/*
 * XAdES4j - A Java library for generation and verification of XAdES signatures.
 * Copyright (C) 2011 Luis Goncalves.
 * 
 * XAdES4j 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 3 of the License, or any later version.
 * 
 * XAdES4j 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 XAdES4j. If not, see <http://www.gnu.org/licenses/>.
 */
package xades4j.production;

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

import xades4j.production.XadesSigner.SignatureAppendingStrategy;

/**
 *
 * @author Luís
 */
public class SignatureAppendingStrategies
{
	private static String signatureLocation;
	public SignatureAppendingStrategies(String signatureLocation)
    {
		this.signatureLocation = signatureLocation;
    }
	
    public SignatureAppendingStrategies()
    {
    }
    /**
     * The signature node should be appended as the first child of the reference
     * node (reference node is the parent).
     */
    public static final SignatureAppendingStrategy AsFirstChild = new AppendAsFirstChildStrategy();
    /**
     * The signature node should be appended as the last child of the reference
     * node (reference node is the parent).
     */
    public static final SignatureAppendingStrategy AsLastChild = new AppendAsLastChildStrategy();
    /**
     * The signature node should be appended as the previous sibling of the reference
     * node (reference node is a sibling).
     */
    public static final SignatureAppendingStrategy AsPreviousSibling = new AppendAsPreviousSiblingStrategy();
    
    public static SignatureAppendingStrategy getAppendAsCertainNodeStrategy(String signatureLocation) {
    	SignatureAppendingStrategy AsCertainNode = new AppendAsCertainNodeStrategy(signatureLocation);
    	return AsCertainNode;
    }
    
}

class AppendAsLastChildStrategy implements SignatureAppendingStrategy
{
    @Override
    public void append(Element signatureElement, Node referenceNode)
    {
        // Reference node is the parent
        referenceNode.appendChild(signatureElement);
        
    }

    @Override
    public void revert(Element signatureElement, Node referenceNode)
    {
        referenceNode.removeChild(signatureElement);
    }
}

class AppendAsFirstChildStrategy implements SignatureAppendingStrategy
{
    @Override
    public void append(Element signatureElement, Node referenceNode)
    {
        // Reference node is the parent
        Node currFirstChild = referenceNode.getFirstChild();
        referenceNode.insertBefore(signatureElement, currFirstChild);
    }

    @Override
    public void revert(Element signatureElement, Node referenceNode)
    {
        referenceNode.removeChild(signatureElement);
    }
}

class AppendAsPreviousSiblingStrategy implements SignatureAppendingStrategy
{
    @Override
    public void append(Element signatureElement, Node referenceNode)
    {
        // Reference node is the sibling
        Node parent = referenceNode.getParentNode();
        parent.insertBefore(signatureElement, referenceNode);
    }

    @Override
    public void revert(Element signatureElement, Node referenceNode)
    {
        Node parent = referenceNode.getParentNode();
        parent.removeChild(signatureElement);
    }
}

class AppendAsCertainNodeStrategy implements SignatureAppendingStrategy
{
	private String nodeName;
	
	public AppendAsCertainNodeStrategy(String nodeName) {
		this.nodeName = nodeName;
	}
	
    @Override
    public void append(Element signatureElement, Node referenceNode)
    {
    	if(this.nodeName != null) {
    		Document doc = referenceNode.getOwnerDocument();
	    	NodeList nl = doc.getElementsByTagName(this.nodeName);
	    	if(nl.getLength() > 0) {
	    		Node n = (Node)nl.item(0);
	    		n.appendChild(signatureElement);
	    	} else {
	    		referenceNode.appendChild(signatureElement);
	    	}
    	} else {
    		referenceNode.appendChild(signatureElement);
    	}
    }

    @Override
    public void revert(Element signatureElement, Node referenceNode)
    {
    	if(this.nodeName != null) {
	    	Document doc = referenceNode.getOwnerDocument();
	    	NodeList nl = doc.getElementsByTagName(this.nodeName);
	    	if(nl.getLength() > 0) {
	    		Node n = (Node)nl.item(0);
	    		n.removeChild(signatureElement);
	    	} else {
	    		referenceNode.removeChild(signatureElement);
	    	}
    	} else {
    		referenceNode.removeChild(signatureElement);
    	}
    }
}