package de.intevation.flys.artifacts;

import de.intevation.artifactdatabase.ProtocolUtils;

import de.intevation.artifactdatabase.state.Output;
import de.intevation.artifactdatabase.state.State;
import de.intevation.artifactdatabase.state.StateEngine;

import de.intevation.artifactdatabase.transition.TransitionEngine;

import de.intevation.artifacts.CallContext;
import de.intevation.artifacts.Message;

import de.intevation.artifacts.common.ArtifactNamespaceContext;

import de.intevation.artifacts.common.utils.XMLUtils.ElementCreator;

import de.intevation.artifacts.common.utils.XMLUtils;

import de.intevation.flys.artifacts.context.FLYSContext;

import de.intevation.flys.artifacts.model.CalculationMessage;
import de.intevation.flys.artifacts.model.FacetTypes;

import de.intevation.flys.artifacts.states.DefaultState;

import de.intevation.flys.utils.FLYSUtils;

import java.util.LinkedList;
import java.util.List;

import org.apache.log4j.Logger;

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

/**
 * The default MINFO artifact.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public class MINFOArtifact
extends      FLYSArtifact
implements   FacetTypes {

    /** The logger for this class. */
    private static Logger logger = Logger.getLogger(MINFOArtifact.class);

    /** The name of the artifact. */
    public static final String ARTIFACT_NAME = "minfo";

    /** XPath */
    public static final String XPATH_STATIC_UI ="/art:result/art:ui/art:static";


    /**
     * The default constructor.
     */
    public MINFOArtifact() {
    }


    /**
     * This method returns a description of this artifact.
     *
     * @param data Some data.
     * @param context The CallContext.
     *
     * @return the description of this artifact.
     */
    public Document describe(Document data, CallContext context) {
        logger.debug("Describe: the current state is: " + getCurrentStateId());

        FLYSContext flysContext = FLYSUtils.getFlysContext(context);
        StateEngine stateEngine = (StateEngine) flysContext.get(
            FLYSContext.STATE_ENGINE_KEY);

        TransitionEngine transitionEngine = (TransitionEngine) flysContext.get(
            FLYSContext.TRANSITION_ENGINE_KEY);

        List<State> reachable = transitionEngine.getReachableStates(
            this, getCurrentState(context), stateEngine);

        Document description            = XMLUtils.newDocument();
        XMLUtils.ElementCreator creator = new XMLUtils.ElementCreator(
            description,
            ArtifactNamespaceContext.NAMESPACE_URI,
            ArtifactNamespaceContext.NAMESPACE_PREFIX);

        Element root = ProtocolUtils.createRootNode(creator);
        description.appendChild(root);

        State current = getCurrentState(context);

        ProtocolUtils.appendDescribeHeader(creator, root, identifier(), hash());
        ProtocolUtils.appendState(creator, root, current);
        ProtocolUtils.appendReachableStates(creator, root, reachable);

        appendBackgroundActivity(creator, root, context);

        Element name = ProtocolUtils.createArtNode(
            creator, "name",
            new String[] { "value" },
            new String[] { getName() });

        Element ui = ProtocolUtils.createArtNode(
            creator, "ui", null, null);

        Element staticUI  = ProtocolUtils.createArtNode(
            creator, "static", null, null);

        Element outs = ProtocolUtils.createArtNode(
            creator, "outputmodes", null, null);
        appendOutputModes(description, outs, context, identifier());

        appendStaticUI(description, staticUI, context, identifier());

        Element dynamic = current.describe(
            this,
            description,
            root,
            context,
            identifier());

        if (dynamic != null) {
            ui.appendChild(dynamic);
        }

        ui.appendChild(staticUI);

        root.appendChild(name);
        root.appendChild(ui);
        root.appendChild(outs);

        return description;
    }


    /**
     * Returns the name of the concrete artifact.
     *
     * @return the name of the concrete artifact.
     */
    public String getName() {
        return ARTIFACT_NAME;
    }


    protected static void appendBackgroundActivity(
        ElementCreator cr,
        Element        root,
        CallContext    context
    ) {
        Element inBackground = cr.create("background-processing");
        root.appendChild(inBackground);

        cr.addAttr(
            inBackground,
            "value",
            String.valueOf(context.isInBackground()),
            true);

        LinkedList<Message> messages = context.getBackgroundMessages();

        if (messages == null) {
            return;
        }

        CalculationMessage  message  = (CalculationMessage) messages.getLast();
        cr.addAttr(
            inBackground,
            "steps",
            String.valueOf(message.getSteps()),
            true);

        cr.addAttr(
            inBackground,
            "currentStep",
            String.valueOf(message.getCurrentStep()),
            true);

        inBackground.setTextContent(message.getMessage());
    }


    /**
     * Append output mode nodes to a document.
     */
    protected void appendOutputModes(
        Document    doc,
        Element     outs,
        CallContext context,
        String      uuid)
    {
        List<Output> generated = getOutputs(context);
        logger.debug("This Artifact has " + generated.size() + " Outputs.");

        ProtocolUtils.appendOutputModes(doc, outs, generated);
    }


    /**
     * This method appends the static data - that has already been inserted by
     * the user - to the static node of the DESCRIBE document.
     *
     * @param doc The document.
     * @param ui The root node.
     * @param context The CallContext.
     * @param uuid The identifier of the artifact.
     */
    protected void appendStaticUI(
        Document    doc,
        Node        ui,
        CallContext context,
        String uuid)
    {
        List<String> stateIds = getPreviousStateIds();

        FLYSContext flysContext = FLYSUtils.getFlysContext(context);
        StateEngine engine      = (StateEngine) flysContext.get(
            FLYSContext.STATE_ENGINE_KEY);

        for (String stateId: stateIds) {
            logger.debug("Append static data for state: " + stateId);
            DefaultState state = (DefaultState) engine.getState(stateId);

            ui.appendChild(state.describeStatic(this, doc, ui, context, uuid));
        }
    }


    /**
     * Determines Facets initial disposition regarding activity (think of
     * selection in Client ThemeList GUI). This will be checked one time
     * when the facet enters a collections describe document.
     *
     * @param facetName name of the facet.
     * @param index     index of the facet.
     * @return 0 if not active
     */
    @Override
    public int getInitialFacetActivity(String outputName, String facetName, int index) {
        logger.warn("MINFOArtifact.getInitialFacetActivity: not implemented!");
        return 1;
    }
}
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