/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * 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.argeo.eclipse.ui.jcr.util;
  
  import java.io.InputStream;
  
  import javax.jcr.Node;
  import javax.jcr.Property;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  import javax.jcr.nodetype.NodeType;
  
  import org.apache.commons.io.IOUtils;
  import org.argeo.eclipse.ui.EclipseUiException;
  import org.argeo.eclipse.ui.FileProvider;
  
  /**
   * Implements a FileProvider for UI purposes. Unlike the
   * <code> JcrFileProvider </code>, it relies on a single session and manages
   * nodes with path only.
   * 
   * Note that considered id is the JCR path
   * 
   * Relies on common approach for JCR file handling implementation.
   */
  @SuppressWarnings("deprecation")
  public class SingleSessionFileProvider implements FileProvider {
  
  	private Session session;
  
  	public SingleSessionFileProvider(Session session) {
  		this.session = session;
  	}
  
  	public byte[] getByteArrayFileFromId(String fileId) {
  		InputStream fis = null;
  		byte[] ba = null;
  		Node child = getFileNodeFromId(fileId);
  		try {
  			fis = (InputStream) child.getProperty(Property.JCR_DATA)
  					.getBinary().getStream();
  			ba = IOUtils.toByteArray(fis);
  
  		} catch (Exception e) {
  			throw new EclipseUiException("Stream error while opening file", e);
  		} finally {
  			IOUtils.closeQuietly(fis);
  		}
  		return ba;
  	}
  
  	public InputStream getInputStreamFromFileId(String fileId) {
  		try {
  			InputStream fis = null;
  
  			Node child = getFileNodeFromId(fileId);
  			fis = (InputStream) child.getProperty(Property.JCR_DATA)
  					.getBinary().getStream();
  			return fis;
  		} catch (RepositoryException re) {
  			throw new EclipseUiException("Cannot get stream from file node for Id "
  					+ fileId, re);
  		}
  	}
  
  	/**
  	 * 
  	 * @param fileId
  	 * @return Returns the child node of the nt:file node. It is the child node
  	 *         that have the jcr:data property where actual file is stored.
  	 *         never null
  	 */
  	private Node getFileNodeFromId(String fileId) {
  		try {
  			Node result = null;
  			result = session.getNode(fileId);
  
  			// Sanity checks
  			if (result == null)
  				throw new EclipseUiException("File node not found for ID" + fileId);
  
  			// Ensure that the node have the correct type.
  			if (!result.isNodeType(NodeType.NT_FILE))
  				throw new EclipseUiException(
  						"Cannot open file children Node that are not of "
  								+ NodeType.NT_RESOURCE + " type.");
 
 			Node child = result.getNodes().nextNode();
 			if (child == null || !child.isNodeType(NodeType.NT_RESOURCE))
 				throw new EclipseUiException(
 						"ERROR: IN the current implemented model, "
 								+ NodeType.NT_FILE
 								+ "  file node must have one and only one child of the nt:ressource, where actual data is stored");
 			return child;
 		} catch (RepositoryException re) {
 			throw new EclipseUiException("Erreur while getting file node of ID "
 					+ fileId, re);
 		}
 	}
 }