/*
 * 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.text.ParseException;
import java.util.Date;

import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import at.gv.egovernment.moa.spss.MOAApplicationException;
import at.gv.egovernment.moa.spss.api.SPSSFactory;
import at.gv.egovernment.moa.spss.api.common.Content;
import at.gv.egovernment.moa.spss.api.common.MetaInfo;
import at.gv.egovernment.moa.spss.api.common.XMLDataObjectAssociation;
import at.gv.egovernment.moaspss.util.Base64Utils;
import at.gv.egovernment.moaspss.util.Constants;
import at.gv.egovernment.moaspss.util.DOMUtils;
import at.gv.egovernment.moaspss.util.DateTimeUtils;
import at.gv.egovernment.moaspss.util.XPathUtils;

/**
 * Utility methods for parsing XML requests definied in the MOA XML schema.
 * 
 * @author Patrick Peck
 * @version $Id$
 */
public class RequestParserUtils {
	//
	// XPath expressions for parsing parts of a request
	//
	private static final String MOA = Constants.MOA_PREFIX + ":";
	private static final String REFERENCE_ATTR_NAME = "Reference";
	private static final String MIME_TYPE_XPATH = MOA + "MimeType";
	private static final String DESCRIPTION_XPATH = MOA + "Description";
	private static final String TYPE_XPATH = MOA + "Type";
	private static final String XML_ASSOC_CONTENT_XPATH = MOA + "Content";
	private static final String CONTENT_XPATH = MOA + "Base64Content | " + MOA + "XMLContent |" + MOA + "LocRefContent";
	private static final String ANY_OTHER_XPATH = "*[namespace-uri() != \"" + Constants.MOA_NS_URI + "\"]";

	/**
	 * Parse a <code>XMLDataObjectAssociationType</code> kind of DOM element.
	 * 
	 * @param assocElem
	 *            The <code>XMLDataObjectAssociationType</code> kind of DOM
	 *            elmeent to parse.
	 * @return The <code>XMLDataObjectAssociation</code> API object containing
	 *         the data from the <code>XMLDataObjectAssociationType</code> DOM
	 *         element.
	 */
	public static XMLDataObjectAssociation parseXMLDataObjectAssociation(Element assocElem) {
		SPSSFactory factory = SPSSFactory.getInstance();
		MetaInfo metaInfo = parseMetaInfo(assocElem);
		Element contentElem = (Element) XPathUtils.selectSingleNode(assocElem, XML_ASSOC_CONTENT_XPATH);
		Content content = parseContent(contentElem);

		return factory.createXMLDataObjectAssociation(metaInfo, content);
	}

	/**
	 * Parse a <code>MetaInfoType</code> kind of DOM element.
	 * 
	 * @param metaInfoElem
	 *            The <code>MetaInfoType</code> kind of DOM element.
	 * @return The <code>MetaInfo</code> API object containing the data from the
	 *         <code>metaInfoElem</code>.
	 */
	public static MetaInfo parseMetaInfo(Element metaInfoElem) {
		SPSSFactory factory = SPSSFactory.getInstance();
		String mimeType = XPathUtils.getElementValue(metaInfoElem, MIME_TYPE_XPATH, null);
		String description = XPathUtils.getElementValue(metaInfoElem, DESCRIPTION_XPATH, null);
		NodeList anyOther = XPathUtils.selectNodeList(metaInfoElem, ANY_OTHER_XPATH);
		String type = XPathUtils.getElementValue(metaInfoElem, TYPE_XPATH, null);

		return factory.createMetaInfo(mimeType, description, anyOther, type);
	}

	/**
	 * Parse a <code>ContentOptionalRefType</code> or
	 * <code>ContentRequiredRefType</code> kind of DOM element.
	 * 
	 * @param contentParentElem
	 *            The DOM element being the parent of the content element.
	 * @return The <code>Content</code> API object containing the data from the
	 *         given DOM element.
	 */
	public static Content parseContent(Element contentParentElem) {
		SPSSFactory factory = SPSSFactory.getInstance();
		String referenceURI = contentParentElem.hasAttribute(REFERENCE_ATTR_NAME)
				? contentParentElem.getAttribute(REFERENCE_ATTR_NAME) : null;
		Element contentElem = (Element) XPathUtils.selectSingleNode(contentParentElem, CONTENT_XPATH);

		if (contentElem == null) {
			return factory.createContent(referenceURI);
		}

		if ("Base64Content".equals(contentElem.getLocalName())) {
			String base64String = DOMUtils.getText(contentElem);
			return factory.createContent(Base64Utils.decodeToStream(base64String, true), referenceURI);
		} else if ("LocRefContent".equals(contentElem.getLocalName())) {
			String locationReferenceURI = DOMUtils.getText(contentElem);
			return factory.createContent(locationReferenceURI, referenceURI);
		} else { // "XMLContent".equals(contentElem.getLocalName())
			return factory.createContent(contentElem.getChildNodes(), referenceURI);
		}
	}

	/**
	 * Get the signing time from a Verfiy(CMS|XML)SignatureRequest.
	 * 
	 * @param requestElem
	 *            A <code>Verify(CMS|XML)SignatureRequest</code> DOM element.
	 * @param dateTimeXPath
	 *            The XPath to lookup the <code>DateTime</code> element within
	 *            the request.
	 * @return Date The date and time corresponding to the <code>DateTime</code>
	 *         element in the request. If no <code>DateTime</code> element
	 *         exists in the request, <code>null</code> is returned.
	 * @throws MOAApplicationException
	 *             An error occurred during a parsing the <code>DateTime</code>
	 *             element or creating the return value.
	 */
	public static Date parseDateTime(Element requestElem, String dateTimeXPath) throws MOAApplicationException {

		Element dateTimeElem;
		String dateTimeText;

		// select the DateTime element
		dateTimeElem = (Element) XPathUtils.selectSingleNode(requestElem, dateTimeXPath);

		// parse a date from the element value
		if (dateTimeElem != null) {
			dateTimeText = DOMUtils.getText(dateTimeElem);
			try {
				return DateTimeUtils.parseDateTime(dateTimeText);
			} catch (ParseException e) {
				throw new MOAApplicationException("1104", new Object[] { dateTimeText });
			}
		} else {
			return null;
		}
	}

	/**
	 * Get the signing time from a Verfiy(CMS|XML)SignatureRequest.
	 * 
	 * @param requestElem
	 *            A <code>Verify(CMS|XML)SignatureRequest</code> DOM element.
	 * @param dateTimeXPath
	 *            The XPath to lookup the <code>DateTime</code> element within
	 *            the request.
	 * @return Date The date and time corresponding to the <code>DateTime</code>
	 *         element in the request. If no <code>DateTime</code> element
	 *         exists in the request, <code>null</code> is returned.
	 * @throws MOAApplicationException
	 *             An error occurred during a parsing the <code>DateTime</code>
	 *             element or creating the return value.
	 */
	public static boolean parseExtendedValidation(Element requestElem, String extendedValidationXPath,
			boolean defaultValue) throws MOAApplicationException {

		Element dateTimeElem;
		String dateTimeText;

		// select the DateTime element
		dateTimeElem = (Element) XPathUtils.selectSingleNode(requestElem, extendedValidationXPath);

		// parse a date from the element value
		if (dateTimeElem != null) {
			dateTimeText = DOMUtils.getText(dateTimeElem);
				String xsdBoolean = dateTimeText.trim();
				if ("".equals(xsdBoolean))
					return defaultValue;
				if("true".equalsIgnoreCase(xsdBoolean) || 
						"1".equalsIgnoreCase(xsdBoolean)) {
					return true;
				} else {
					return false;
				}
		} else {
			return defaultValue;
		}
	}

}