/**
 *
 */
package de.intevation.gnv.artifacts;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import de.intevation.artifactdatabase.Config;
import de.intevation.artifactdatabase.DefaultArtifact;
import de.intevation.gnv.artifacts.context.GNVArtifactContext;
import de.intevation.gnv.transition.Transition;
import de.intevation.gnv.transition.TransitionFactory;

/**
 * @author Tim Englich <tim.englich@intevation.de>
 *
 */
public abstract class GNVArtifactBase extends DefaultArtifact {
    /**
     * the logger, used to log exceptions and additonaly information
     */
    private static Logger log = Logger.getLogger(GNVArtifactBase.class);
    /**
     * The UID of this Class
     */
    private static final long serialVersionUID = -8907096744400741458L;
    
    /**
     * The Identifier for the Replacement of the Artifactname
     */
    public static final String XPATH_IDENTIFIER_REPLACE = "IDENTIFIER";
    
    /**
     * The XPATH to the XML-Fragment that should be used for the Configuration
     */
    public static final String XPATH_ARTIFACT_CONFIGURATION= "/artifact-database/artifacts/artifact[@name='"+XPATH_IDENTIFIER_REPLACE+"']";
    
    
    /**
     * The current Transition
     */
    protected Transition current = null;
    
    /**
     * The Transitions that can be used
     */
    protected Map<String, Transition> transitions = null;

    /**
     * The Name of the Artifact
     */
    protected String name = null;
    
    /**
     * Constructor
     */
    public GNVArtifactBase() {
        super();
    }
    
    protected Node getConfigurationFragment(Document document){
        log.debug("GNVArtifactBase.getConfigurationFragment");
        String xpathQuery = XPATH_ARTIFACT_CONFIGURATION.replaceAll(XPATH_IDENTIFIER_REPLACE, this.name);
        log.debug(xpathQuery);
        return Config.getNodeXPath(document,xpathQuery);
    }
    
    /**
     * @see de.intevation.artifactdatabase.DefaultArtifact#setup(java.lang.String, java.lang.Object)
     */
    @Override
    public void setup(String identifier, Object context) {
        log.debug("GNVArtifactBase.setup");
        super.setup(identifier, context);
        if (context instanceof GNVArtifactContext){
            GNVArtifactContext gnvContext = (GNVArtifactContext)context;
            Document doc = gnvContext.getConfig();
            Node artifactNode = this.getConfigurationFragment(doc);
            NodeList transitionList = Config.getNodeSetXPath(artifactNode, "transitions/transition");
            this.transitions = new HashMap<String, Transition>(transitionList.getLength());
            for (int i  = 0 ; i < transitionList.getLength(); i++){
                Transition tmpTransition = TransitionFactory.getInstance().createTransition(transitionList.item(i));
                if (tmpTransition != null){
                    this.transitions.put(tmpTransition.getID(), tmpTransition);
                    if (this.current == null){
                        this.current = tmpTransition;
                    }
                }
            }
            
        }
    }
    
    
    protected Document createDescibeOutput(){
        log.debug("GNVArtifactBase.createDescibeOutput");
        Document document = super.newDocument();
        Element rootNode = this.createRootNode(document);
        this.createHeader(rootNode, document, "describe");
        this.createCurrentState(rootNode, document);
        this.createReachableStates(rootNode, document);
        this.createModel(rootNode, document);
        this.createUserInterface(rootNode, document);
        
        return document;
    }
    
    protected Element createRootNode(Document document){
        Element rootNode = createElement(document,"result");
        document.appendChild(rootNode);
        return rootNode;
    }
    
    protected void createHeader(Element parent, Document document, String documentType){
        Element typeNode = createElement(document,"type");
        typeNode.setAttribute("name", documentType);
        parent.appendChild(typeNode);
        
        Element uuidNode = createElement(document,"uuid");
        uuidNode.setAttribute("value", super.identifier);
        parent.appendChild(uuidNode);
        
        Element hashNode = createElement(document,"hash");
        hashNode.setAttribute("value", this.hash());
        parent.appendChild(hashNode);

        
    }
    protected void createReachableStates(Element parent,Document document){
        Element stateNode = createElement(document,"reachable-states");
        if (this.current != null){
            Iterator<String> states = this.current.reachableTransitions().iterator();
            while(states.hasNext()){
                String value = states.next();
                Element currentNode = createElement(document,"state");
                currentNode.setAttribute("name", value);
                currentNode.setAttribute("description", transitions.get(value).getDescription());
                stateNode.appendChild(currentNode);
            }
        }
        parent.appendChild(stateNode);
    }
    
    protected void createCurrentState(Element parent, Document document){
        Element stateNode = createElement(document,"state");
        stateNode.setAttribute("name", this.current.getID());
        stateNode.setAttribute("description", this.current.getDescription());
        parent.appendChild(stateNode);
    }
    
    
    protected void createModel(Element parent, Document document){
        Element modelNode = createElement(document,"model");
        // TODO mit leben f�llen.
        
        parent.appendChild(modelNode);
    }
    
    protected void createUserInterface(Element parent, Document document){
        Element uiNode = createElement(document,"ui");
        
        // TODO mit leben f�llen.
        
        parent.appendChild(uiNode);
    }
    
    protected void createOutputs(Element parent, Document document){
        Element outputsNode = createElement(document,"outputs");
        
        // TODO mit leben f�llen.
        
        parent.appendChild(outputsNode);
    }

    /**
     * @param document
     * @return
     */
    private Element createElement(Document document, String name) {
        Element node = document.createElementNS(DefaultArtifact.NAMESPACE_URI, name);
        node.setPrefix(DefaultArtifact.NAMESPACE_PREFIX);
        return node;
    }
    

}