/*
    * Copyright 2002-2006 the original author or authors.
    *
    * Licensed 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.springbyexample.httpclient;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Map;
  
  import org.apache.commons.httpclient.HttpException;
  import org.apache.commons.httpclient.HttpMethod;
  import org.apache.commons.httpclient.methods.ByteArrayRequestEntity;
  import org.apache.commons.httpclient.methods.InputStreamRequestEntity;
  import org.apache.commons.httpclient.methods.PostMethod;
  import org.apache.commons.httpclient.methods.RequestEntity;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.stereotype.Component;
  
  /**
   * Template for easier use of <code>HttpClient</code>.
   * 
   * @author David Winterfeldt
   */
  @Component
  public class HttpClientTemplate extends AbstractHttpClientTemplate<RequestEntity> {
  
      final Logger logger = LoggerFactory.getLogger(HttpClientTemplate.class);
  
      /**
       * Constructor.
       */
      public HttpClientTemplate() {}
  
      /**
       * Constructor.
       * 
       * @param   defaultUri      Default uri.
       */
      public HttpClientTemplate(String defaultUri) {
          super(defaultUri, false);
      }
  
      /**
       * Constructor.
       * 
       * @param   defaultUri      Default uri.
       * @param   init            Whether or not to initialize the bean.
       */
      public HttpClientTemplate(String defaultUri, boolean init) {
          super(defaultUri, init);
      }
  
      /**
       * Execute post method.
       * 
       * @param   input           Byte array <code>RequestEntity</code> to post 
       *                          for the request's data.
       */
      public void executePostMethod(byte[] input) {
          executePostMethod(input, null);
      }
      
      /**
       * Execute post method.
       * 
       * @param   input           Byte array <code>RequestEntity</code> to post 
       *                          for the request's data.
       * @param   callback        Callback with HTTP method's response.
       */
      public void executePostMethod(byte[] input, ResponseCallback<?> callback) {
          executePostMethod(defaultUri,  
                            (input != null ? new ByteArrayRequestEntity(input) : null), 
                            null, callback);
      }
      
      /**
       * Execute post method.
       * 
       * @param   input           <code>String</code> to post 
       *                          for the request's data.
       */
      public void executePostMethod(String input) {
          executePostMethod(input, null);
      }
 
     /**
      * Execute post method.
      * 
      * @param   input           <code>String</code> to post 
      *                          for the request's data.
      * @param   callback        Callback with HTTP method's response.
      */
     public void executePostMethod(String input, ResponseCallback<?> callback) {
         executePostMethod((input != null ? new ByteArrayInputStream(input.getBytes()) : null),
                           callback);
     }
 
     /**
      * Execute post method.
      * 
      * @param   input           <code>InputStream</code> to post 
      *                          for the request's data.
      */
     public void executePostMethod(InputStream input) {
         executePostMethod(input, null);
     }
 
     /**
      * Execute post method.
      * 
      * @param   input           <code>InputStream</code> to post 
      *                          for the request's data.
      * @param   callback        Callback with HTTP method's response.
      */
     public void executePostMethod(InputStream input, ResponseCallback<?> callback) {
         executePostMethod(defaultUri, new InputStreamRequestEntity(input), null, callback);
     }
     
     /**
      * Execute post method.
      * 
      * @param   uri             URI to use when processing this HTTP request instead 
      *                          of using the default URI.
      * @param   requestPayload  <code>RequestEntity</code> data to post.
      * @param   hParams         Parameters for the HTTP post.
      * @param   callback        Callback with HTTP method's response.
      */
     public void executePostMethod(String uri,  
                                   RequestEntity requestPayload, Map<String, String> hParams,
                                   ResponseCallback<?> callback) {
         PostMethod post = new PostMethod(uri);
         
         if (requestPayload != null) {
             post.setRequestEntity(requestPayload);
         }
         
         processHttpMethodParams(post, hParams);
         
         processHttpMethod(post, callback);
     }
 
     /**
      * Processes <code>HttpMethod</code> by executing the method, 
      * validating the response, and calling the callback.
      * 
      * @param   httpMethod      <code>HttpMethod</code> to process.
      * @param   callback        Callback with HTTP method's response.
      */
     protected void processHttpMethod(HttpMethod httpMethod, ResponseCallback<?> callback) {
         try {
             client.executeMethod(httpMethod);
             
             validateResponse(httpMethod);
             
             if (callback instanceof ResponseByteCallback) {
                 ((ResponseByteCallback)callback).doWithResponse(httpMethod.getResponseBody());
             } else if (callback instanceof ResponseStreamCallback) {
                 ((ResponseStreamCallback)callback).doWithResponse(httpMethod.getResponseBodyAsStream());
             } else if (callback instanceof ResponseStringCallback) {
                 ((ResponseStringCallback)callback).doWithResponse(httpMethod.getResponseBodyAsString());
             }
         } catch (HttpException e) {
             throw new HttpAccessException(e.getMessage(), e, httpMethod.getStatusCode());
         } catch (IOException e) {
             throw new HttpAccessException(e.getMessage(), e);
         } finally {
             httpMethod.releaseConnection();
         }
     }
     
 }