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

// WIFI config
const char* ssid = "Wokwi-GUEST";
const char* password =  "";
WiFiClient wifiClient;
// MQTT client config
const char* mqttServer = "broker.hivemq.com";
const int mqttPort = 1883;
const char* mqttUser = "";
const char* mqttPassword = "";
const char* topic_pub = "fah/Lab/counter";
PubSubClient mqttClient(wifiClient);
// some variables buffer
String publishMessage;
int i = 0;

void setup_wifi() {
  // Start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("WiFi connected on ");
  Serial.print("IP address: ");
  Serial.print(WiFi.localIP());
  Serial.print(" MAC address: ");
  Serial.println(WiFi.macAddress());
}

void reconnectMQTT() {
  // Loop until we're reconnected
  char mqttinfo[80];
  char clientId[100] = "\0";
  snprintf (mqttinfo, 75, "Attempting MQTT connection at %s:%d (%s/%s)...", mqttServer, mqttPort, mqttUser, mqttPassword);
  while (!mqttClient.connected()) {
    Serial.println(mqttinfo);
    sprintf(clientId, "ESP32Client-%04X", random(0xffff));
    if (mqttClient.connect(clientId)) {
      Serial.println("...MQTT Broker connected..."); // subscribe here after connected
      // ในตัวอยา่ งของฝงั่ สง่ ไมม่ ีการ subscribe topic ใด
      // Subscribe topic
    } else {
      Serial.print("failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  mqttClient.setServer(mqttServer, mqttPort);
}
void loop() {
  if (!mqttClient.connected()) {
    reconnectMQTT();
  }
  mqttClient.loop();
  // testing process
  i = i + 1;
  // prepare send message/payload
  publishMessage = String(i);
  // send command
  mqttClient.publish(topic_pub, publishMessage.c_str());
  // debug
  Serial.println(publishMessage);
  delay(2000); // this speeds up the simulation
}