TransformationService.java

package com.lmco.spectrum.systemnavigation3d.service;

import com.lmco.spectrum.systemnavigation3d.domain.catia.DocumentSMG;
import com.lmco.spectrum.systemnavigation3d.dto.TransformerOptions;
import org.springframework.stereotype.Service;
import org.w3c.dom.Element;
import org.w3c.dom.Document;

import javax.annotation.Nullable;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.*;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;

import java.text.SimpleDateFormat;

@Service
public class TransformationService {


    private static final String SERVER_TYPE_CLitList = "CLitList";
    private static final String SERVER_TYPE_CLitIOManager = "CLitIOManager";

    private static final String TAG_SERVER = "Server";
    private static final String TAG_LAUNCH_ACTION = "LaunchAction";

    private static final String ATTR_TYPE = "Type";
    private static final String ATTR_NAME = "Name";
    private static final String ATTR_VALUE = "Value";

    // view tags
    private static final String TAG_VIEW = "CLitView";
    private static final String ATTR_IDENT = "Ident";

    // TODO make functional
    // TODO consider types of transformations we need to make
    // accept list of transformation options?
    // accept GEIA dtos and infer transformations?
    // pending
    public String transform(String smgXml, @Nullable TransformerOptions options){
        DocumentSMG doc = unmarshal(smgXml);
        if(doc == null) {
            // TODO ??
            return smgXml;
        }
        doc = processTransformations(doc, options);
        return marshal(doc);
    }

    private DocumentSMG processTransformations(DocumentSMG doc, @Nullable TransformerOptions options){
        if(options == null) {
            return doc;
        }
        if(options.getSetFocusedView() != null) {
            ensureViewMode(doc);
            setFocusedView(doc, options.getSetFocusedView());
            createView(doc, "test");
        }
        return doc;
    }

    private void createView(DocumentSMG doc, String viewName) {

        for(Element el : doc.getNodes()){
            if(el.getTagName().equals(TAG_SERVER)
                    && el.hasAttribute(ATTR_TYPE)
                    && el.getAttribute(ATTR_TYPE).equals(SERVER_TYPE_CLitList)
            ) {
                Document smgDoc = el.getOwnerDocument();
                Element newView = smgDoc.createElement(TAG_VIEW);
                el.appendChild(newView);

                newView.setAttribute(ATTR_IDENT, new SimpleDateFormat("HH.mm.ss").format(new java.util.Date()));

                newView.setAttribute(ATTR_NAME, viewName);

                newView.setAttribute(ATTR_TYPE, "1");

                break;
            }
        }
    }

    private void ensureViewMode(DocumentSMG doc) {
        for(Element el : doc.getNodes()) {
            if(el.getTagName().equals(TAG_SERVER)
                    && el.hasAttribute(ATTR_TYPE)
                    && el.getAttribute(ATTR_TYPE).equals(SERVER_TYPE_CLitIOManager)
                    && el.hasChildNodes()
            ) {
                Element currentChild = (Element) el.getFirstChild();
                while(currentChild != null) {
                    if(currentChild.getTagName().equals(TAG_LAUNCH_ACTION)) {
                        if(currentChild.hasAttribute(ATTR_VALUE)) {
                            currentChild.setAttribute(ATTR_VALUE, "1");
                            currentChild = null;
                        }
                    } else {
                        currentChild = (Element) currentChild.getNextSibling();
                    }
                }
                break;
            }
        }
    }

    // TODO make there is an additional CLitList, ensure we are looking at the correct one.
    private void setFocusedView(DocumentSMG doc, String viewName) {
        for(Element el : doc.getNodes()) {
            if(el.getTagName().equals(TAG_SERVER)
                    && el.hasAttribute(ATTR_TYPE)
                    && el.getAttribute(ATTR_TYPE).equals(SERVER_TYPE_CLitList)
                    && el.hasChildNodes()
            ) {
                Element target = null;
                Element currentChild = (Element) el.getFirstChild();
                while(currentChild != null) {
                    if(currentChild.getAttribute(ATTR_NAME).equalsIgnoreCase(viewName)) {
                        target = currentChild;
                        currentChild = null;
                    } else {
                        currentChild = (Element) currentChild.getNextSibling();
                    }
                }
                if(target != null) {
                    el.removeChild(target);
                    el.insertBefore(target, el.getFirstChild());
                    break;
                }

            }
        }
    }

    private String marshal(DocumentSMG doc) {
        try(StringWriter stringWriter = new StringWriter()) {
            JAXBContext jaxbContext = JAXBContext.newInstance(DocumentSMG.class);
            Marshaller marshaller = jaxbContext.createMarshaller();
            marshaller.marshal(doc, stringWriter);
            return stringWriter.toString();
        } catch (JAXBException | IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    private DocumentSMG unmarshal(String smgXml) {
        try {
            JAXBContext jaxbContext = JAXBContext.newInstance(DocumentSMG.class);
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            XMLStreamReader reader = XMLInputFactory.newInstance().createXMLStreamReader(new StringReader(smgXml));
            try {
                return unmarshaller.unmarshal(reader, DocumentSMG.class).getValue();
            } finally {
                reader.close();
            }
        } catch (JAXBException | XMLStreamException e) {
            e.printStackTrace();
            return null;
        }
    }

}