/*
 * Copyright 2000-2015 JetBrains s.r.o.
 *
 * Licensed 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 com.jetbrains.lang.dart.ide.hierarchy.type;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.intellij.ide.hierarchy.HierarchyNodeDescriptor;
import com.intellij.ide.hierarchy.HierarchyTreeStructure;
import com.intellij.openapi.project.Project;
import com.intellij.util.ArrayUtil;
import com.jetbrains.lang.dart.psi.DartClass;
import com.jetbrains.lang.dart.util.DartResolveUtil;
import org.dartlang.analysis.server.protocol.TypeHierarchyItem;
import org.jetbrains.annotations.NotNull;

import java.util.List;
import java.util.Set;

import static com.jetbrains.lang.dart.ide.hierarchy.DartHierarchyUtil.findDartClass;
import static com.jetbrains.lang.dart.ide.hierarchy.DartHierarchyUtil.getTypeHierarchyItems;

public final class DartServerSupertypesHierarchyTreeStructure extends HierarchyTreeStructure {

  public DartServerSupertypesHierarchyTreeStructure(final Project project, final DartClass dartClass) {
    super(project, new DartTypeHierarchyNodeDescriptor(project, null, dartClass, true));
  }

  @NotNull
  protected final Object[] buildChildren(@NotNull final HierarchyNodeDescriptor descriptor) {
    final DartClass dartClass = ((DartTypeHierarchyNodeDescriptor)descriptor).getDartClass();
    if (dartClass == null || DartResolveUtil.OBJECT.equals(dartClass.getName())) {
      return ArrayUtil.EMPTY_OBJECT_ARRAY;
    }

    final List<TypeHierarchyItem> items = getTypeHierarchyItems(dartClass);
    if (items.isEmpty()) return ArrayUtil.EMPTY_OBJECT_ARRAY;

    addSuperClassHierarchy(Sets.newHashSet(), myProject, items, items.get(0), descriptor);

    return descriptor.getCachedChildren();
  }

  private static void addSuperClassHierarchy(@NotNull final Set<TypeHierarchyItem> stackItems,
                                             @NotNull final Project project,
                                             @NotNull final List<TypeHierarchyItem> items,
                                             @NotNull final TypeHierarchyItem item,
                                             @NotNull final HierarchyNodeDescriptor descriptor) {
    if (!stackItems.add(item)) {
      descriptor.setCachedChildren(ArrayUtil.EMPTY_OBJECT_ARRAY);
      return;
    }

    List<HierarchyNodeDescriptor> superDescriptors = Lists.newArrayList();
    try {
      // superclass
      final Integer superIndex = item.getSuperclass();
      if (superIndex != null) {
        addSuperClassNode(stackItems, project, items, descriptor, superDescriptors, superIndex);
      }
      // mixins
      for (int index : item.getMixins()) {
        addSuperClassNode(stackItems, project, items, descriptor, superDescriptors, index);
      }
      // interfaces
      for (int index : item.getInterfaces()) {
        addSuperClassNode(stackItems, project, items, descriptor, superDescriptors, index);
      }
    }
    finally {
      stackItems.remove(item);
    }
    descriptor.setCachedChildren(superDescriptors.toArray(new HierarchyNodeDescriptor[superDescriptors.size()]));
  }

  private static void addSuperClassNode(@NotNull final Set<TypeHierarchyItem> stackItems,
                                        @NotNull final Project project,
                                        @NotNull final List<TypeHierarchyItem> items,
                                        @NotNull final HierarchyNodeDescriptor parentNode,
                                        @NotNull final List<HierarchyNodeDescriptor> descriptors,
                                        final int index) {
    final TypeHierarchyItem superItem = items.get(index);
    if (DartResolveUtil.OBJECT.equals(superItem.getClassElement().getName())) {
      return;
    }
    final DartClass superClass = findDartClass(project, superItem);
    final HierarchyNodeDescriptor superDescriptor = new DartTypeHierarchyNodeDescriptor(project, parentNode, superClass, false);
    descriptors.add(superDescriptor);
    addSuperClassHierarchy(stackItems, project, items, superItem, superDescriptor);
  }
}