/*

  * 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.mail.resolver;

 import javax.activation.DataSource;

 import javax.activation.URLDataSource;

 import java.io.IOException;

 import java.net.MalformedURLException;

 import java.net.URL;

 /**

  * Creates a <code>DataSource</code> based on an URL.

  *

  * @since 1.3

  * @version $Id: DataSourceUrlResolver.java 1420381 2012-12-11 20:18:05Z tn $

  */

 public class DataSourceUrlResolver extends DataSourceBaseResolver

 {

     /** the base url of the resource when resolving relative paths */

     private final URL baseUrl;

     /**

      * Constructor.

      *

      * @param baseUrl the base URL used for resolving relative resource locations

      */

     public DataSourceUrlResolver(final URL baseUrl)

     {

         super();

         this.baseUrl = baseUrl;

     }

     /**

      * Constructor.

      *

      * @param baseUrl the base URL used for resolving relative resource locations

      * @param lenient shall we ignore resources not found or complain with an exception

      */

     public DataSourceUrlResolver(final URL baseUrl, final boolean lenient)

     {

         super(lenient);

         this.baseUrl = baseUrl;

     }

     /**

      * Get the base URL used for resolving relative resource locations.

      *

      * @return the baseUrl

      */

     public URL getBaseUrl()

     {

         return baseUrl;

     }

     /** {@inheritDoc} */

     public DataSource resolve(String resourceLocation) throws IOException

     {

         return resolve(resourceLocation, isLenient());

     }

     /** {@inheritDoc} */

     public DataSource resolve(final String resourceLocation, final boolean isLenient) throws IOException

     {

         DataSource result = null;

         try

         {

             if (!isCid(resourceLocation))

             {

                 URL url = createUrl(resourceLocation);

                 result = new URLDataSource(url);

                 result.getInputStream();

             }

             return result;

         }

         catch (IOException e)

         {

             if (isLenient)

             {

                 return null;

             }

             else

             {

                 throw e;

             }

         }

     }

     /**

      * Create an URL based on a base URL and a resource location suitable for loading

      * the resource.

      *

      * @param resourceLocation a resource location

      * @return the corresponding URL

      * @throws java.net.MalformedURLException creating the URL failed

      */

     private URL createUrl(final String resourceLocation) throws MalformedURLException

     {

         // if we get an non-existing base url than the resource can

         // be directly used to create an URL

         if (baseUrl == null)

         {

             return new URL(resourceLocation);

         }

         // if we get an non-existing location what we shall do?

         if (resourceLocation == null || resourceLocation.length() == 0)

         {

             throw new IllegalArgumentException("No resource defined");

         }

         // if we get a stand-alone resource than ignore the base url

         if (isFileUrl(resourceLocation) || isHttpUrl(resourceLocation))

         {

             return new URL(resourceLocation);

         }

         return new URL(getBaseUrl(), resourceLocation.replaceAll("&", "&"));

     }

 }