/*
    * 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
    *
    *      https://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.Format;
  import java.text.NumberFormat;
  import java.util.Locale;
  
  /**
   * <p><strong>Integer Validation</strong> and Conversion routines ({{@link Integer}).</p>
   *
   * <p>This validator provides a number of methods for
   *    validating/converting a {@link String} value to
   *    a {@code Integer} using {@link NumberFormat}
   *    to parse either:</p>
   *    <ul>
   *       <li>using the default format for the default {@link Locale}</li>
   *       <li>using a specified pattern with the default {@link Locale}</li>
   *       <li>using the default format for a specified {@link Locale}</li>
   *       <li>using a specified pattern with a specified {@link Locale}</li>
   *    </ul>
   *
   * <p>Use one of the {@code isValid()} methods to just validate or
   *    one of the {@code validate()} methods to validate and receive a
   *    <em>converted</em> {@code Integer} value.</p>
   *
   * <p>Once a value has been successfully converted the following
   *    methods can be used to perform minimum, maximum and range checks:</p>
   *    <ul>
   *       <li>{@code minValue()} checks whether the value is greater
   *           than or equal to a specified minimum.</li>
   *       <li>{@code maxValue()} checks whether the value is less
   *           than or equal to a specified maximum.</li>
   *       <li>{@code isInRange()} checks whether the value is within
   *           a specified range of values.</li>
   *    </ul>
   *
   * <p>So that the same mechanism used for parsing an <em>input</em> value
   *    for validation can be used to format <em>output</em>, corresponding
   *    {@code format()} methods are also provided. That is you can
   *    format either:</p>
   *    <ul>
   *       <li>using the default format for the default {@link Locale}</li>
   *       <li>using a specified pattern with the default {@link Locale}</li>
   *       <li>using the default format for a specified {@link Locale}</li>
   *       <li>using a specified pattern with a specified {@link Locale}</li>
   *    </ul>
   *
   * @since 1.3.0
   */
  public class IntegerValidator extends AbstractNumberValidator {
  
      private static final long serialVersionUID = 422081746310306596L;
  
      private static final IntegerValidator VALIDATOR = new IntegerValidator();
  
      /**
       * Gets the singleton instance of this validator.
       *
       * @return A singleton instance of the IntegerValidator.
       */
      public static IntegerValidator getInstance() {
          return VALIDATOR;
      }
  
      /**
       * Constructs a <em>strict</em> instance.
       */
      public IntegerValidator() {
          this(true, STANDARD_FORMAT);
      }
  
      /**
       * <p>Construct an instance with the specified strict setting
       *    and format type.</p>
       *
       * <p>The {@code formatType} specified what type of
       *    {@code NumberFormat} is created - valid types
       *    are:</p>
       *    <ul>
       *       <li>AbstractNumberValidator.STANDARD_FORMAT -to create
       *           <em>standard</em> number formats (the default).</li>
       *       <li>AbstractNumberValidator.CURRENCY_FORMAT -to create
       *           <em>currency</em> number formats.</li>
       *       <li>AbstractNumberValidator.PERCENT_FORMAT -to create
      *           <em>percent</em> number formats (the default).</li>
      *    </ul>
      *
      * @param strict {@code true} if strict
      *        {@code Format} parsing should be used.
      * @param formatType The {@code NumberFormat} type to
      *        create for validation, default is STANDARD_FORMAT.
      */
     public IntegerValidator(final boolean strict, final int formatType) {
         super(strict, formatType, false);
     }
 
     /**
      * Check if the value is within a specified range.
      *
      * @param value The {@code Number} value to check.
      * @param min The minimum value of the range.
      * @param max The maximum value of the range.
      * @return {@code true} if the value is within the
      *         specified range.
      */
     public boolean isInRange(final int value, final int min, final int max) {
         return value >= min && value <= max;
     }
 
     /**
      * Check if the value is within a specified range.
      *
      * @param value The {@code Number} value to check.
      * @param min The minimum value of the range.
      * @param max The maximum value of the range.
      * @return {@code true} if the value is within the
      *         specified range.
      */
     public boolean isInRange(final Integer value, final int min, final int max) {
         return isInRange(value.intValue(), min, max);
     }
 
     /**
      * Check if the value is less than or equal to a maximum.
      *
      * @param value The value validation is being performed on.
      * @param max The maximum value.
      * @return {@code true} if the value is less than
      *         or equal to the maximum.
      */
     public boolean maxValue(final int value, final int max) {
         return value <= max;
     }
 
     /**
      * Check if the value is less than or equal to a maximum.
      *
      * @param value The value validation is being performed on.
      * @param max The maximum value.
      * @return {@code true} if the value is less than
      *         or equal to the maximum.
      */
     public boolean maxValue(final Integer value, final int max) {
         return maxValue(value.intValue(), max);
     }
 
     /**
      * Check if the value is greater than or equal to a minimum.
      *
      * @param value The value validation is being performed on.
      * @param min The minimum value.
      * @return {@code true} if the value is greater than
      *         or equal to the minimum.
      */
     public boolean minValue(final int value, final int min) {
         return value >= min;
     }
 
     /**
      * Check if the value is greater than or equal to a minimum.
      *
      * @param value The value validation is being performed on.
      * @param min The minimum value.
      * @return {@code true} if the value is greater than
      *         or equal to the minimum.
      */
     public boolean minValue(final Integer value, final int min) {
         return minValue(value.intValue(), min);
     }
 
     /**
      * <p>Perform further validation and convert the {@code Number} to
      * an {@code Integer}.</p>
      *
      * @param value The parsed {@code Number} object created.
      * @param formatter The Format used to parse the value with.
      * @return The parsed {@code Number} converted to an
      *   {@code Integer} if valid or {@code null} if invalid.
      */
     @Override
     protected Object processParsedValue(final Object value, final Format formatter) {
 
         // Parsed value will be Long if it fits in a long and is not fractional
         if (value instanceof Long) {
             final long longValue = ((Long) value).longValue();
             if (longValue >= Integer.MIN_VALUE &&
                 longValue <= Integer.MAX_VALUE) {
                 return Integer.valueOf((int) longValue);
             }
         }
         return null;
     }
 
     /**
      * <p>Validate/convert an {@code Integer} using the default
      *    {@link Locale}.
      *
      * @param value The value validation is being performed on.
      * @return The parsed {@code Integer} if valid or {@code null}
      *  if invalid.
      */
     public Integer validate(final String value) {
         return (Integer) parse(value, (String) null, (Locale) null);
     }
 
     /**
      * <p>Validate/convert an {@code Integer} using the
      *    specified {@link Locale}.
      *
      * @param value The value validation is being performed on.
      * @param locale The locale to use for the number format, system default if null.
      * @return The parsed {@code Integer} if valid or {@code null} if invalid.
      */
     public Integer validate(final String value, final Locale locale) {
         return (Integer) parse(value, (String) null, locale);
     }
 
     /**
      * <p>Validate/convert an {@code Integer} using the
      *    specified <em>pattern</em>.
      *
      * @param value The value validation is being performed on.
      * @param pattern The pattern used to validate the value against.
      * @return The parsed {@code Integer} if valid or {@code null} if invalid.
      */
     public Integer validate(final String value, final String pattern) {
         return (Integer) parse(value, pattern, (Locale) null);
     }
 
     /**
      * <p>Validate/convert a {@code Integer} using the
      *    specified pattern and/ or {@link Locale}.
      *
      * @param value The value validation is being performed on.
      * @param pattern The pattern used to validate the value against, or the
      *        default for the {@link Locale} if {@code null}.
      * @param locale The locale to use for the date format, system default if null.
      * @return The parsed {@code Integer} if valid or {@code null} if invalid.
      */
     public Integer validate(final String value, final String pattern, final Locale locale) {
         return (Integer) parse(value, pattern, locale);
     }
 }