package org.apache.lucene.index;

/**
 * Copyright 2004 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 junit.framework.TestCase;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.store.Directory;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;

import java.io.IOException;

public class TestSegmentTermDocs extends TestCase {
  private Document testDoc = new Document();
  private Directory dir = new RAMDirectory();

  public TestSegmentTermDocs(String s) {
    super(s);
  }

  protected void setUp() {
    DocHelper.setupDoc(testDoc);
    DocHelper.writeDoc(dir, testDoc);
  }


  protected void tearDown() {

  }

  public void test() {
    assertTrue(dir != null);
  }
  
  public void testTermDocs() {
    try {
      //After adding the document, we should be able to read it back in
      SegmentReader reader = new SegmentReader(new SegmentInfo("test", 1, dir));
      assertTrue(reader != null);
      SegmentTermDocs segTermDocs = new SegmentTermDocs(reader);
      assertTrue(segTermDocs != null);
      segTermDocs.seek(new Term(DocHelper.TEXT_FIELD_2_KEY, "field"));
      if (segTermDocs.next() == true)
      {
        int docId = segTermDocs.doc();
        assertTrue(docId == 0);
        int freq = segTermDocs.freq();
        assertTrue(freq == 3);  
      }
      reader.close();
    } catch (IOException e) {
      assertTrue(false);
    }
  }  
  
  public void testBadSeek() {
    try {
      //After adding the document, we should be able to read it back in
      SegmentReader reader = new SegmentReader(new SegmentInfo("test", 3, dir));
      assertTrue(reader != null);
      SegmentTermDocs segTermDocs = new SegmentTermDocs(reader);
      assertTrue(segTermDocs != null);
      segTermDocs.seek(new Term("textField2", "bad"));
      assertTrue(segTermDocs.next() == false);
      reader.close();
    } catch (IOException e) {
      assertTrue(false);
    }
    try {
      //After adding the document, we should be able to read it back in
      SegmentReader reader = new SegmentReader(new SegmentInfo("test", 3, dir));
      assertTrue(reader != null);
      SegmentTermDocs segTermDocs = new SegmentTermDocs(reader);
      assertTrue(segTermDocs != null);
      segTermDocs.seek(new Term("junk", "bad"));
      assertTrue(segTermDocs.next() == false);
      reader.close();
    } catch (IOException e) {
      assertTrue(false);
    }
  }
  
  public void testSkipTo() {
    try {
      Directory dir = new RAMDirectory();
      IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), true);
      
      Term ta = new Term("content","aaa");
      for(int i = 0; i < 10; i++)
        addDoc(writer, "aaa aaa aaa aaa");
        
      Term tb = new Term("content","bbb");
      for(int i = 0; i < 16; i++)
        addDoc(writer, "bbb bbb bbb bbb");
        
      Term tc = new Term("content","ccc");
      for(int i = 0; i < 50; i++)
        addDoc(writer, "ccc ccc ccc ccc");
        
      // assure that we deal with a single segment  
      writer.optimize();
      writer.close();
      
      IndexReader reader = IndexReader.open(dir);
      TermDocs tdocs = reader.termDocs();
      
      // without optimization (assumption skipInterval == 16)
      
      // with next
      tdocs.seek(ta);
      assertTrue(tdocs.next());
      assertEquals(0, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.next());
      assertEquals(1, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.skipTo(0));
      assertEquals(2, tdocs.doc());
      assertTrue(tdocs.skipTo(4));
      assertEquals(4, tdocs.doc());
      assertTrue(tdocs.skipTo(9));
      assertEquals(9, tdocs.doc());
      assertFalse(tdocs.skipTo(10));
      
      // without next
      tdocs.seek(ta);
      assertTrue(tdocs.skipTo(0));
      assertEquals(0, tdocs.doc());
      assertTrue(tdocs.skipTo(4));
      assertEquals(4, tdocs.doc());
      assertTrue(tdocs.skipTo(9));
      assertEquals(9, tdocs.doc());
      assertFalse(tdocs.skipTo(10));
      
      // exactly skipInterval documents and therefore with optimization
      
      // with next
      tdocs.seek(tb);
      assertTrue(tdocs.next());
      assertEquals(10, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.next());
      assertEquals(11, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.skipTo(5));
      assertEquals(12, tdocs.doc());
      assertTrue(tdocs.skipTo(15));
      assertEquals(15, tdocs.doc());
      assertTrue(tdocs.skipTo(24));
      assertEquals(24, tdocs.doc());
      assertTrue(tdocs.skipTo(25));
      assertEquals(25, tdocs.doc());
      assertFalse(tdocs.skipTo(26));
      
      // without next
      tdocs.seek(tb);
      assertTrue(tdocs.skipTo(5));
      assertEquals(10, tdocs.doc());
      assertTrue(tdocs.skipTo(15));
      assertEquals(15, tdocs.doc());
      assertTrue(tdocs.skipTo(24));
      assertEquals(24, tdocs.doc());
      assertTrue(tdocs.skipTo(25));
      assertEquals(25, tdocs.doc());
      assertFalse(tdocs.skipTo(26));
      
      // much more than skipInterval documents and therefore with optimization
      
      // with next
      tdocs.seek(tc);
      assertTrue(tdocs.next());
      assertEquals(26, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.next());
      assertEquals(27, tdocs.doc());
      assertEquals(4, tdocs.freq());
      assertTrue(tdocs.skipTo(5));
      assertEquals(28, tdocs.doc());
      assertTrue(tdocs.skipTo(40));
      assertEquals(40, tdocs.doc());
      assertTrue(tdocs.skipTo(57));
      assertEquals(57, tdocs.doc());
      assertTrue(tdocs.skipTo(74));
      assertEquals(74, tdocs.doc());
      assertTrue(tdocs.skipTo(75));
      assertEquals(75, tdocs.doc());
      assertFalse(tdocs.skipTo(76));
      
      //without next
      tdocs.seek(tc);
      assertTrue(tdocs.skipTo(5));
      assertEquals(26, tdocs.doc());
      assertTrue(tdocs.skipTo(40));
      assertEquals(40, tdocs.doc());
      assertTrue(tdocs.skipTo(57));
      assertEquals(57, tdocs.doc());
      assertTrue(tdocs.skipTo(74));
      assertEquals(74, tdocs.doc());
      assertTrue(tdocs.skipTo(75));
      assertEquals(75, tdocs.doc());
      assertFalse(tdocs.skipTo(76));
      
      tdocs.close();
      reader.close();
      dir.close();
    } catch (IOException e) {
        assertTrue(false);
    }
  }
  
  private void addDoc(IndexWriter writer, String value) throws IOException
  {
      Document doc = new Document();
      doc.add(Field.UnStored("content", value));
      writer.addDocument(doc);
  }
}