/*
 * Copyright 2003 Federal Chancellery Austria
 * MOA-SPSS 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.spss.api.xmlbind;

import java.io.InputStream;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.StringTokenizer;

import org.w3c.dom.Element;

import at.gv.egovernment.moa.spss.MOAApplicationException;
import at.gv.egovernment.moa.spss.api.SPSSFactory;
import at.gv.egovernment.moa.spss.api.cmsverify.CMSContent;
import at.gv.egovernment.moa.spss.api.cmsverify.CMSDataObject;
import at.gv.egovernment.moa.spss.api.cmsverify.VerifyCMSSignatureRequest;
import at.gv.egovernment.moa.spss.api.common.MetaInfo;
import at.gv.egovernment.moaspss.logging.Logger;
import at.gv.egovernment.moaspss.util.Base64Utils;
import at.gv.egovernment.moaspss.util.CollectionUtils;
import at.gv.egovernment.moaspss.util.Constants;
import at.gv.egovernment.moaspss.util.DOMUtils;
import at.gv.egovernment.moaspss.util.XPathUtils;

/**
 * A parser to parse <code>VerifyCMSSignatureRequest</code> DOM trees into
 * <code>VerifyCMSSignatureRequest</code> API objects.
 * 
 * @author Patrick Peck
 * @version $Id$
 */
public class VerifyCMSSignatureRequestParser {

  //
  // XPath expressions for selecting parts of the DOM message
  //
  private static final String MOA = Constants.MOA_PREFIX + ":";
  private static final String DATE_TIME_XPATH = MOA + "DateTime";
  private static final String EXTENDED_VALIDATION_XPATH = MOA + "ExtendedValidation";
  private static final String CMS_SIGNATURE_XPATH = MOA + "CMSSignature";
  private static final String PDF_SIGNATURE_XPATH = MOA + "PDFSignature";
  
  private static final String TRUST_PROFILE_ID_XPATH = MOA + "TrustProfileID";
  private static final String DATA_OBJECT_XPATH = MOA + "DataObject";
  private static final String META_INFO_XPATH = MOA + "MetaInfo";
  private static final String CONTENT_XPATH = MOA + "Content";
  private static final String BASE64_CONTENT_XPATH = MOA + "Base64Content";
  private static final String EXCLUDEBYTERANGE_FROM_XPATH = MOA + "ExcludedByteRange/" + MOA + "From";
  private static final String EXCLUDEBYTERANGE_TO_XPATH = MOA + "ExcludedByteRange/" + MOA + "To";


  /** The <code>SPSSFactory</code> for creating new API objects. */
  private SPSSFactory factory = SPSSFactory.getInstance();

  /**
   * Parse a <code>VerifyCMSSignatureRequest</code> DOM element, as defined
   * by the MOA schema.
   * 
   * @param requestElem The <code>VerifyCMSSignatureRequest</code> to parse. The
   * request must have been successfully parsed against the schema for this
   * method to succeed.
   * @return A <code>VerifyCMSSignatureRequest</code> API objects containing
   * the data from the DOM element.
   * @throws MOAApplicationException An error occurred parsing the request.
   */
  public VerifyCMSSignatureRequest parsePDF(Element requestElem)
    throws MOAApplicationException {

    int[] signatories = parseSignatories(requestElem);
    Date dateTime =
      RequestParserUtils.parseDateTime(requestElem, DATE_TIME_XPATH);
    boolean extendedValidation = 
    		RequestParserUtils.parseExtendedValidation(requestElem, EXTENDED_VALIDATION_XPATH, false);
    
    String cmsSignatureStr =
      XPathUtils.getElementValue(requestElem, PDF_SIGNATURE_XPATH, "");
    CMSDataObject dataObject = parseDataObject(requestElem);
    String trustProfileID =
      XPathUtils.getElementValue(requestElem, TRUST_PROFILE_ID_XPATH, null);
    //Logger.info("CMSSignature: " + cmsSignatureStr);
    InputStream cmsSignature =
      Base64Utils.decodeToStream(cmsSignatureStr, true);

    return factory.createVerifyCMSSignatureRequest(
      signatories,
      dateTime,
      cmsSignature,
      dataObject,
      trustProfileID,
      true,
      extendedValidation);
  }
  
  /**
   * Parse a <code>VerifyCMSSignatureRequest</code> DOM element, as defined
   * by the MOA schema.
   * 
   * @param requestElem The <code>VerifyCMSSignatureRequest</code> to parse. The
   * request must have been successfully parsed against the schema for this
   * method to succeed.
   * @return A <code>VerifyCMSSignatureRequest</code> API objects containing
   * the data from the DOM element.
   * @throws MOAApplicationException An error occurred parsing the request.
   */
  public VerifyCMSSignatureRequest parse(Element requestElem)
    throws MOAApplicationException {

    int[] signatories = parseSignatories(requestElem);
    Date dateTime =
      RequestParserUtils.parseDateTime(requestElem, DATE_TIME_XPATH);
    boolean extendedValidation = 
    		RequestParserUtils.parseExtendedValidation(requestElem, EXTENDED_VALIDATION_XPATH, false);
    
    String cmsSignatureStr =
      XPathUtils.getElementValue(requestElem, CMS_SIGNATURE_XPATH, "");
    CMSDataObject dataObject = parseDataObject(requestElem);
    String trustProfileID =
      XPathUtils.getElementValue(requestElem, TRUST_PROFILE_ID_XPATH, null);
    InputStream cmsSignature =
      Base64Utils.decodeToStream(cmsSignatureStr, true);

    return factory.createVerifyCMSSignatureRequest(
      signatories,
      dateTime,
      cmsSignature,
      dataObject,
      trustProfileID,
      false,
      extendedValidation);
  }

  /**
   * Parse the <code>Signatories</code> attribute contained in the 
   * <code>VerifyCMSSignatureRequest</code> DOM element.
   * 
   * @param requestElem The <code>VerifyCMSSignatureRequest</code> DOM element.
   * @return The signatories contained in the given 
   * <code>VerifyCMSSignatureRequest</code> DOM element. 
   */
  private int[] parseSignatories(Element requestElem) {
    String signatoriesStr = requestElem.getAttribute("Signatories");

    if ("all".equals(signatoriesStr)) {
      return VerifyCMSSignatureRequest.ALL_SIGNATORIES;
    } else {
      StringTokenizer tokenizer = new StringTokenizer(signatoriesStr);
      List signatoriesList = new ArrayList();
      int[] signatories;

      // put the signatories into a List
      while (tokenizer.hasMoreTokens()) {
        try {
          signatoriesList.add(new Integer(tokenizer.nextToken()));
        } catch (NumberFormatException e) {
          // this cannot occur if the request has been validated
        }
      }

      // convert the List into an int array
      signatories = CollectionUtils.toIntArray(signatoriesList);

      return signatories;
    }
  }

  /**
   * Parse a the <code>DataObject</code> DOM element contained in a given 
   * <code>VerifyCMSSignatureRequest</code> DOM element.
   * 
   * @param requestElem The <code>VerifyCMSSignatureRequest</code> DOM element
   * to parse.
   * @return The <code>CMSDataObject</code> API object containing the data
   * from the <code>DataObject</code> DOM element.
   */
  private CMSDataObject parseDataObject(Element requestElem) {
    Element dataObjectElem =
      (Element) XPathUtils.selectSingleNode(requestElem, DATA_OBJECT_XPATH);

    if (dataObjectElem != null) {
      Element metaInfoElem =
        (Element) XPathUtils.selectSingleNode(dataObjectElem, META_INFO_XPATH);
      MetaInfo metaInfo = null;
      Element contentElem =
        (Element) XPathUtils.selectSingleNode(dataObjectElem, CONTENT_XPATH);
      CMSContent content = parseContent(contentElem);

      if (metaInfoElem != null) {
        metaInfo = RequestParserUtils.parseMetaInfo(metaInfoElem);
      }

      String excludeByteRangeFromStr = XPathUtils.getElementValue(dataObjectElem, EXCLUDEBYTERANGE_FROM_XPATH, null);
      String excludeByteRangeToStr = XPathUtils.getElementValue(dataObjectElem, EXCLUDEBYTERANGE_TO_XPATH, null);
      
      BigDecimal excludeByteRangeFrom = null;
      BigDecimal excludeByteRangeTo = null;
      
      if (excludeByteRangeFromStr != null)
    	  excludeByteRangeFrom = new BigDecimal(excludeByteRangeFromStr);
      if (excludeByteRangeToStr != null)
    	  excludeByteRangeTo = new BigDecimal(excludeByteRangeToStr);

      return factory.createCMSDataObject(metaInfo, content, excludeByteRangeFrom, excludeByteRangeTo);
      
      
    } else {
      return null;
    }

  }

  /**
   * Parse the content contained in a <code>CMSContentBaseType</code> kind of
   * DOM element.
   * 
   * @param contentElem The <code>CMSContentBaseType</code> kind of element to
   * parse.
   * @return A <code>CMSDataObject</code> API object containing the data
   * from the given DOM element.
   */
  private CMSContent parseContent(Element contentElem) {
    Element base64ContentElem =
      (Element) XPathUtils.selectSingleNode(contentElem, BASE64_CONTENT_XPATH);

    if (base64ContentElem != null) {
      String base64Str = DOMUtils.getText(base64ContentElem);
      InputStream binaryContent = Base64Utils.decodeToStream(base64Str, true);
      return factory.createCMSContent(binaryContent);
    } else {
      return factory.createCMSContent(
        contentElem.getAttribute("Reference"));
    }
  }
}