/*
    * Copyright 2014 James Pether Sörling
    *
    * 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.
   *
   *	$Id$
   *  $HeadURL$
  */
  package com.hack23.cia.web.impl.ui.application.views.common.pagelinks.impl;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.vaadin.server.StreamResource;
  import com.vaadin.ui.Link;
  
  /**
   * The Class ExternalAttachmentDownloadLink.
   */
  public final class ExternalAttachmentDownloadLink extends Link {
  
  	/** The Constant serialVersionUID. */
  	private static final long serialVersionUID = 1L;
  
  	/** The Constant LOGGER. */
  	private static final Logger LOGGER = LoggerFactory.getLogger(ExternalAttachmentDownloadLink.class);
  
  	/** The file name. */
  	private final String fileName;
  
  	/** The file type. */
  	private final String fileType;
  
  	/** The file url. */
  	private final String fileUrl;
  
  	/**
  	 * Instantiates a new external attachment download link.
  	 *
  	 * @param fileName
  	 *            the file name
  	 * @param fileType
  	 *            the file type
  	 * @param fileUrl
  	 *            the file url
  	 */
  	public ExternalAttachmentDownloadLink(final String fileName, final String fileType, final String fileUrl) {
  		super();
  		this.fileName = fileName;
  		this.fileType = fileType;
  		this.fileUrl = fileUrl;
  		setCaption(fileName);
  		setDescription("Download " + fileName);
  		setTargetName("_blank");
  	}
  
  	@Override
  	public void attach() {
  		super.attach();
  
  		final StreamResource.StreamSource source = new StreamResource.StreamSource() {
  
  			/** The Constant serialVersionUID. */
  			private static final long serialVersionUID = 1L;
  
  			@Override
  			public InputStream getStream() {
  
  				try {
  					return new URL(fileUrl).openStream();
  				} catch (final IOException e) {
  					LOGGER.warn("Problem opening url:"+ fileUrl,e);
  					return new ByteArrayInputStream(new byte[0]);
  				}
  			}
  		};
  
  		final StreamResource resource = new StreamResource(source, fileName);
  
  		resource.getStream().setParameter("Content-Disposition", "attachment;filename=\"" + fileName + "\"");
  		resource.setMIMEType("application/" + fileType);
  		resource.setCacheTime(0);
  
  		setResource(resource);
 	}
 }