content: /*
   *  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.causeway.core.metamodel.facets.object.navchild;
  
  import java.lang.invoke.MethodHandle;
  import java.util.function.BiConsumer;
  import java.util.stream.Stream;
  
  import org.springframework.util.ClassUtils;
  
  import org.apache.causeway.commons.collections.Can;
  import org.apache.causeway.commons.internal.base._NullSafe;
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  import org.apache.causeway.core.metamodel.facetapi.Facet;
  import org.apache.causeway.core.metamodel.facetapi.FacetHolder;
  
  import lombok.extern.log4j.Log4j2;
  
  @Log4j2
  record NavigableSubtreeFacetRecord (
      Can<MethodHandle> subNodesMethodHandles, 
      FacetHolder facetHolder) 
  implements NavigableSubtreeFacet {
      
      @Override
      public Class<? extends Facet> facetType() {
          return NavigableSubtreeFacet.class;
      }
  
      @Override
      public Precedence getPrecedence() {
          return Precedence.DEFAULT;
      }
      
      @Override
      public FacetHolder getFacetHolder() {
          return facetHolder;
      }
  
      @Override
      public final int childCountOf(final Object node) {
          return subNodesMethodHandles.stream()
              .mapToInt(mh->{
                  try {
                      return _NullSafe.sizeAutodetect(mh.invoke(node));
                  } catch (Throwable e) {
                      log.error("failed to invoke subNodesMethodHandle {}",
                              mh.toString(), e);
                      return 0;
                  }
              })
              .sum();
      }
  
      @Override
      public final Stream<Object> childrenOf(final Object node) {
          return subNodesMethodHandles.stream()
              .flatMap(mh->{
                  try {
                      return _NullSafe.streamAutodetect(mh.invoke(node));
                  } catch (Throwable e) {
                      throw _Exceptions.unrecoverable(e);
                  }
              });
      }
  
      @Override
      public void visitAttributes(final BiConsumer<String, Object> visitor) {
          visitor.accept("facet", ClassUtils.getShortName(getClass()));
          visitor.accept("precedence", getPrecedence().name());
          visitor.accept("subNodesMethodHandles", subNodesMethodHandles.map(MethodHandle::toString));
      }
      
  }
  
  