package de.intevation.flys.artifacts.services;

import java.util.List;

import de.intevation.artifactdatabase.DefaultService;

import de.intevation.artifacts.CallMeta;
import de.intevation.artifacts.GlobalContext;
import de.intevation.artifacts.Service;

import de.intevation.flys.artifacts.model.FixingsFilterBuilder;
import de.intevation.flys.artifacts.model.FixingsOverview;
import de.intevation.flys.artifacts.model.FixingsColumn;
import de.intevation.flys.artifacts.model.FixingsColumnFactory;
import de.intevation.flys.artifacts.model.FixingsOverviewFactory;

import de.intevation.flys.artifacts.model.FixingsOverview.Fixing;

import de.intevation.flys.backend.SessionHolder;

import org.apache.log4j.Logger;

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

public class FixingsKMChartService
extends      DefaultService
{
    private static final Logger log =
        Logger.getLogger(FixingsKMChartService.class);

    public static final byte [] EMPTY = {
        (byte)0x89, (byte)0x50, (byte)0x4e, (byte)0x47, 
        (byte)0x0d, (byte)0x0a, (byte)0x1a, (byte)0x0a, 
        (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x0d, 
        (byte)0x49, (byte)0x48, (byte)0x44, (byte)0x52, 
        (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x01, 
        (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x01, 
        (byte)0x08, (byte)0x00, (byte)0x00, (byte)0x00, 
        (byte)0x00, (byte)0x3a, (byte)0x7e, (byte)0x9b, 
        (byte)0x55, (byte)0x00, (byte)0x00, (byte)0x00, 
        (byte)0x01, (byte)0x73, (byte)0x52, (byte)0x47, 
        (byte)0x42, (byte)0x00, (byte)0xae, (byte)0xce, 
        (byte)0x1c, (byte)0xe9, (byte)0x00, (byte)0x00, 
        (byte)0x00, (byte)0x09, (byte)0x70, (byte)0x48, 
        (byte)0x59, (byte)0x73, (byte)0x00, (byte)0x00, 
        (byte)0x0b, (byte)0x13, (byte)0x00, (byte)0x00, 
        (byte)0x0b, (byte)0x13, (byte)0x01, (byte)0x00, 
        (byte)0x9a, (byte)0x9c, (byte)0x18, (byte)0x00, 
        (byte)0x00, (byte)0x00, (byte)0x07, (byte)0x74, 
        (byte)0x49, (byte)0x4d, (byte)0x45, (byte)0x07, 
        (byte)0xdc, (byte)0x04, (byte)0x04, (byte)0x10, 
        (byte)0x30, (byte)0x15, (byte)0x7d, (byte)0x77, 
        (byte)0x36, (byte)0x0b, (byte)0x00, (byte)0x00, 
        (byte)0x00, (byte)0x08, (byte)0x74, (byte)0x45, 
        (byte)0x58, (byte)0x74, (byte)0x43, (byte)0x6f, 
        (byte)0x6d, (byte)0x6d, (byte)0x65, (byte)0x6e, 
        (byte)0x74, (byte)0x00, (byte)0xf6, (byte)0xcc, 
        (byte)0x96, (byte)0xbf, (byte)0x00, (byte)0x00, 
        (byte)0x00, (byte)0x0a, (byte)0x49, (byte)0x44, 
        (byte)0x41, (byte)0x54, (byte)0x08, (byte)0xd7, 
        (byte)0x63, (byte)0xf8, (byte)0x0f, (byte)0x00, 
        (byte)0x01, (byte)0x01, (byte)0x01, (byte)0x00, 
        (byte)0x1b, (byte)0xb6, (byte)0xee, (byte)0x56, 
        (byte)0x00, (byte)0x00, (byte)0x00, (byte)0x00, 
        (byte)0x49, (byte)0x45, (byte)0x4e, (byte)0x44, 
        (byte)0xae, (byte)0x42, (byte)0x60, (byte)0x82
    };

    private static final Output empty() {
        return new Output(EMPTY, "image/png");
    }

    @Override
    public Service.Output process(
        Document      data,
        GlobalContext globalContext,
        CallMeta      callMeta
    ) {
        log.debug("FixingsKMChartService.process");

        SessionHolder.acquire();
        try {
            return doProcess(data, globalContext, callMeta);
        }
        finally {
            SessionHolder.HOLDER.get().close();
            SessionHolder.release();
        }
    }

    protected Service.Output doProcess(
        Document      data,
        GlobalContext globalContext,
        CallMeta      callMeta
    ) {
        NodeList rivers = data.getElementsByTagName("river");
        NodeList kms    = data.getElementsByTagName("km");

        if (rivers.getLength() == 0 || kms.getLength() == 0) {
            log.warn("Missing river and/or km.");
            return empty();
        }

        String river = ((Element)rivers.item(0)).getAttribute("name");
        String kmS   = ((Element)kms   .item(0)).getAttribute("value");

        if (river.length() == 0 || kmS.length() == 0) {
            log.warn("River and/or km empty string.");
            return empty();
        }

        double km;
        try {
            km = Double.parseDouble(kmS);
        }
        catch (NumberFormatException nfe) {
            log.warn("Km '" + kmS + " is not a valid number.");
            return empty();
        }

        FixingsOverview overview = FixingsOverviewFactory.getOverview(river);

        if (overview == null) {
            log.warn("No overview found for river '" + river + "'");
            return empty();
        }

        FixingsFilterBuilder ffb = new FixingsFilterBuilder(data);

        List<Fixing.Column> columns = overview.filter(
            ffb.getRange(),
            ffb.getFilter());

        for (Fixing.Column column: columns) {
            FixingsColumn columnData =
                FixingsColumnFactory.INSTANCE.getColumnData(column);
            if (columnData == null) {
                continue;
            }
        }
        // TODO: Implement chart generation!

        return empty();
    }
}
// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :