package at.gv.egovernment.moa.id.proxy.parser;

import org.w3c.dom.Element;

import at.gv.egovernment.moa.id.ParseException;
import at.gv.egovernment.moa.id.data.AuthenticationData;
import at.gv.egovernment.moa.id.data.SAMLStatus;
import at.gv.egovernment.moa.util.Constants;
import at.gv.egovernment.moa.util.XPathUtils;

/**
 * Parser for the <code>&lt;samlp:Response&gt;</code> returned by the
 * <code>GetAuthenticationData</code> web service.
 * @author Paul Ivancsics
 * @version $Id$
 */
public class SAMLResponseParser implements Constants {
  /** Element containing the samlResponse */
  private Element samlResponse;
  /** Xpath prefix for reaching SAMLP Namespaces */
  private static String SAMLP = SAMLP_PREFIX + ":";
  /** Xpath prefix for reaching SAML Namespaces */
  private static String SAML = SAML_PREFIX + ":";
  /** Xpath prefix for reaching PersonData Namespaces */
  private static String PR = PD_PREFIX + ":";
  /** Xpath expression for reaching the SAMLP:Response element */
  private static final String ROOT = 
    "/" + SAMLP + "Response/";
  /** Xpath expression for reaching the SAMLP:Status element */
  private static final String STATUS_XPATH =
    ROOT +
    SAMLP + "Status/";
  /** Xpath expression for reaching the SAMLP:StatusCode_Value attribute */    
  private static final String STATUSCODE_XPATH =
    STATUS_XPATH +
    SAMLP + "StatusCode/@Value";
  /** Xpath expression for reaching the SAMLP:SubStatusCode_Value attribute */            
  private static final String SUBSTATUSCODE_XPATH =
    STATUS_XPATH +
    SAMLP + "StatusCode/" +
    SAMLP + "StatusCode/@Value";
  /** Xpath expression for reaching the SAMLP:StatusMessage element */        
  private static final String STATUSMESSAGE_XPATH =
    STATUS_XPATH +
    SAMLP + "StatusMessage";
  /** Xpath expression for reaching the SAML:Assertion element */        
  private static String ASSERTION_XPATH = 
    ROOT + 
    SAML + "Assertion";
    
  /**
   * Constructor
   * @param samlResponse the <code>&lt;samlp:Response&gt;</code> as a DOM element
   */
  public SAMLResponseParser(Element samlResponse) {
    this.samlResponse = samlResponse;
  }

  /**
   * Parses the <code>&lt;samlp:StatusCode&gt;</code> from the <code>&lt;samlp:Response&gt;</code>.
   * @return <code>AuthenticationData</code> object
   * @throws ParseException on any parsing error
   */
  public SAMLStatus parseStatusCode() 
    throws ParseException {
      
    SAMLStatus status = new SAMLStatus();
    try {
      status.setStatusCode(
        XPathUtils.getAttributeValue(samlResponse, STATUSCODE_XPATH, ""));
      status.setSubStatusCode(
        XPathUtils.getAttributeValue(samlResponse, SUBSTATUSCODE_XPATH, ""));
      status.setStatusMessage(
        XPathUtils.getElementValue(samlResponse, STATUSMESSAGE_XPATH, ""));
    }
    catch (Throwable t) {
      throw new ParseException("parser.01", new Object[] { t.toString() }, t);
    }
    return status;
  }
    
  /**
   * Parses the <code>&lt;saml:Assertion&gt;</code> from the <code>&lt;samlp:Response&gt;</code>.
   * @return <code>AuthenticationData</code> object
   * @throws ParseException on any parsing error
   */
  public AuthenticationData parseAuthenticationData() 
    throws ParseException {
      
    Element samlAssertion;
    try {
      samlAssertion = (Element)XPathUtils.selectSingleNode(samlResponse, ASSERTION_XPATH);
    }
    catch (Throwable t) {
      throw new ParseException("parser.01", new Object[] { t.toString() }, t);
    }
    return new AuthenticationDataAssertionParser(samlAssertion).parseAuthenticationData();
  }

}