/*
    * Copyright (C) 2010 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 com.google.common.annotations.GwtCompatible;
  
  import junit.framework.TestCase;
  
  /**
   * @author Luiz-Otavio "Z" Zorzella
   */
  @GwtCompatible
  public class TearDownStackTest extends TestCase {
  
    private TearDownStack tearDownStack = new TearDownStack();
  
    public void testSingleTearDown() throws Exception {
      final TearDownStack stack = buildTearDownStack();
  
      final SimpleTearDown tearDown = new SimpleTearDown();
      stack.addTearDown(tearDown);
  
      assertEquals(false, tearDown.ran);
  
      stack.runTearDown();
  
      assertEquals("tearDown should have run", true, tearDown.ran);
    }
  
    public void testMultipleTearDownsHappenInOrder() throws Exception {
      final TearDownStack stack = buildTearDownStack();
  
      final SimpleTearDown tearDownOne = new SimpleTearDown();
      stack.addTearDown(tearDownOne);
  
      final Callback callback = new Callback() {
        @Override
        public void run() {
          assertEquals("tearDownTwo should have been run before tearDownOne",
            false, tearDownOne.ran);
        }
      };
  
      final SimpleTearDown tearDownTwo = new SimpleTearDown(callback);
      stack.addTearDown(tearDownTwo);
  
      assertEquals(false, tearDownOne.ran);
      assertEquals(false, tearDownTwo.ran);
  
      stack.runTearDown();
  
      assertEquals("tearDownOne should have run", true, tearDownOne.ran);
      assertEquals("tearDownTwo should have run", true, tearDownTwo.ran);
    }
  
    public void testThrowingTearDown() throws Exception {
      final TearDownStack stack = buildTearDownStack();
  
      final ThrowingTearDown tearDownOne = new ThrowingTearDown("one");
      stack.addTearDown(tearDownOne);
  
      final ThrowingTearDown tearDownTwo = new ThrowingTearDown("two");
      stack.addTearDown(tearDownTwo);
  
      assertEquals(false, tearDownOne.ran);
      assertEquals(false, tearDownTwo.ran);
  
      try {
        stack.runTearDown();
        fail("runTearDown should have thrown an exception");
      } catch (ClusterException expected) {
        assertEquals("two", expected.getCause().getMessage());
      } catch (RuntimeException e) {
        throw new RuntimeException(
          "A ClusterException should have been thrown, rather than a " + e.getClass().getName(), e);
      }
  
      assertEquals(true, tearDownOne.ran);
      assertEquals(true, tearDownTwo.ran);
    }
  
    @Override public final void runBare() throws Throwable {
      try {
        setUp();
        runTest();
     } finally {
       tearDown();
     }
   }
 
   @Override protected void tearDown() {
     tearDownStack.runTearDown();
   }
 
   /**
    * Builds a {@link TearDownStack} that makes sure it's clear by the end of
    * this test.
    */
   private TearDownStack buildTearDownStack() {
     final TearDownStack result = new TearDownStack();
     tearDownStack.addTearDown(new TearDown() {
 
       @Override
       public void tearDown() throws Exception {
         assertEquals(
           "The test should have cleared the stack (say, by virtue of running runTearDown)",
           0, result.stack.size());
       }
     });
     return result;
   }
 
   private static final class ThrowingTearDown implements TearDown {
 
     private final String id;
     boolean ran = false;
 
     ThrowingTearDown(String id) {
       this.id = id;
     }
 
     @Override
     public void tearDown() throws Exception {
       ran = true;
       throw new RuntimeException(id);
     }
   }
 
   private static final class SimpleTearDown implements TearDown {
 
     boolean ran = false;
     Callback callback = null;
 
     public SimpleTearDown() {}
 
     public SimpleTearDown(Callback callback) {
       this.callback = callback;
     }
 
     @Override
     public void tearDown() throws Exception {
       if (callback != null) {
         callback.run();
       }
       ran = true;
     }
   }
 
   private interface Callback {
     void run();
   }
 }