#include <Adafruit_NeoPixel.h>

// ================= CONSTANTES =================
constexpr uint8_t LED_PIN = 4;
constexpr uint8_t NUM_LEDS = 2;
constexpr uint8_t SW1_PIN = 6;
constexpr unsigned long DEBOUNCE_MS = 50;
constexpr uint8_t NUM_COLORES = 5;

// ================= ESTRUCTURAS =================

struct Button {
  uint8_t pin;           ///< Pin asignado al botón.
  bool state;            ///< Estado estable del botón (HIGH/LOW).
  bool lastRead;         ///< Última lectura cruda del pin.
  unsigned long lastChange; ///< Último instante en que cambió la lectura bruta.
};

// ================= VARIABLES GLOBALES =================

Adafruit_NeoPixel leds(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);
uint32_t colores[NUM_COLORES];
uint8_t colorIndexPerLed[NUM_LEDS] = {0};
uint8_t ledSeleccionado = 0;
Button btn1;
Button btn2;

// ================= PROTOTIPOS =================
void initializeLeds();
void initializeColors();
void initializeButtons();
bool updateButton(Button &b);
void applyColors();
void cycleColorSelected();
void cycleSelectedLed();

// ================= IMPLEMENTACIÓN =================

void initializeLeds() {
  leds.begin();
  leds.show();
}

void initializeColors() {
  colores[0] = leds.Color(255, 255, 0);   // Amarillo
  colores[1] = leds.Color(0, 0, 255);     // Azul
  colores[2] = leds.Color(255, 0, 0);     // Rojo
  colores[3] = leds.Color(0, 255, 0);     // Verde
  colores[4] = leds.Color(255, 255, 255); // Blanco
}

void initializeButtons() {
  btn1.pin = SW1_PIN;
  btn1.state = HIGH;
  btn1.lastRead = HIGH;
  btn1.lastChange = 0;
  pinMode(btn1.pin, INPUT_PULLUP);
}

bool updateButton(Button &b) {
  bool raw = digitalRead(b.pin);

  if (raw != b.lastRead) {
    b.lastChange = millis();
    b.lastRead = raw;
  }

  if ((millis() - b.lastChange) > DEBOUNCE_MS) {
    if (b.state != raw) {
      b.state = raw;
      return (b.state == LOW); // Pulsación detectada
    }
  }
  return false;
}

void applyColors() {
  for (uint8_t i = 0; i < NUM_LEDS; ++i) {
    leds.setPixelColor(i, colores[colorIndexPerLed[i] % NUM_COLORES]);
  }
  leds.show();
}

void cycleColorSelected() {
  colorIndexPerLed[ledSeleccionado] =
      (colorIndexPerLed[ledSeleccionado] + 1) % NUM_COLORES;
  applyColors();
}

void cycleSelectedLed() {
  ledSeleccionado = (ledSeleccionado + 1) % NUM_LEDS;
}

// ================= SETUP & LOOP =================

void setup() {
  initializeLeds();
  initializeColors();
  initializeButtons();
  applyColors();
}

void loop() {
  if (updateButton(btn1)) {
    cycleColorSelected();
  }
}