/*
    * 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.functor.range;
  
  import java.util.Iterator;
  
  import org.apache.commons.functor.BinaryFunction;
  import org.apache.commons.lang3.Validate;
  
  /**
   * A range of longs.
   *
   * @since 1.0
   * @version $Revision: 1385335 $ $Date: 2012-09-16 15:08:31 -0300 (Sun, 16 Sep 2012) $
   */
  public final class LongRange extends NumericRange<Long> {
      // attributes
      //---------------------------------------------------------------
  
      /**
       * Calculate default step.
       */
      public static final BinaryFunction<Long, Long, Long> DEFAULT_STEP = new BinaryFunction<Long, Long, Long>() {
  
          public Long evaluate(Long left, Long right) {
              return left > right ? -1L : 1L;
          }
      };
  
      // constructors
      // ---------------------------------------------------------------
      /**
       * Create a new LongRange.
       *
       * @param from start
       * @param to end
       */
      public LongRange(Number from, Number to) {
          this(from.longValue(), to.longValue());
      }
  
      /**
       * Create a new LongRange.
       *
       * @param from start
       * @param to end
       * @param step increment
       */
      public LongRange(Number from, Number to, Number step) {
          this(from.longValue(), to.longValue(), step.longValue());
      }
  
      /**
       * Create a new LongRange.
       *
       * @param from start
       * @param to end
       */
      public LongRange(long from, long to) {
          this(from, to, DEFAULT_STEP.evaluate(from, to).longValue());
      }
  
      /**
       * Create a new LongRange.
       *
       * @param from start
       * @param to end
       * @param step increment
       */
      public LongRange(long from, long to, long step) {
          this(from, DEFAULT_LEFT_BOUND_TYPE, to, DEFAULT_RIGHT_BOUND_TYPE, step);
      }
  
      /**
       * Create a new LongRange.
       *
       * @param from start
       * @param to end
       * @throws NullPointerException if either {@link Endpoint} is {@code null}
       */
      public LongRange(Endpoint<Long> from, Endpoint<Long> to) {
          this(from, to, DEFAULT_STEP.evaluate(from.getValue(), to.getValue()));
      }
  
      /**
      * Create a new LongRange.
      *
      * @param from start
      * @param to end
      * @param step increment
      * @throws NullPointerException if either {@link Endpoint} is {@code null}
      */
     public LongRange(Endpoint<Long> from, Endpoint<Long> to, int step) {
         this(from, to, (long) step);
     }
 
     /**
      * Create a new LongRange.
      *
      * @param from start
      * @param leftBoundType type of left bound
      * @param to end
      * @param rightBoundType type of right bound
      * @throws NullPointerException if either {@link BoundType} is {@code null}
      */
     public LongRange(long from, BoundType leftBoundType, long to, BoundType rightBoundType) {
         this(from, leftBoundType, to, rightBoundType, DEFAULT_STEP.evaluate(from, to));
     }
 
     /**
      * Create a new LongRange.
      *
      * @param from start
      * @param to end
      * @param step increment
      * @throws NullPointerException if either {@link Endpoint} is {@code null}
      */
     public LongRange(Endpoint<Long> from, Endpoint<Long> to, long step) {
         super(from, to, Long.valueOf(step), new BinaryFunction<Long, Long, Long>() {
 
             public Long evaluate(Long left, Long right) {
                 return Long.valueOf(left.longValue() + right.longValue());
             }
         });
 
         final long f = from.getValue();
         final long t = to.getValue();
 
         Validate.isTrue(f == t || Long.signum(step) == Long.signum(t - f),
             "Will never reach '%s' from '%s' using step %s", t, f, step);
     }
 
     /**
      * Create a new LongRange.
      *
      * @param from start
      * @param leftBoundType type of left bound
      * @param to end
      * @param rightBoundType type of right bound
      * @param step increment
      * @throws NullPointerException if either {@link BoundType} is {@code null}
      */
     public LongRange(long from, BoundType leftBoundType, long to,
                      BoundType rightBoundType, long step) {
         this(new Endpoint<Long>(from, leftBoundType), new Endpoint<Long>(to, rightBoundType), step);
     }
 
     // iterable
     // ---------------------------------------------------------------
 
     /**
      * {@inheritDoc}
      */
     protected Iterator<Long> createIterator() {
         return new Iterator<Long>() {
             private long currentValue;
 
             {
                 currentValue = leftEndpoint.getValue();
 
                 if (leftEndpoint.getBoundType() == BoundType.OPEN) {
                     this.currentValue += step;
                 }
             }
 
             public void remove() {
                 throw new UnsupportedOperationException();
             }
 
             public Long next() {
                 final long step = getStep();
                 final long r = currentValue;
                 currentValue += step;
                 return Long.valueOf(r);
             }
 
             public boolean hasNext() {
                 final int cmp = Long.valueOf(currentValue).compareTo(rightEndpoint.getValue());
 
                 if (cmp == 0) {
                     return rightEndpoint.getBoundType() == BoundType.CLOSED;
                 }
                 if (step > 0L) {
                     return cmp < 0;
                 }
                 return cmp > 0;
             }
         };
     }
 
 }