#include <WiFi.h>
#include "PubSubClient.h"
#include <Keypad.h>
const char * MQTTServer = "broker.hivemq.com";
const char * MQTT_Topic = "Keypad";

// Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
const char * MQTT_ID = "9392e878-a5de-48cf-9e1c-f8523020d1";
int Port = 1883;

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};


uint8_t colPins[COLS] = { 16, 4, 2, 15}; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 19, 18, 5, 17}; // Pins connected to R1, R2, R3, R4
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
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(1000);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected");
  Serial.print(", IP address: ");
  Serial.println(WiFi.localIP());
}
String pass="";
void GuiPass(String a){
  client.publish("KeyPad",String(a).c_str());
}

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;

  if(stMessage="success"){
    tone(21,100,1000);
    delay(2000);
  }else if(stMessage="error"){
    digitalWrite(21, HIGH);
    delay(1000);
    digitalWrite(21, LOW);
    delay(1000);
  }
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  Serial.println();
  
}

void setup() {
  Serial.begin(115200);
  delay(10);
  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  
  pinMode(21, OUTPUT);
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    
    if(key!='#'){
      Serial.println(key);
      pass +=key;
    }
    else{
      GuiPass(pass);
      Serial.println(pass);
      pass="";
    }
  }

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