package org.xmlsh.core;

import java.io.Closeable;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.xmlsh.util.ReferenceCounter;

@SuppressWarnings("serial")
public class ReferenceCountedHandle<T extends IHandleable & Closeable>
    implements IReferencedCountedHandle<T> {
  private static Logger mLogger = LogManager.getLogger();
  private volatile ReferenceCounter mCounter;
  private volatile T mObj;

  @Override
  public String toString() {
    return mObj == null ? "null" : mObj.toString() + super.toString();
  }

  public ReferenceCountedHandle(T obj) {
    this(obj, new ReferenceCounter());
  }

  public ReferenceCountedHandle(T obj, ReferenceCounter counter) {
    mLogger.entry(obj, counter);
    mCounter = counter;
    mLogger.entry(obj);
    mObj = obj;
    mLogger.exit();
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.xmlsh.core.IManagedHandle#release()
   */
  @Override
  final public boolean release() throws IOException {
    mLogger.entry(this);
    assert (!isNull());
    if(mCounter.decrement() <= 0) {
      mLogger.info("Closing : {} ", mObj);
      mObj.close();
      mObj = null;
      return mLogger.exit(true);
    }
    return mLogger.exit(false);
  }

  @Override
  public void addRef() {

    mLogger.entry();
    assert (!isNull());
    mLogger.entry(this);
    mLogger.exit(mCounter.increment());
  }

  @Override
  final public T get() {
    return mObj;
  }

  @Override
  final public boolean isNull() {
    return mObj == null;
  }

  @Override
  public int getRefCount() {
    return mCounter.getRefCount();
  }
}