package org.apache.lucene.index;

/**
 * Copyright 2005 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.
 */

import java.io.IOException;
import java.util.Collection;

import junit.framework.TestCase;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.search.BooleanClause.Occur;
import org.apache.lucene.search.*;

public class TestParallelReader extends TestCase {

  private Searcher parallel;
  private Searcher single;
  
  protected void setUp() throws Exception {
    single = single();
    parallel = parallel();
  }

  public void testQueries() throws Exception {
    queryTest(new TermQuery(new Term("f1", "v1")));
    queryTest(new TermQuery(new Term("f1", "v2")));
    queryTest(new TermQuery(new Term("f2", "v1")));
    queryTest(new TermQuery(new Term("f2", "v2")));
    queryTest(new TermQuery(new Term("f3", "v1")));
    queryTest(new TermQuery(new Term("f3", "v2")));
    queryTest(new TermQuery(new Term("f4", "v1")));
    queryTest(new TermQuery(new Term("f4", "v2")));

    BooleanQuery bq1 = new BooleanQuery();
    bq1.add(new TermQuery(new Term("f1", "v1")), Occur.MUST);
    bq1.add(new TermQuery(new Term("f4", "v1")), Occur.MUST);
    queryTest(bq1);
  }

  public void testFieldNames() throws Exception {
    Directory dir1 = getDir1();
    Directory dir2 = getDir2();
    ParallelReader pr = new ParallelReader();
    pr.add(IndexReader.open(dir1));
    pr.add(IndexReader.open(dir2));
    Collection fieldNames = pr.getFieldNames(IndexReader.FieldOption.ALL);
    assertEquals(4, fieldNames.size());
    assertTrue(fieldNames.contains("f1"));
    assertTrue(fieldNames.contains("f2"));
    assertTrue(fieldNames.contains("f3"));
    assertTrue(fieldNames.contains("f4"));
  }
  
  public void testIncompatibleIndexes() throws IOException {
    // two documents:
    Directory dir1 = getDir1();

    // one document only:
    Directory dir2 = new RAMDirectory();
    IndexWriter w2 = new IndexWriter(dir2, new StandardAnalyzer(), true);
    Document d3 = new Document();
    d3.add(new Field("f3", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    w2.addDocument(d3);
    w2.close();
    
    ParallelReader pr = new ParallelReader();
    pr.add(IndexReader.open(dir1));
    try {
      pr.add(IndexReader.open(dir2));
      fail("didn't get exptected exception: indexes don't have same number of documents");
    } catch (IllegalArgumentException e) {
      // expected exception
    }
  }

  private void queryTest(Query query) throws IOException {
    Hits parallelHits = parallel.search(query);
    Hits singleHits = single.search(query);
    assertEquals(parallelHits.length(), singleHits.length());
    for(int i = 0; i < parallelHits.length(); i++) {
      assertEquals(parallelHits.score(i), singleHits.score(i), 0.001f);
      Document docParallel = parallelHits.doc(i);
      Document docSingle = singleHits.doc(i);
      assertEquals(docParallel.get("f1"), docSingle.get("f1"));
      assertEquals(docParallel.get("f2"), docSingle.get("f2"));
      assertEquals(docParallel.get("f3"), docSingle.get("f3"));
      assertEquals(docParallel.get("f4"), docSingle.get("f4"));
    }
  }

  // Fiels 1-4 indexed together:
  private Searcher single() throws IOException {
    Directory dir = new RAMDirectory();
    IndexWriter w = new IndexWriter(dir, new StandardAnalyzer(), true);
    Document d1 = new Document();
    d1.add(new Field("f1", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    d1.add(new Field("f2", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    d1.add(new Field("f3", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    d1.add(new Field("f4", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    w.addDocument(d1);
    Document d2 = new Document();
    d2.add(new Field("f1", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    d2.add(new Field("f2", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    d2.add(new Field("f3", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    d2.add(new Field("f4", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    w.addDocument(d2);
    w.close();

    return new IndexSearcher(dir);
  }

  // Fields 1 & 2 in one index, 3 & 4 in other, with ParallelReader:
  private Searcher parallel() throws IOException {
    Directory dir1 = getDir1();
    Directory dir2 = getDir2();
    ParallelReader pr = new ParallelReader();
    pr.add(IndexReader.open(dir1));
    pr.add(IndexReader.open(dir2));
    return new IndexSearcher(pr);
  }

  private Directory getDir1() throws IOException {
    Directory dir1 = new RAMDirectory();
    IndexWriter w1 = new IndexWriter(dir1, new StandardAnalyzer(), true);
    Document d1 = new Document();
    d1.add(new Field("f1", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    d1.add(new Field("f2", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    w1.addDocument(d1);
    Document d2 = new Document();
    d2.add(new Field("f1", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    d2.add(new Field("f2", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    w1.addDocument(d2);
    w1.close();
    return dir1;
  }

  private Directory getDir2() throws IOException {
    Directory dir2 = new RAMDirectory();
    IndexWriter w2 = new IndexWriter(dir2, new StandardAnalyzer(), true);
    Document d3 = new Document();
    d3.add(new Field("f3", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    d3.add(new Field("f4", "v1", Field.Store.YES, Field.Index.TOKENIZED));
    w2.addDocument(d3);
    Document d4 = new Document();
    d4.add(new Field("f3", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    d4.add(new Field("f4", "v2", Field.Store.YES, Field.Index.TOKENIZED));
    w2.addDocument(d4);
    w2.close();
    return dir2;
  }

}