package de.intevation.flys.artifacts;

import org.apache.log4j.Logger;

import java.util.List;

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

import de.intevation.artifacts.Artifact;

import de.intevation.artifacts.ArtifactFactory;
import de.intevation.artifacts.CallMeta;
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.state.Facet;
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.model.River;
import de.intevation.flys.utils.FLYSUtils;

import de.intevation.flys.artifacts.states.DefaultState;
import de.intevation.flys.artifacts.context.FLYSContext;
import de.intevation.flys.artifacts.resources.Resources;


public class ChartArtifact extends FLYSArtifact {

    private static final Logger logger =
        Logger.getLogger(ChartArtifact.class);

    @Override
    public void setup(
        String          identifier,
        ArtifactFactory factory,
        Object          context,
        CallMeta        callmeta,
        Document        data)
    {
        logger.debug("ChartArtifact.setup");
        this.identifier = identifier;
        name = "new_chart";

        List<State> states = getStates(context);

        setCurrentState(states.get(0));
    }


    @Override
    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);

        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;

    }


    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);
    }


    /**
     * Append output mode nodes to a document.
     */
    protected void appendOutputModes(
        Document    doc,
        Element     outs,
        CallContext context,
        String      uuid)
    {
        List<String> stateIds = getPreviousStateIds();

        XMLUtils.ElementCreator creator = new XMLUtils.ElementCreator(
            doc,
            ArtifactNamespaceContext.NAMESPACE_URI,
            ArtifactNamespaceContext.NAMESPACE_PREFIX);

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

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

            List<Output> list = state.getOutputs();
            if (list == null || list.size() == 0) {
                logger.debug("-> No output modes for this state.");
                continue;
            }

            List<Facet> fs = facets.get(stateId);

            if (fs == null || fs.size() == 0) {
                logger.debug("No facets for previous state found.");
                continue;
            }

            logger.debug("Found " + fs.size() + " facets in previous states.");

            List<Output> generated = generateOutputs(list, fs);

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

        try {
            DefaultState cur = (DefaultState) getCurrentState(context);
            if (cur.validate(this)) {
                List<Output> list = cur.getOutputs();
                if (list != null && list.size() > 0) {
                    logger.debug(
                        "Append output modes for current state: " + cur.getID());

                    List<Facet> fs = facets.get(cur.getID());

                    if (fs != null && fs.size() > 0) {
                        List<Output> generated = generateOutputs(list, fs);

                        logger.debug("Found " + fs.size() + " current facets.");
                        if (!generated.isEmpty()) {
                            ProtocolUtils.appendOutputModes(
                                doc, outs, generated);
                        }
                    }
                    else {
                        logger.debug("No facets found for the current state.");
                    }
                }
            }
        }
        catch (IllegalArgumentException iae) {
            // state is not valid, so we do not append its outputs.
        }
    }


    /**
     * 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();

        logger.debug("previous states: " + stateIds);
        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));
        }
    }


    public static class ChartState extends DefaultState {

        public static final String FIELD_MODE = "chart_type";

        public static final String DURATION_CURVE =
            "chart.new.durationcurve";

        public static final String COMPUTED_DISCHARGE_CURVE =
            "chart.new.computeddischargecurve";

        public static final String DISCHARGE_LONGITUDINAL_CURVE =
            "chart.new.discharge_longitudinal_section";

        public static final String W_DIFFERENCES =
            "chart.new.w_differences";

        public static final String WATERLEVEL =
            "chart.new.waterlevel";

        public static final String[] CHARTS = {
            COMPUTED_DISCHARGE_CURVE,
            DURATION_CURVE,
            DISCHARGE_LONGITUDINAL_CURVE,
            W_DIFFERENCES,
            WATERLEVEL };



        @Override
        public Object computeAdvance(
            FLYSArtifact artifact,
            String       hash,
            CallContext  context,
            List<Facet>  facets,
            Object       old)
        {
            logger.debug("ChartState.computeAdvance");


            return null;
        }


        @Override
        protected Element[] createItems(
            XMLUtils.ElementCreator cr,
            Artifact    artifact,
            String      name,
            CallContext context)
        {
            CallMeta meta   = context.getMeta();
            Element[] charts = new Element[CHARTS.length];

            int i = 0;

            for (String chart: CHARTS) {
                charts[i++] = createItem(
                    cr, new String[] {
                        Resources.getMsg(meta, chart, chart),
                        chart
                    });
            }

            return charts;
        }


    }
}