/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.mahout.cf.taste.similarity.precompute;

import java.util.ArrayList;
import java.util.List;

import org.apache.mahout.cf.taste.impl.TasteTestCase;
import org.apache.mahout.cf.taste.impl.recommender.GenericRecommendedItem;
import org.apache.mahout.cf.taste.recommender.RecommendedItem;
import org.hamcrest.Matchers;
import org.junit.Test;

public class SimilarItemsTest extends TasteTestCase {

  @Test
  public void testIterator() {
	List<RecommendedItem> recommendedItems = new ArrayList<>();
	for (long itemId = 2; itemId < 10; itemId++) {
	  recommendedItems.add(new GenericRecommendedItem(itemId, itemId));
	}

	SimilarItems similarItems = new SimilarItems(1, recommendedItems);

	assertThat(similarItems.getSimilarItems(), Matchers.<SimilarItem> iterableWithSize(recommendedItems.size()));

	int byHandIndex = 0;
	for (SimilarItem simItem : similarItems.getSimilarItems()) {
	  RecommendedItem recItem = recommendedItems.get(byHandIndex++);
	  assertEquals(simItem.getItemID(), recItem.getItemID());
	  assertEquals(simItem.getSimilarity(), recItem.getValue(), EPSILON);
	}

  }
}
