/*
    * 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.chemistry.opencmis.client.runtime.util;
  
  import org.apache.chemistry.opencmis.client.api.ItemIterable;
  
  /**
   * Abstract <code>ItemIterable</code> implementation.
   *
   * @param <T> the type returned by the iterable's iterator
   */
  public abstract class AbstractIterable<T> implements ItemIterable<T> {
  
      private final AbstractPageFetcher<T> pageFetcher;
      private final long skipCount;
      private AbstractIterator<T> iterator;
  
      protected AbstractIterable(AbstractPageFetcher<T> pageFetcher) {
          this(0, pageFetcher);
      }
  
      protected AbstractIterable(long position, AbstractPageFetcher<T> pageFetcher) {
          this.pageFetcher = pageFetcher;
          this.skipCount = position;
      }
  
      /**
       * Gets the skip count
       *
       * @return  skip count
       */
      protected long getSkipCount() {
          return skipCount;
      }
  
      /**
       * Gets the page fetcher
       *
       * @return  page fetcher
       */
      protected AbstractPageFetcher<T> getPageFetcher() {
          return pageFetcher;
      }
  
      /**
       * Construct the iterator
       *
       * @return  iterator
       */
      protected abstract AbstractIterator<T> createIterator();
  
      public AbstractIterator<T> iterator() {
          return getIterator();
      }
  
      public ItemIterable<T> skipTo(long position) {
          return new CollectionIterable<T>(position, pageFetcher);
      }
  
      public ItemIterable<T> getPage() {
          return new CollectionPageIterable<T>(skipCount, pageFetcher);
      }
  
      public ItemIterable<T> getPage(int maxNumItems) {
          this.pageFetcher.setMaxNumItems(maxNumItems);
          return new CollectionPageIterable<T>(skipCount, pageFetcher);
      }
  
      public long getPageNumItems() {
          return getIterator().getPageNumItems();
      }
  
      public boolean getHasMoreItems() {
          return getIterator().getHasMoreItems();
      }
  
      public long getTotalNumItems() {
          return getIterator().getTotalNumItems();
      }
  
      private AbstractIterator<T> getIterator() {
          if (this.iterator == null) {
              this.iterator = createIterator();
         }
         return this.iterator;
     }
 }