/*******************************************************************************
    *  Imixs Workflow 
    *  Copyright (C) 2001, 2011 Imixs Software Solutions GmbH,  
    *  http://www.imixs.com
    *  
    *  This program is free software; you can redistribute it and/or 
    *  modify it under the terms of the GNU General Public License 
    *  as published by the Free Software Foundation; either version 2 
    *  of the License, or (at your option) any later version.
   *  
   *  This program is distributed in the hope that it will be useful, 
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
   *  General Public License for more details.
   *  
   *  You can receive a copy of the GNU General Public
   *  License at http://www.gnu.org/licenses/gpl.html
   *  
   *  Project: 
   *  	http://www.imixs.org
   *  	http://java.net/projects/imixs-workflow
   *  
   *  Contributors:  
   *  	Imixs Software Solutions GmbH - initial API and implementation
   *  	Ralph Soika - Software Developer
   *******************************************************************************/
  package org.imixs.workflow.services.rest;
  
  import java.io.BufferedWriter;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.net.HttpURLConnection;
  import java.net.URL;
  
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.Marshaller;
  
  import org.imixs.workflow.util.Base64;
  import org.imixs.workflow.xml.EntityCollection;
  import org.imixs.workflow.xml.XMLItemCollection;
  
  /**
   * This ServiceClient is a WebService REST Client which encapsulate the
   * communication with a REST web serice based on the Imixs Workflow REST API.
   * The Implementation is based on the JAXB API.
   * 
   * The ServiceClient supports methods for posting EntityCollections and
   * XMLItemCollections.
   * 
   * The post method expects the rest service URI and a Dataobject based ont the
   * Imixs Workflow XML API
   * 
   * @see org.imixs.workflow.jee.rest
   * @author Ralph Soika
   * 
   */
  public class RestClient {
  
  	// private String NAME_SPACE = "http://imixs.org/workflow/services";
  
  	private String serviceEndpoint;
  
  	private String sUser = null;
  
  	private String sPassword = null;
  
  	private String encoding = "UTF-8";
  
  	private int iLastHTTPResult = 0;
  
  	// Sets credentials
  	public void setCredentials(String auser, String apw) {
  		sUser = auser;
  		sPassword = apw;
  	}
  
  	public void setEncoding(String aEncoding) {
  		encoding = aEncoding;
  	}
  
  	/**
  	 * This method posts an XMLItemCollection in the Imixs XML Format to a Rest
  	 * Service URI Endpoint.
  	 * 
  	 * 
  	 * @param uri
  	 *            - Rest Endpoint RUI
  	 * @param entityCol
  	 *            - an Entity Collection
  	 * @return HTTPResult
  	 */
  	public int postEntity(String uri, XMLItemCollection aItemCol)
  			throws Exception {
  		PrintWriter printWriter = null;
  
  		HttpURLConnection urlConnection = null;
  		try {
  			serviceEndpoint = uri;
 			iLastHTTPResult = 500;
 
 			urlConnection = (HttpURLConnection) new URL(serviceEndpoint)
 					.openConnection();
 			urlConnection.setRequestMethod("POST");
 			urlConnection.setDoOutput(true);
 			urlConnection.setDoInput(true);
 			urlConnection.setAllowUserInteraction(false);
 
 			// Authorization
 			if (sUser != null) {
 				urlConnection.setRequestProperty("Authorization", "Basic "
 						+ this.getAccessByUser());
 			}
 			/** * HEADER ** */
 			urlConnection.setRequestProperty("Content-Type",
 					"application/xml; charset=" + encoding);
 
 			StringWriter writer = new StringWriter();
 
 			JAXBContext context = JAXBContext
 					.newInstance(XMLItemCollection.class);
 			Marshaller m = context.createMarshaller();
 			m.marshal(aItemCol, writer);
 
 			// System.out.println(writer.toString());
 
 			// compute length
 			urlConnection.setRequestProperty("Content-Length", ""
 					+ Integer.valueOf(writer.toString().getBytes().length));
 
 			printWriter = new PrintWriter(new BufferedWriter(
 					new OutputStreamWriter(urlConnection.getOutputStream(),
 							encoding)));
 
 			printWriter.write(writer.toString());
 			printWriter.close();
 			String sHTTPResponse = urlConnection.getHeaderField(0);
 			try {
 				iLastHTTPResult = Integer.parseInt(sHTTPResponse.substring(9,
 						12));
 			} catch (Exception eNumber) {
 				// eNumber.printStackTrace();
 				iLastHTTPResult = 500;
 			}
 		} catch (Exception ioe) {
 			// ioe.printStackTrace();
 			throw ioe;
 		} finally {
 			// Release current connection
 			if (printWriter != null)
 				printWriter.close();
 		}
 
 		return iLastHTTPResult;
 	}
 
 	/**
 	 * This method posts an Entitycollection in the Imixs XML Format to a Rest
 	 * Service URI Endpoint.
 	 * 
 	 * 
 	 * @param uri
 	 *            - Rest Endpoint RUI
 	 * @param entityCol
 	 *            - an Entity Collection
 	 * @return HTTPResult
 	 */
 	public int postCollection(String uri, EntityCollection aEntityCol)
 			throws Exception {
 		PrintWriter printWriter = null;
 
 		HttpURLConnection urlConnection = null;
 		try {
 			serviceEndpoint = uri;
 			iLastHTTPResult = 500;
 
 			urlConnection = (HttpURLConnection) new URL(serviceEndpoint)
 					.openConnection();
 			urlConnection.setRequestMethod("POST");
 			urlConnection.setDoOutput(true);
 			urlConnection.setDoInput(true);
 			urlConnection.setAllowUserInteraction(false);
 
 			// Authorization
 			if (sUser != null) {
 				urlConnection.setRequestProperty("Authorization", "Basic "
 						+ this.getAccessByUser());
 			}
 
 			/** * HEADER ** */
 			urlConnection.setRequestProperty("Content-Type",
 					"application/xml; charset=" + encoding);
 
 			StringWriter writer = new StringWriter();
 
 			JAXBContext context = JAXBContext
 					.newInstance(EntityCollection.class);
 			Marshaller m = context.createMarshaller();
 			m.marshal(aEntityCol, writer);
 
 			// System.out.println(writer.toString());
 
 			// compute length
 			urlConnection.setRequestProperty("Content-Length", ""
 					+ Integer.valueOf(writer.toString().getBytes().length));
 
 			printWriter = new PrintWriter(new BufferedWriter(
 					new OutputStreamWriter(urlConnection.getOutputStream(),
 							encoding)));
 
 			printWriter.write(writer.toString());
 			printWriter.close();
 			String sHTTPResponse = urlConnection.getHeaderField(0);
 			try {
 				iLastHTTPResult = Integer.parseInt(sHTTPResponse.substring(9,
 						12));
 			} catch (Exception eNumber) {
 				// eNumber.printStackTrace();
 				iLastHTTPResult = 500;
 			}
 
 			/*
 			 * InputStream is = urlConnection.getInputStream(); // create the
 			 * parser XMLStreamReader parser = XMLInputFactory.newInstance()
 			 * .createXMLStreamReader(is); // create the builder //
 			 * StAXOMBuilder builder = new StAXOMBuilder(parser); // now we can
 			 * do something with the response... // get the root element (in
 			 * this case the envelope) // OMElement responseElement =
 			 * builder.getDocumentElement(); // ...
 			 */
 		} catch (Exception ioe) {
 			// ioe.printStackTrace();
 			throw ioe;
 		} finally {
 			// Release current connection
 			if (printWriter != null)
 				printWriter.close();
 		}
 
 		return iLastHTTPResult;
 	}
 
 	/*
 	 * private Object createXMLTree(EntityCollection envList) {
 	 * 
 	 * QName opName = new QName(NAME_SPACE, "entityCollection"); // create
 	 * Parameter for Operation
 	 * 
 	 * Object[] opArgs = new Object[] { envList }; // create OMElement for
 	 * Request
 	 * 
 	 * // OMElement requestData = DataObjectUtil.getOMElement(opName, opArgs, //
 	 * new String[] { "entitylist" }); // return requestData;
 	 * 
 	 * return null; }
 	 */
 
 	/**
 	 * Diese Methode setzt für den Zugriff auf eine URL eine Definierte UserID +
 	 * Passwort
 	 */
 	private String getAccessByUser() {
 		String sURLAccess = "";
 		// UserID:Passwort
 		String sUserCode = sUser + ":" + sPassword;
 		// String convertieren
 		// sURLAccess = Base64.encodeBase64(sUserCode.getBytes()).toString();
 		char[] authcode = Base64.encode(sUserCode.getBytes());
 
 		sURLAccess = String.valueOf(authcode);
 		return sURLAccess;
 	}
 
 }