/**
 * DSS - Digital Signature Services
 * Copyright (C) 2015 European Commission, provided under the CEF programme
 *
 * This file is part of the "DSS - Digital Signature Services" project.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
package eu.europa.esig.dss.xades.signature;

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

import eu.europa.esig.dss.DSSException;
import eu.europa.esig.dss.DomUtils;
import eu.europa.esig.dss.XAdESNamespaces;
import eu.europa.esig.dss.validation.CertificateVerifier;
import eu.europa.esig.dss.xades.validation.XAdESSignature;

public abstract class ExtensionBuilder extends XAdESBuilder {

	/*
	 * This object allows to access DOM signature representation using XPATH
	 */
	protected XAdESSignature xadesSignature;

	/**
	 * This field represents the current signature being extended.
	 */
	protected Element currentSignatureDom;

	/**
	 * This field represents the signature qualifying properties
	 */
	protected Element qualifyingPropertiesDom;

	/**
	 * This field represents the unsigned properties
	 */
	protected Element unsignedPropertiesDom;

	/**
	 * This field contains unsigned signature properties
	 */
	protected Element unsignedSignaturePropertiesDom;

	/**
	 * This field represents the signed properties
	 */
	protected Element signedPropertiesDom;

	/**
	 * This field contains signed data object properties
	 */
	protected Element signedDataObjectPropertiesDom;

	protected ExtensionBuilder(final CertificateVerifier certificateVerifier) {
		super(certificateVerifier);
	}

	/**
	 * Returns or creates (if it does not exist) the UnsignedPropertiesType DOM object.
	 *
	 * @return
	 * @throws DSSException
	 */
	protected void ensureUnsignedProperties() throws DSSException {

		final NodeList qualifyingPropertiesNodeList = currentSignatureDom.getElementsByTagNameNS(XAdESNamespaces.XAdES, "QualifyingProperties");
		if (qualifyingPropertiesNodeList.getLength() != 1) {

			throw new DSSException("The signature does not contain QualifyingProperties element (or contains more than one)! Extension is not possible.");
		}

		qualifyingPropertiesDom = (Element) qualifyingPropertiesNodeList.item(0);

		final NodeList unsignedPropertiesNodeList = currentSignatureDom.getElementsByTagNameNS(XAdESNamespaces.XAdES, "UnsignedProperties");
		final int length = unsignedPropertiesNodeList.getLength();
		if (length == 1) {

			unsignedPropertiesDom = (Element) qualifyingPropertiesNodeList.item(0);
		} else if (length == 0) {

			unsignedPropertiesDom = DomUtils.addElement(documentDom, qualifyingPropertiesDom, XAdESNamespaces.XAdES, "xades:UnsignedProperties");
		} else {

			throw new DSSException("The signature contains more then one UnsignedProperties element! Extension is not possible.");
		}
	}

	/**
	 * Returns or creates (if it does not exist) the UnsignedSignaturePropertiesType DOM object.
	 *
	 * @return
	 * @throws DSSException
	 */
	protected void ensureUnsignedSignatureProperties() throws DSSException {

		final NodeList unsignedSignaturePropertiesNodeList = currentSignatureDom.getElementsByTagNameNS(XAdESNamespaces.XAdES, "UnsignedSignatureProperties");
		final int length = unsignedSignaturePropertiesNodeList.getLength();
		if (length == 1) {

			unsignedSignaturePropertiesDom = (Element) unsignedSignaturePropertiesNodeList.item(0);
		} else if (length == 0) {

			unsignedSignaturePropertiesDom = DomUtils.addElement(documentDom, unsignedPropertiesDom, XAdESNamespaces.XAdES,
					"xades:UnsignedSignatureProperties");
		} else {

			throw new DSSException("The signature contains more then one UnsignedSignatureProperties element! Extension is not possible.");
		}
	}

	/**
	 * Returns or create (if it does not exist) the SignedDataObjectProperties DOM object.
	 *
	 * @throws DSSException
	 */
	protected void ensureSignedDataObjectProperties() throws DSSException {

		final NodeList signedDataObjectPropertiesNodeList = currentSignatureDom.getElementsByTagNameNS(XAdESNamespaces.XAdES, "SignedDataObjectProperties");
		final int length = signedDataObjectPropertiesNodeList.getLength();
		if (length == 1) {
			signedDataObjectPropertiesDom = (Element) signedDataObjectPropertiesNodeList.item(0);
		} else if (length > 1) {
			throw new DSSException("The signature contains more than one SignedDataObjectProperties element! Extension is not possible.");
		}
	}
}