();
        colorWipe(strip.Color(255,  255,   0), 0);    // Yellow
        delay(0)  ;
        break;
         }
    }
  }

  // Set the last-read button state to the old state.
  oldState = newState;
}

void colorWipe(uint32_t color, int wait) {
  for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}