/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.http.impl.client.cache;
  
  import java.io.Closeable;
  import java.io.File;
  import java.io.IOException;
  
  import org.apache.http.client.cache.HttpCacheInvalidator;
  import org.apache.http.client.cache.HttpCacheStorage;
  import org.apache.http.client.cache.ResourceFactory;
  import org.apache.http.impl.client.HttpClientBuilder;
  import org.apache.http.impl.execchain.ClientExecChain;
  
  /**
   * Builder for {@link org.apache.http.impl.client.CloseableHttpClient}
   * instances capable of client-side caching.
   *
   * @since 4.3
   */
  public class CachingHttpClientBuilder extends HttpClientBuilder {
  
      private ResourceFactory resourceFactory;
      private HttpCacheStorage storage;
      private File cacheDir;
      private CacheConfig cacheConfig;
      private SchedulingStrategy schedulingStrategy;
      private HttpCacheInvalidator httpCacheInvalidator;
      private boolean deleteCache;
  
      public static CachingHttpClientBuilder create() {
          return new CachingHttpClientBuilder();
      }
  
      protected CachingHttpClientBuilder() {
          super();
          this.deleteCache = true;
      }
  
      public final CachingHttpClientBuilder setResourceFactory(
              final ResourceFactory resourceFactory) {
          this.resourceFactory = resourceFactory;
          return this;
      }
  
      public final CachingHttpClientBuilder setHttpCacheStorage(
              final HttpCacheStorage storage) {
          this.storage = storage;
          return this;
      }
  
      public final CachingHttpClientBuilder setCacheDir(
              final File cacheDir) {
          this.cacheDir = cacheDir;
          return this;
      }
  
      public final CachingHttpClientBuilder setCacheConfig(
              final CacheConfig cacheConfig) {
          this.cacheConfig = cacheConfig;
          return this;
      }
  
      public final CachingHttpClientBuilder setSchedulingStrategy(
              final SchedulingStrategy schedulingStrategy) {
          this.schedulingStrategy = schedulingStrategy;
          return this;
      }
  
      public final CachingHttpClientBuilder setHttpCacheInvalidator(
              final HttpCacheInvalidator cacheInvalidator) {
          this.httpCacheInvalidator = cacheInvalidator;
          return this;
      }
  
     public CachingHttpClientBuilder setDeleteCache(final boolean deleteCache) {
         this.deleteCache = deleteCache;
         return this;
     }
 
     @Override
     protected ClientExecChain decorateMainExec(final ClientExecChain mainExec) {
         final CacheConfig config = this.cacheConfig != null ? this.cacheConfig : CacheConfig.DEFAULT;
         // We copy the instance fields to avoid changing them, and rename to avoid accidental use of the wrong version
         ResourceFactory resourceFactoryCopy = this.resourceFactory;
         if (resourceFactoryCopy == null) {
             if (this.cacheDir == null) {
                 resourceFactoryCopy = new HeapResourceFactory();
             } else {
                 resourceFactoryCopy = new FileResourceFactory(cacheDir);
             }
         }
         HttpCacheStorage storageCopy = this.storage;
         if (storageCopy == null) {
             if (this.cacheDir == null) {
                 storageCopy = new BasicHttpCacheStorage(config);
             } else {
                 final ManagedHttpCacheStoragecheStorage.html#ManagedHttpCacheStorage">ManagedHttpCacheStorage managedStorage = new ManagedHttpCacheStorage(config);
                 if (this.deleteCache) {
                     addCloseable(new Closeable() {
 
                         @Override
                         public void close() throws IOException {
                             managedStorage.shutdown();
                         }
 
                     });
                 } else {
                     addCloseable(managedStorage);
                 }
                 storageCopy = managedStorage;
             }
         }
         final AsynchronousValidator revalidator = createAsynchronousRevalidator(config);
         final CacheKeyGeneratorKeyGenerator.html#CacheKeyGenerator">CacheKeyGenerator uriExtractor = new CacheKeyGenerator();
 
         HttpCacheInvalidator cacheInvalidator = this.httpCacheInvalidator;
         if (cacheInvalidator == null) {
             cacheInvalidator = new CacheInvalidator(uriExtractor, storageCopy);
         }
 
         return new CachingExec(mainExec,
                 new BasicHttpCache(
                         resourceFactoryCopy,
                         storageCopy, config,
                         uriExtractor,
                         cacheInvalidator), config, revalidator);
     }
 
     private AsynchronousValidator createAsynchronousRevalidator(final CacheConfig config) {
         if (config.getAsynchronousWorkersMax() > 0) {
             final SchedulingStrategy configuredSchedulingStrategy = createSchedulingStrategy(config);
             final AsynchronousValidatornousValidator.html#AsynchronousValidator">AsynchronousValidator revalidator = new AsynchronousValidator(
                     configuredSchedulingStrategy);
             addCloseable(revalidator);
             return revalidator;
         }
         return null;
     }
 
     private SchedulingStrategy createSchedulingStrategy(final CacheConfig config) {
         return schedulingStrategy != null ? schedulingStrategy : new ImmediateSchedulingStrategy(config);
     }
 
 }