package com.fasterxml.aalto.dom;

import javax.xml.namespace.NamespaceContext;

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

Context object that holds information about an open element
(one for which START_ELEMENT has been sent, but no END_ELEMENT)
Author:
Tatu Saloranta/**
 * Context object that holds information about an open element
 * (one for which START_ELEMENT has been sent, but no END_ELEMENT)
 *
 * @author Tatu Saloranta
 */
public class DOMOutputElement
    extends OutputElementBase
{
    
Reference to the parent element, element enclosing this element.
Null for root element.
Non-final to allow temporary pooling
(on per-writer basis, to keep these short-lived).
/**
     * Reference to the parent element, element enclosing this element.
     * Null for root element.
     * Non-final to allow temporary pooling
     * (on per-writer basis, to keep these short-lived).
     */
    private DOMOutputElement _parent;
    
    
Actual DOM element for which this element object acts as a proxy.
/**
     * Actual DOM element for which this element object acts as a proxy.
     */
    private Element _element;

    private boolean _defaultNsSet;

    
Constructor for the virtual root element
/**
     * Constructor for the virtual root element
     */
    private DOMOutputElement()
    {
        super();
        _parent = null;
        _element = null;
        _nsMapping = null;
        _nsMapShared = false;
        _defaultNsURI = "";
        _rootNsContext = null;
        _defaultNsSet = false;
    }

    private DOMOutputElement(DOMOutputElement parent,
                             Element element,
                             BijectiveNsMap ns)
    {
        super(parent, ns);
        _parent = parent;
        _element = element;
        _nsMapping = ns;
        _nsMapShared = (ns != null);
        _defaultNsURI = parent._defaultNsURI;
        _rootNsContext = parent._rootNsContext;
        _defaultNsSet = false;
    }

    
Method called to reuse a pooled instance.
/**
     * Method called to reuse a pooled instance.
     */
    private void relink(DOMOutputElement parent, Element element)
    {
        super.relink(parent);
        _parent = parent;
        _element = element;
        parent.appendNode(element);
        _defaultNsSet = false;
    }

    public static DOMOutputElement createRoot()
    {
        return new DOMOutputElement();
    }
    
    
Simplest factory method, which gets called when a 1-argument
element output method is called. Element is assumed to
use the current default namespace.
Will both create the child element and attach it to parent element,
or lacking own owner document.
/**
     * Simplest factory method, which gets called when a 1-argument
     * element output method is called. Element is assumed to
     * use the current default namespace.
     * Will both create the child element and attach it to parent element,
     * or lacking own owner document.
     */
    protected DOMOutputElement createAndAttachChild(Element element)
    {
        if(isRoot()) {
            element.getOwnerDocument().appendChild(element);
        } else {
            _element.appendChild(element);
        }
        return createChild(element);
    }

    protected DOMOutputElement createChild(Element element)
    {
        return new DOMOutputElement(this, element, _nsMapping);
    }

    
Returns:
New head of the recycle pool/**
     * @return New head of the recycle pool
     */
    protected DOMOutputElement reuseAsChild(DOMOutputElement parent,
                                               Element element)
    {
        DOMOutputElement poolHead = _parent;
        relink(parent, element);
        return poolHead;
    }

    
Method called to temporarily link this instance to a pool, to
allow reusing of instances with the same reader.
/**
     * Method called to temporarily link this instance to a pool, to
     * allow reusing of instances with the same reader.
     */
    protected void addToPool(DOMOutputElement poolHead)
    {
        _parent = poolHead;
    }
    
    /*
    ////////////////////////////////////////////
    // Public API, accessors
    ////////////////////////////////////////////
     */

    public DOMOutputElement getParent() {
        return _parent;
    }

    @Override
    public boolean isRoot() {
        // (Virtual) Root element has no parent...
        return (_parent == null);
    }
    
    
Returns:
String presentation of the fully-qualified name, in
  "prefix:localName" format (no URI). Useful for error and
  debugging messages./**
     * @return String presentation of the fully-qualified name, in
     *   "prefix:localName" format (no URI). Useful for error and
     *   debugging messages.
     */
    @Override
    public String getNameDesc() {
        if(_element != null) {
            return _element.getLocalName();
        }
        return "#error"; // unexpected case
    }
    
    /*
    ////////////////////////////////////////////
    // Public API, mutators
    ////////////////////////////////////////////
     */

    @Override
    public void setDefaultNsUri(String uri) {
        _defaultNsURI = uri;
        _defaultNsSet = true;
    }

    @Override
    protected void setRootNsContext(NamespaceContext ctxt)
    {
        _rootNsContext = ctxt;
        /* Let's also see if we have an active default ns mapping:
         * (provided it hasn't yet explicitly been set for this element)
         */
        if (!_defaultNsSet) {
            String defURI = ctxt.getNamespaceURI("");
            if (defURI != null && defURI.length() > 0) {
                _defaultNsURI = defURI;
            }
        }
    }

    /*
    ////////////////////////////////////////////
    // Public API, DOM manipulation
    ////////////////////////////////////////////
     */
    
    protected void appendNode(Node n)
    {
        if (isRoot()) {
            _element.getOwnerDocument().appendChild(n);
        } else {
            _element.appendChild(n);
        }
    }

    protected void addAttribute(String pname, String value)
    {
        _element.setAttribute(pname, value);
    }

    protected void addAttribute(String uri, String qname, String value)
    {
        _element.setAttributeNS(uri, qname, value);
    }

    public void appendChild(Node n) {
        _element.appendChild(n);
    }
}