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

import java.util.Calendar;

import org.apache.axis.AxisFault;
import org.w3c.dom.Element;

import org.w3c.dom.NodeList;

import at.gv.egovernment.moa.id.AuthenticationException;
import at.gv.egovernment.moa.id.MOAIDException;
import at.gv.egovernment.moa.id.auth.AuthenticationServer;
import at.gv.egovernment.moa.id.auth.builder.SAMLResponseBuilder;
import at.gv.egovernment.moa.id.data.AuthenticationData;
import at.gv.egovernment.moa.id.util.MOAIDMessageProvider;
import at.gv.egovernment.moa.id.util.Random;
import at.gv.egovernment.moa.util.Constants;
import at.gv.egovernment.moa.util.DOMUtils;
import at.gv.egovernment.moa.util.DateTimeUtils;
import at.gv.egovernment.moa.util.XPathUtils;

/**
 * Web service for picking up authentication data created in the MOA-ID Auth component.
 * 
 * @author Paul Ivancsics
 * @version $Id$
 * @see at.gv.egovernment.moa.id.auth.AuthenticationServer#getAuthenticationData
 */
public class GetAuthenticationDataService implements Constants {

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

	/**
	 * Takes a <code>lt;samlp:Request&gt;</code> containing a 
	 * <code>SAML artifact</code> and returns the corresponding 
	 * authentication data <code>lt;saml:Assertion&gt;</code> 
	 * (obtained from the <code>AuthenticationServer</code>),
	 * enclosed in a <code>lt;samlp:Response&gt;</code>.
	 * <br/>Bad requests are mapped into various <code>lt;samlp:StatusCode&gt;</code>s,
	 * possibly containing enclosed sub-<code>lt;samlp:StatusCode&gt;</code>s.
	 * The status codes are defined in the SAML specification.
	 * 
	 * @param requests request elements of type <code>lt;samlp:Request&gt;</code>;
	 * 				 only 1 request element is allowed
	 * @return response element of type <code>lt;samlp:Response&gt;</code>,
	 * 				  packed into an <code>Element[]</code>
	 * @throws AxisFault thrown when an error occurs in assembling the 
	 * 					<code>lt;samlp:Response&gt;</code>
	 */
  public Element[] Request(Element[] requests) 
  	throws AxisFault {
  		
		Element request = requests[0];
    Element[] responses = new Element[1];
		String requestID = "";
		String statusCode = "";
		String subStatusCode = null;
		String statusMessageCode = null;
    String statusMessage = null;
		String samlAssertion = "";
		if (requests.length > 1) {
			// more than 1 request given as parameter
			statusCode = "samlp:Requester";
			subStatusCode = "samlp:TooManyResponses";
			statusMessageCode = "1201";
		}
		else {
			try {
				DOMUtils.validateElement(request, ALL_SCHEMA_LOCATIONS, null);
				NodeList samlArtifactList = XPathUtils.selectNodeList(request, "samlp:AssertionArtifact");
				if (samlArtifactList.getLength() == 0) {
					// no SAML artifact given in request
					statusCode = "samlp:Requester";
					statusMessageCode = "1202";
				}
				else if (samlArtifactList.getLength() > 1) {
					// too many SAML artifacts given in request
					statusCode = "samlp:Requester";
					subStatusCode = "samlp:TooManyResponses";
					statusMessageCode = "1203";
				}
				else {
					Element samlArtifactElem = (Element)samlArtifactList.item(0);
					requestID = samlArtifactElem.getAttribute("RequestID");
					String samlArtifact = DOMUtils.getText(samlArtifactElem);
					try {
            AuthenticationData authData = AuthenticationServer.getInstance().
  						getAuthenticationData(samlArtifact);
            // success
            samlAssertion = authData.getSamlAssertion();
            statusCode = "samlp:Success";
            statusMessageCode = "1200";
          }
          catch (AuthenticationException ex) {
						// no authentication data for given SAML artifact
						statusCode = "samlp:Requester";
						subStatusCode = "samlp:ResourceNotRecognized";
						statusMessage = ex.toString();
					}
				}
			}
	    catch (Throwable t) {
	    	// invalid request format
				statusCode = "samlp:Requester";
				statusMessageCode = "1204";
	    }
		}
    try {
			String responseID = Random.nextRandom();
			String issueInstant = DateTimeUtils.buildDateTime(Calendar.getInstance());
      if (statusMessage == null)
			  statusMessage = MOAIDMessageProvider.getInstance().getMessage(statusMessageCode, null);
	    responses[0] = new SAMLResponseBuilder().build(
	    	responseID, requestID, issueInstant, statusCode, subStatusCode, statusMessage, samlAssertion);
  	}
    catch (MOAIDException e) {
	    AxisFault fault = AxisFault.makeFault(e);
	    fault.setFaultDetail(new Element[] { e.toErrorResponse()});
	    throw fault;
    } 
    catch (Throwable t) {
	    MOAIDException e = new MOAIDException("1299", null, t);
	    AxisFault fault = AxisFault.makeFault(e);
	    fault.setFaultDetail(new Element[] { e.toErrorResponse()});
	    throw fault;
    }
    return responses;
  }
  	
}