package de.intevation.flys.artifacts;

import java.util.List;

import org.apache.log4j.Logger;

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

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

import de.intevation.artifactdatabase.ProtocolUtils;
import de.intevation.artifactdatabase.data.StateData;
import de.intevation.artifactdatabase.state.State;
import de.intevation.artifactdatabase.state.StateEngine;
import de.intevation.artifactdatabase.state.Output;
import de.intevation.artifactdatabase.transition.TransitionEngine;

import de.intevation.flys.artifacts.model.FacetTypes;
import de.intevation.flys.artifacts.context.FLYSContext;
import de.intevation.flys.artifacts.states.DefaultState;

import de.intevation.flys.utils.FLYSUtils;

/**
 * The default fixation analysis artifact.
 *
 * @author <a href="mailto:raimund.renkert@intevation.de">Raimund Renkert</a>
 */
public class FixationArtifact
extends      FLYSArtifact
implements   FacetTypes {

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

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

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

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

    public Document describe(Document data, CallContext context) {
        logger.debug("Describe: the current state is: " + getCurrentStateId());

        if (logger.isDebugEnabled()) {
            dumpArtifact();
        }

        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);

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

        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;
    }


    /**
     * 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));
        }
    }

}