/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.pool2.proxy;
  
  import org.apache.commons.pool2.ObjectPool;
  import org.apache.commons.pool2.UsageTracking;
  
  /**
   * Create a new object pool where the pooled objects are wrapped in proxies
   * allowing better control of pooled objects and in particular the prevention
   * of the continued use of an object by a client after that client returns the
   * object to the pool.
   *
   * @param <T> type of the pooled object
   * @since 2.0
   */
  public class ProxiedObjectPool<T> implements ObjectPool<T> {
  
      private final ObjectPool<T> pool;
      private final ProxySource<T> proxySource;
  
      /**
       * Constructs a new proxied object pool.
       *
       * @param pool  The object pool to wrap
       * @param proxySource The source of the proxy objects
       */
      public ProxiedObjectPool(final ObjectPool<T> pool, final ProxySource<T> proxySource) {
          this.pool = pool;
          this.proxySource = proxySource;
      }
  
      @Override
      public void addObject() throws Exception {
          pool.addObject();
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public T borrowObject() throws Exception {
          UsageTracking<T> usageTracking = null;
          if (pool instanceof UsageTracking) {
              usageTracking = (UsageTracking<T>) pool;
          }
          return proxySource.createProxy(pool.borrowObject(), usageTracking);
      }
  
      @Override
      public void clear() throws Exception {
          pool.clear();
      }
  
      @Override
      public void close() {
          pool.close();
      }
  
      @Override
      public int getNumActive() {
          return pool.getNumActive();
      }
  
      @Override
      public int getNumIdle() {
          return pool.getNumIdle();
      }
  
      @Override
      public void invalidateObject(final T proxy) throws Exception {
          pool.invalidateObject(proxySource.resolveProxy(proxy));
      }
  
      @Override
      public void returnObject(final T proxy) throws Exception {
          pool.returnObject(proxySource.resolveProxy(proxy));
      }
  
      /**
       * @since 2.4.3
       */
      @Override
      public String toString() {
          final StringBuilder builder = new StringBuilder();
          builder.append("ProxiedObjectPool [pool=");
          builder.append(pool);
         builder.append(", proxySource=");
         builder.append(proxySource);
         builder.append("]");
         return builder.toString();
     }
 }