EDIT

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.vaadin.util.converter;

import java.util.Arrays;

import java.util.List;

import java.util.Locale;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;

import org.joda.time.DateTimeFieldType;

import org.joda.time.Partial;

import com.vaadin.data.util.converter.Converter;

/**

 *

 * @author a.kohlbecker

 * @since Apr 7, 2017

 *

 */

public class JodaTimePartialConverter implements Converter<String, Partial> {

    /**

     * iso8601: YYY-MM-DD

     * yyyymmddDot: dd.mm.yyyy

     *

     * @author a.kohlbecker

     * @since Apr 10, 2017

     *

     */

    public enum DateFormat {

        ISO8601,

        DAY_MONTH_YEAR_DOT

    }

    private static final long serialVersionUID = 976413549472527584L;

    DateFormat format;

    Pattern partialPatternIso8601 = Pattern.compile("^(?<year>(?:[1,2][7,8,9,0,1])?[0-9]{2})(?:-(?<month>[0-1]?[0-9])(?:-(?<day>[0-3]?[0-9]))?)?$");

    Pattern partialPatternDayMonthYearDot = Pattern.compile("^(?:(?:(?<day>[0-3]?[0-9])\\.)?(?<month>[0-1]?[0-9])\\.)?(?<year>(?:[1,2][7,8,9,0,1])?[0-9]{2})$");

    List<Pattern> patterns = Arrays.asList(new Pattern[]{partialPatternIso8601, partialPatternDayMonthYearDot});

    /**

     * @param format The format of the string representation

     */

    public JodaTimePartialConverter(DateFormat format) {

        super();

        this.format = format;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public Partial convertToModel(String value, Class<? extends Partial> targetType, Locale locale)

            throws com.vaadin.data.util.converter.Converter.ConversionException {

        Partial partial = null;

        if(value != null){

            partial = new Partial();

            for(Pattern pattern : patterns){

            Matcher m = pattern.matcher(value);

                if(m.matches()){

                    partial = makePartial(m);

                    break;

                }

            }

        }

        return partial;

    }

    /**

     * @param partial

     * @param m

     */

    private Partial makePartial(Matcher m) {

        Partial partial = new Partial();

        try {

            try {

                String year = m.group("year");

                partial = partial.with(DateTimeFieldType.year(), Integer.parseInt(year));

            } catch (IllegalArgumentException e) {

                // a valid year should be present here

                throw new ConversionException(e);

            }

            try {

                String month = m.group("month");

                partial = partial.with(DateTimeFieldType.monthOfYear(), Integer.parseInt(month));

                try {

                    String day = m.group("day");

                    partial = partial.with(DateTimeFieldType.dayOfMonth(), Integer.parseInt(day));

                } catch (IllegalArgumentException e) {

                    /* IGNORE days are not required */

                }

            } catch (IllegalArgumentException e) {

                /* IGNORE months are not required */

            }

        } catch (NumberFormatException ne) {

            // all numbers should be parsable, this is guaranteed by the partialPattern

            throw new ConversionException(ne);

        }

        return partial;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public String convertToPresentation(Partial value, Class<? extends String> targetType, Locale locale)

            throws com.vaadin.data.util.converter.Converter.ConversionException {

        if(value != null){

            switch(format) {

            case ISO8601:

                return formatIso8601(value);

            case DAY_MONTH_YEAR_DOT:

                return formatYyyymmddDot(value);

            default:

                return "JodaTimePartialConverter Error: unsupported format";

           }

        }

        return "";

    }

    /**

     * @param value

     * @param sb

     */

    private String formatIso8601(Partial value) {

        StringBuffer sb = new StringBuffer();

        String glue = "-";

        try {

            sb.append(value.get(DateTimeFieldType.year()));

            try {

                String month = StringUtils.leftPad(Integer.toString((value.get(DateTimeFieldType.monthOfYear()))), 2, "0");

                sb.append(glue).append(month);

                try {

                    String day = StringUtils.leftPad(Integer.toString((value.get(DateTimeFieldType.dayOfMonth()))), 2, "0");

                    sb.append(glue).append(day);

                } catch (IllegalArgumentException e){

                    /* IGNORE */

                }

            } catch (IllegalArgumentException e){

                /* IGNORE */

            }

        } catch (IllegalArgumentException e){

            /* IGNORE */

        }

        return sb.toString();

    }

    /**

     * @param value

     * @param sb

     */

    private String formatYyyymmddDot(Partial value) {

        StringBuffer sb = new StringBuffer();

        String glue = ".";

        try {

            sb.append(StringUtils.reverse(Integer.toString(value.get(DateTimeFieldType.year()))));

            try {

                String month = StringUtils.leftPad(Integer.toString((value.get(DateTimeFieldType.monthOfYear()))), 2, "0");

                sb.append(glue).append(StringUtils.reverse(month));

                try {

                    String day = StringUtils.leftPad(Integer.toString((value.get(DateTimeFieldType.dayOfMonth()))), 2, "0");

                    sb.append(glue).append(StringUtils.reverse(day));

                } catch (IllegalArgumentException e){

                    /* IGNORE */

                }

            } catch (IllegalArgumentException e){

                /* IGNORE */

            }

        } catch (IllegalArgumentException e){

            /* IGNORE */

        }

        return StringUtils.reverse(sb.toString());

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public Class<Partial> getModelType() {

        return Partial.class;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public Class<String> getPresentationType() {

        return String.class;

    }

}