/*
    * 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.collect.testing.testers;
  
  import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE;
  import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE;
  import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
  import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.annotations.GwtIncompatible;
  import com.google.common.collect.testing.AbstractCollectionTester;
  import com.google.common.collect.testing.Helpers;
  import com.google.common.collect.testing.IteratorFeature;
  import com.google.common.collect.testing.IteratorTester;
  import com.google.common.collect.testing.features.CollectionFeature;
  
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Iterator;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Set;
  
  /**
   * A generic JUnit test which tests {@code iterator} operations on a collection.
   * Can't be invoked directly; please see
   * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
   *
   * @author Chris Povirk
   */
  @GwtCompatible(emulated = true)
  public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> {
    public void testIterator() {
      List<E> iteratorElements = new ArrayList<E>();
      for (E element : collection) { // uses iterator()
        iteratorElements.add(element);
      }
      Helpers.assertEqualIgnoringOrder(
          Arrays.asList(createSamplesArray()), iteratorElements);
    }
  
    @CollectionFeature.Require(KNOWN_ORDER)
    public void testIterationOrdering() {
      List<E> iteratorElements = new ArrayList<E>();
      for (E element : collection) { // uses iterator()
        iteratorElements.add(element);
      }
      List<E> expected = Helpers.copyToList(getOrderedElements());
      assertEquals("Different ordered iteration", expected, iteratorElements);
    }
  
    // TODO: switch to DerivedIteratorTestSuiteBuilder
  
    @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
    public void testIterator_knownOrderRemoveSupported() {
      runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
          getOrderedElements());
    }
  
    @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_ITERATOR_REMOVE)
    public void testIterator_knownOrderRemoveUnsupported() {
      runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
          getOrderedElements());
    }
  
    @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_ITERATOR_REMOVE)
    public void testIterator_unknownOrderRemoveSupported() {
      runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
          getSampleElements());
    }
  
    @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
    public void testIterator_unknownOrderRemoveUnsupported() {
      runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
          getSampleElements());
    }
  
    private void runIteratorTest(Set<IteratorFeature> features,
        IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
      new IteratorTester<E>(Platform.collectionIteratorTesterNumIterations(), features, elements,
          knownOrder) {
        @Override protected Iterator<E> newTargetIterator() {
          resetCollection();
         return collection.iterator();
       }
 
       @Override protected void verify(List<E> elements) {
         expectContents(elements);
       }
     }.test();
   }
 
   public void testIteratorNoSuchElementException() {
     Iterator<E> iterator = collection.iterator();
     while (iterator.hasNext()) {
       iterator.next();
     }
 
     try {
       iterator.next();
       fail("iterator.next() should throw NoSuchElementException");
     } catch (NoSuchElementException expected) {}
   }
 
   /**
    * Returns the {@link Method} instance for
    * {@link #testIterator_knownOrderRemoveUnsupported()} so that tests of
    * {@code ArrayStack} can suppress it with
    * {@code FeatureSpecificTestSuiteBuilder.suppressing()}. {@code ArrayStack}
    * supports {@code remove()} on only the first element, and the iterator
    * tester can't handle that.
    */
   @GwtIncompatible("reflection")
   public static Method getIteratorKnownOrderRemoveUnsupportedMethod() {
     return Helpers.getMethod(
         CollectionIteratorTester.class, "testIterator_knownOrderRemoveUnsupported");
   }
 }