/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde
 * Software engineering by Intevation GmbH
 *
 * This file is Free Software under the GNU AGPL (>=v3)
 * and comes with ABSOLUTELY NO WARRANTY! Check out the
 * documentation coming with Dive4Elements River for details.
 */

package org.dive4elements.river.artifacts.sinfo.flowdepth;

import java.io.OutputStream;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.dive4elements.artifacts.CallMeta;
import org.dive4elements.artifacts.common.utils.Config;
import org.dive4elements.river.FLYS;
import org.dive4elements.river.artifacts.model.CalculationResult;
import org.dive4elements.river.artifacts.resources.Resources;
import org.dive4elements.river.artifacts.sinfo.util.MetaAndTableJRDataSource;
import org.dive4elements.river.exports.AbstractExporter;
import org.dive4elements.river.model.River;
import org.dive4elements.river.model.Unit;
import org.dive4elements.river.utils.RiverUtils;

import au.com.bytecode.opencsv.CSVWriter;
import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;

/**
 * Generates different output formats (csv, pdf) of data that resulted from a flow depths computation.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 * @author Gernot Belger
 */
// REMARK: must be public because its registered in generators.xml
public class FlowDepthExporter extends AbstractExporter {

    /** The log used in this exporter. */
    private static Logger log = Logger.getLogger(FlowDepthExporter.class);

    private static final String CSV_KM_HEADER = "sinfo.export.flow_depth.csv.header.km";
    private static final String CSV_FLOWDEPTH_HEADER = "sinfo.export.flow_depth.csv.header.flowdepth";
    private static final String CSV_FLOWDEPTHTKH_HEADER = "sinfo.export.flow_depth.csv.header.flowdepthTkh";
    private static final String CSV_TKH_HEADER = "sinfo.export.flow_depth.csv.header.tkh";
    private static final String CSV_WATERLEVEL_HEADER = "sinfo.export.flow_depth.csv.header.waterlevel";
    private static final String CSV_DISCHARGE_HEADER = "sinfo.export.flow_depth.csv.header.discharge";
    private static final String CSV_LABEL_HEADER = "sinfo.export.flow_depth.csv.header.label";
    private static final String CSV_GAUGE_HEADER = "sinfo.export.flow_depth.csv.header.gauge";
    private static final String CSV_MEAN_BED_HEIGHT_HEADER = "sinfo.export.flow_depth.csv.header.mean_bed_height";
    private static final String CSV_MEAN_BED_HEIGHT_HEADER_SHORT = "sinfo.export.flow_depth.csv.header.mean_bed_height.short";
    private static final String CSV_SOUNDING_HEADER = "sinfo.export.flow_depth.csv.header.sounding";
    private static final String CSV_LOCATION_HEADER = "sinfo.export.flow_depth.csv.header.location";

    private static final String CSV_META_HEADER_RESULT = "sinfo.export.flow_depth.csv.meta.header.result";

    private static final String CSV_META_HEADER_RESULT_LABEL = "sinfo.export.flow_depth.csv.meta.header.result.label";

    private static final String CSV_META_VERSION = "sinfo.export.flow_depth.csv.meta.version";

    private static final String CSV_META_VERSION_LABEL = "sinfo.export.flow_depth.csv.meta.version.label";

    private static final String CSV_META_USER = "sinfo.export.flow_depth.csv.meta.user";

    private static final String CSV_META_USER_LABEL = "sinfo.export.flow_depth.csv.meta.user.label";

    private static final String CSV_META_CREATION = "sinfo.export.flow_depth.csv.meta.creation";

    private static final String CSV_META_CREATION_LABEL = "sinfo.export.flow_depth.csv.meta.creation.label";

    private static final String CSV_META_RIVER = "sinfo.export.flow_depth.csv.meta.river";

    private static final String CSV_META_RIVER_LABEL = "sinfo.export.flow_depth.csv.meta.river.label";

    private static final String CSV_META_HEADER_SOUNDING = "sinfo.export.flow_depth.csv.meta.header.sounding";

    private static final String CSV_META_HEADER_SOUNDING_YEAR = "sinfo.export.flow_depth.csv.meta.header.sounding.year";

    private static final String CSV_META_HEADER_SOUNDING_TYPE = "sinfo.export.flow_depth.csv.meta.header.sounding.type";

    private static final String CSV_META_HEADER_SOUNDING_EVALUATOR = "sinfo.export.flow_depth.csv.meta.header.sounding.evaluator";

    private static final String CSV_META_HEADER_SOUNDING_PRJ = "sinfo.export.flow_depth.csv.meta.header.sounding.prj";

    private static final String CSV_META_HEADER_SOUNDING_ELEVATIOIN_MODEL = "sinfo.export.flow_depth.csv.meta.header.sounding.elevationmodel";

    private static final String CSV_META_HEADER_SOUNDING_ELEVATIOIN_MODEL_ORIGINAL = "sinfo.export.flow_depth.csv.meta.header.sounding.elevationmodel.original";

    private static final String CSV_META_HEADER_WATERLEVEL = "sinfo.export.flow_depth.csv.meta.header.waterlevel";

    private static final String CSV_META_HEADER_WATERLEVEL_NAME = "sinfo.export.flow_depth.csv.meta.header.waterlevel.name";


    private static final String CSV_META_HEADER_WATERLEVEL_GAUGE = "sinfo.export.flow_depth.csv.meta.header.waterlevel.gauge";

    private static final String CSV_META_HEADER_WATERLEVEL_YEAR = "sinfo.export.flow_depth.csv.meta.header.waterlevel.year";

    private static final String CSV_META_RANGE = "sinfo.export.flow_depth.csv.meta.range";

    private static final String CSV_META_RANGE_LABEL = "sinfo.export.flow_depth.csv.meta.range.label";

    private static final String CSV_META_HEIGHT_UNIT_RIVER = "sinfo.export.flow_depth.csv.meta.height_unit.river";

    private static final String JASPER_FILE = "/jasper/sinfo.flowdepth.jasper";

    private static final String UNIT_M = "m";

    private static final String UNIT_CM = "cm";

    private static final String UNIT_CUBIC_M = "m³/s";

    /** The storage that contains the current calculation result. */
    private FlowDepthCalculationResults data = null;

    /**
     * Formats header with unit
     */
    private String msgUnit(final String key, final String unit) {

        final String msg = msg(key);
        return String.format("%s [%s]", msg, unit);
    }

    @Override
    protected void addData(final Object d) {
        /* reset */
        this.data = null;

        if (d instanceof CalculationResult) {

            final Object dat = ((CalculationResult) d).getData();
            if (dat != null)
                this.data = (FlowDepthCalculationResults) dat;
        }
    }

    @Override
    protected void writeCSVData(final CSVWriter writer) {
        log.info("FlowDepthExporter.writeCSVData");

        /* fetch calculation results */
        final FlowDepthCalculationResults results = this.data;

        final boolean useTkh = results.isUseTkh();
        final River river = results.getRiver();

        /* write as csv */
        writeCSVMeta(writer, results);
        writeCSVHeader(writer, river, useTkh);

        for (final FlowDepthCalculationResult result : results.getResults()) {
            writeCSVFlowDepthResult(writer, result, useTkh);
        }
    }

    private void writeCSVFlowDepthResult(final CSVWriter writer, final FlowDepthCalculationResult result,
            final boolean useTkh) {

        /* first some specific metadata */
        final BedHeightInfo sounding = result.getSounding();
        final WstInfo wst = result.getWst();

        // "##METADATEN PEILUNG"
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING);

        // "# Jahr der Peilung: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_YEAR, Integer.toString(sounding.getYear()));
        // "# Aufnahmeart: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_TYPE, sounding.getType());
        // "# Auswerter: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_EVALUATOR, sounding.getEvaluationBy());
        // "# Lagesystem: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_PRJ, sounding.getLocationSystem());
        // "# Höhensystem: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_ELEVATIOIN_MODEL, sounding.getCurElevationModelUnit());
        // "# ursprüngliches Höhensystem: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_SOUNDING_ELEVATIOIN_MODEL_ORIGINAL,
                sounding.getOldElevationModelUnit());

        // "##METADATEN WASSERSPIEGELLAGE"
        writeCSVMetaEntry(writer, CSV_META_HEADER_WATERLEVEL);
        // "# Bezeichnung der Wasserspiegellage: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_WATERLEVEL_NAME, wst.getLabel());
        // "# Bezugspegel: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_WATERLEVEL_GAUGE, wst.getGauge());
        // "# Jahr/Zeitraum der Wasserspiegellage: "
        writeCSVMetaEntry(writer, CSV_META_HEADER_WATERLEVEL_YEAR, Integer.toString(wst.getYear()));

        /* nwo the value rows */
        final Collection<FlowDepthRow> rows = result.getRows();
        for (final FlowDepthRow flowDepthRow : rows) {
            writeCSVFlowDepthRow(writer, flowDepthRow, useTkh);
        }
    }

    private void writeCSVMeta(final CSVWriter writer, final FlowDepthCalculationResults results) {
        log.info("FlowDepthExporter.writeCSVMeta");

        final String calcModeLabel = results.getCalcModeLabel();
        final River river = results.getRiver();
        writeCSVMetaEntry(writer, CSV_META_HEADER_RESULT, msg(CSV_META_HEADER_RESULT_LABEL), river.getName(),
                calcModeLabel);

        // "# FLYS-Version: "
        writeCSVMetaEntry(writer, CSV_META_VERSION, msg(CSV_META_VERSION_LABEL), FLYS.VERSION);

        // "# Bearbeiter: "
        writeCSVMetaEntry(writer, CSV_META_USER, msg(CSV_META_USER_LABEL), results.getUser());

        // "# Datum der Erstellung: "
        final Locale locale = Resources.getLocale(this.context.getMeta());
        final DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT, locale);
        writeCSVMetaEntry(writer, CSV_META_CREATION, msg(CSV_META_CREATION_LABEL), df.format(new Date()));

        // "# Gewässer: "
        writeCSVMetaEntry(writer, CSV_META_RIVER, msg(CSV_META_RIVER_LABEL), river.getName());

        // "# Höhensystem des Flusses: "
        final Unit wstUnit = river.getWstUnit();
        writeCSVMetaEntry(writer, CSV_META_HEIGHT_UNIT_RIVER, wstUnit.getName());

        // "# Ort/Bereich (km): "
        writeCSVMetaEntry(writer, CSV_META_RANGE, msg(CSV_META_RANGE_LABEL), getKmFormatter().format(results.getFrom()),
                getKmFormatter().format(results.getTo()));

        writer.writeNext(new String[] { "" });
    }

    private void writeCSVMetaEntry(final CSVWriter writer, final String message, final Object... messageArgs) {

        final CallMeta meta = this.context.getMeta();

        writer.writeNext(new String[] { Resources.getMsg(meta, message, message, messageArgs) });
    }

    /**
     * Write the header, with different headings depending on whether at a
     * gauge or at a location.
     *
     * @param river
     * @param useTkh
     */
    private void writeCSVHeader(final CSVWriter writer, final River river, final boolean useTkh) {
        log.info("FlowDepthExporter.writeCSVHeader");

        final Collection<String> header = new ArrayList<>(11);

        header.add(msg(CSV_KM_HEADER));
        header.add(msgUnit(CSV_FLOWDEPTH_HEADER, UNIT_M));
        if (useTkh) {
            header.add(msgUnit(CSV_FLOWDEPTHTKH_HEADER, UNIT_M));
            header.add(msgUnit(CSV_TKH_HEADER, UNIT_CM));
        }

        final String wstUnitName = river.getWstUnit().getName();
        header.add(msgUnit(CSV_WATERLEVEL_HEADER, wstUnitName));
        header.add(msgUnit(CSV_DISCHARGE_HEADER, UNIT_CUBIC_M));
        header.add(msg(CSV_LABEL_HEADER));
        header.add(msg(CSV_GAUGE_HEADER));
        header.add(msgUnit(CSV_MEAN_BED_HEIGHT_HEADER, wstUnitName));
        header.add(msg(CSV_SOUNDING_HEADER));
        header.add(msg(CSV_LOCATION_HEADER));

        writer.writeNext(header.toArray(new String[header.size()]));
    }

    /**
     * Format a row of a flow depth result into an array of string, both used by csv and pdf
     *
     * @param useTkh
     */
    private String[] formatFlowDepthRow(final FlowDepthRow row, final boolean useTkh) {

        final Collection<String> lines = new ArrayList<>(11);

        // Fluss-km
        lines.add(getKmFormatter().format(row.getStation()));

        // Fließtiefe [m]
        lines.add(getFlowDepthFormatter().format(row.getFlowDepth()));

        if (useTkh) {
            // Fließtiefe mit TKH [m]
            lines.add(getFlowDepthFormatter().format(row.getFlowDepthWithTkh()));

            // TKH [cm]
            lines.add(getTkhFormatter().format(row.getTkh()));
        }

        // Wasserstand [NN + m]
        lines.add(getW2Formatter().format(row.getWaterlevel()));

        // Q [m³/s]
        final double discharge = row.getDischarge();
        if( Double.isNaN(discharge))
            lines.add(StringUtils.EMPTY);
        else
        {
            final double roundedDischarge = RiverUtils.roundQ(discharge);
            lines.add(getQFormatter().format(roundedDischarge));
        }

        // Bezeichnung
        lines.add(row.getWaterlevelLabel());

        // Bezugspegel
        lines.add(row.getGauge());

        // Mittlere Sohlhöhe [NN + m]
        lines.add(getMeanBedHeighFormatter().format(row.getMeanBedHeight()));

        // Peilung/Epoche
        lines.add(row.getSoundageLabel());

        // Lage
        lines.add(row.getLocation());

        return lines.toArray(new String[lines.size()]);
    }

    /**
     * Write "rows" of csv data from wqkms with writer.
     *
     * @param useTkh
     */
    private void writeCSVFlowDepthRow(final CSVWriter writer, final FlowDepthRow row, final boolean useTkh) {
        log.debug("FlowDepthExporter.writeCSVFlowDepthRow");

        final String[] formattedRow = formatFlowDepthRow(row, useTkh);
        writer.writeNext(formattedRow);
    }

    @Override
    protected void writePDF(final OutputStream outStream) {
        log.debug("write PDF");

        final JRDataSource source = createJRData();

        final String confPath = Config.getConfigDirectory().toString();

        // FIXME: distinguish between with and without tkh: we need two jasper reports!

        final Map<String, Object> parameters = new HashMap<>();
        parameters.put("ReportTitle", "Exported Data");
        try {
            final JasperPrint print = JasperFillManager.fillReport(confPath + JASPER_FILE, parameters, source);
            JasperExportManager.exportReportToPdfStream(print, outStream);
        }
        catch (final JRException je) {
            log.warn("Error generating PDF Report!", je);
        }
    }

    private JRDataSource createJRData() {

        /* fetch calculation results */
        final FlowDepthCalculationResults results = this.data;

        final MetaAndTableJRDataSource source = new MetaAndTableJRDataSource();

        addJRMetaData(source, results);

        final boolean useTkh = results.isUseTkh();

        for (final FlowDepthCalculationResult result : results.getResults()) {
            addJRTableData(source, result, useTkh);
        }

        return source;
    }

    private void addJRMetaData(final MetaAndTableJRDataSource source, final FlowDepthCalculationResults results) {

        final River river = results.getRiver();
        final String wstUnitName = river.getWstUnit().getName();

        /* general metadata */
        source.addMetaData("header", msg(CSV_META_HEADER_RESULT_LABEL));
        source.addMetaData("calcMode", results.getCalcModeLabel());

        source.addMetaData("version_label", msg(CSV_META_VERSION_LABEL));
        source.addMetaData("version", FLYS.VERSION);

        source.addMetaData("user_label", msg(CSV_META_USER_LABEL));
        source.addMetaData("user", results.getUser());

        final Locale locale = Resources.getLocale(this.context.getMeta());
        final DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT, locale);
        source.addMetaData("date_label", msg(CSV_META_CREATION_LABEL));
        source.addMetaData("date", df.format(new Date()));

        source.addMetaData("river_label", msg(CSV_META_RIVER_LABEL));
        source.addMetaData("river", river.getName());

        final String rangeValue = String.format("%s - %s", getKmFormatter().format(results.getFrom()),
                getKmFormatter().format(results.getTo()));
        source.addMetaData("range_label", msg(CSV_META_RANGE_LABEL));
        source.addMetaData("range", rangeValue);

        /* column headings */
        source.addMetaData("station_header", msg(CSV_KM_HEADER));
        source.addMetaData("flowdepth_header", msg(CSV_FLOWDEPTH_HEADER));
        source.addMetaData("flowdepth_tkh_header", msg(CSV_FLOWDEPTHTKH_HEADER));
        source.addMetaData("tkh_header", msg(CSV_TKH_HEADER));
        source.addMetaData("waterlevel_header", msg(CSV_WATERLEVEL_HEADER));
        source.addMetaData("river_unit", wstUnitName);
        source.addMetaData("discharge_header", msg(CSV_DISCHARGE_HEADER));
        source.addMetaData("waterlevel_name_header", msg(CSV_LABEL_HEADER));
        source.addMetaData("gauge_header", msg(CSV_GAUGE_HEADER));
        source.addMetaData("bedheight_header", msg(CSV_MEAN_BED_HEIGHT_HEADER_SHORT));
        source.addMetaData("sounding_name_header", msg(CSV_SOUNDING_HEADER));
        source.addMetaData("location_header", msg(CSV_LOCATION_HEADER));
    }

    private void addJRTableData(final MetaAndTableJRDataSource source, final FlowDepthCalculationResult result,
            final boolean useTkh) {

        final Collection<FlowDepthRow> rows = result.getRows();

        for (final FlowDepthRow row : rows) {

            final String[] formattedRow = formatFlowDepthRow(row, useTkh);
            source.addData(formattedRow);
        }
    }
}