/*
    * Copyright (C) 2008 The Guava Authors
    *
    * 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.google.common.testing;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import com.google.common.annotations.Beta;
  import com.google.common.annotations.GwtCompatible;
  
  import java.util.ArrayList;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  /**
   * A {@code TearDownStack} contains a stack of {@link TearDown} instances.
   *
   * @author Kevin Bourrillion
   * @since 10.0
   */
  @Beta
  @GwtCompatible
  public class TearDownStack implements TearDownAccepter {
    private static final Logger logger = Logger.getLogger(TearDownStack.class.getName());
  
    final LinkedList<TearDown> stack = new LinkedList<TearDown>();
  
    private final boolean suppressThrows;
  
    public TearDownStack() {
      this.suppressThrows = false;
    }
  
    public TearDownStack(boolean suppressThrows) {
      this.suppressThrows = suppressThrows;
    }
  
    @Override
    public final void addTearDown(TearDown tearDown) {
      stack.addFirst(checkNotNull(tearDown));
    }
  
    /**
     * Causes teardown to execute.
     */
    public final void runTearDown() {
      List<Throwable> exceptions = new ArrayList<Throwable>();
      for (TearDown tearDown : stack) {
        try {
          tearDown.tearDown();
        } catch (Throwable t) {
          if (suppressThrows) {
            logger.log(Level.INFO, "exception thrown during tearDown", t);
          } else {
            exceptions.add(t);
          }
        }
      }
      stack.clear();
      if ((!suppressThrows) && (exceptions.size() > 0)) {
        throw ClusterException.create(exceptions);
      }
    }
  }