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

#define ROW_NUM     4 
#define COLUMN_NUM  4 

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

byte pin_rows[ROW_NUM]      = {13, 12, 14, 27};
byte pin_column[COLUMN_NUM] = {26, 25, 33, 32};

int buzzerPin = 5;
//------------------------------------------

const char * MQTTServer = "broker.emqx.io";
const char * MQTT_Topic = "keyp21004250";
const char * MQTT_ID = "2288c5f5-e215-437d-9c96-2c8ef979ed88"; // Tạo ID ngẫu nhiên tại: https://www.guidgen.com/
int Port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);

String str;
String pass;

//---------------------------------------

void setup() {
  Serial.begin(115200);
  pinMode(buzzerPin, OUTPUT);
  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  Serial.println("Press '#' to change the password");
}

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

  //------------------------------------
  char key = keypad.getKey();
  if(key == '#') {
    pass = str;
    str = "";
    Serial.print("New password: ");
    Serial.println(pass);
    sendData(pass);
  }
  if(key && key != '#') {
    str += key;
    Serial.println(str);
    for (int i = 0; i < LIST_MAX; i++) {
      if (keypad.key[i].stateChanged) {
        if (keypad.key[i].kstate == PRESSED) {
          tone(buzzerPin, 1500, 200);
          delay(300);
          noTone(buzzerPin);
        }
      }
    }
  }
}

//---------------------------------------------------------

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];
  }
  Serial.println();
}

void sendData(String chuoi) {
  char charArray[200]; 
  chuoi.toCharArray(charArray, 200);
  client.publish(MQTT_Topic, charArray);
}