/*
 * Copyright 2000-2009 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.
 */

/*
 * @author max
 */
package com.intellij.psi.impl.source.text;

import com.intellij.lang.ASTNode;
import com.intellij.pom.PomManager;
import com.intellij.pom.tree.TreeAspect;
import com.intellij.pom.tree.events.ChangeInfo;
import com.intellij.pom.tree.events.impl.ChangeInfoImpl;
import com.intellij.pom.tree.events.impl.ReplaceChangeInfoImpl;
import com.intellij.pom.tree.events.impl.TreeChangeEventImpl;
import com.intellij.psi.impl.source.PsiFileImpl;
import com.intellij.psi.impl.source.tree.FileElement;
import com.intellij.util.diff.DiffTreeChangeBuilder;
import org.jetbrains.annotations.NotNull;

public class ASTDiffBuilder implements DiffTreeChangeBuilder<ASTNode, ASTNode> {
  private final TreeChangeEventImpl myEvent;

  public ASTDiffBuilder(@NotNull PsiFileImpl fileImpl) {
    TreeAspect modelAspect = PomManager.getModel(fileImpl.getProject()).getModelAspect(TreeAspect.class);
    myEvent = new TreeChangeEventImpl(modelAspect, fileImpl.getTreeElement());
  }

  @Override
  public void nodeReplaced(@NotNull ASTNode oldNode, @NotNull ASTNode newNode) {
    if (oldNode instanceof FileElement && newNode instanceof FileElement) {
    }
    else {
      final ReplaceChangeInfoImpl change = new ReplaceChangeInfoImpl(newNode);
      change.setReplaced(oldNode);

      myEvent.addElementaryChange(newNode, change);
    }
  }

  @Override
  public void nodeDeleted(@NotNull ASTNode parent, @NotNull final ASTNode child) {
    myEvent.addElementaryChange(child, ChangeInfoImpl.create(ChangeInfo.REMOVED, child));
  }

  @Override
  public void nodeInserted(@NotNull final ASTNode oldParent, @NotNull ASTNode newNode, final int pos) {
    myEvent.addElementaryChange(newNode, ChangeInfoImpl.create(ChangeInfo.ADD, newNode));
  }

  @NotNull
  public TreeChangeEventImpl getEvent() {
    return myEvent;
  }
}