/**
    * This file Copyright (c) 2019 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.resources.app.data;
  
  import info.magnolia.config.registry.DefinitionMetadata;
  import info.magnolia.config.registry.DefinitionProvider;
  import info.magnolia.config.registry.RegistryFacade;
  import info.magnolia.module.ModuleRegistry;
  import info.magnolia.objectfactory.Components;
  import info.magnolia.resourceloader.Resource;
  import info.magnolia.resourceloader.ResourceOrigin;
  import info.magnolia.resourceloader.classpath.ClasspathResource;
  import info.magnolia.ui.filter.DataFilter;
  
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.stream.Stream;
  
  import javax.inject.Inject;
  
  import com.vaadin.data.provider.AbstractBackEndHierarchicalDataProvider;
  import com.vaadin.data.provider.HierarchicalQuery;
  
  /**
   * Data provider used to show non filtered tree structure of resources.
   */
  public class ResourceDataProvider extends AbstractBackEndHierarchicalDataProvider<Resource, DataFilter> implements ResourceHelper {
  
      private final ResourceOrigin<?> resourceOrigin;
      private final Collection<String> moduleFolders;
  
      @Inject
      ResourceDataProvider(ResourceOrigin<?> resourceOrigin, ModuleRegistry moduleRegistry, RegistryFacade registryFacade) {
          this.resourceOrigin = resourceOrigin;
          this.moduleFolders = new HashSet<>(moduleRegistry.getModuleNames()); //include all java modules (including those without any definitions, but might have e.g. CSS files)
          final Collection<DefinitionProvider<?>> definitionProviders = registryFacade.query().findMultiple(); //add all modules (including light modules)
          definitionProviders
                  .stream()
                  .map(DefinitionProvider::getMetadata)
                  .map(DefinitionMetadata::getModule)
                  .forEach(moduleFolders::add);
      }
  
      /**
       * @deprecated since 3.0.3. Use {@link #ResourceDataProvider(info.magnolia.resourceloader.ResourceOrigin, info.magnolia.module.ModuleRegistry, info.magnolia.config.registry.RegistryFacade)} instead.
       */
      @Deprecated
      public ResourceDataProvider(ResourceOrigin<?> resourceOrigin, ModuleRegistry moduleRegistry) {
          this(resourceOrigin, moduleRegistry, Components.getComponent(RegistryFacade.class));
      }
  
      @Override
      public Object getId(Resource item) {
          return item.getPath();
      }
  
      @Override
      protected Stream<Resource> fetchChildrenFromBackEnd(HierarchicalQuery<Resource, DataFilter> query) {
          boolean isRoot = query.getParent() == null;
          Stream<Resource> children = getChildren(isRoot ? resourceOrigin.getRoot() : query.getParent());
          if (isRoot) { //if no column filter is set, filter resources outside of modules
              children = children.filter(resource -> {
                  boolean isClasspathOnlyResource = getFirstResource(resource)
                          .map(ClasspathResource.class::isInstance)
                          .orElse(false);
  
                  return !isClasspathOnlyResource || moduleFolders.contains(resource.getName());
              });
         }
         return children
                 .skip(query.getOffset())
                 .limit(query.getLimit());
     }
 
     @Override
     public int getChildCount(HierarchicalQuery<Resource, DataFilter> query) {
         return (int) fetchChildrenFromBackEnd(query).count();
     }
 
     @Override
     public boolean hasChildren(Resource item) {
         return getChildren(item).findFirst().isPresent();
     }
 
     private Stream<Resource> getChildren(Resource parent) {
         return !parent.isDirectory() ? Stream.empty() : parent.listChildren().stream();
     }
 }