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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

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/*

 * Copyright 1999-2004 The Apache Software Foundation.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/*

 * $Id: ExsltDatetime.java,v 1.2.4.1 2005/09/10 18:50:49 jeffsuttor Exp $

 */

package com.sun.org.apache.xalan.internal.lib;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.util.Locale;

import java.util.TimeZone;

import com.sun.org.apache.xpath.internal.objects.XBoolean;

import com.sun.org.apache.xpath.internal.objects.XNumber;

import com.sun.org.apache.xpath.internal.objects.XObject;

/**

 * This class contains EXSLT dates and times extension functions.

 * It is accessed by specifying a namespace URI as follows:

 * <pre>

 *    xmlns:datetime="http://exslt.org/dates-and-times"

 * </pre>

 *

 * The documentation for each function has been copied from the relevant

 * EXSLT Implementer page.

 *

 * @see <a href="http://www.exslt.org/">EXSLT</a>

 * @xsl.usage general

 */

public class ExsltDatetime

{

    // Datetime formats (era and zone handled separately).

    static final String dt = "yyyy-MM-dd'T'HH:mm:ss";

    static final String d = "yyyy-MM-dd";

    static final String gym = "yyyy-MM";

    static final String gy = "yyyy";

    static final String gmd = "--MM-dd";

    static final String gm = "--MM--";

    static final String gd = "---dd";

    static final String t = "HH:mm:ss";

    static final String EMPTY_STR = "";

    /**

     * The date:date-time function returns the current date and time as a date/time string.

     * The date/time string that's returned must be a string in the format defined as the

     * lexical representation of xs:dateTime in

     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and

     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details.

     * The date/time string format must include a time zone, either a Z to indicate Coordinated

     * Universal Time or a + or - followed by the difference between the difference from UTC

     * represented as hh:mm.

     */

    public static String dateTime()

    {

      Calendar cal = Calendar.getInstance();

      Date datetime = cal.getTime();

      // Format for date and time.

      SimpleDateFormat dateFormat = new SimpleDateFormat(dt);

      StringBuffer buff = new StringBuffer(dateFormat.format(datetime));

      // Must also include offset from UTF.

      // Get the offset (in milliseconds).

      int offset = cal.get(Calendar.ZONE_OFFSET) + cal.get(Calendar.DST_OFFSET);

      // If there is no offset, we have "Coordinated

      // Universal Time."

      if (offset == 0)

        buff.append("Z");

      else

      {

        // Convert milliseconds to hours and minutes

        int hrs = offset/(60*60*1000);

        // In a few cases, the time zone may be +/-hh:30.

        int min = offset%(60*60*1000);

        char posneg = hrs < 0? '-': '+';

        buff.append(posneg).append(formatDigits(hrs)).append(':').append(formatDigits(min));

      }

      return buff.toString();

    }

    /**

     * Represent the hours and minutes with two-digit strings.

     * @param q hrs or minutes.

     * @return two-digit String representation of hrs or minutes.

     */

    private static String formatDigits(int q)

    {

      String dd = String.valueOf(Math.abs(q));

      return dd.length() == 1 ? '0' + dd : dd;

    }

    /**

     * The date:date function returns the date specified in the date/time string given

     * as the argument. If no argument is given, then the current local date/time, as

     * returned by date:date-time is used as a default argument.

     * The date/time string that's returned must be a string in the format defined as the

     * lexical representation of xs:dateTime in

     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * If the argument is not in either of these formats, date:date returns an empty string ('').

     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and

     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details.

     * The date is returned as a string with a lexical representation as defined for xs:date in

     * [3.2.9 date] of [XML Schema Part 2: Datatypes]. The date format is basically CCYY-MM-DD,

     * although implementers should consult [XML Schema Part 2: Datatypes] and [ISO 8601] for details.

     * If no argument is given or the argument date/time specifies a time zone, then the date string

     * format must include a time zone, either a Z to indicate Coordinated Universal Time or a + or -

     * followed by the difference between the difference from UTC represented as hh:mm. If an argument

     * is specified and it does not specify a time zone, then the date string format must not include

     * a time zone.

     */

    public static String date(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String leader = edz[0];

      String datetime = edz[1];

      String zone = edz[2];

      if (datetime == null || zone == null)

        return EMPTY_STR;

      String[] formatsIn = {dt, d};

      String formatOut = d;

      Date date = testFormats(datetime, formatsIn);

      if (date == null) return EMPTY_STR;

      SimpleDateFormat dateFormat = new SimpleDateFormat(formatOut);

      dateFormat.setLenient(false);

      String dateOut = dateFormat.format(date);

      if (dateOut.length() == 0)

          return EMPTY_STR;

      else

        return (leader + dateOut + zone);

    }

    /**

     * See above.

     */

    public static String date()

    {

      String datetime = dateTime().toString();

      String date = datetime.substring(0, datetime.indexOf("T"));

      String zone = datetime.substring(getZoneStart(datetime));

      return (date + zone);

    }

    /**

     * The date:time function returns the time specified in the date/time string given

     * as the argument. If no argument is given, then the current local date/time, as

     * returned by date:date-time is used as a default argument.

     * The date/time string that's returned must be a string in the format defined as the

     * lexical representation of xs:dateTime in

     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * If the argument string is not in this format, date:time returns an empty string ('').

     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and

     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details.

     * The date is returned as a string with a lexical representation as defined for xs:time in

     * <a href="http://www.w3.org/TR/xmlschema-2/#time">[3.2.8 time]</a> of [XML Schema Part 2: Datatypes].

     * The time format is basically hh:mm:ss, although implementers should consult [XML Schema Part 2:

     * Datatypes] and [ISO 8601] for details.

     * If no argument is given or the argument date/time specifies a time zone, then the time string

     * format must include a time zone, either a Z to indicate Coordinated Universal Time or a + or -

     * followed by the difference between the difference from UTC represented as hh:mm. If an argument

     * is specified and it does not specify a time zone, then the time string format must not include

     * a time zone.

     */

    public static String time(String timeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(timeIn);

      String time = edz[1];

      String zone = edz[2];

      if (time == null || zone == null)

        return EMPTY_STR;

      String[] formatsIn = {dt, d, t};

      String formatOut =  t;

      Date date = testFormats(time, formatsIn);

      if (date == null) return EMPTY_STR;

      SimpleDateFormat dateFormat = new SimpleDateFormat(formatOut);

      String out = dateFormat.format(date);

      return (out + zone);

    }

    /**

     * See above.

     */

    public static String time()

    {

      String datetime = dateTime().toString();

      String time = datetime.substring(datetime.indexOf("T")+1);

          // The datetime() function returns the zone on the datetime string.  If we

          // append it, we get the zone substring duplicated.

          // Fix for JIRA 2013

      // String zone = datetime.substring(getZoneStart(datetime));

      // return (time + zone);

      return (time);

    }

    /**

     * The date:year function returns the year of a date as a number. If no

     * argument is given, then the current local date/time, as returned by

     * date:date-time is used as a default argument.

     * The date/time string specified as the first argument must be a right-truncated

     * string in the format defined as the lexical representation of xs:dateTime in one

     * of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *   xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *   xs:date (CCYY-MM-DD)

     *   xs:gYearMonth (CCYY-MM)

     *   xs:gYear (CCYY)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double year(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      boolean ad = edz[0].length() == 0; // AD (Common Era -- empty leader)

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, d, gym, gy};

      double yr = getNumber(datetime, formats, Calendar.YEAR);

      if (ad || yr == Double.NaN)

        return yr;

      else

        return -yr;

    }

    /**

     * See above.

     */

    public static double year()

    {

      Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.YEAR);

    }

    /**

     * The date:month-in-year function returns the month of a date as a number. If no argument

     * is given, then the current local date/time, as returned by date:date-time is used

     * as a default argument.

     * The date/time string specified as the first argument is a left or right-truncated

     * string in the format defined as the lexical representation of xs:dateTime in one of

     * the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *    xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *    xs:date (CCYY-MM-DD)

     *    xs:gYearMonth (CCYY-MM)

     *    xs:gMonth (--MM--)

     *    xs:gMonthDay (--MM-DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double monthInYear(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, d, gym, gm, gmd};

      return getNumber(datetime, formats, Calendar.MONTH) + 1;

    }

    /**

     * See above.

     */

    public static double monthInYear()

    {

      Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.MONTH) + 1;

   }

    /**

     * The date:week-in-year function returns the week of the year as a number. If no argument

     * is given, then the current local date/time, as returned by date:date-time is used as the

     * default argument. For the purposes of numbering, counting follows ISO 8601: week 1 in a year

     * is the week containing the first Thursday of the year, with new weeks beginning on a Monday.

     * The date/time string specified as the argument is a right-truncated string in the format

     * defined as the lexical representation of xs:dateTime in one of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>. The

     * permitted formats are as follows:

     *    xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *    xs:date (CCYY-MM-DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double weekInYear(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, d};

      return getNumber(datetime, formats, Calendar.WEEK_OF_YEAR);

    }

    /**

     * See above.

     */

    public static double weekInYear()

    {

       Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.WEEK_OF_YEAR);

   }

    /**

     * The date:day-in-year function returns the day of a date in a year

     * as a number. If no argument is given, then the current local

     * date/time, as returned by date:date-time is used the default argument.

     * The date/time string specified as the argument is a right-truncated

     * string in the format defined as the lexical representation of xs:dateTime

     * in one of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *     xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *     xs:date (CCYY-MM-DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double dayInYear(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, d};

      return getNumber(datetime, formats, Calendar.DAY_OF_YEAR);

    }

    /**

     * See above.

     */

    public static double dayInYear()

    {

       Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.DAY_OF_YEAR);

   }

    /**

     * The date:day-in-month function returns the day of a date as a number.

     * If no argument is given, then the current local date/time, as returned

     * by date:date-time is used the default argument.

     * The date/time string specified as the argument is a left or right-truncated

     * string in the format defined as the lexical representation of xs:dateTime

     * in one of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *      xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *      xs:date (CCYY-MM-DD)

     *      xs:gMonthDay (--MM-DD)

     *      xs:gDay (---DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double dayInMonth(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      String[] formats = {dt, d, gmd, gd};

      double day = getNumber(datetime, formats, Calendar.DAY_OF_MONTH);

      return day;

    }

    /**

     * See above.

     */

    public static double dayInMonth()

    {

      Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.DAY_OF_MONTH);

   }

    /**

     * The date:day-of-week-in-month function returns the day-of-the-week

     * in a month of a date as a number (e.g. 3 for the 3rd Tuesday in May).

     * If no argument is given, then the current local date/time, as returned

     * by date:date-time is used the default argument.

     * The date/time string specified as the argument is a right-truncated string

     * in the format defined as the lexical representation of xs:dateTime in one

     * of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *      xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *      xs:date (CCYY-MM-DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double dayOfWeekInMonth(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats =  {dt, d};

      return getNumber(datetime, formats, Calendar.DAY_OF_WEEK_IN_MONTH);

    }

    /**

     * See above.

     */

    public static double dayOfWeekInMonth()

    {

       Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.DAY_OF_WEEK_IN_MONTH);

   }

    /**

     * The date:day-in-week function returns the day of the week given in a

     * date as a number. If no argument is given, then the current local date/time,

     * as returned by date:date-time is used the default argument.

     * The date/time string specified as the argument is a right-truncated string

     * in the format defined as the lexical representation of xs:dateTime in one

     * of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *      xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *      xs:date (CCYY-MM-DD)

     * If the date/time string is not in one of these formats, then NaN is returned.

                            The numbering of days of the week starts at 1 for Sunday, 2 for Monday and so on up to 7 for Saturday.

     */

    public static double dayInWeek(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, d};

      return getNumber(datetime, formats, Calendar.DAY_OF_WEEK);

    }

    /**

     * See above.

     */

    public static double dayInWeek()

    {

       Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.DAY_OF_WEEK);

   }

    /**

     * The date:hour-in-day function returns the hour of the day as a number.

     * If no argument is given, then the current local date/time, as returned

     * by date:date-time is used the default argument.

     * The date/time string specified as the argument is a right-truncated

     * string  in the format defined as the lexical representation of xs:dateTime

     * in one of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *     xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *     xs:time (hh:mm:ss)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double hourInDay(String datetimeIn)

      throws ParseException

    {

      String[] edz = getEraDatetimeZone(datetimeIn);

      String datetime = edz[1];

      if (datetime == null)

        return Double.NaN;

      String[] formats = {dt, t};

      return getNumber(datetime, formats, Calendar.HOUR_OF_DAY);

    }

    /**

     * See above.

     */

    public static double hourInDay()

    {

       Calendar cal = Calendar.getInstance();

      return cal.get(Calendar.HOUR_OF_DAY);

   }

    /**

     * The date:minute-in-hour function returns the minute of the hour

     * as a number. If no argument is given, then the current local

     * date/time, as returned by date:date-time is used the default argument.

     * The date/time string specified as the argument is a right-truncated

     * string in the format defined as the lexical representation of xs:dateTime

     * in one of the formats defined in

     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.

     * The permitted formats are as follows:

     *      xs:dateTime (CCYY-MM-DDThh:mm:ss)

     *      xs:time (hh:mm:ss)

     * If the date/time string is not in one of these formats, then NaN is returned.

     */

    public static double minuteInHour(String datetimeIn)