/*
    * 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.specific;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.argeo.eclipse.ui.EclipseUiUtils;
  import org.argeo.eclipse.ui.util.SingleSourcingConstants;
  import org.eclipse.core.commands.AbstractHandler;
  import org.eclipse.core.commands.ExecutionEvent;
  import org.eclipse.rap.rwt.RWT;
  import org.eclipse.rap.rwt.client.service.UrlLauncher;
  
  /**
   * RWT specific object to open a file retrieved from the server. It forwards the
   * request to the correct service after encoding file name and path in the
   * request URI.
   * 
   * <p>
   * The parameter "URI" is used to determine the correct file service, the path
   * and the file name. An optional file name can be added to present the end user
   * with a different file name as the one used to retrieve it.
   * </p>
   * 
   * 
   * <p>
   * The instance specific service is called by its ID and must have been
   * externally created
   * </p>
   */
  public class OpenFile extends AbstractHandler {
  	private final static Log log = LogFactory.getLog(OpenFile.class);
  
  	public final static String ID = SingleSourcingConstants.OPEN_FILE_CMD_ID;
  	public final static String PARAM_FILE_NAME = SingleSourcingConstants.PARAM_FILE_NAME;
  	public final static String PARAM_FILE_URI = SingleSourcingConstants.PARAM_FILE_URI;;
  	
  	/* DEPENDENCY INJECTION */
  	private String openFileServiceId;
  
  	public Object execute(ExecutionEvent event) {
  		String fileName = event.getParameter(PARAM_FILE_NAME);
  		String fileUri = event.getParameter(PARAM_FILE_URI);
  		// Sanity check
  		if (fileUri == null || "".equals(fileUri.trim()) || openFileServiceId == null
  				|| "".equals(openFileServiceId.trim()))
  			return null;
  
  		org.argeo.eclipse.ui.specific.OpenFile openFileClient = new org.argeo.eclipse.ui.specific.OpenFile();
  		openFileClient.execute(openFileServiceId, fileUri, fileName);
  		return null;
  	}
  
  	public Object execute(String openFileServiceId, String fileUri, String fileName) {
  		StringBuilder url = new StringBuilder();
  		url.append(RWT.getServiceManager().getServiceHandlerUrl(openFileServiceId));
  
  		if (EclipseUiUtils.notEmpty(fileName))
  			url.append("&").append(SingleSourcingConstants.PARAM_FILE_NAME).append("=").append(fileName);
  		url.append("&").append(SingleSourcingConstants.PARAM_FILE_URI).append("=").append(fileUri);
  
  		String downloadUrl = url.toString();
  		if (log.isTraceEnabled())
  			log.trace("Calling OpenFileService with ID: " + openFileServiceId + " , with download URL: " + downloadUrl);
  
  		UrlLauncher launcher = RWT.getClient().getService(UrlLauncher.class);
  		launcher.openURL(downloadUrl);
  		return null;
  	}
  
  	/* DEPENDENCY INJECTION */
  	public void setOpenFileServiceId(String openFileServiceId) {
  		this.openFileServiceId = openFileServiceId;
  	}
  }