#include < WiFi.h>
#include < PubSubClient.h>
#include < Adafruit_NeoPixel.h>

const char* ssid = "TuSSID";
const char* password = "TuContraseña";
const char* mqtt_server = "broker.emqx.io";

const char* topic = "hans/switch";

#define NEOPIXEL_PIN 10
#define NUM_PIXELS 1

WiFiClient espClient;
PubSubClient client(espClient);

Adafruit_NeoPixel pixels(NUM_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  pixels.begin();
}

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Conectando a ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi conectado");
  Serial.println("Dirección IP: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.print("Mensaje recibido desde el topic ");
  Serial.print(topic);
  Serial.print(": ");
  Serial.println(message);

  if (message == "a") {
    pixels.setPixelColor(0, pixels.Color(255, 0, 0)); // Rojo
    pixels.show();
  } else {
    pixels.setPixelColor(0, pixels.Color(0, 255, 0)); // Verde
    pixels.show();
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Conectando al servidor MQTT...");
    if (client.connect("neopixelClient")) {
      Serial.println("Conectado");
      client.subscribe(topic);
    } else {
      Serial.print("falló, rc=");
      Serial.print(client.state());
      Serial.println(" intentando nuevamente en 5 segundos");
      delay(5000);
    }
  }
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}