#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include "PubSubClient.h"

const char * MQTTServer = "broker.emqx.io";
const char * MQTT_Topic = "IoT/led";

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

unsigned int led [] = {17,16,4,0};


// Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
const char * MQTT_ID = "c5afa5ae-d3a0-48b7-b850-92015a281909";
int Port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);

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.println(" connected");
      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 receivedMessage;
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    receivedMessage += (char)message[i];
  }
    
  Serial.println();

  if (String(topic) == MQTT_Topic) {
      if (receivedMessage == "chan") {
          for(int i = 0 ; i < 4 ; i++) {
            if(i % 2 == 0) {
              digitalWrite(led[i], HIGH);
            } else {
              digitalWrite(led[i],LOW);
            }
            lcd.clear();
            lcd.setCursor(0,0);
            lcd.print("Chan: ON");
            lcd.setCursor(0,1);
            lcd.print("Le: OFF");
          } 
        } else if(receivedMessage == "le") {
            for(int i = 0 ; i < 4 ; i++) {
            if(i % 2 != 0) {
              digitalWrite(led[i], HIGH);
            } else {
              digitalWrite(led[i],LOW);
            }
            lcd.clear();
            lcd.setCursor(0,0);
            lcd.print("Chan: OFF");
            lcd.setCursor(0,1);
            lcd.print("Le: ON");
          }
      }
    }
} 

void setup() {
  // Init
  lcd.init();
  lcd.backlight();

  // Print something
  lcd.setCursor(3, 0);
  lcd.print("Welcome!");

  Serial.begin(115200);

  for(int i = 0; i < 4; i++) {
    pinMode(led[i], OUTPUT);
  }


  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  client.subscribe(MQTT_Topic); // Đăng ký topic để nhận dữ liệu

}

void loop() {
  delay(10);
 if (!client.connected()) {
    MQTT_Reconnect();
    client.subscribe(MQTT_Topic); // Đăng ký lại topic sau khi kết nối lại với MQTT
  }
  client.loop();
  delay(1000);
}