/*
    *  Copyright 2001-2005 Stephen Colebourne
    *
    *  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.
   */
  package org.joda.time.field;
  
  import org.joda.time.DurationField;
  import org.joda.time.DurationFieldType;
  
  /**
   * Scales a DurationField such that it's unit millis becomes larger in
   * magnitude.
   * <p>
   * ScaledDurationField is thread-safe and immutable.
   *
   * @see PreciseDurationField
   *
   * @author Brian S O'Neill
   * @since 1.0
   */
  public class ScaledDurationField extends DecoratedDurationField {
  
      private static final long serialVersionUID = -3205227092378684157L;
  
      private final int iScalar;
  
      /**
       * Constructor
       * 
       * @param field  the field to wrap, like "year()".
       * @param type  the type this field will actually use
       * @param scalar  scalar, such as 100 years in a century
       * @throws IllegalArgumentException if scalar is zero or one.
       */
      public ScaledDurationField(DurationField field, DurationFieldType type, int scalar) {
          super(field, type);
          if (scalar == 0 || scalar == 1) {
              throw new IllegalArgumentException("The scalar must not be 0 or 1");
          }
          iScalar = scalar;
      }
  
      public int getValue(long duration) {
          return getWrappedField().getValue(duration) / iScalar;
      }
  
      public long getValueAsLong(long duration) {
          return getWrappedField().getValueAsLong(duration) / iScalar;
      }
  
      public int getValue(long duration, long instant) {
          return getWrappedField().getValue(duration, instant) / iScalar;
      }
  
      public long getValueAsLong(long duration, long instant) {
          return getWrappedField().getValueAsLong(duration, instant) / iScalar;
      }
  
      public long getMillis(int value) {
          long scaled = ((long) value) * ((long) iScalar);
          return getWrappedField().getMillis(scaled);
      }
  
      public long getMillis(long value) {
          long scaled = FieldUtils.safeMultiply(value, iScalar);
          return getWrappedField().getMillis(scaled);
      }
  
      public long getMillis(int value, long instant) {
          long scaled = ((long) value) * ((long) iScalar);
          return getWrappedField().getMillis(scaled, instant);
      }
  
      public long getMillis(long value, long instant) {
          long scaled = FieldUtils.safeMultiply(value, iScalar);
          return getWrappedField().getMillis(scaled, instant);
      }
  
      public long add(long instant, int value) {
          long scaled = ((long) value) * ((long) iScalar);
          return getWrappedField().add(instant, scaled);
      }
  
      public long add(long instant, long value) {
          long scaled = FieldUtils.safeMultiply(value, iScalar);
          return getWrappedField().add(instant, scaled);
      }
  
     public int getDifference(long minuendInstant, long subtrahendInstant) {
         return getWrappedField().getDifference(minuendInstant, subtrahendInstant) / iScalar;
     }
 
     public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
         return getWrappedField().getDifferenceAsLong(minuendInstant, subtrahendInstant) / iScalar;
     }
 
     public long getUnitMillis() {
         return getWrappedField().getUnitMillis() * iScalar;
     }
 
     //-----------------------------------------------------------------------
     /**
      * Returns the scalar applied, in the field's units.
      * 
      * @return the scalar
      */
     public int getScalar() {
         return iScalar;
     }
 
     /**
      * Compares this duration field to another.
      * Two fields are equal if of the same type and duration.
      * 
      * @param obj  the object to compare to
      * @return if equal
      */
     public boolean equals(Object obj) {
         if (this == obj) {
             return true;
         } else if (obj instanceof ScaledDurationField) {
             ScaledDurationField other = (ScaledDurationField) obj;
             return (getWrappedField().equals(other.getWrappedField())) &&
                    (getType() == other.getType()) &&
                    (iScalar == other.iScalar);
         }
         return false;
     }
 
     /**
      * Gets a hash code for this instance.
      * 
      * @return a suitable hashcode
      */
     public int hashCode() {
         long scalar = iScalar;
         int hash = (int) (scalar ^ (scalar >>> 32));
         hash += getType().hashCode();
         hash += getWrappedField().hashCode();
         return hash;
     }
 
 }