#include <WiFi.h>
#include <PubSubClient.h>
#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
#define buzz 27

const char * MQTTServer = "broker.emqx.io";
const char * MQTT_Topic = "PTUDIOT/buzzer";

// Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
const char * MQTT_ID = "19eca5f8-7e56-48a3-ab64-6cf33a133392";
int Port = 1883;
int password = 8005;

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.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;
  lcd.clear();

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  lcd.setCursor(0, 0);
  password= stMessage.toInt(); 
  
  delay(1000);
}


const int row = 4;
const int col = 4;
char keys[row][col] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins [row] = {14,12,19,18};
byte colPins [col] = {5,4,2,15};
Keypad customKeypad = Keypad ( makeKeymap(keys), rowPins, colPins, row, col);
  char customKey;
  int number = 0;
  


void setup() {
  Serial.begin(9600);
  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  pinMode(buzz, OUTPUT);
  lcd.init();
  lcd.setBacklight(HIGH);
}

void loop() {
  delay(10);
  if (!client.connected()) {
    MQTT_Reconnect();
  }
  client.loop();

  lcd.setCursor (0,0);
  lcd.print("Input Password");

  customKey = customKeypad.getKey();
  switch(customKey){
    case '0'...'9':
    lcd.setCursor(0,1);
    number = number * 10 + (customKey - '0');
    lcd.print(number);
    break;

    case '#':
    
      if (number == password){
        lcd.clear();
        lcd.setCursor(0,1);
        lcd.print("OK");
        delay(1000);
        tone(buzz,1000);
        delay(50);
        noTone(buzz);
      } else {
        lcd.clear();
        lcd.setCursor(0,1);
        lcd.print("wrong");
        delay(2000);
      }
      break;

    case '*':
    lcd.clear();
    lcd.setCursor(0,1);
    number=0;
    break;

  }
}