#include <ESP8266WiFi.h>
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <WiFiManager.h>
#include <PubSubClient.h>

// GPIO 5 D1
#define LED 5


// MQTT Broker
//，，，，
const char *mqtt_broker = "###";//设置MQTT 地址
const char *topic = "esp8266/led";//订阅名称
const char *mqtt_username = "###";//连接用户名
const char *mqtt_password = "####";//密码
const int mqtt_port = 1883;//端口

//创建一个wificlient对象
WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
    //设置板载LED管脚为输出模式
    pinMode(LED_BUILTIN, OUTPUT);
    // Set software serial baud to 9600;
    //设置软件串口波特率为9600；
    Serial.begin(9600);
  
    //以下这两句是建立自动配网最主要的函数
   // 建立WiFiManager对象
    WiFiManager wifiManager; 
    // 自动连接WiFi。以下语句的参数是连接ESP8266时的WiFi名称
    wifiManager.autoConnect("AutoConnectAP");


    // WiFi连接成功后将通过串口监视器输出连接成功信息 
    Serial.println(""); 
    Serial.print("ESP8266 Connected to ");
    Serial.println(WiFi.SSID());              // WiFi名称
    Serial.print("IP address:\t");
    Serial.println(WiFi.localIP());           // IP

    //connecting to a mqtt broker
    //连接MQTT服务器
    client.setServer(mqtt_broker, mqtt_port);//
    client.setCallback(callback);
    while (!client.connected()) {
        String client_id = "esp8266-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, "hello emqx");
    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++) {
        message = message + (char) payload[i];  // convert *byte to string
    }
    Serial.print(message);
    if (message == "on") { digitalWrite(LED_BUILTIN, LOW); }   // LED on
    if (message == "off") { digitalWrite(LED_BUILTIN, HIGH); } // LED off
    Serial.println();
    Serial.println("-----------------------");
}

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