// Week 10 — WS2812B (10 LEDs) + push button on XIAO ESP32-C3
// Button: D0 (same net as Week 8 PCB — press = HIGH with pull-down wiring)
// NeoPixel data: D1

#include <Adafruit_NeoPixel.h>

#define PIN_NEO   D3
#define PIN_BTN   D0
#define NUMPIXELS 10

Adafruit_NeoPixel pixels(NUMPIXELS, PIN_NEO, NEO_GRB + NEO_KHZ800);

const unsigned long DEBOUNCE_MS = 50;
const unsigned long CELEBRATE_MS = 5000;
const unsigned long BLINK_MS = 250;

int pressCount = 0;
int buttonState = LOW;
int lastReading = LOW;
unsigned long lastDebounceTime = 0;

bool celebrating = false;
unsigned long celebrateStart = 0;

void showProgress(int count) {
  pixels.clear();
  for (int i = 0; i < count; i++) {
    pixels.setPixelColor(i, pixels.Color(0, 80, 255));  // blue
  }
  pixels.show();
}

void startCelebration() {
  celebrating = true;
  celebrateStart = millis();
}

void setup() {
  pinMode(PIN_BTN, INPUT);
  pixels.begin();
  pixels.setBrightness(80);
  pixels.clear();
  pixels.show();
  Serial.begin(115200);
  Serial.println(F("WS2812B button demo: press to light LEDs one by one."));
}

void loop() {
  if (celebrating) {
    unsigned long elapsed = millis() - celebrateStart;
    if (elapsed >= CELEBRATE_MS) {
      celebrating = false;
      pressCount = 0;
      pixels.clear();
      pixels.show();
      Serial.println(F("Reset — all LEDs off."));
      return;
    }
    if (((elapsed / BLINK_MS) % 2) == 0) {
      for (int i = 0; i < NUMPIXELS; i++) {
        pixels.setPixelColor(i, pixels.Color(255, 255, 255));
      }
    } else {
      pixels.clear();
    }
    pixels.show();
    return;
  }

  int reading = digitalRead(PIN_BTN);
  if (reading != lastReading) {
    lastDebounceTime = millis();
  }
  if ((millis() - lastDebounceTime) > DEBOUNCE_MS) {
    if (reading != buttonState) {
      buttonState = reading;
      if (buttonState == HIGH) {
        pressCount++;
        Serial.print(F("Press #"));
        Serial.println(pressCount);
        if (pressCount >= NUMPIXELS) {
          showProgress(NUMPIXELS);
          startCelebration();
        } else {
          showProgress(pressCount);
        }
      }
    }
  }
  lastReading = reading;
}