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

#define LED_PIN 15

const char *mqtt_broker = "broker.emqx.io";
const char *topic = "esp32/ZenLED";
const char *mqtt_username = "emqx";
const char *mqtt_password = "public";
const int mqtt_port = 1883;

bool led_status = false;

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  pinMode(LED_PIN, OUTPUT); // 将 LED_PIN 引脚设置为输出模式
  Serial.begin(115200);
  Serial.print("Connecting to WiFi");
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  client.setServer(mqtt_broker, mqtt_port);
  client.setCallback(callback);
  while (!client.connected()) {
      String client_id = "esp32-client-";
      client_id += String(WiFi.macAddress());
      Serial.printf("The client %s connects to the public mqtt broker\n", client_id.c_str());
      if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
          Serial.println("Public emqx mqtt broker connected");
      } else {
          Serial.print("failed with state ");
          Serial.print(client.state());
          delay(2000);
      }
  }
  // publish and subscribe
  client.publish(topic, "Hi EMQX I'm ESP32 ^^");
  client.subscribe(topic);
}

void callback(char *topic, byte *payload, unsigned int length) {
  Serial.print("Message arrived in topic: ");
  Serial.println(topic);
  Serial.print("Message:");
  String message;
  for (int i = 0; i < length; i++) {
      // Serial.print((char) payload[i]);
      message += (char) payload[i];
  }
  Serial.println(message);
  Serial.println("-----------------------");

  if(message == "on" && !led_status ){
    digitalWrite(LED_PIN, HIGH);
    led_status = true;
  }

  if(message == "off" && led_status ){
    digitalWrite(LED_PIN, LOW);
    led_status = false;
  }
}

void loop() {
  client.loop();
}