#include <FastLED.h>

#define LED_PIN 12
#define NUM_LEDS 1
CRGB leds[NUM_LEDS];

// Joystick 接腳
const int xPin = A4; // HORZ
const int yPin = A5; // VERT

void setup() {
  FastLED.addLeds<WS2811, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.clear();
  FastLED.show();
}

void loop() {
  int xVal = analogRead(xPin);
  int yVal = analogRead(yPin);

  int x = xVal - 512;
  int y = yVal - 512;

  const int threshold = 100;

  byte r = 0, g = 0, b = 0;

  if (abs(x) < threshold && abs(y) < threshold) {
    r = g = b = 0; // 中間，全暗
  } else {
    if (x < -threshold && abs(y) < threshold) {
      r = map(abs(x), threshold, 512, 0, 255); // 左 = 紅
    } else if (x > threshold && abs(y) < threshold) {
      b = map(abs(x), threshold, 512, 0, 255); // 右 = 藍
    }

    if (y > threshold && abs(x) < threshold) {
      g = map(abs(y), threshold, 512, 0, 255); // 上 = 綠
    }

    if (x < -threshold && y > threshold) {
      r = map(abs(x), threshold, 512, 0, 255);
      g = map(abs(y), threshold, 512, 0, 255); // 左上 = 紅+綠
    }

    if (x > threshold && y > threshold) {
      b = map(abs(x), threshold, 512, 0, 255);
      g = map(abs(y), threshold, 512, 0, 255); // 右上 = 藍+綠
    }
  }

  leds[0] = CRGB(r, g, b);
  FastLED.show();
  delay(10);
}