#define NUMELEMENTS(x) (sizeof(x) / sizeof(x[0]))

struct COLOR {
  String name;
  int red;
  int green;
  int blue;
};

COLOR colors[] = {
  {"red", 255, 0, 0},
  {"green", 0, 255, 0},
  {"blue", 0, 0, 255},
  {"off", 0, 0, 0},
  {"yellow", 255, 255, 0},
  {"cyan", 92, 255, 255},
  {"magenta", 255, 0, 255},
  {"aqua", 0, 255, 255}
};

byte redPin = 11;
byte greenPin = 10;
byte bluePin = 9;

String myColor;
bool found = false;

// Fade control variables
int currentRed = 0, currentGreen = 0, currentBlue = 0;
int targetRed = 0, targetGreen = 0, targetBlue = 0;
int steps = 50;
int stepCount = 0;
unsigned long lastFadeTime = 0;
unsigned long fadeInterval = 20; // ms

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  Serial.begin(115200);
  Serial.println("Ready for color input.");
}

void loop() {
  // Handle serial input
  if (Serial.available()) {
    myColor = Serial.readStringUntil('\n');
    myColor.trim(); // remove whitespace/newlines

    for (uint8_t cnt = 0; cnt < NUMELEMENTS(colors); cnt++) {
      if (colors[cnt].name.equalsIgnoreCase(myColor)) {
        setTargetColor(colors[cnt].red, colors[cnt].green, colors[cnt].blue);
        found = true;
        break;
      }
    }

    if (!found) {
      Serial.println("I do not know that color");
      setTargetColor(0, 0, 0); // turn off
    } else {
      found = false;
    }
  }

  // Handle fading effect
  fadeStep();
}

void setTargetColor(int r, int g, int b) {
  targetRed = r;
  targetGreen = g;
  targetBlue = b;
  stepCount = 0;
}

void fadeStep() {
  if (stepCount >= steps) return;

  unsigned long now = millis();
  if (now - lastFadeTime >= fadeInterval) {
    lastFadeTime = now;
    stepCount++;

    int r = map(stepCount, 0, steps, currentRed, targetRed);
    int g = map(stepCount, 0, steps, currentGreen, targetGreen);
    int b = map(stepCount, 0, steps, currentBlue, targetBlue);

    analogWrite(redPin, r);
    analogWrite(greenPin, g);
    analogWrite(bluePin, b);

    if (stepCount == steps) {
      currentRed = targetRed;
      currentGreen = targetGreen;
      currentBlue = targetBlue;
    }
  }
}