package de.intevation.flys.artifacts.states;

import java.text.NumberFormat;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.List;

import org.apache.log4j.Logger;

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

import de.intevation.artifacts.Artifact;
import de.intevation.artifacts.ArtifactNamespaceContext;
import de.intevation.artifacts.CallContext;
import de.intevation.artifacts.CallMeta;

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

import de.intevation.artifactdatabase.ProtocolUtils;

import de.intevation.artifactdatabase.data.StateData;

import de.intevation.artifactdatabase.state.AbstractState;
import de.intevation.artifactdatabase.state.Facet;

import de.intevation.flys.artifacts.FLYSArtifact;

import de.intevation.flys.artifacts.resources.Resources;


/**
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public abstract class DefaultState extends AbstractState {

    /** The logger that is used in this class. */
    private static Logger logger = Logger.getLogger(DefaultState.class);

    public static enum ComputeType {
        FEED, ADVANCE, INIT
    }

    protected StateData getData(FLYSArtifact artifact,  String name) {
        return artifact.getData(name);
    }


    /**
     * Append to a node and return xml description relevant for gui.
     */
    public Element describeStatic(
        Artifact    artifact,
        Document    document,
        Node        root,
        CallContext context,
        String      uuid)
    {
        XMLUtils.ElementCreator creator = new XMLUtils.ElementCreator(
            document,
            ArtifactNamespaceContext.NAMESPACE_URI,
            ArtifactNamespaceContext.NAMESPACE_PREFIX);

        CallMeta meta = context.getMeta();

        String label = Resources.getMsg(meta, getID(), getID());
        Element ui   = ProtocolUtils.createArtNode(
            creator, "state",
            new String[] { "name", "uiprovider", "label" },
            new String[] { getID(), getUIProvider(), label });

        Map<String, StateData> theData = getData();
        if (theData == null) {
            return ui;
        }

        Iterator<String> iter = theData.keySet().iterator();
        FLYSArtifact     flys = (FLYSArtifact) artifact;

        while (iter.hasNext()) {
            String    name = iter.next();
            StateData data = getData(flys, name);

            String value = (data != null) ? (String) data.getValue() : null;

            if (value == null) {
                continue;
            }

            logger.debug("Append element '" + name + "' (" + value + ")");

            Element dataElement = creator.create("data");
            creator.addAttr(dataElement, "name", name, true);
            creator.addAttr(dataElement, "type", data.getType(), true);

            Element itemElement = creator.create("item");
            creator.addAttr(itemElement, "value", value, true);

            String attrValue = "";
            try {
                // XXX A better way to format the output would be to use the
                // 'type' value of the data objects.
                double doubleVal = Double.valueOf(value);
                Locale         l = Resources.getLocale(meta);
                NumberFormat  nf = NumberFormat.getInstance(l);

                attrValue = nf.format(doubleVal);
            }
            catch (NumberFormatException nfe) {
                attrValue = Resources.getMsg(meta, value, value);
            }

            creator.addAttr(itemElement, "label", attrValue, true);

            dataElement.appendChild(itemElement);
            ui.appendChild(dataElement);
        }

        return ui;
    }


    public Element describe(
        Artifact    artifact,
        Document    document,
        Node        root,
        CallContext context,
        String      uuid)
    {
        XMLUtils.ElementCreator creator = new XMLUtils.ElementCreator(
            document,
            ArtifactNamespaceContext.NAMESPACE_URI,
            ArtifactNamespaceContext.NAMESPACE_PREFIX);

        Element ui        = null;
        String uiprovider = getUIProvider();
        if (uiprovider != null) {
            ui = ProtocolUtils.createArtNode(
                creator, "dynamic",
                new String[] { "uiprovider" },
                new String[] { uiprovider });
        }
        else {
            ui = ProtocolUtils.createArtNode(creator, "dynamic", null, null);
        }

        Map<String, StateData> theData = getData();
        if (theData == null) {
            return ui;
        }

        Iterator<String> iter = theData.keySet().iterator();
        FLYSArtifact     flys = (FLYSArtifact) artifact;

        while (iter.hasNext()) {
            String    name = iter.next();
            StateData data = getData(flys, name);

            data = data != null ? data : getData(name);

            Element select = createData(creator, artifact, data, context);

            String defValue = (String) data.getValue();
            String defDesc  = null;

            if (defValue != null && defValue.length() > 0) {
                defDesc = Resources.getMsg(
                    context.getMeta(),
                    defValue,
                    defValue);
            }

            if (defValue != null && defDesc != null) {
                creator.addAttr(select, "defaultValue", defValue, true);
                creator.addAttr(select, "defaultLabel", defDesc, true);
            }

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

            select.appendChild(choices);
            ui.appendChild(select);

            Element[] items = createItems(creator, artifact, name, context);
            if (items != null) {
                for (Element item: items) {
                    choices.appendChild(item);
                }
            }
        }

        return ui;
    }


    /**
     * This method creates the root node that contains the list of selectable
     * items.
     *
     * @param cr The ElementCreator.
     * @param name The name of the amount of data.
     *
     * @return the root node of the item list.
     */
    protected Element createData(
        XMLUtils.ElementCreator cr,
        Artifact    artifact,
        StateData   data,
        CallContext context)
    {
        Element select = ProtocolUtils.createArtNode(
            cr, "select", null, null);
        cr.addAttr(select, "name", data.getName(), true);

        Element label = ProtocolUtils.createArtNode(
            cr, "label", null, null);

        select.appendChild(label);

        label.setTextContent(Resources.getMsg(
            context.getMeta(),
            getID(),
            getID()));

        return select;
    }


    /**
     * This method creates a list of items. These items represent the amount of
     * input data that is possible for this state.
     *
     * @param cr The ElementCreator.
     * @param name The name of the amount of data.
     *
     * @return a list of items.
     */
    protected Element[] createItems(
        XMLUtils.ElementCreator cr,
        Artifact    artifact,
        String      name,
        CallContext context
    ) {
        return null;
    }


    /**
     * This method validates the inserted data and returns true, if everything
     * was correct, otherwise an exception is thrown.
     *
     * @param artifact A reference to the owner artifact.
     *
     * @return true, if everything was fine.
     */
    public boolean validate(Artifact artifact)
    throws IllegalArgumentException
    {
        return true;
    }


    protected String getUIProvider() {
        return null;
    }


    public Object computeAdvance(
        FLYSArtifact artifact,
        String       hash,
        CallContext  context,
        List<Facet>  facets,
        Object       old
    ) {
        return null;
    }


    public Object computeFeed(
        FLYSArtifact artifact,
        String       hash,
        CallContext  context,
        List<Facet>  facets,
        Object       old
    ) {
        return null;
    }


    public Object computeInit(
        FLYSArtifact artifact,
        String       hash,
        Object       context,
        CallMeta     meta,
        List<Facet>  facets)
    {
        return null;
    }
}
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