/**
    * This file Copyright (c) 2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.contentapp;
  
  import info.magnolia.ui.filter.DataFilter;
  
  import java.util.stream.Stream;
  
  import com.vaadin.data.provider.ConfigurableFilterDataProvider;
  import com.vaadin.data.provider.DataProvider;
  import com.vaadin.data.provider.HierarchicalDataProvider;
  import com.vaadin.data.provider.HierarchicalQuery;
  import com.vaadin.data.provider.Query;
  
  /**
   * Filterable wrapper for a data provider of the specified type.
   * @param <T> item type.
   */
  public class FilterableHierarchicalDataProvider<T> extends HierarchicalDataProviderWrapper<T, DataFilter> implements ConfigurableFilterDataProvider<T, DataFilter, DataFilter> {
  
      private final DataProvider<T, DataFilter> filteringDataProvider;
  
      public static <T> FilterableHierarchicalDataProvider<T> wrap(HierarchicalDataProvider<T, DataFilter> hierarchicalDataProvider, DataProvider<T, DataFilter> filteringDataProvider) {
          return new FilterableHierarchicalDataProvider<>(hierarchicalDataProvider, filteringDataProvider);
      }
  
      /**
       * @deprecated since 6.2.4. Use {@link info.magnolia.ui.contentapp.FilterableHierarchicalDataProvider#wrap(com.vaadin.data.provider.HierarchicalDataProvider, com.vaadin.data.provider.DataProvider)} instead.
       */
      @Deprecated
      public static <T> FilterableHierarchicalDataProvider<T> wrap(HierarchicalDataProvider<T, DataFilter> src) {
          return new FilterableHierarchicalDataProvider<>(src, null);
      }
  
      private FilterableHierarchicalDataProvider(HierarchicalDataProvider<T, DataFilter> dataProvider, DataProvider<T, DataFilter> filteringDataProvider) {
          super(dataProvider);
          this.filteringDataProvider = filteringDataProvider;
      }
  
      private DataFilter filter;
  
      /**
       * @deprecated since 6.2.1. Use {@link #setFilter(info.magnolia.ui.filter.DataFilter)} instead.
       */
      @Deprecated
      public void setDataFilter(DataFilter dataFilter) {
          setFilter(dataFilter);
      }
  
      @Override
      public void setFilter(DataFilter filter) {
          this.filter = filter;
      }
  
      @Override
      public Stream<T> fetch(Query<T, DataFilter> t) {
          return dataProvider.fetch(new HierarchicalQuery<>(t.getOffset(), t.getLimit(),
                  t.getSortOrders(), t.getInMemorySorting(), getFilter(t), null));
      }
  
      @Override
      public Stream<T> fetchChildren(HierarchicalQuery<T, DataFilter> query) {
          Stream<T> stream;
          if (isFlatFiltering()) {
              stream = filteringDataProvider.fetch(createQueryWithFilter(query));
          } else {
              stream = super.fetchChildren(query);
          }
         if (query.getInMemorySorting() != null) {
             stream = stream.sorted(query.getInMemorySorting());
         }
         return stream;
     }
 
     @Override
     public int getChildCount(HierarchicalQuery<T, DataFilter> query) {
         if (isFlatFiltering()) {
             if (query.getParent() == null) {
                 return (int) fetchChildren(query).count(); //children just at root level while filtering
             } else {
                 return 0; //flat structure, no children
             }
         }
         return super.getChildCount(query);
     }
 
     @Override
     public DataFilter getFilter(Query<T, DataFilter> query) {
         return filter;
     }
 
     @Override
     public boolean hasChildren(T item) {
         return isFlatFiltering() ? getChildCount(new HierarchicalQuery<>(filter, item)) > 0 : super.hasChildren(item);
     }
 
     private boolean isFlatFiltering() {
         return filteringDataProvider != null && filter != null && !filter.isEmpty();
     }
 }