#include <WiFi.h>
#include <PubSubClient.h>
#define LED 4
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "mqtt.my.id";


WiFiClient espClient;
PubSubClient client(espClient);


String data;


void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);


  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password, 6);


  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }


  randomSeed(micros());


  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}


void callback(char* topic, byte* payload, unsigned int length) {
  data = "";
  for (int i = 0; i < length; i++) {
      data += (char) payload[i];
  }

  String text = decrypt(data);
  Serial.println(text);

  // Konversi data ke integer
  int value = data.toInt(); // Ubah string ke integer

  // Logika untuk mengontrol LED
  if (value < 200) {
    digitalWrite(LED, LOW); // Matikan LED
  } else {
    digitalWrite(LED, HIGH); // Nyalakan LED
  }
}


void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      client.subscribe("wokwi/klp8/encrypt");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}


// the decryption function
String decrypt(String encryptedBase64Text) {

    // calculate the original length before it was coded into base64 string
    int originalBytesLength = base64::decodeLength(encryptedBase64Text.c_str());

    // declare empty byte array (a memory storage)
    byte encryptedBytes[originalBytesLength];
    byte decryptedBytes[originalBytesLength];

    // convert the base64 string into original bytes
    // which is the encryptedBytes
    base64::decode(encryptedBase64Text.c_str(), encryptedBytes);

    // initializing AES engine

    // Cipher Mode and Key Size are preset in AESLib
    // Cipher Mode = CBC
    // Key Size = 128

    // declare the KEY and IV
    byte aesKey[] = { 23, 45, 56, 67, 67, 87, 98, 12, 32, 34, 45, 56, 67, 87, 65, 5 };
    byte aesIv[] = { 123, 43, 46, 89, 29, 187, 58, 213, 78, 50, 19, 106, 205, 1, 5, 7 };

    // set the padding mode to paddingMode.CMS
    aesLib.set_paddingmode((paddingMode)0);

    // decrypt bytes in "encryptedBytes" and save the output in "decryptedBytes"
    // param 1 = the source bytes to be decrypted
    // param 2 = the length of source bytes
    // param 3 = the destination of decrypted bytes that will be saved
    // param 4 = KEY
    // param 5 = the length of KEY bytes (16)
    // param 6 = IV
    aesLib.decrypt(encryptedBytes, originalBytesLength, decryptedBytes, aesKey, 16, aesIv);

    // convert the decrypted bytes into original string
    String decryptedText = String((char*)decryptedBytes);

    return decryptedText;
}


void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  pinMode(LED, OUTPUT);
}


void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}