/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You 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.

  */

 package org.apache.commons.validator.routines;

 import java.text.DateFormat;

 import java.text.Format;

 import java.util.Calendar;

 import java.util.Date;

 import java.util.Locale;

 import java.util.TimeZone;

 /**

  * <p><b>Date Validation</b> and Conversion routines (<code>java.util.Date</code>).</p>

  *

  * <p>This validator provides a number of methods for validating/converting

  *    a <code>String</code> date value to a <code>java.util.Date</code> using

  *    <code>java.text.DateFormat</code> to parse either:</p>

  *    <ul>

  *       <li>using the default format for the default <code>Locale</code></li>

  *       <li>using a specified pattern with the default <code>Locale</code></li>

  *       <li>using the default format for a specified <code>Locale</code></li>

  *       <li>using a specified pattern with a specified <code>Locale</code></li>

  *    </ul>

  *

  * <p>For each of the above mechanisms, conversion method (i.e the

  *    <code>validate</code> methods) implementations are provided which

  *    either use the default <code>TimeZone</code> or allow the

  *    <code>TimeZone</code> to be specified.</p>

  *

  * <p>Use one of the <code>isValid()</code> methods to just validate or

  *    one of the <code>validate()</code> methods to validate and receive a

  *    <i>converted</i> <code>Date</code> value.</p>

  *

  * <p>Implementations of the <code>validate()</code> method are provided

  *    to create <code>Date</code> objects for different <i>time zones</i>

  *    if the system default is not appropriate.</p>

  *

  * <p>Once a value has been successfully converted the following

  *    methods can be used to perform various date comparison checks:</p>

  *    <ul>

  *       <li><code>compareDates()</code> compares the day, month and

  *           year of two dates, returning 0, -1 or +1 indicating

  *           whether the first date is equal, before or after the second.</li>

  *       <li><code>compareWeeks()</code> compares the week and

  *           year of two dates, returning 0, -1 or +1 indicating

  *           whether the first week is equal, before or after the second.</li>

  *       <li><code>compareMonths()</code> compares the month and

  *           year of two dates, returning 0, -1 or +1 indicating

  *           whether the first month is equal, before or after the second.</li>

  *       <li><code>compareQuarters()</code> compares the quarter and

  *           year of two dates, returning 0, -1 or +1 indicating

  *           whether the first quarter is equal, before or after the second.</li>

  *       <li><code>compareYears()</code> compares the

  *           year of two dates, returning 0, -1 or +1 indicating

  *           whether the first year is equal, before or after the second.</li>

  *    </ul>

  *

  * <p>So that the same mechanism used for parsing an <i>input</i> value

  *    for validation can be used to format <i>output</i>, corresponding

  *    <code>format()</code> methods are also provided. That is you can

  *    format either:</p>

  *    <ul>

  *       <li>using a specified pattern</li>

  *       <li>using the format for a specified <code>Locale</code></li>

  *       <li>using the format for the <i>default</i> <code>Locale</code></li>

  *    </ul>

  *

  * @version $Revision: 1739356 $

  * @since Validator 1.3.0

  */

 public class DateValidator extends AbstractCalendarValidator {

     private static final long serialVersionUID = -3966328400469953190L;

     private static final DateValidator VALIDATOR = new DateValidator();

     /**

      * Return a singleton instance of this validator.

      * @return A singleton instance of the DateValidator.

      */

     public static DateValidator getInstance() {

         return VALIDATOR;

     }

     /**

      * Construct a <i>strict</i> instance with <i>short</i>

      * date style.

      */

     public DateValidator() {

         this(true, DateFormat.SHORT);

     }

     /**

      * Construct an instance with the specified <i>strict</i>

      * and <i>date style</i> parameters.

      *

      * @param strict <code>true</code> if strict

      *        <code>Format</code> parsing should be used.

      * @param dateStyle the date style to use for Locale validation.

      */

     public DateValidator(boolean strict, int dateStyle) {

         super(strict, dateStyle, -1);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the default

      *    <code>Locale</code> and <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @return The parsed <code>Date</code> if valid or <code>null</code>

      *  if invalid.

      */

     public Date validate(String value) {

         return (Date)parse(value, (String)null, (Locale)null, (TimeZone)null);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    <code>TimeZone</code> and default <code>Locale</code>.

      *

      * @param value The value validation is being performed on.

      * @param timeZone The Time Zone used to parse the date, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, TimeZone timeZone) {

         return (Date)parse(value, (String)null, (Locale)null, timeZone);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    <i>pattern</i> and default <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param pattern The pattern used to validate the value against, or the

      *        default for the <code>Locale</code> if <code>null</code>.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, String pattern) {

         return (Date)parse(value, pattern, (Locale)null, (TimeZone)null);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    <i>pattern</i> and <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param pattern The pattern used to validate the value against, or the

      *        default for the <code>Locale</code> if <code>null</code>.

      * @param timeZone The Time Zone used to parse the date, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, String pattern, TimeZone timeZone) {

         return (Date)parse(value, pattern, (Locale)null, timeZone);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    <code>Locale</code> and default <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param locale The locale to use for the date format, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, Locale locale) {

         return (Date)parse(value, (String)null, locale, (TimeZone)null);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    <code>Locale</code> and <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param locale The locale to use for the date format, system default if null.

      * @param timeZone The Time Zone used to parse the date, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, Locale locale, TimeZone timeZone) {

         return (Date)parse(value, (String)null, locale, timeZone);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified pattern

      *    and <code>Locale</code> and the default <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param pattern The pattern used to validate the value against, or the

      *        default for the <code>Locale</code> if <code>null</code>.

      * @param locale The locale to use for the date format, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, String pattern, Locale locale) {

         return (Date)parse(value, pattern, locale, (TimeZone)null);

     }

     /**

      * <p>Validate/convert a <code>Date</code> using the specified

      *    pattern, and <code>Locale</code> and <code>TimeZone</code>.

      *

      * @param value The value validation is being performed on.

      * @param pattern The pattern used to validate the value against, or the

      *        default for the <code>Locale</code> if <code>null</code>.

      * @param locale The locale to use for the date format, system default if null.

      * @param timeZone The Time Zone used to parse the date, system default if null.

      * @return The parsed <code>Date</code> if valid or <code>null</code> if invalid.

      */

     public Date validate(String value, String pattern, Locale locale, TimeZone timeZone) {

         return (Date)parse(value, pattern, locale, timeZone);

     }

     /**

      * <p>Compare Dates (day, month and year - not time).</p>

      *

      * @param value The <code>Calendar</code> value to check.

      * @param compare The <code>Calendar</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @return Zero if the dates are equal, -1 if first

      * date is less than the seconds and +1 if the first

      * date is greater than.

      */

     public int compareDates(Date value, Date compare, TimeZone timeZone) {

         Calendar calendarValue   = getCalendar(value, timeZone);

         Calendar calendarCompare = getCalendar(compare, timeZone);

         return compare(calendarValue, calendarCompare, Calendar.DATE);

     }

     /**

      * <p>Compare Weeks (week and year).</p>

      *

      * @param value The <code>Date</code> value to check.

      * @param compare The <code>Date</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @return Zero if the weeks are equal, -1 if first

      * parameter's week is less than the seconds and +1 if the first

      * parameter's week is greater than.

      */

     public int compareWeeks(Date value, Date compare, TimeZone timeZone) {

         Calendar calendarValue   = getCalendar(value, timeZone);

         Calendar calendarCompare = getCalendar(compare, timeZone);

         return compare(calendarValue, calendarCompare, Calendar.WEEK_OF_YEAR);

     }

     /**

      * <p>Compare Months (month and year).</p>

      *

      * @param value The <code>Date</code> value to check.

      * @param compare The <code>Date</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @return Zero if the months are equal, -1 if first

      * parameter's month is less than the seconds and +1 if the first

      * parameter's month is greater than.

      */

     public int compareMonths(Date value, Date compare, TimeZone timeZone) {

         Calendar calendarValue   = getCalendar(value, timeZone);

         Calendar calendarCompare = getCalendar(compare, timeZone);

         return compare(calendarValue, calendarCompare, Calendar.MONTH);

     }

     /**

      * <p>Compare Quarters (quarter and year).</p>

      *

      * @param value The <code>Date</code> value to check.

      * @param compare The <code>Date</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @return Zero if the months are equal, -1 if first

      * parameter's quarter is less than the seconds and +1 if the first

      * parameter's quarter is greater than.

      */

     public int compareQuarters(Date value, Date compare, TimeZone timeZone) {

         return compareQuarters(value, compare, timeZone, 1);

     }

     /**

      * <p>Compare Quarters (quarter and year).</p>

      *

      * @param value The <code>Date</code> value to check.

      * @param compare The <code>Date</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @param monthOfFirstQuarter The  month that the first quarter starts.

      * @return Zero if the quarters are equal, -1 if first

      * parameter's quarter is less than the seconds and +1 if the first

      * parameter's quarter is greater than.

      */

     public int compareQuarters(Date value, Date compare, TimeZone timeZone, int monthOfFirstQuarter) {

         Calendar calendarValue   = getCalendar(value, timeZone);

         Calendar calendarCompare = getCalendar(compare, timeZone);

         return super.compareQuarters(calendarValue, calendarCompare, monthOfFirstQuarter);

     }

     /**

      * <p>Compare Years.</p>

      *

      * @param value The <code>Date</code> value to check.

      * @param compare The <code>Date</code> to compare the value to.

      * @param timeZone The Time Zone used to compare the dates, system default if null.

      * @return Zero if the years are equal, -1 if first

      * parameter's year is less than the seconds and +1 if the first

      * parameter's year is greater than.

      */

     public int compareYears(Date value, Date compare, TimeZone timeZone) {

         Calendar calendarValue   = getCalendar(value, timeZone);

         Calendar calendarCompare = getCalendar(compare, timeZone);

         return compare(calendarValue, calendarCompare, Calendar.YEAR);

     }

     /**

      * <p>Returns the parsed <code>Date</code> unchanged.</p>

      *

      * @param value The parsed <code>Date</code> object created.

      * @param formatter The Format used to parse the value with.

      * @return The parsed value converted to a <code>Calendar</code>.

      */

     @Override

     protected Object processParsedValue(Object value, Format formatter) {

         return value;

     }

     /**

      * <p>Convert a <code>Date</code> to a <code>Calendar</code>.</p>

      *

      * @param value The date value to be converted.

      * @return The converted <code>Calendar</code>.

      */

     private Calendar getCalendar(Date value, TimeZone timeZone) {

         Calendar calendar = null;

         if (timeZone != null) {

             calendar = Calendar.getInstance(timeZone);

         } else {

             calendar = Calendar.getInstance();

         }

         calendar.setTime(value);

         return calendar;

     }

 }