package at.gv.egiz.eaaf.core.impl.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.List;

import org.springframework.lang.Nullable;

public class EaafSerializationUtils {

  private EaafSerializationUtils() {

  }

  /**
   * Serialize a given Java object into a byte array.
   *
   * @param object Java object to serialize.
   * @return Serialized Java object
   */
  @Nullable
  public static byte[] serialize(@Nullable Object object) {
    if (object == null) {
      return null;
      
    }
    
    final ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);
    try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
      oos.writeObject(object);
      oos.flush();

    } catch (final IOException ex) {
      throw new IllegalArgumentException("Failed to serialize object of type: " + object.getClass(), ex);
      
    }
    
    return baos.toByteArray();
  }

  /**
   * Deserialize the byte array into an object.
   *
   * @param bytes a serialized object
   * @param allowedClassName List of classnames that are allowed for deserialization
   * @return the result of deserializing the bytes
   */
  @Nullable
  public static Object deserialize(@Nullable byte[] bytes, List<String> allowedClassName) {
    if (bytes == null) {
      return null;
      
    }    
    
    try (ObjectInputStream ois = new EaafObjectInputStream(new ByteArrayInputStream(bytes), allowedClassName)) {
      return ois.readObject();
      
    } catch (final IOException ex) {
      throw new IllegalArgumentException("Failed to deserialize object", ex);
      
    } catch (final ClassNotFoundException ex) {
      throw new IllegalStateException("Failed to deserialize object type", ex);
      
    }
  }
}