/*
 * Copyright 2003 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */


package at.gv.egovernment.moa.id.auth.servlet;

import iaik.pki.PKIException;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.GeneralSecurityException;
import java.util.List;

import javax.net.ssl.SSLSocketFactory;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.lang.StringEscapeUtils;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;

import at.gv.egovernment.moa.id.BuildException;
import at.gv.egovernment.moa.id.MOAIDException;
import at.gv.egovernment.moa.id.auth.AuthenticationServer;
import at.gv.egovernment.moa.id.auth.MOAIDAuthConstants;
import at.gv.egovernment.moa.id.auth.WrongParametersException;
import at.gv.egovernment.moa.id.auth.builder.DataURLBuilder;
import at.gv.egovernment.moa.id.auth.builder.GetIdentityLinkFormBuilder;
import at.gv.egovernment.moa.id.auth.data.AuthenticationSession;
import at.gv.egovernment.moa.id.config.ConnectionParameter;
import at.gv.egovernment.moa.id.config.auth.AuthConfigurationProvider;
import at.gv.egovernment.moa.id.util.ParamValidatorUtils;
import at.gv.egovernment.moa.id.util.SSLUtils;
import at.gv.egovernment.moa.id.util.client.mis.simple.MISMandate;
import at.gv.egovernment.moa.id.util.client.mis.simple.MISSimpleClient;
import at.gv.egovernment.moa.id.util.client.mis.simple.MISSimpleClientException;
import at.gv.egovernment.moa.logging.Logger;
import at.gv.egovernment.moa.util.DOMUtils;

/**
 * Servlet requested for getting the foreign eID
 * provided by the security layer implementation.
 * Utilizes the {@link AuthenticationServer}.
 *
 */
public class GetMISSessionIDServlet extends AuthServlet {

  /**
   * Constructor for GetMISSessionIDServlet.
   */
  public GetMISSessionIDServlet() {
    super();
  }

  /**
   * GET requested by security layer implementation to verify
   * that data URL resource is available.
   * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest, HttpServletResponse)
   */
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException { 
    	
	  doPost(req, resp);
	  
//		Logger.debug("GET GetMISSessionIDServlet");
//		
//		resp.setHeader(MOAIDAuthConstants.HEADER_EXPIRES,MOAIDAuthConstants.HEADER_VALUE_EXPIRES);
//		resp.setHeader(MOAIDAuthConstants.HEADER_PRAGMA,MOAIDAuthConstants.HEADER_VALUE_PRAGMA);
//		resp.setHeader(MOAIDAuthConstants.HEADER_CACHE_CONTROL,MOAIDAuthConstants.HEADER_VALUE_CACHE_CONTROL);
//		resp.addHeader(MOAIDAuthConstants.HEADER_CACHE_CONTROL,MOAIDAuthConstants.HEADER_VALUE_CACHE_CONTROL_IE);
  }

  /**
   * Gets the signer certificate from the InfoboxReadRequest and 
   * responds with a new 
   * <code>CreateXMLSignatureRequest</code>.
   * <br>
   * Request parameters:
   * <ul>
   * <li>MOASessionID: ID of associated authentication session</li>
   * <li>XMLResponse: <code>&lt;InfoboxReadResponse&gt;</code></li>
   * </ul>
   * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest, HttpServletResponse)
   */
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException {

		Logger.debug("POST GetMISSessionIDServlet");
		
		resp.setHeader(MOAIDAuthConstants.HEADER_EXPIRES,MOAIDAuthConstants.HEADER_VALUE_EXPIRES);
		resp.setHeader(MOAIDAuthConstants.HEADER_PRAGMA,MOAIDAuthConstants.HEADER_VALUE_PRAGMA);
		resp.setHeader(MOAIDAuthConstants.HEADER_CACHE_CONTROL,MOAIDAuthConstants.HEADER_VALUE_CACHE_CONTROL);
		resp.addHeader(MOAIDAuthConstants.HEADER_CACHE_CONTROL,MOAIDAuthConstants.HEADER_VALUE_CACHE_CONTROL_IE);
		
//		Map parameters;
//	    try 
//	    {
//	      parameters = getParameters(req);
//	    } catch (FileUploadException e) 
//	    {
//	      Logger.error("Parsing mulitpart/form-data request parameters failed: " + e.getMessage());
//	      throw new IOException(e.getMessage());
//	     	}
		
	    String sessionID = req.getParameter(PARAM_SESSIONID);
	    
	    // escape parameter strings
		sessionID = StringEscapeUtils.escapeHtml(sessionID);
		
	    AuthenticationSession session = null;
	    try {
	       // check parameter
	       if (!ParamValidatorUtils.isValidSessionID(sessionID))
	          throw new WrongParametersException("VerifyCertificate", PARAM_SESSIONID, "auth.12");
	       
	       session = AuthenticationServer.getSession(sessionID);
	    	
	    	String misSessionID = session.getMISSessionID();
	    	
	    	//System.out.println("MIS Session ID (GetMISServlet): " + misSessionID);
	    	
	    	AuthConfigurationProvider authConf= AuthConfigurationProvider.getInstance();
	    	ConnectionParameter connectionParameters = authConf.getOnlineMandatesConnectionParameter();	
	    	SSLSocketFactory sslFactory = SSLUtils.getSSLSocketFactory(AuthConfigurationProvider.getInstance(), connectionParameters);

	    	List list = MISSimpleClient.sendGetMandatesRequest(connectionParameters.getUrl(), misSessionID, sslFactory);
	    	
	    	if (list == null) {
	    		Logger.error("Keine Vollmacht gefunden.");
	    		throw new MISSimpleClientException("Keine Vollmacht gefunden");
	    	}
	    	if (list.size() == 0) {
	    		Logger.error("Keine Vollmacht gefunden.");
	    		throw new MISSimpleClientException("Keine Vollmacht gefunden");
	    	}
	    	
	    	// for now: list contains only one element
	    	MISMandate mandate = (MISMandate)list.get(0);	    	
   	
	    	// verify mandate signature
	    	String createXMLSignatureRequestOrRedirect = AuthenticationServer.getInstance().verifyMandate(sessionID, mandate);

	    	byte[] byteMandate = mandate.getMandate();
	    	String stringMandate = new String(byteMandate);
	    	Document mandateDoc = DOMUtils.parseDocument(stringMandate, false, null, null);
	    	session.setMandateElem(mandateDoc.getDocumentElement());
	    	//System.out.println("stringMandate: " + stringMandate);
	    	
	    	String dataurl =
	             new DataURLBuilder().buildDataURL(
	               session.getAuthURL(),
	               REQ_VERIFY_AUTH_BLOCK,
	               session.getSessionID());
	    	
	    	Logger.debug(createXMLSignatureRequestOrRedirect);
 
	    	String request = getHTMLForm(createXMLSignatureRequestOrRedirect, session.getBkuURL(), dataurl, session.getPublicOAURLPrefix());

	    	resp.setContentType("text/html;charset=UTF-8");
			PrintWriter out = new PrintWriter(resp.getOutputStream());
			out.print(request);
			out.flush();
	    	
			    		      
	    }
	    catch (MOAIDException ex) {
	      handleError(null, ex, req, resp);
	    } catch (GeneralSecurityException ex) {
	    	handleError(null, ex, req, resp);
		} catch (PKIException e) {
			handleError(null, e, req, resp);
		} catch (MISSimpleClientException e) {
			handleError(null, e, req, resp);
		} catch (SAXException e) {
			handleError(null, e, req, resp);
		} catch (ParserConfigurationException e) {
			handleError(null, e, req, resp);
		} 
  }
  
  private static String getHTMLForm(String request, String bkuURI, String dataURL, String oaUrl) throws BuildException {
	  return new GetIdentityLinkFormBuilder().buildCreateSignature(bkuURI, request, dataURL, oaUrl);
	  
  }
  
  
 
 }