EDIT

/**

* Copyright (C) 2007 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.strategy.parser;

import java.text.DateFormat;

import java.text.ParsePosition;

import java.util.Calendar;

import java.util.Date;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;

import org.apache.log4j.Logger;

import org.joda.time.DateTime;

import org.joda.time.DateTimeFieldType;

import org.joda.time.Partial;

import eu.etaxonomy.cdm.common.CdmUtils;

import eu.etaxonomy.cdm.common.UTF8;

import eu.etaxonomy.cdm.model.common.TimePeriod;

/**

 * Class for parsing all types of date string to TimePeriod

 * @author a.mueller

 * @created 14-Jul-2013

 */

public class TimePeriodParser {

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

	//patter for first year in string;

	private static final Pattern firstYearPattern =  Pattern.compile("\\d{4}");

	//case "1806"[1807];

	private static final Pattern uncorrectYearPatter =  Pattern.compile("[\""+UTF8.ENGLISH_QUOT_START+"]\\d{4}[\""+UTF8.ENGLISH_QUOT_END+"]\\s*\\[\\d{4}\\]");

	//case fl. 1806 or c. 1806 or fl. 1806?

	private static final Pattern prefixedYearPattern =  Pattern.compile("(fl|c)\\.\\s*\\d{4}(\\s*-\\s*\\d{4})?\\??");

	//standard

	private static final Pattern standardPattern =  Pattern.compile("\\s*\\d{2,4}(\\s*-(\\s*\\d{2,4})?)?");

	private static final String strDotDate = "[0-3]?\\d\\.[01]?\\d\\.\\d{4,4}";

	private static final String strDotDatePeriodPattern = String.format("%s(\\s*-\\s*%s?)?", strDotDate, strDotDate);

	private static final Pattern dotDatePattern =  Pattern.compile(strDotDatePeriodPattern);

	private static final Pattern lifeSpanPattern =  Pattern.compile(String.format("%s--%s", firstYearPattern, firstYearPattern));

	public static TimePeriod parseString(TimePeriod timePeriod, String periodString){

		//TODO move to parser class

		//TODO until now only quick and dirty (and partly wrong)

		TimePeriod result = timePeriod;

		if(timePeriod == null){

			return timePeriod;

		}

		if (periodString == null){

			return result;

		}

		periodString = periodString.trim();

		result.setFreeText(null);

		Date date;

		//case "1806"[1807];

		if (uncorrectYearPatter.matcher(periodString).matches()){

			result.setFreeText(periodString);

			String realYear = periodString.split("\\[")[1];

			realYear = realYear.replace("]", "");

			result.setStartYear(Integer.valueOf(realYear));

			result.setFreeText(periodString);

		//case fl. 1806 or c. 1806 or fl. 1806?

		}else if(prefixedYearPattern.matcher(periodString).matches()){

			result.setFreeText(periodString);

			Matcher yearMatcher = firstYearPattern.matcher(periodString);

			yearMatcher.find();

			String startYear = yearMatcher.group();

			result.setStartYear(Integer.valueOf(startYear));

			if (yearMatcher.find()){

				String endYear = yearMatcher.group();

				result.setEndYear(Integer.valueOf(endYear));

			}

		}else if (dotDatePattern.matcher(periodString).matches()){

			parseDotDatePattern(periodString, result);

		}else if (lifeSpanPattern.matcher(periodString).matches()){

			parseLifeSpanPattern(periodString, result);

		}else if (standardPattern.matcher(periodString).matches()){

			parseStandardPattern(periodString, result);

//TODO first check ambiguity of parser results e.g. for 7/12/11

//			}else if (isDateString(periodString)){

//				String[] startEnd = makeStartEnd(periodString);

//				String start = startEnd[0];

//				DateTime startDateTime = dateStringParse(start, true);

//				result.setStart(startDateTime);

//				if (startEnd.length > 1){

//					DateTime endDateTime = dateStringParse(startEnd[1], true);

//					;

//					result.setEnd(endDateTime.toLocalDate());

//				}

		}else{

			result.setFreeText(periodString);

		}

		return result;

	}

	private static boolean isDateString(String periodString) {

		String[] startEnd = makeStartEnd(periodString);

		String start = startEnd[0];

		DateTime startDateTime = dateStringParse(start, true);

		if (startDateTime == null){

			return false;

		}

		if (startEnd.length > 1){

			DateTime endDateTime = dateStringParse(startEnd[1], true);

			if (endDateTime != null){

				return true;

			}

		}

		return false;

	}

	/**

	 * @param periodString

	 * @return

	 */

	private static String[] makeStartEnd(String periodString) {

		String[] startEnd = new String[]{periodString};

		if (periodString.contains("-") && periodString.matches("^-{2,}-^-{2,}")){

			startEnd = periodString.split("-");

		}

		return startEnd;

	}

	private static DateTime dateStringParse(String string, boolean strict) {

		DateFormat dateFormat = DateFormat.getDateInstance();

		ParsePosition pos = new ParsePosition(0);

		Date a = dateFormat.parse(string, pos);

		if (a == null || pos.getIndex() != string.length()){

			return null;

		}

		Calendar cal = Calendar.getInstance();

		cal.setTime(a);

		DateTime result = new DateTime(cal);

		return result;

	}

	/**

	 * @param periodString

	 * @param result

	 */

	private static void parseDotDatePattern(String periodString,TimePeriod result) {

		String[] dates = periodString.split("-");

		Partial dtStart = null;

		Partial dtEnd = null;

		if (dates.length > 2 || dates.length <= 0){

			logger.warn("More than 1 '-' in period String: " + periodString);

			result.setFreeText(periodString);

		}else {

			try {

				//start

				if (! StringUtils.isBlank(dates[0])){

					dtStart = parseSingleDotDate(dates[0].trim());

				}

				//end

				if (dates.length >= 2 && ! StringUtils.isBlank(dates[1])){

					dtEnd = parseSingleDotDate(dates[1].trim());

				}

				result.setStart(dtStart);

				result.setEnd(dtEnd);

			} catch (IllegalArgumentException e) {

				//logger.warn(e.getMessage());

				result.setFreeText(periodString);

			}

		}

	}

	private static void parseLifeSpanPattern(String periodString, TimePeriod result) {

		try{

			String[] years = periodString.split("--");

			String start = years[0];

			String end = years[1];

			result.setStartYear(Integer.valueOf(start));

			result.setEndYear(Integer.valueOf(end));

		} catch (Exception e) {

			//logger.warn(e.getMessage());

			result.setFreeText(periodString);

		}

	}

	/**

	 * @param periodString

	 * @param result

	 */

	private static void parseStandardPattern(String periodString,

			TimePeriod result) {

		String[] years = periodString.split("-");

		Partial dtStart = null;

		Partial dtEnd = null;

		if (years.length > 2 || years.length <= 0){

			logger.warn("More than 1 '-' in period String: " + periodString);

		}else {

			try {

				//start

				if (! CdmUtils.isEmpty(years[0])){

					dtStart = parseSingleDate(years[0].trim());

				}

				//end

				if (years.length >= 2 && ! CdmUtils.isEmpty(years[1])){

					years[1] = years[1].trim();

					if (years[1].length()==2 && dtStart != null && dtStart.isSupported(DateTimeFieldType.year())){

						years[1] = String.valueOf(dtStart.get(DateTimeFieldType.year())/100) + years[1];

					}

					dtEnd = parseSingleDate(years[1]);

				}

				result.setStart(dtStart);

				result.setEnd(dtEnd);

			} catch (IllegalArgumentException e) {

				//logger.warn(e.getMessage());

				result.setFreeText(periodString);

			}

		}

	}

	public static TimePeriod parseString(String strPeriod) {

		TimePeriod timePeriod = TimePeriod.NewInstance();

		return parseString(timePeriod, strPeriod);

	}

	protected static Partial parseSingleDate(String singleDateString) throws IllegalArgumentException{

		//FIXME until now only quick and dirty and incomplete

		Partial partial =  new Partial();

		singleDateString = singleDateString.trim();

		if (CdmUtils.isNumeric(singleDateString)){

			try {

				Integer year = Integer.valueOf(singleDateString.trim());

				if (year < 1000 && year > 2100){

					logger.warn("Not a valid year: " + year + ". Year must be between 1000 and 2100");

				}else if (year < 1700 && year > 2100){

					logger.warn("Not a valid taxonomic year: " + year + ". Year must be between 1750 and 2100");

					partial = partial.with(TimePeriod.YEAR_TYPE, year);

				}else{

					partial = partial.with(TimePeriod.YEAR_TYPE, year);

				}

			} catch (NumberFormatException e) {

				logger.debug("Not a Integer format in getCalendar()");

				throw new IllegalArgumentException(e);

			}

		}else{

			throw new IllegalArgumentException("Until now only years can be parsed as single dates. But date is: " + singleDateString);

		}

		return partial;

	}

	protected static Partial parseSingleDotDate(String singleDateString) throws IllegalArgumentException{

		Partial partial =  new Partial();

		singleDateString = singleDateString.trim();

		String[] split = singleDateString.split("\\.");

		int length = split.length;

		if (length > 3){

			throw new IllegalArgumentException(String.format("More than 2 dots in date '%s'", singleDateString));

		}

		String strYear = split[split.length-1];

		String strMonth = length >= 2? split[split.length-2]: null;

		String strDay = length >= 3? split[split.length-3]: null;

		try {

			Integer year = Integer.valueOf(strYear.trim());

			Integer month = Integer.valueOf(strMonth.trim());

			Integer day = Integer.valueOf(strDay.trim());

			if (year < 1000 && year > 2100){

				logger.warn("Not a valid year: " + year + ". Year must be between 1000 and 2100");

			}else if (year < 1700 && year > 2100){

				logger.warn("Not a valid taxonomic year: " + year + ". Year must be between 1750 and 2100");

				partial = partial.with(TimePeriod.YEAR_TYPE, year);

			}else{

				partial = partial.with(TimePeriod.YEAR_TYPE, year);

			}

			if (month != null && month != 0){

				partial = partial.with(TimePeriod.MONTH_TYPE, month);

			}

			if (day != null && day != 0){

				partial = partial.with(TimePeriod.DAY_TYPE, day);

			}

		} catch (NumberFormatException e) {

			logger.debug("Not a Integer format somewhere in " + singleDateString);

			throw new IllegalArgumentException(e);

		}

		return partial;

	}

}