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

import java.text.MessageFormat;

import org.w3c.dom.Element;

import at.gv.egovernment.moa.id.BuildException;
import at.gv.egovernment.moa.util.Constants;
import at.gv.egovernment.moa.util.DOMUtils;

/**
 * Builder for the <code>lt;samlp:Response&gt;</code> used for passing
 * result and status information from the <code>GetAuthenticationData</code>
 * web service.
 * 
 * @author Paul Ivancsics
 * @version $Id$
 */
public class SAMLResponseBuilder implements Constants {
	/** XML - Template for samlp:Response */
	private static final String RESPONSE = 
    "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" +
    "<samlp:Response xmlns:samlp=\"" + SAMLP_NS_URI + "\" xmlns:saml=\"" + SAML_NS_URI + "\"" +
    " ResponseID=\"{0}\" InResponseTo=\"{1}\" MajorVersion=\"1\" MinorVersion=\"0\" IssueInstant=\"{2}\">" +
    "  <samlp:Status>" +
    "    <samlp:StatusCode Value=\"{3}\">" +
    "      {4}" +
    "    </samlp:StatusCode>" +
    "    <samlp:StatusMessage>{5}</samlp:StatusMessage>" +
    "  </samlp:Status>" +
    "  {6}" +
    "</samlp:Response>";
  /** XML - Template for samlp:StatusCode */  
  private static final String SUB_STATUS_CODE = 
    "<samlp:StatusCode Value=\"{0}\"></samlp:StatusCode>";
	
  /**
   * Constructor for SAMLResponseBuilder.
   */
  public SAMLResponseBuilder() {
    super();
  }
  /**
   * Builds the SAML response.
   * @param responseID response ID
   * @param inResponseTo request ID of <code>lt;samlp:Request&gt;</code> responded to
   * @param issueInstant current timestamp
   * @param statusCode status code
   * @param subStatusCode sub-status code refining the status code; may be <code>null</code>
   * @param statusMessage status message
   * @param samlAssertion SAML assertion representing authentication data
   * @return SAML response as a DOM element
	 */
  public Element build(
  	String responseID, 
  	String inResponseTo, 
  	String issueInstant, 
  	String statusCode, 
  	String subStatusCode, 
  	String statusMessage, 
  	String samlAssertion)
  	throws BuildException {
  	
  	try {
	  	String xmlSubStatusCode = 
	  		subStatusCode == null ? 
	  		"" : 
	  		MessageFormat.format(SUB_STATUS_CODE, new Object[] {subStatusCode});
	  	
	  	String xmlResponse = MessageFormat.format(RESPONSE, new Object[] {
  			responseID, 
        inResponseTo, 
        issueInstant, 
        statusCode, 
        xmlSubStatusCode, 
        statusMessage, 
        removeXMLDeclaration(samlAssertion) });
  		Element domResponse = DOMUtils.parseDocument(xmlResponse, true, ALL_SCHEMA_LOCATIONS, null).getDocumentElement();
		  return domResponse;
  	}
  	catch (Throwable ex) {
  		throw new BuildException(
  			"builder.00",
  			new Object[] { "samlp:Response", ex.toString() },
  			ex);
  	}
  }
  /**
   * Removes the XML declaration from an XML expression.
   * @param xmlString XML expression as String
   * @return XML expression, XML declaration removed
   */
  private String removeXMLDeclaration(String xmlString) {
    if (xmlString.startsWith("<?xml")) {
      int firstElement = xmlString.indexOf("<", 1);
      return xmlString.substring(firstElement);
    }
      else return xmlString;
  }

}