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

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.w3c.dom.Element;
import org.w3c.dom.traversal.NodeIterator;

import at.gv.egovernment.moa.id.AuthenticationException;
import at.gv.egovernment.moa.id.ParseException;
import at.gv.egovernment.moa.id.auth.data.CreateXMLSignatureResponse;
import at.gv.egovernment.moa.id.auth.data.SAMLAttribute;
import at.gv.egovernment.moa.util.Constants;
import at.gv.egovernment.moa.util.DOMUtils;
import at.gv.egovernment.moa.util.XPathUtils;

/**
 * Parses an <code>&lt;InfoboxReadResponse&gt;</code> returned from
 * the security layer
 * 
 * @author Stefan Knirsch
 * @version $Id$
 */

public class CreateXMLSignatureResponseParser {
  //
  // XPath namespace prefix shortcuts
  //

  /** Xpath prefix for reaching SAML Namespaces */
  private static final String SAML = Constants.SAML_PREFIX + ":";
  /** Xpath prefix for reaching XML-DSIG Namespaces */
  private static final String DSIG = Constants.DSIG_PREFIX + ":";
  /** Xpath expression to the root element */
  private static final String ROOT = ":CreateXMLSignatureResponse/";
  /** Xpath expression to the SAML:Assertion element */
  private static final String SAML_ASSERTION_XPATH = ROOT + SAML + "Assertion";
  /** Xpath expression to the SAML:NameIdentifier element */
  private static final String SAML_SUBJECT_NAME_IDENTIFIER_XPATH = SAML_ASSERTION_XPATH + "/" + SAML + "AttributeStatement/" + SAML + "Subject/" + SAML + "NameIdentifier";
  /** Xpath expression to the AttributeStatement element */
  private static final String SAML_ATTRIBUTE_XPATH = SAML_ASSERTION_XPATH + "/" + SAML + "AttributeStatement/" + SAML + "Attribute";
  /** Xpath expression to the AttributeValue element */
  private static final String SAML_ATTRIBUTE_VALUE_XPATH = SAML + "AttributeValue";
  
  
  /** This is the root element of the CreateXMLsignatureResponse */
  private Element sigResponse_;

  /**
   * Parses and validates the document given as string and extracts the 
   * root element.
   * 
   * @param xmlResponse <code>&lt;CreateXMLSignatureResponse&gt;</code> as String
   * 
   * @throws AuthenticationException if any authentication error occurs
   * @throws ParseException if an element cannot be parsed
   */
  public CreateXMLSignatureResponseParser(String xmlResponse) throws AuthenticationException, ParseException {
    try {
      InputStream s = new ByteArrayInputStream(xmlResponse.getBytes("UTF-8"));
      init(s);
    }
    catch (Throwable t) {
      throw new ParseException("parser.01", new Object[] { t.toString()}, t);
    }
  }

  /**
   * Parses and validates the document given as stream and extracts the 
   * root element.
   * 
   * @param xmlResponse <code>&lt;CreateXMLSignatureResponse&gt;</code> as String
   * 
   * @throws AuthenticationException if any authentication error occurs
   * @throws ParseException if an element cannot be parsed
   */
  public CreateXMLSignatureResponseParser(InputStream is) throws AuthenticationException, ParseException {
    init(is); 
  }

  /**
  * Constructor for CreateXMLSignatureResponseParser.
  * The incoming Element will be used for further operations
  * @param xmlResponse <code>&lt;InfoboxReadResponse&gt;</code> as InputStream
  */
  public CreateXMLSignatureResponseParser(Element xmlResponse) {
    sigResponse_ = xmlResponse;
  }
  
  /**
   * Initializes the parser.
   * Parses and validates the document given as stream and extracts the 
   * root element.
   * 
   * @param is  The CreateXMLSignatureResponse as stream.
   * @throws AuthenticationException if an authentication error occurs.
   * @throws ParseException If an error occurs on parsing the the document.
   */
  private void init(InputStream is) throws AuthenticationException, ParseException {
    try {
      
      Element responseElem = DOMUtils.parseXmlValidating(is);
      
      if ("CreateXMLSignatureResponse".equals(responseElem.getLocalName())) {
        sigResponse_ = responseElem;
      } else {
        ErrorResponseParser erp = new ErrorResponseParser(responseElem);
        throw new AuthenticationException("auth.08", new Object[] { erp.getErrorCode(), erp.getErrorInfo()});
      }
      
    } catch (Throwable t) {
      throw new ParseException("parser.01", new Object[] { t.toString()}, t);
    }
  }

  /**
   * Unmarshalls the <@link sigResponse> to an 
   * <code>&lt;CreateXMLSignatureResponse&gt;</code> object.
   * 
   * @return a <code>&lt;CreateXMLSignatureResponse&gt;</code> object
   * @throws ParseException
   */

  public CreateXMLSignatureResponse parseResponse() throws ParseException {
    CreateXMLSignatureResponse cResp;
    try {
      cResp = new CreateXMLSignatureResponse();
      String slPrefix = XPathUtils.getSlPrefix(sigResponse_);
      cResp.setSamlNameIdentifier(XPathUtils.getElementValue(sigResponse_, "/" + slPrefix + SAML_SUBJECT_NAME_IDENTIFIER_XPATH, null));
      cResp.setSamlAssertion((Element) XPathUtils.selectSingleNode(sigResponse_, "/" + slPrefix + SAML_ASSERTION_XPATH));
      NodeIterator attrIter = XPathUtils.selectNodeIterator(sigResponse_, "/" + slPrefix + SAML_ATTRIBUTE_XPATH);
      Element samlAttr;
      List samlAttributes = new ArrayList();
      while ((samlAttr = (Element) attrIter.nextNode()) != null) {
        String attrName = XPathUtils.getAttributeValue(samlAttr, "@AttributeName", "");
        String attrNamespace = XPathUtils.getAttributeValue(samlAttr, "@AttributeNamespace", "");
        Object attrValue;
        if ("wbPK".equals(attrName)) {
          Element attrValueElem = (Element)XPathUtils.selectSingleNode(samlAttr, SAML_ATTRIBUTE_VALUE_XPATH);
          attrValue = DOMUtils.getElementFromNodeList(attrValueElem.getChildNodes());
        } else {
          attrValue = XPathUtils.getElementValue(samlAttr, SAML_ATTRIBUTE_VALUE_XPATH, "");
        }
        samlAttributes.add(new SAMLAttribute(attrName, attrNamespace, attrValue));
      }
      SAMLAttribute[] result = new SAMLAttribute[samlAttributes.size()];
      samlAttributes.toArray(result);
      cResp.setSamlAttributes(result);
    }
    catch (Throwable t) {
      throw new ParseException("parser.01", new Object[] { t.toString()}, t);
    }
    return cResp;
  }
  
//  public CreateXMLSignatureResponse parseResponse() throws ParseException {
//    CreateXMLSignatureResponse cResp;
//    try {
//      cResp = new CreateXMLSignatureResponse();
//      Element samlAssertion = (Element)sigResponse.getElementsByTagNameNS(Constants.SAML_NS_URI, "Assertion").item(0);
//      cResp.setSamlAssertion(samlAssertion);
//      Element samlAttributeStatement = (Element)samlAssertion.getElementsByTagNameNS(Constants.SAML_NS_URI, "AttributeStatement").item(0);
//      Element samlSubject = (Element)samlAttributeStatement.getElementsByTagNameNS(Constants.SAML_NS_URI, "Subject").item(0);
//      Element samlNameIdentifier = (Element)samlSubject.getElementsByTagNameNS(Constants.SAML_NS_URI, "NameIdentifier").item(0);
//      cResp.setSamlNameIdentifier(samlNameIdentifier.getFirstChild().getNodeValue());
//      NodeList nl = samlAttributeStatement.getElementsByTagNameNS(Constants.SAML_NS_URI, "Attribute");
//      List samlAttributes = new ArrayList();
//      for (int i=0; i<nl.getLength(); i++) {
//        Element samlAttribute = (Element)nl.item(i);
//        String attrName = samlAttribute.getAttribute("AttributeName");  
//        String attrNamespace = samlAttribute.getAttribute("AttributeNamespace");
//        String attrValue = ((Element)samlAttribute.getElementsByTagNameNS(Constants.SAML_NS_URI, "AttributeValue").item(0)).getFirstChild().getNodeValue();
//        samlAttributes.add(new SAMLAttribute(attrName, attrNamespace, attrValue));
//      }
//      SAMLAttribute[] result = new SAMLAttribute[samlAttributes.size()];
//      samlAttributes.toArray(result);
//      cResp.setSamlAttributes(result);
//    }
//    catch (Throwable t) {
//      throw new ParseException("parser.01", new Object[] { t.toString()}, t);
//    }
//    return cResp;
//  }
  
  
 
  
}