/**
 * Copyright 2006 The Apache Software Foundation
 *
 * 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 org.apache.lucene.store.instantiated;

import java.io.IOException;
import java.util.Arrays;
import java.util.Random;

import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.MultiFields;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;

public class TestEmptyIndex extends LuceneTestCase {

  public void testSearch() throws Exception {

    InstantiatedIndex ii = new InstantiatedIndex();

    IndexReader r = new InstantiatedIndexReader(ii);
    IndexSearcher s = new IndexSearcher(r);

    TopDocs td = s.search(new TermQuery(new Term("foo", "bar")), 1);

    assertEquals(0, td.totalHits);

    s.close();
    r.close();
    ii.close();

  }

  public void testNorms() throws Exception {

    InstantiatedIndex ii = new InstantiatedIndex();
    IndexReader r = new InstantiatedIndexReader(ii);
    testNorms(r);
    r.close();
    ii.close();

    // make sure a Directory acts the same
    Random random = newRandom();
    Directory d = newDirectory(random);
    new IndexWriter(d, newIndexWriterConfig(random, TEST_VERSION_CURRENT, new MockAnalyzer())).close();
    r = IndexReader.open(d, false);
    testNorms(r);
    r.close();
    d.close();

  }

  private void testNorms(IndexReader r) throws IOException {
    byte[] norms;
    norms = r.norms("foo");
    if (norms != null) {
      assertEquals(0, norms.length);
      norms = new byte[10];
      Arrays.fill(norms, (byte)10);
      r.norms("foo", norms, 10);
      for (byte b : norms) {
        assertEquals((byte)10, b);
      }
    }
  }

  public void testTermsEnum() throws Exception {

    InstantiatedIndex ii = new InstantiatedIndex();
    IndexReader r = new InstantiatedIndexReader(ii);
    termsEnumTest(r);
    r.close();
    ii.close();

    // make sure a Directory acts the same
    Random random = newRandom();
    Directory d = newDirectory(random);
    new IndexWriter(d, newIndexWriterConfig(random, TEST_VERSION_CURRENT, new MockAnalyzer())).close();
    r = IndexReader.open(d, false);
    termsEnumTest(r);
    r.close();
    d.close();
  }

  public void termsEnumTest(IndexReader r) throws Exception {
    assertNull(MultiFields.getFields(r));
  }

}