package org.apache.lucene.search;

/**
 * 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.
 */

import java.io.IOException;

import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Index;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.PhraseQuery;
import org.apache.lucene.store.Directory;

public class TestSloppyPhraseQuery extends LuceneTestCase {

  private static final String S_1 = "A A A";
  private static final String S_2 = "A 1 2 3 A 4 5 6 A";

  private static final Document DOC_1 = makeDocument("X " + S_1 + " Y");
  private static final Document DOC_2 = makeDocument("X " + S_2 + " Y");
  private static final Document DOC_3 = makeDocument("X " + S_1 + " A Y");
  private static final Document DOC_1_B = makeDocument("X " + S_1 + " Y N N N N " + S_1 + " Z");
  private static final Document DOC_2_B = makeDocument("X " + S_2 + " Y N N N N " + S_2 + " Z");
  private static final Document DOC_3_B = makeDocument("X " + S_1 + " A Y N N N N " + S_1 + " A Y");
  private static final Document DOC_4 = makeDocument("A A X A X B A X B B A A X B A A");
  private static final Document DOC_5_3 = makeDocument("H H H X X X H H H X X X H H H");
  private static final Document DOC_5_4 = makeDocument("H H H H");

  private static final PhraseQuery QUERY_1 = makePhraseQuery( S_1 );
  private static final PhraseQuery QUERY_2 = makePhraseQuery( S_2 );
  private static final PhraseQuery QUERY_4 = makePhraseQuery( "X A A");
  private static final PhraseQuery QUERY_5_4 = makePhraseQuery( "H H H H");

  /**
   * Test DOC_4 and QUERY_4.
   * QUERY_4 has a fuzzy (len=1) match to DOC_4, so all slop values > 0 should succeed.
   * But only the 3rd sequence of A's in DOC_4 will do.
   */
  public void testDoc4_Query4_All_Slops_Should_match() throws Exception {
    for (int slop=0; slop<30; slop++) {
      int numResultsExpected = slop<1 ? 0 : 1;
      checkPhraseQuery(DOC_4, QUERY_4, slop, numResultsExpected);
    }
  }

  /**
   * Test DOC_1 and QUERY_1.
   * QUERY_1 has an exact match to DOC_1, so all slop values should succeed.
   * Before LUCENE-1310, a slop value of 1 did not succeed.
   */
  public void testDoc1_Query1_All_Slops_Should_match() throws Exception {
    for (int slop=0; slop<30; slop++) {
      float score1 = checkPhraseQuery(DOC_1, QUERY_1, slop, 1);
      float score2 = checkPhraseQuery(DOC_1_B, QUERY_1, slop, 1);
      assertTrue("slop="+slop+" score2="+score2+" should be greater than score1 "+score1, score2>score1);
    }
  }

  /**
   * Test DOC_2 and QUERY_1.
   * 6 should be the minimum slop to make QUERY_1 match DOC_2.
   * Before LUCENE-1310, 7 was the minimum.
   */
  public void testDoc2_Query1_Slop_6_or_more_Should_match() throws Exception {
    for (int slop=0; slop<30; slop++) {
      int numResultsExpected = slop<6 ? 0 : 1;
      float score1 = checkPhraseQuery(DOC_2, QUERY_1, slop, numResultsExpected);
      if (numResultsExpected>0) {
        float score2 = checkPhraseQuery(DOC_2_B, QUERY_1, slop, 1);
        assertTrue("slop="+slop+" score2="+score2+" should be greater than score1 "+score1, score2>score1);
      }
    }
  }

  /**
   * Test DOC_2 and QUERY_2.
   * QUERY_2 has an exact match to DOC_2, so all slop values should succeed.
   * Before LUCENE-1310, 0 succeeds, 1 through 7 fail, and 8 or greater succeeds.
   */
  public void testDoc2_Query2_All_Slops_Should_match() throws Exception {
    for (int slop=0; slop<30; slop++) {
      float score1 = checkPhraseQuery(DOC_2, QUERY_2, slop, 1);
      float score2 = checkPhraseQuery(DOC_2_B, QUERY_2, slop, 1);
      assertTrue("slop="+slop+" score2="+score2+" should be greater than score1 "+score1, score2>score1);
    }
  }

  /**
   * Test DOC_3 and QUERY_1.
   * QUERY_1 has an exact match to DOC_3, so all slop values should succeed.
   */
  public void testDoc3_Query1_All_Slops_Should_match() throws Exception {
    for (int slop=0; slop<30; slop++) {
      float score1 = checkPhraseQuery(DOC_3, QUERY_1, slop, 1);
      float score2 = checkPhraseQuery(DOC_3_B, QUERY_1, slop, 1);
      assertTrue("slop="+slop+" score2="+score2+" should be greater than score1 "+score1, score2>score1);
    }
  }

  /** LUCENE-3412 */
  public void testDoc5_Query5_Any_Slop_Should_be_consistent() throws Exception {
    int nRepeats = 5;
    for (int slop=0; slop<3; slop++) {
      for (int trial=0; trial<nRepeats; trial++) {
        // should steadily always find this one
        checkPhraseQuery(DOC_5_4, QUERY_5_4, slop, 1);
      }
      for (int trial=0; trial<nRepeats; trial++) {
        // should steadily never find this one
        checkPhraseQuery(DOC_5_3, QUERY_5_4, slop, 0);
      }
    }
  }
  
  private float  checkPhraseQuery(Document doc, PhraseQuery query, int slop, int expectedNumResults) throws Exception {
    query.setSlop(slop);

    Directory ramDir = newDirectory();
    RandomIndexWriter writer = new RandomIndexWriter(random, ramDir, new MockAnalyzer(random, MockTokenizer.WHITESPACE, false));
    writer.addDocument(doc);

    IndexReader reader = writer.getReader();

    IndexSearcher searcher = newSearcher(reader);
    TopDocs td = searcher.search(query,null,10);
    //System.out.println("slop: "+slop+"  query: "+query+"  doc: "+doc+"  Expecting number of hits: "+expectedNumResults+" maxScore="+td.getMaxScore());
    assertEquals("slop: "+slop+"  query: "+query+"  doc: "+doc+"  Wrong number of hits", expectedNumResults, td.totalHits);

    //QueryUtils.check(query,searcher);
    writer.close();
    searcher.close();
    reader.close();
    ramDir.close();

    return td.getMaxScore();
  }

  private static Document makeDocument(String docText) {
    Document doc = new Document();
    Field f = new Field("f", docText, Field.Store.NO, Field.Index.ANALYZED);
    f.setOmitNorms(true);
    doc.add(f);
    return doc;
  }

  private static PhraseQuery makePhraseQuery(String terms) {
    PhraseQuery query = new PhraseQuery();
    String[] t = terms.split(" +");
    for (int i=0; i<t.length; i++) {
      query.add(new Term("f", t[i]));
    }
    return query;
  }

  
  /** checks that no scores or freqs are infinite */
  private void assertSaneScoring(PhraseQuery pq, IndexSearcher searcher) throws Exception {
    searcher.search(pq, new Collector() {
      Scorer scorer;
      
      @Override
      public void setScorer(Scorer scorer) throws IOException {
        this.scorer = scorer;
      }
      
      @Override
      public void collect(int doc) throws IOException {
        assertFalse(Float.isInfinite(scorer.freq()));
        assertFalse(Float.isInfinite(scorer.score()));
      }
      
      @Override
      public void setNextReader(IndexReader reader, int docBase) throws IOException {
        // do nothing
      }
      
      @Override
      public boolean acceptsDocsOutOfOrder() {
        return false;
      }

    });
    QueryUtils.check(random, pq, searcher);
  }

  // LUCENE-3215
  public void testSlopWithHoles() throws Exception {  
    Directory dir = newDirectory();
    RandomIndexWriter iw = new RandomIndexWriter(random, dir);
    Field f = new Field("lyrics", "", Field.Store.NO, Field.Index.ANALYZED_NO_NORMS);
    Document doc = new Document();
    doc.add(f);
    f.setValue("drug drug");
    iw.addDocument(doc);
    f.setValue("drug druggy drug");
    iw.addDocument(doc);
    f.setValue("drug druggy druggy drug");
    iw.addDocument(doc);
    f.setValue("drug druggy drug druggy drug");
    iw.addDocument(doc);
    IndexReader ir = iw.getReader();
    iw.close();
    IndexSearcher is = newSearcher(ir);
    
    PhraseQuery pq = new PhraseQuery();
    // "drug the drug"~1
    pq.add(new Term("lyrics", "drug"), 1);
    pq.add(new Term("lyrics", "drug"), 4);
    pq.setSlop(0);
    assertEquals(0, is.search(pq, 4).totalHits);
    pq.setSlop(1);
    assertEquals(3, is.search(pq, 4).totalHits);
    pq.setSlop(2);
    assertEquals(4, is.search(pq, 4).totalHits);
    is.close();
    ir.close();
    dir.close();
  }

  // LUCENE-3215
  public void testInfiniteFreq1() throws Exception {
    String document = "drug druggy drug drug drug";
    
    Directory dir = newDirectory();
    RandomIndexWriter iw = new RandomIndexWriter(random, dir);
    Document doc = new Document();
    doc.add(newField("lyrics", document, Store.NO, Index.ANALYZED_NO_NORMS));
    iw.addDocument(doc);
    IndexReader ir = iw.getReader();
    iw.close();
    
    IndexSearcher is = newSearcher(ir);
    PhraseQuery pq = new PhraseQuery();
    // "drug the drug"~1
    pq.add(new Term("lyrics", "drug"), 1);
    pq.add(new Term("lyrics", "drug"), 3);
    pq.setSlop(1);
    assertSaneScoring(pq, is);
    is.close();
    ir.close();
    dir.close();
  }
  
  // LUCENE-3215
  public void testInfiniteFreq2() throws Exception {
    String document = 
      "So much fun to be had in my head " +
      "No more sunshine " +
      "So much fun just lying in my bed " +
      "No more sunshine " +
      "I can't face the sunlight and the dirt outside " +
      "Wanna stay in 666 where this darkness don't lie " +
      "Drug drug druggy " +
      "Got a feeling sweet like honey " +
      "Drug drug druggy " +
      "Need sensation like my baby " +
      "Show me your scars you're so aware " +
      "I'm not barbaric I just care " +
      "Drug drug drug " +
      "I need a reflection to prove I exist " +
      "No more sunshine " +
      "I am a victim of designer blitz " +
      "No more sunshine " +
      "Dance like a robot when you're chained at the knee " +
      "The C.I.A say you're all they'll ever need " +
      "Drug drug druggy " +
      "Got a feeling sweet like honey " +
      "Drug drug druggy " +
      "Need sensation like my baby " +
      "Snort your lines you're so aware " +
      "I'm not barbaric I just care " +
      "Drug drug druggy " +
      "Got a feeling sweet like honey " +
      "Drug drug druggy " +
      "Need sensation like my baby";
        
     Directory dir = newDirectory();

     RandomIndexWriter iw = new RandomIndexWriter(random, dir);
     Document doc = new Document();
     doc.add(newField("lyrics", document, Store.NO, Index.ANALYZED_NO_NORMS));
     iw.addDocument(doc);
     IndexReader ir = iw.getReader();
     iw.close();
        
     IndexSearcher is = newSearcher(ir);
     
     PhraseQuery pq = new PhraseQuery();
     // "drug the drug"~5
     pq.add(new Term("lyrics", "drug"), 1);
     pq.add(new Term("lyrics", "drug"), 3);
     pq.setSlop(5);
     assertSaneScoring(pq, is);
     is.close();
     ir.close();
     dir.close();
  }
}