/*
 * Copyright (c) 1998, 2021 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
// mmacivor - September 9/2009 - 1.0 - Initial implementation
package org.eclipse.persistence.internal.oxm.record;

import java.util.ArrayList;

import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamException;

import org.eclipse.persistence.internal.oxm.Constants;
import org.eclipse.persistence.internal.oxm.NamespaceResolver;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class DomToXMLEventWriter{
    private final XMLEventFactory xmlEventFactory;

    public DomToXMLEventWriter() {
        this.xmlEventFactory = XMLEventFactory.newInstance();
    }

    public DomToXMLEventWriter(XMLEventFactory xmlEventFactory) {
        this.xmlEventFactory = xmlEventFactory;
    }

    public void writeToEventWriter(Node dom, String uri, String name, XMLEventWriter xew) throws XMLStreamException {
        Node currentNode = dom;
        if(dom.getNodeType() == Node.DOCUMENT_NODE) {
            Document doc = (Document)dom;
            xew.add(xmlEventFactory.createStartDocument(doc.getXmlEncoding(), doc.getXmlVersion()));
            currentNode = doc.getDocumentElement();
        }
        if(currentNode.getNodeType() == Node.ELEMENT_NODE) {
            writeElement((Element)currentNode, uri, name, xew);
        } else if(currentNode.getNodeType() == Node.ATTRIBUTE_NODE) {
            Attr attribute = (Attr)currentNode;
            if(attribute.getPrefix() != null && attribute.getPrefix().equals(javax.xml.XMLConstants.XMLNS_ATTRIBUTE)) {
                xew.add(xmlEventFactory.createNamespace(attribute.getLocalName(), attribute.getValue()));
            } else {
                if(attribute.getPrefix() == null) {
                    xew.add(xmlEventFactory.createAttribute(attribute.getName(), attribute.getValue()));
                } else {
                    xew.add(xmlEventFactory.createAttribute(attribute.getPrefix(), attribute.getNamespaceURI(), attribute.getLocalName(), attribute.getValue()));
                }
            }
        } else if(currentNode.getNodeType() == Node.TEXT_NODE) {
                xew.add(xmlEventFactory.createCharacters(currentNode.getNodeValue()));
        }
        if(dom.getNodeType() == Node.DOCUMENT_NODE) {
            xew.add(xmlEventFactory.createEndDocument());
        }
    }
    private void writeElement(Element elem, String newNamespace, String newName, XMLEventWriter xew) throws XMLStreamException {
        String prefix = null;
        String namespace = null;
        String localName = null;
        String nodeName = null;
        if(newName != null){
            namespace = newNamespace;
            localName = newName;
            nodeName = newName;
            if(newNamespace != null && newNamespace.length() > 0) {
                NamespaceResolver tempNR = new NamespaceResolver();
                tempNR.setDOM(elem);
                prefix = tempNR.resolveNamespaceURI(namespace);

                if(prefix == null || prefix.length() == 0){
                    String defaultNamespace = elem.getAttributeNS(javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI, javax.xml.XMLConstants.XMLNS_ATTRIBUTE);
                    if(defaultNamespace == null){
                        prefix = tempNR.generatePrefix();
                    }else if(defaultNamespace != namespace){
                        prefix = tempNR.generatePrefix();
                    }else{
                        prefix = Constants.EMPTY_STRING;
                    }
                }
            }
        }else{
            prefix = elem.getPrefix();
            namespace = elem.getNamespaceURI();
            localName = elem.getLocalName();
            nodeName = elem.getNodeName();
        }

        String defaultNamespace = xew.getNamespaceContext().getNamespaceURI(Constants.EMPTY_STRING);
        boolean needToAddDefaultNS = false;
        if(prefix != null && prefix.length() > 0) {
            String namespaceURI = xew.getNamespaceContext().getNamespaceURI(prefix);
            xew.add(xmlEventFactory.createStartElement(prefix, namespace, localName));
            if(!(namespace.equals(namespaceURI))) {
                xew.add(xmlEventFactory.createNamespace(prefix, namespace));
            }
        } else {
            if(namespace == null || namespace.length() == 0) {
                xew.add(xmlEventFactory.createStartElement("", "", nodeName));
                if(defaultNamespace != null &&  defaultNamespace.length() >0) {
                    //write default namespace declaration
                    xew.add(xmlEventFactory.createNamespace(Constants.EMPTY_STRING));
                }
            } else {
                needToAddDefaultNS = true;
                xew.add(xmlEventFactory.createStartElement(Constants.EMPTY_STRING, namespace, localName));
            }
        }
        NodeList childNodes = elem.getChildNodes();
        NamedNodeMap attrs = elem.getAttributes();

        ArrayList<Attr> nonNamespaceDeclAttrs = new ArrayList<>();
        //write out any namespace decls first
        for(int i = 0; i < attrs.getLength(); i++) {
            Attr next = (Attr)attrs.item(i);
            if(next.getNodeType() == Node.ATTRIBUTE_NODE) {
                if(next.getPrefix() != null && next.getPrefix().equals(javax.xml.XMLConstants.XMLNS_ATTRIBUTE)) {
                    String currentUri = xew.getNamespaceContext().getNamespaceURI(next.getLocalName());
                    if(currentUri == null || !currentUri.equals(next.getValue())) {
                        xew.add(xmlEventFactory.createNamespace(next.getLocalName(), next.getValue()));
                    }
                } else {
                    if (next.getName().equals(javax.xml.XMLConstants.XMLNS_ATTRIBUTE)){
                        //Part of bug fix 398446 modified fix for Bug 387464.
                        xew.add(xmlEventFactory.createNamespace(next.getValue()));
                        needToAddDefaultNS = false;
                    }else{
                        nonNamespaceDeclAttrs.add(next);
                    }
                }
            }
        }
        if(needToAddDefaultNS){
            if(defaultNamespace == null || !defaultNamespace.equals(namespace)){
                xew.add(xmlEventFactory.createNamespace(namespace));
            }
        }
        for(Attr next:nonNamespaceDeclAttrs) {
            if(next.getPrefix() == null) {
                xew.add(xmlEventFactory.createAttribute(next.getName(), next.getValue()));
            } else {
                xew.add(xmlEventFactory.createAttribute(next.getPrefix(), next.getNamespaceURI(), next.getLocalName(), next.getValue()));
            }
        }
        for(int i = 0; i < childNodes.getLength(); i++) {
            Node next = childNodes.item(i);
            if(next.getNodeType() == Node.TEXT_NODE) {
                xew.add(xmlEventFactory.createCharacters(next.getNodeValue()));
            } else if(next.getNodeType() == Node.CDATA_SECTION_NODE) {
                xew.add(xmlEventFactory.createCData(next.getNodeValue()));
            } else if(next.getNodeType() == Node.COMMENT_NODE) {
                xew.add(xmlEventFactory.createComment(next.getNodeValue()));
            } else if(next.getNodeType() == Node.ELEMENT_NODE) {
                writeElement((Element)next, null, null, xew);
            }
        }
        if(elem.getPrefix() != null && elem.getPrefix().length() > 0) {
            xew.add(xmlEventFactory.createEndElement(elem.getPrefix(), elem.getNamespaceURI(), elem.getLocalName()));
        } else if(elem.getNamespaceURI() != null && elem.getNamespaceURI().length() > 0) {
            xew.add(xmlEventFactory.createEndElement("", elem.getNamespaceURI(), elem.getLocalName()));
        } else {
            xew.add(xmlEventFactory.createEndElement("", "", elem.getNodeName()));
        }
    }


}