/*
 * 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.lucene.queries.payloads;

import java.io.IOException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.PayloadAttribute;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.spans.SpanQuery;
import org.apache.lucene.queries.spans.SpanTermQuery;
import org.apache.lucene.queries.spans.SpanWeight;
import org.apache.lucene.queries.spans.Spans;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.ScoreMode;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.similarities.ClassicSimilarity;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.store.Directory;
import org.apache.lucene.tests.analysis.MockTokenizer;
import org.apache.lucene.tests.index.RandomIndexWriter;
import org.apache.lucene.tests.search.CheckHits;
import org.apache.lucene.tests.search.QueryUtils;
import org.apache.lucene.tests.util.English;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.apache.lucene.util.BytesRef;
import org.junit.AfterClass;
import org.junit.BeforeClass;

/** */
public class TestPayloadTermQuery extends LuceneTestCase {
  @SuppressWarnings("NonFinalStaticField")
  private static IndexSearcher searcher;

  @SuppressWarnings("NonFinalStaticField")
  private static IndexReader reader;

  private static final Similarity similarity = new BoostingSimilarity();
  private static final byte[] payloadField = new byte[] {1};
  private static final byte[] payloadMultiField1 = new byte[] {2};
  private static final byte[] payloadMultiField2 = new byte[] {4};

  @SuppressWarnings("NonFinalStaticField")
  protected static Directory directory;

  private static class PayloadAnalyzer extends Analyzer {

    private PayloadAnalyzer() {
      super(PER_FIELD_REUSE_STRATEGY);
    }

    @Override
    public TokenStreamComponents createComponents(String fieldName) {
      Tokenizer result = new MockTokenizer(MockTokenizer.SIMPLE, true);
      return new TokenStreamComponents(result, new PayloadFilter(result, fieldName));
    }
  }

  private static class PayloadFilter extends TokenFilter {
    private final String fieldName;
    private int numSeen = 0;

    private final PayloadAttribute payloadAtt;

    public PayloadFilter(TokenStream input, String fieldName) {
      super(input);
      this.fieldName = fieldName;
      payloadAtt = addAttribute(PayloadAttribute.class);
    }

    @Override
    public boolean incrementToken() throws IOException {
      boolean hasNext = input.incrementToken();
      if (hasNext) {
        if (fieldName.equals("field")) {
          payloadAtt.setPayload(new BytesRef(payloadField));
        } else if (fieldName.equals("multiField")) {
          if (numSeen % 2 == 0) {
            payloadAtt.setPayload(new BytesRef(payloadMultiField1));
          } else {
            payloadAtt.setPayload(new BytesRef(payloadMultiField2));
          }
          numSeen++;
        }
        return true;
      } else {
        return false;
      }
    }

    @Override
    public void reset() throws IOException {
      super.reset();
      this.numSeen = 0;
    }
  }

  @BeforeClass
  public static void beforeClass() throws Exception {
    directory = newDirectory();
    RandomIndexWriter writer =
        new RandomIndexWriter(
            random(),
            directory,
            newIndexWriterConfig(new PayloadAnalyzer())
                .setSimilarity(similarity)
                .setMergePolicy(newLogMergePolicy()));
    // writer.infoStream = System.out;
    for (int i = 0; i < 1000; i++) {
      Document doc = new Document();
      Field noPayloadField =
          newTextField(PayloadHelper.NO_PAYLOAD_FIELD, English.intToEnglish(i), Field.Store.YES);
      // noPayloadField.setBoost(0);
      doc.add(noPayloadField);
      doc.add(newTextField("field", English.intToEnglish(i), Field.Store.YES));
      doc.add(
          newTextField(
              "multiField",
              English.intToEnglish(i) + "  " + English.intToEnglish(i),
              Field.Store.YES));
      writer.addDocument(doc);
    }
    writer.forceMerge(1);
    reader = writer.getReader();
    writer.close();

    searcher = newSearcher(getOnlyLeafReader(reader));
    searcher.setSimilarity(similarity);
  }

  @AfterClass
  public static void afterClass() throws Exception {
    searcher = null;
    reader.close();
    reader = null;
    directory.close();
    directory = null;
  }

  public void test() throws IOException {
    SpanQuery query =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term("field", "seventy")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    TopDocs hits = searcher.search(query, 100);
    assertTrue("hits is null and it shouldn't be", hits != null);
    assertTrue(
        "hits Size: " + hits.totalHits.value() + " is not: " + 100, hits.totalHits.value() == 100);

    // they should all have the exact same score, because they all contain seventy once, and we set
    // all the other similarity factors to be 1

    for (int i = 0; i < hits.scoreDocs.length; i++) {
      ScoreDoc doc = hits.scoreDocs[i];
      assertTrue(doc.score + " does not equal: " + 1, doc.score == 1);
    }
    CheckHits.checkExplanations(query, PayloadHelper.FIELD, searcher, true);
    Spans spans =
        query
            .createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f)
            .getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
    assertTrue("spans is null and it shouldn't be", spans != null);
    /*float score = hits.score(0);
    for (int i =1; i < hits.length(); i++)
    {
      assertTrue("scores are not equal and they should be", score == hits.score(i));
    }*/

  }

  public void testQuery() {
    SpanQuery boostingFuncTermQuery =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.MULTI_FIELD, "seventy")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    QueryUtils.check(boostingFuncTermQuery);

    SpanTermQuery spanTermQuery = new SpanTermQuery(new Term(PayloadHelper.MULTI_FIELD, "seventy"));

    assertTrue(
        boostingFuncTermQuery.equals(spanTermQuery) == spanTermQuery.equals(boostingFuncTermQuery));

    SpanQuery boostingFuncTermQuery2 =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.MULTI_FIELD, "seventy")),
            new AveragePayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);

    QueryUtils.checkUnequal(boostingFuncTermQuery, boostingFuncTermQuery2);
  }

  public void testMultipleMatchesPerDoc() throws Exception {
    SpanQuery query =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.MULTI_FIELD, "seventy")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    TopDocs hits = searcher.search(query, 100);
    assertTrue("hits is null and it shouldn't be", hits != null);
    assertTrue(
        "hits Size: " + hits.totalHits.value() + " is not: " + 100, hits.totalHits.value() == 100);

    // they should all have the exact same score, because they all contain seventy once, and we set
    // all the other similarity factors to be 1

    // System.out.println("Hash: " + seventyHash + " Twice Hash: " + 2*seventyHash);
    // there should be exactly 10 items that score a 4, all the rest should score a 2
    // The 10 items are: 70 + i*100 where i in [0-9]
    int numTens = 0;
    for (int i = 0; i < hits.scoreDocs.length; i++) {
      ScoreDoc doc = hits.scoreDocs[i];
      if (doc.doc % 10 == 0) {
        numTens++;
        assertTrue(doc.score + " does not equal: " + 4.0, doc.score == 4.0);
      } else {
        assertTrue(doc.score + " does not equal: " + 2, doc.score == 2);
      }
    }
    assertTrue(numTens + " does not equal: " + 10, numTens == 10);
    CheckHits.checkExplanations(query, "field", searcher, true);
    Spans spans =
        query
            .createWeight(searcher, ScoreMode.COMPLETE_NO_SCORES, 1f)
            .getSpans(searcher.getIndexReader().leaves().get(0), SpanWeight.Postings.POSITIONS);
    assertTrue("spans is null and it shouldn't be", spans != null);
    // should be two matches per document
    int count = 0;
    // 100 hits times 2 matches per hit, we should have 200 in count
    while (spans.nextDoc() != Spans.NO_MORE_DOCS) {
      while (spans.nextStartPosition() != Spans.NO_MORE_POSITIONS) {
        count++;
      }
    }
    assertTrue(count + " does not equal: " + 200, count == 200);
  }

  public void testNoMatch() throws Exception {
    SpanQuery query =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.FIELD, "junk")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    TopDocs hits = searcher.search(query, 100);
    assertTrue("hits is null and it shouldn't be", hits != null);
    assertTrue(
        "hits Size: " + hits.totalHits.value() + " is not: " + 0, hits.totalHits.value() == 0);
  }

  public void testNoPayload() throws Exception {
    SpanQuery q1 =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.NO_PAYLOAD_FIELD, "zero")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    SpanQuery q2 =
        new PayloadScoreQuery(
            new SpanTermQuery(new Term(PayloadHelper.NO_PAYLOAD_FIELD, "foo")),
            new MaxPayloadFunction(),
            PayloadDecoder.FLOAT_DECODER);
    BooleanClause c1 = new BooleanClause(q1, BooleanClause.Occur.MUST);
    BooleanClause c2 = new BooleanClause(q2, BooleanClause.Occur.MUST_NOT);
    BooleanQuery.Builder query = new BooleanQuery.Builder();
    query.add(c1);
    query.add(c2);
    TopDocs hits = searcher.search(query.build(), 100);
    assertTrue("hits is null and it shouldn't be", hits != null);
    assertTrue(
        "hits Size: " + hits.totalHits.value() + " is not: " + 1, hits.totalHits.value() == 1);
    int[] results = new int[1];
    results[0] = 0; // hits.scoreDocs[0].doc;
    CheckHits.checkHitCollector(
        random(), query.build(), PayloadHelper.NO_PAYLOAD_FIELD, searcher, results);
  }

  static class BoostingSimilarity extends ClassicSimilarity {

    // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    // Make everything else 1 so we see the effect of the payload
    // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    @Override
    public float lengthNorm(int length) {
      return 1;
    }

    @Override
    public float idf(long docFreq, long docCount) {
      return 1;
    }

    @Override
    public float tf(float freq) {
      return freq == 0 ? 0 : 1;
    }
  }
}
