/**
 * 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.
 *
 * Copyright 2012-2015 the original author or authors.
 */
package org.assertj.swing.driver;

import static org.assertj.core.util.Lists.newArrayList;

import java.util.List;

import javax.annotation.Nonnull;
import javax.swing.JTree;
import javax.swing.tree.TreePath;

import org.assertj.swing.annotation.RunsInCurrentThread;

/**
 * <p>
 * Adds the root node of a {@code JTree} to a given path if such root is invisible.
 * </p>
 * 
 * <p>
 * <b>Note:</b> Methods in this class are accessed in the current executing thread. Such thread may or may not be the
 * event dispatch thread (EDT). Client code must call methods in this class from the EDT.
 * </p>
 * 
 * @author Alex Ruiz
 */
final class JTreeAddRootIfInvisibleTask {
  /*
   * Adds the root node to the path, only if the JTree has an invisible root. If this is not done, a path missing the
   * root node cannot be expanded (issue 293).
   */
  @RunsInCurrentThread
  static @Nonnull TreePath addRootIfInvisible(@Nonnull JTree tree, @Nonnull TreePath path) {
    Object root = tree.getModel().getRoot();
    if (tree.isRootVisible() || root == null) {
      return path;
    }
    // root is invisible but path already contains root
    if (path.getPathCount() > 0 && root == path.getPathComponent(0)) {
      return path;
    }
    Object[] pathAsArray = path.getPath();
    if (pathAsArray == null) {
      return new TreePath(newArrayList(root));
    }
    List<Object> newPath = newArrayList(pathAsArray);
    newPath.add(0, root);
    return new TreePath(newPath.toArray());
  }

  private JTreeAddRootIfInvisibleTask() {
  }
}