#include <FastLED.h>

#define LED_PIN 6
#define NUM_LEDS 12

#define POT_R A0
#define POT_G A1
#define POT_B A2

#define BUTTON_SELECT 3   // Button: selection
#define BUTTON_ONOFF 2    // Button: ON/OFF
#define BUTTON_MODE 4     // Button: mode control

CRGB leds[NUM_LEDS];
int selectedLED = 0;
bool ledsOn = true;
int mode = 0; // 0 = single-LED, 1 = all LEDs

bool buttonSelectPressed = false;
bool buttonOnOffPressed = false;
bool buttonModePressed = false;

void setup() {
  pinMode(BUTTON_SELECT, INPUT_PULLUP);
  pinMode(BUTTON_ONOFF, INPUT_PULLUP);
  pinMode(BUTTON_MODE, INPUT_PULLUP);
  
  FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
  fill_solid(leds, NUM_LEDS, CRGB::Black);
  FastLED.show();
}

void loop() {

  // --- LED-selection ---
  if (mode == 0 && digitalRead(BUTTON_SELECT) == LOW && !buttonSelectPressed) {
    buttonSelectPressed = true;
    selectedLED++;
    if (selectedLED >= NUM_LEDS) selectedLED = 0;
    delay(200); // simple gradient
  }
  if (digitalRead(BUTTON_SELECT) == HIGH) {
    buttonSelectPressed = false;
  }

  // --- ON/OFF ---
  if (digitalRead(BUTTON_ONOFF) == LOW && !buttonOnOffPressed) {
    buttonOnOffPressed = true;
    ledsOn = !ledsOn;
    delay(200); // simple gradient
  }
  if (digitalRead(BUTTON_ONOFF) == HIGH) {
    buttonOnOffPressed = false;
  }

  // --- mode control ---
  if (digitalRead(BUTTON_MODE) == LOW && !buttonModePressed) {
    buttonModePressed = true;
    mode = (mode + 1) % 2; // toggles between 0 and 1

    // --- Feedback mode-switch ---
    for(int i=0; i<3; i++) {   // 3 blinks
      fill_solid(leds, NUM_LEDS, CRGB::White);
      FastLED.show();
      delay(i==0 ? 400 : 100); // first 400ms, then 100ms blink
      fill_solid(leds, NUM_LEDS, CRGB::Black);
      FastLED.show();
      delay(100);
    }

    delay(200);                             //simple debounce
  }
  if (digitalRead(BUTTON_MODE) == HIGH) {
    buttonModePressed = false;
  }

  // --- RGB potentiometer ---      analog values are shifted to 8-bit (0-255) for perfect rgb control
  uint8_t r = analogRead(POT_R) >> 2;
  uint8_t g = analogRead(POT_G) >> 2;
  uint8_t b = analogRead(POT_B) >> 2;

  // --- control LEDs ---
  if (!ledsOn) {
    fill_solid(leds, NUM_LEDS, CRGB::Black); // all off
  } else if (mode == 0) {
    // single LED
    leds[selectedLED] = CRGB(r, g, b);
  } else {
    // all LEDs
    fill_solid(leds, NUM_LEDS, CRGB(r, g, b));
  }

  FastLED.show();
}