/* Copyright (C) 2017 by Bundesanstalt für Gewässerkunde
 * Software engineering by
 *  Björnsen Beratende Ingenieure GmbH
 *  Dr. Schumacher Ingenieurbüro für Wasser und Umwelt
 *
 * 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.importer.sinfo.parsers;

import java.io.File;
import java.io.FilenameFilter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.log4j.Logger;
import org.dive4elements.river.importer.Config;
import org.dive4elements.river.importer.ImportRiver;
import org.dive4elements.river.importer.common.AbstractParser;
import org.dive4elements.river.importer.common.ParsingState;
import org.dive4elements.river.importer.sinfo.importitem.DailyDischargeDayLineImport;
import org.dive4elements.river.importer.sinfo.importitem.DailyDischargeSeriesImport;
import org.dive4elements.river.model.sinfo.DailyDischarge;
import org.dive4elements.river.model.sinfo.DailyDischargeValue;

/**
 * Reads and parses a daily discharge file
 *
 * @author Matthias Schäfer
 *
 */
public class DailyDischargeParser extends AbstractParser<DailyDischarge, DailyDischargeValue, DailyDischargeDayLineImport, DailyDischargeSeriesImport> {

    /***** FIELDS *****/

    private static final Logger log = Logger.getLogger(DailyDischargeParser.class);

    static final Pattern IMPORT_FILENAME = Pattern.compile("^(.+)_mittlerer_Tagesabfluss.csv", Pattern.CASE_INSENSITIVE);

    private static final Pattern META_GAUGENAME = Pattern.compile("^#\\s*Stations-*Name:\\s*(\\S[^;]*).*", Pattern.CASE_INSENSITIVE);

    private static final Pattern META_GAUGENUMBER = Pattern.compile("^#\\s*Stations-*Nummer:\\s*(\\S[^;]*).*", Pattern.CASE_INSENSITIVE);

    private static final Pattern META_COLUMNTITLES = Pattern.compile("^#*\\s*Datum\\s*;\\s*Q.*", Pattern.CASE_INSENSITIVE);

    private static final DateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");


    /***** CONSTRUCTORS *****/

    public DailyDischargeParser(final File importPath, final File rootRelativePath, final ImportRiver river) {
        super(importPath, rootRelativePath, river);
    }


    /***** METHODS *****/

    @Override
    protected Logger getLog() {
        return log;
    }

    /**
     * Whether this import type shall be skipped
     */
    public static boolean shallSkip() {
        return Config.INSTANCE.skipSInfoDailyDischarge();
    }

    /**
     * Creates a list of parsers for all daily discharge import files in a directory
     */
    public static List<DailyDischargeParser> createParsers(final File importDir, final File relativeDir, final ImportRiver river) {
        final List<DailyDischargeParser> parsers = new ArrayList<>();
        if (importDir.exists()) {
            final File[] files = importDir.listFiles(new FilenameFilter() {
                @Override
                public boolean accept(final File dir, final String name) {
                    return IMPORT_FILENAME.matcher(name).matches();
                }
            });
            for (final File file : files)
                parsers.add(new DailyDischargeParser(file, new File(relativeDir, file.getName()), river));
        }
        return parsers;
    }

    @Override
    protected KmMode kmMode() {
        return KmMode.NONE;
    }

    @Override
    protected DailyDischargeSeriesImport createSeriesImport(final String filename) {
        return new DailyDischargeSeriesImport(filename);
    }

    @Override
    protected DailyDischargeDayLineImport createKmLineImport(final Double km, final String[] values) {
        Date day = null;
        try {
            day = dateFormat.parse(values[0]);
        }
        catch (final Exception e) {
            logError("Invalid date in line " + this.in.getLineNumber());
            return null;
        }
        if (parseDoubleWithNull(values[1]) == null) {
            logError("Invalid discharge value in line " + this.in.getLineNumber());
            return null;
        }
        return new DailyDischargeDayLineImport(day, Double.valueOf(parseDoubleWithNull(values[1]).doubleValue()));
    }

    @Override
    protected boolean handleMetaOther() {
        if (handleMetaGaugeName())
            return true;
        else if (handleMetaGaugeNumber())
            return true;
        else
            return false;
    }

    private boolean handleMetaGaugeName() {
        final Matcher m = META_GAUGENAME.matcher(this.currentLine);
        if (m.matches()) {
            this.metaPatternsMatched.add(META_GAUGENAME);
            this.seriesHeader.setGaugeName(m.group(1).trim());
            return true;
        }
        return false;
    }

    private boolean handleMetaGaugeNumber() {
        final Matcher m = META_GAUGENUMBER.matcher(this.currentLine);
        if (m.matches()) {
            this.metaPatternsMatched.add(META_GAUGENUMBER);
            this.seriesHeader.setGaugeNumber(Long.parseLong(m.group(1)));
            return true;
        }
        return false;
    }

    @Override
    protected boolean handleMetaColumnTitles() {
        if (!META_COLUMNTITLES.matcher(this.currentLine).matches())
            return false;
        this.metaPatternsMatched.add(META_COLUMNTITLES);
        this.columnTitles.clear();
        final String[] titles = this.currentLine.split(SEPARATOR_CHAR, 0);
        for (int i = 0; i <= titles.length - 1; i++)
            this.columnTitles.add(titles[i].trim());
        this.seriesHeader.setGauge(this.river.getPeer().findGauge(this.seriesHeader.getGaugeNumber(), this.seriesHeader.getGaugeName()));
        if (this.seriesHeader.getGauge() == null) {
            logError("Gauge not found, file skipped");
            this.headerParsingState = ParsingState.STOP;
        }
        return true;
    }
}