//YWROBOT
//Compatible with the Arduino IDE 1.0
//Library version:1.1
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include "PubSubClient.h"

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 for a 16 chars and 2 line display

const char * MQTTServer = "broker.emqx.io";
const char * MQTT_Topic = "DKLCD2004";

// Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
const char * MQTT_ID = "d4742b19-c6b1-436e-9b8d-b7c8cee891c0";
int Port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);
const int ledPin = 2;

void WIFIConnect() {
  Serial.println("Connecting to SSID: Wokwi-GUEST");
  WiFi.begin("Wokwi-GUEST", "");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected");
  Serial.print(", IP address: ");
  Serial.println(WiFi.localIP());
}

void MQTT_Reconnect() {
  while (!client.connected()) {
    if (client.connect(MQTT_ID)) {
      Serial.print("MQTT Topic: ");
      Serial.print(MQTT_Topic);
      Serial.print(" connected");
      client.subscribe(MQTT_Topic);
      Serial.println("");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.println(topic);
  Serial.print("Message: ");
  String stMessage;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  lcd.setCursor(3,0);
  lcd.print(stMessage);
  delay(10000);
  lcd.clear();
}


void setup()
{
  lcd.init();                      // initialize the lcd
  // Print a message to the LCD.
  lcd.backlight();
   

  Serial.begin(115200);

  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
}


int i = 0;

void loop()
{
  
  delay(10);

  if (!client.connected()) {
    MQTT_Reconnect();
  }
  client.loop();

}