/*
 * 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.tests.index;

import static org.apache.lucene.index.PostingsEnum.ALL;
import static org.apache.lucene.index.PostingsEnum.FREQS;
import static org.apache.lucene.index.PostingsEnum.NONE;
import static org.apache.lucene.index.PostingsEnum.OFFSETS;
import static org.apache.lucene.index.PostingsEnum.PAYLOADS;
import static org.apache.lucene.index.PostingsEnum.POSITIONS;

import java.io.IOException;
import java.nio.file.Path;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.codecs.FieldsConsumer;
import org.apache.lucene.codecs.FieldsProducer;
import org.apache.lucene.codecs.FilterCodec;
import org.apache.lucene.codecs.NormsProducer;
import org.apache.lucene.codecs.PostingsFormat;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.FieldType;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.CodecReader;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.Fields;
import org.apache.lucene.index.IndexOptions;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.index.IndexableField;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.MultiTerms;
import org.apache.lucene.index.PostingsEnum;
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.index.SegmentWriteState;
import org.apache.lucene.index.SerialMergeScheduler;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.index.TermsEnum.SeekStatus;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.IOContext;
import org.apache.lucene.tests.analysis.CannedTokenStream;
import org.apache.lucene.tests.analysis.MockAnalyzer;
import org.apache.lucene.tests.analysis.MockTokenizer;
import org.apache.lucene.tests.analysis.Token;
import org.apache.lucene.tests.util.LineFileDocs;
import org.apache.lucene.tests.util.RamUsageTester;
import org.apache.lucene.tests.util.TestUtil;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.IOUtils;
import org.junit.AfterClass;
import org.junit.BeforeClass;

/**
 * Abstract class to do basic tests for a postings format. NOTE: This test focuses on the postings
 * (docs/freqs/positions/payloads/offsets) impl, not the terms dict. The [stretch] goal is for this
 * test to be so thorough in testing a new PostingsFormat that if this test passes, then all Lucene
 * tests should also pass. Ie, if there is some bug in a given PostingsFormat that this test fails
 * to catch then this test needs to be improved!
 */

// TODO can we make it easy for testing to pair up a "random terms dict impl" with your postings
// base format...

// TODO test when you reuse after skipping a term or two, eg the block reuse case

/* TODO
  - threads
  - assert doc=-1 before any nextDoc
  - if a PF passes this test but fails other tests then this
    test has a bug!!
  - test tricky reuse cases, eg across fields
  - verify you get null if you pass needFreq/needOffset but
    they weren't indexed
*/

public abstract class BasePostingsFormatTestCase extends BaseIndexFileFormatTestCase {

  static RandomPostingsTester postingsTester;

  // TODO maybe instead of @BeforeClass just make a single test run: build postings & index & test
  // it?

  @BeforeClass
  public static void createPostings() throws IOException {
    postingsTester = new RandomPostingsTester(random());
  }

  @AfterClass
  public static void afterClass() throws Exception {
    postingsTester = null;
  }

  public void testDocsOnly() throws Exception {
    postingsTester.testFull(
        getCodec(), createTempDir("testPostingsFormat.testExact"), IndexOptions.DOCS, false);
  }

  public void testDocsAndFreqs() throws Exception {
    postingsTester.testFull(
        getCodec(),
        createTempDir("testPostingsFormat.testExact"),
        IndexOptions.DOCS_AND_FREQS,
        false);
  }

  public void testDocsAndFreqsAndPositions() throws Exception {
    postingsTester.testFull(
        getCodec(),
        createTempDir("testPostingsFormat.testExact"),
        IndexOptions.DOCS_AND_FREQS_AND_POSITIONS,
        false);
  }

  public void testDocsAndFreqsAndPositionsAndPayloads() throws Exception {
    postingsTester.testFull(
        getCodec(),
        createTempDir("testPostingsFormat.testExact"),
        IndexOptions.DOCS_AND_FREQS_AND_POSITIONS,
        true);
  }

  public void testDocsAndFreqsAndPositionsAndOffsets() throws Exception {
    postingsTester.testFull(
        getCodec(),
        createTempDir("testPostingsFormat.testExact"),
        IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
        false);
  }

  public void testDocsAndFreqsAndPositionsAndOffsetsAndPayloads() throws Exception {
    postingsTester.testFull(
        getCodec(),
        createTempDir("testPostingsFormat.testExact"),
        IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
        true);
  }

  public void testRandom() throws Exception {

    int iters = 5;

    for (int iter = 0; iter < iters; iter++) {
      Path path = createTempDir("testPostingsFormat");
      Directory dir = newFSDirectory(path);

      boolean indexPayloads = random().nextBoolean();
      // TODO test thread safety of buildIndex too
      FieldsProducer fieldsProducer =
          postingsTester.buildIndex(
              getCodec(),
              dir,
              IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
              indexPayloads,
              false);

      postingsTester.testFields(fieldsProducer);

      // NOTE: you can also test "weaker" index options than
      // you indexed with:
      postingsTester.testTerms(
          fieldsProducer,
          EnumSet.allOf(RandomPostingsTester.Option.class),
          IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
          IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
          false);

      fieldsProducer.close();
      fieldsProducer = null;

      dir.close();
    }
  }

  protected boolean isPostingsEnumReuseImplemented() {
    return true;
  }

  public void testPostingsEnumReuse() throws Exception {

    Path path = createTempDir("testPostingsEnumReuse");
    Directory dir = newFSDirectory(path);

    FieldsProducer fieldsProducer =
        postingsTester.buildIndex(
            getCodec(),
            dir,
            IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
            random().nextBoolean(),
            true);
    Collections.shuffle(postingsTester.allTerms, random());
    RandomPostingsTester.FieldAndTerm fieldAndTerm = postingsTester.allTerms.get(0);

    Terms terms = fieldsProducer.terms(fieldAndTerm.field);
    TermsEnum te = terms.iterator();

    te.seekExact(fieldAndTerm.term);
    checkReuse(te, PostingsEnum.FREQS, PostingsEnum.ALL, false);
    if (isPostingsEnumReuseImplemented()) {
      checkReuse(te, PostingsEnum.ALL, PostingsEnum.ALL, true);
    }

    fieldsProducer.close();
    dir.close();
  }

  protected static void checkReuse(
      TermsEnum termsEnum, int firstFlags, int secondFlags, boolean shouldReuse)
      throws IOException {
    PostingsEnum postings1 = termsEnum.postings(null, firstFlags);
    PostingsEnum postings2 = termsEnum.postings(postings1, secondFlags);
    if (shouldReuse) {
      assertSame(
          "Expected PostingsEnum " + postings1.getClass().getName() + " to be reused",
          postings1,
          postings2);
    } else {
      assertNotSame(
          "Expected PostingsEnum " + postings1.getClass().getName() + " to not be reused",
          postings1,
          postings2);
    }
  }

  public void testJustEmptyField() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
    Document doc = new Document();
    doc.add(newStringField("", "something", Field.Store.NO));
    iw.addDocument(doc);
    DirectoryReader ir = iw.getReader();
    LeafReader ar = getOnlyLeafReader(ir);
    assertEquals(1, ar.getFieldInfos().size());
    Terms terms = ar.terms("");
    assertNotNull(terms);
    TermsEnum termsEnum = terms.iterator();
    assertNotNull(termsEnum.next());
    assertEquals(termsEnum.term(), new BytesRef("something"));
    assertNull(termsEnum.next());
    ir.close();
    iw.close();
    dir.close();
  }

  public void testEmptyFieldAndEmptyTerm() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
    Document doc = new Document();
    doc.add(newStringField("", "", Field.Store.NO));
    iw.addDocument(doc);
    DirectoryReader ir = iw.getReader();
    LeafReader ar = getOnlyLeafReader(ir);
    assertEquals(1, ar.getFieldInfos().size());
    Terms terms = ar.terms("");
    assertNotNull(terms);
    TermsEnum termsEnum = terms.iterator();
    assertNotNull(termsEnum.next());
    assertEquals(termsEnum.term(), new BytesRef(""));
    assertNull(termsEnum.next());
    ir.close();
    iw.close();
    dir.close();
  }

  public void testDidntWantFreqsButAskedAnyway() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = newIndexWriterConfig(new MockAnalyzer(random()));
    iwc.setCodec(getCodec());
    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
    Document doc = new Document();
    doc.add(newTextField("field", "value", Field.Store.NO));
    iw.addDocument(doc);
    iw.addDocument(doc);
    DirectoryReader ir = iw.getReader();
    LeafReader ar = getOnlyLeafReader(ir);
    TermsEnum termsEnum = ar.terms("field").iterator();
    assertTrue(termsEnum.seekExact(new BytesRef("value")));
    PostingsEnum docsEnum = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(0, docsEnum.nextDoc());
    assertEquals(1, docsEnum.freq());
    assertEquals(1, docsEnum.nextDoc());
    assertEquals(1, docsEnum.freq());
    ir.close();
    iw.close();
    dir.close();
  }

  public void testAskForPositionsWhenNotThere() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = newIndexWriterConfig(new MockAnalyzer(random()));
    iwc.setCodec(getCodec());
    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
    Document doc = new Document();
    doc.add(newStringField("field", "value", Field.Store.NO));
    iw.addDocument(doc);
    iw.addDocument(doc);
    DirectoryReader ir = iw.getReader();
    LeafReader ar = getOnlyLeafReader(ir);
    TermsEnum termsEnum = ar.terms("field").iterator();
    assertTrue(termsEnum.seekExact(new BytesRef("value")));
    PostingsEnum docsEnum = termsEnum.postings(null, PostingsEnum.POSITIONS);
    assertEquals(0, docsEnum.nextDoc());
    assertEquals(1, docsEnum.freq());
    assertEquals(1, docsEnum.nextDoc());
    assertEquals(1, docsEnum.freq());
    ir.close();
    iw.close();
    dir.close();
  }

  // tests that ghost fields still work
  // TODO: can this be improved?
  public void testGhosts() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    iwc.setMergePolicy(newLogMergePolicy());
    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
    Document doc = new Document();
    iw.addDocument(doc);
    doc.add(newStringField("ghostField", "something", Field.Store.NO));
    iw.addDocument(doc);
    iw.forceMerge(1);
    iw.deleteDocuments(new Term("ghostField", "something")); // delete the only term for the field
    iw.forceMerge(1);
    DirectoryReader ir = iw.getReader();
    LeafReader ar = getOnlyLeafReader(ir);
    // Ghost busting terms dict impls will have
    // fields.size() == 0; all others must be == 1:
    assertTrue(ar.getFieldInfos().size() <= 1);
    Terms terms = ar.terms("ghostField");
    if (terms != null) {
      TermsEnum termsEnum = terms.iterator();
      BytesRef term = termsEnum.next();
      if (term != null) {
        PostingsEnum postingsEnum = termsEnum.postings(null);
        assertTrue(postingsEnum.nextDoc() == PostingsEnum.NO_MORE_DOCS);
      }
    }
    ir.close();
    iw.close();
    dir.close();
  }

  // Test seek in disorder.
  public void testDisorder() throws Exception {
    Directory dir = newDirectory();

    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    iwc.setMergePolicy(newTieredMergePolicy());
    IndexWriter iw = new IndexWriter(dir, iwc);

    for (int i = 0; i < 10000; i++) {
      Document document = new Document();
      document.add(new StringField("id", i + "", Field.Store.NO));
      iw.addDocument(document);
    }
    iw.commit();
    iw.forceMerge(1);

    DirectoryReader reader = DirectoryReader.open(iw);
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("id").iterator();

    for (int i = 0; i < 20000; i++) {
      int n = random().nextInt(0, 10000);
      BytesRef target = new BytesRef(n + "");
      // seekExact.
      assertTrue(termsEnum.seekExact(target));
      assertEquals(termsEnum.term(), target);
      // seekCeil.
      assertEquals(SeekStatus.FOUND, termsEnum.seekCeil(target));
      assertEquals(termsEnum.term(), target);
    }

    reader.close();
    iw.close();
    dir.close();
  }

  protected void subCheckBinarySearch(TermsEnum termsEnum) throws Exception {}

  public void testBinarySearchTermLeaf() throws Exception {
    Directory dir = newDirectory();

    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    iwc.setMergePolicy(newTieredMergePolicy());
    IndexWriter iw = new IndexWriter(dir, iwc);

    for (int i = 100000; i <= 100400; i++) {
      // only add odd number
      if (i % 2 == 1) {
        Document document = new Document();
        document.add(new StringField("id", i + "", Field.Store.NO));
        iw.addDocument(document);
      }
    }
    iw.commit();
    iw.forceMerge(1);

    DirectoryReader reader = DirectoryReader.open(iw);
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("id").iterator();
    // test seekExact
    for (int i = 100000; i <= 100400; i++) {
      BytesRef target = new BytesRef(i + "");
      if (i % 2 == 1) {
        assertTrue(termsEnum.seekExact(target));
        assertEquals(termsEnum.term(), target);
      } else {
        assertFalse(termsEnum.seekExact(target));
      }
    }

    subCheckBinarySearch(termsEnum);
    // test seekCeil
    for (int i = 100000; i < 100400; i++) {
      BytesRef target = new BytesRef(i + "");
      if (i % 2 == 1) {
        assertEquals(SeekStatus.FOUND, termsEnum.seekCeil(target));
        assertEquals(termsEnum.term(), target);
        if (i <= 100397) {
          assertEquals(new BytesRef(i + 2 + ""), termsEnum.next());
        }
      } else {
        assertEquals(SeekStatus.NOT_FOUND, termsEnum.seekCeil(target));
        assertEquals(new BytesRef(i + 1 + ""), termsEnum.term());
      }
    }
    assertEquals(SeekStatus.END, termsEnum.seekCeil(new BytesRef(100400 + "")));
    reader.close();
    iw.close();
    dir.close();
  }

  // tests that level 2 ghost fields still work
  public void testLevel2Ghosts() throws Exception {
    Directory dir = newDirectory();

    IndexWriterConfig iwc = newIndexWriterConfig(null);
    iwc.setCodec(getCodec());
    iwc.setMergePolicy(newLogMergePolicy());
    IndexWriter iw = new IndexWriter(dir, iwc);

    Document document = new Document();
    document.add(new StringField("id", "0", Field.Store.NO));
    document.add(new StringField("suggest_field", "apples", Field.Store.NO));
    iw.addDocument(document);
    // need another document so whole segment isn't deleted
    iw.addDocument(new Document());
    iw.commit();

    document = new Document();
    document.add(new StringField("id", "1", Field.Store.NO));
    document.add(new StringField("suggest_field2", "apples", Field.Store.NO));
    iw.addDocument(document);
    iw.commit();

    iw.deleteDocuments(new Term("id", "0"));
    // first force merge creates a level 1 ghost field
    iw.forceMerge(1);

    // second force merge creates a level 2 ghost field, causing MultiFields to include
    // "suggest_field" in its iteration, yet a null Terms is returned (no documents have
    // this field anymore)
    iw.addDocument(new Document());
    iw.forceMerge(1);

    DirectoryReader reader = DirectoryReader.open(iw);
    IndexSearcher indexSearcher = new IndexSearcher(reader);

    assertEquals(1, indexSearcher.count(new TermQuery(new Term("id", "1"))));

    reader.close();
    iw.close();
    dir.close();
  }

  private static class TermFreqs {
    long totalTermFreq;
    int docFreq;
  }

  // LUCENE-5123: make sure we can visit postings twice
  // during flush/merge
  public void testInvertedWrite() throws Exception {
    Directory dir = newDirectory();
    MockAnalyzer analyzer = new MockAnalyzer(random());
    analyzer.setMaxTokenLength(TestUtil.nextInt(random(), 1, IndexWriter.MAX_TERM_LENGTH));
    IndexWriterConfig iwc = newIndexWriterConfig(analyzer);

    // Must be concurrent because thread(s) can be merging
    // while up to one thread flushes, and each of those
    // threads iterates over the map while the flushing
    // thread might be adding to it:
    final Map<String, TermFreqs> termFreqs = new ConcurrentHashMap<>();

    final AtomicLong sumDocFreq = new AtomicLong();
    final AtomicLong sumTotalTermFreq = new AtomicLong();

    // TODO: would be better to use / delegate to the current
    // Codec returned by getCodec()

    iwc.setCodec(
        new FilterCodec(getCodec().getName(), getCodec()) {
          @Override
          public PostingsFormat postingsFormat() {

            final PostingsFormat defaultPostingsFormat = delegate.postingsFormat();

            final Thread mainThread = Thread.currentThread();

            // A PF that counts up some stats and then in
            // the end we verify the stats match what the
            // final IndexReader says, just to exercise the
            // new freedom of iterating the postings more
            // than once at flush/merge:

            return new PostingsFormat(defaultPostingsFormat.getName()) {

              @Override
              public FieldsConsumer fieldsConsumer(final SegmentWriteState state)
                  throws IOException {

                final FieldsConsumer fieldsConsumer = defaultPostingsFormat.fieldsConsumer(state);

                return new FieldsConsumer() {
                  @Override
                  public void write(Fields fields, NormsProducer norms) throws IOException {
                    fieldsConsumer.write(fields, norms);

                    boolean isMerge = state.context.context() == IOContext.Context.MERGE;

                    // We only use one thread for flushing
                    // in this test:
                    assert isMerge || Thread.currentThread() == mainThread;

                    // We iterate the provided TermsEnum
                    // twice, so we excercise this new freedom
                    // with the inverted API; if
                    // addOnSecondPass is true, we add up
                    // term stats on the 2nd iteration:
                    boolean addOnSecondPass = random().nextBoolean();

                    // System.out.println("write isMerge=" + isMerge + " 2ndPass=" +
                    // addOnSecondPass);

                    // Gather our own stats:
                    Terms terms = fields.terms("body");
                    assert terms != null;

                    TermsEnum termsEnum = terms.iterator();
                    PostingsEnum docs = null;
                    while (termsEnum.next() != null) {
                      BytesRef term = termsEnum.term();
                      // TODO: also sometimes ask for payloads/offsets?
                      boolean noPositions = random().nextBoolean();
                      if (noPositions) {
                        docs = termsEnum.postings(docs, PostingsEnum.FREQS);
                      } else {
                        docs = termsEnum.postings(null, PostingsEnum.POSITIONS);
                      }
                      int docFreq = 0;
                      long totalTermFreq = 0;
                      while (docs.nextDoc() != PostingsEnum.NO_MORE_DOCS) {
                        docFreq++;
                        totalTermFreq += docs.freq();
                        int limit = TestUtil.nextInt(random(), 1, docs.freq());
                        if (!noPositions) {
                          for (int i = 0; i < limit; i++) {
                            docs.nextPosition();
                          }
                        }
                      }

                      String termString = term.utf8ToString();

                      // During merge we should only see terms
                      // we had already seen during a
                      // previous flush:
                      assertTrue(isMerge == false || termFreqs.containsKey(termString));

                      if (isMerge == false) {
                        if (addOnSecondPass == false) {
                          TermFreqs tf = termFreqs.get(termString);
                          if (tf == null) {
                            tf = new TermFreqs();
                            termFreqs.put(termString, tf);
                          }
                          tf.docFreq += docFreq;
                          tf.totalTermFreq += totalTermFreq;
                          sumDocFreq.addAndGet(docFreq);
                          sumTotalTermFreq.addAndGet(totalTermFreq);
                        } else if (termFreqs.containsKey(termString) == false) {
                          // Add placeholder (2nd pass will
                          // set its counts):
                          termFreqs.put(termString, new TermFreqs());
                        }
                      }
                    }

                    // Also test seeking the TermsEnum:
                    for (String term : termFreqs.keySet()) {
                      if (termsEnum.seekExact(new BytesRef(term))) {
                        // TODO: also sometimes ask for payloads/offsets?
                        boolean noPositions = random().nextBoolean();
                        if (noPositions) {
                          docs = termsEnum.postings(docs, PostingsEnum.FREQS);
                        } else {
                          docs = termsEnum.postings(null, PostingsEnum.POSITIONS);
                        }

                        int docFreq = 0;
                        long totalTermFreq = 0;
                        while (docs.nextDoc() != PostingsEnum.NO_MORE_DOCS) {
                          docFreq++;
                          totalTermFreq += docs.freq();
                          int limit = TestUtil.nextInt(random(), 1, docs.freq());
                          if (!noPositions) {
                            for (int i = 0; i < limit; i++) {
                              docs.nextPosition();
                            }
                          }
                        }

                        if (isMerge == false && addOnSecondPass) {
                          TermFreqs tf = termFreqs.get(term);
                          assert tf != null;
                          tf.docFreq += docFreq;
                          tf.totalTermFreq += totalTermFreq;
                          sumDocFreq.addAndGet(docFreq);
                          sumTotalTermFreq.addAndGet(totalTermFreq);
                        }

                        // System.out.println("  term=" + term + " docFreq=" + docFreq + " ttDF=" +
                        // termToDocFreq.get(term));
                        assertTrue(docFreq <= termFreqs.get(term).docFreq);
                        assertTrue(totalTermFreq <= termFreqs.get(term).totalTermFreq);
                      }
                    }

                    // Also test seekCeil
                    for (int iter = 0; iter < 10; iter++) {
                      BytesRef term = new BytesRef(TestUtil.randomRealisticUnicodeString(random()));
                      SeekStatus status = termsEnum.seekCeil(term);
                      if (status == SeekStatus.NOT_FOUND) {
                        assertTrue(term.compareTo(termsEnum.term()) < 0);
                      }
                    }
                  }

                  @Override
                  public void close() throws IOException {
                    fieldsConsumer.close();
                  }
                };
              }

              @Override
              public FieldsProducer fieldsProducer(SegmentReadState state) throws IOException {
                return defaultPostingsFormat.fieldsProducer(state);
              }
            };
          }
        });

    RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);

    LineFileDocs docs = new LineFileDocs(random());
    int bytesToIndex = atLeast(100) * 1024;
    int bytesIndexed = 0;
    while (bytesIndexed < bytesToIndex) {
      Document doc = docs.nextDoc();
      Document justBodyDoc = new Document();
      justBodyDoc.add(doc.getField("body"));
      w.addDocument(justBodyDoc);
      bytesIndexed += RamUsageTester.ramUsed(justBodyDoc);
    }

    IndexReader r = w.getReader();
    w.close();

    Terms terms = MultiTerms.getTerms(r, "body");
    assertEquals(sumDocFreq.get(), terms.getSumDocFreq());
    assertEquals(sumTotalTermFreq.get(), terms.getSumTotalTermFreq());

    TermsEnum termsEnum = terms.iterator();
    long termCount = 0;
    boolean supportsOrds = true;
    while (termsEnum.next() != null) {
      BytesRef term = termsEnum.term();
      assertEquals(termFreqs.get(term.utf8ToString()).docFreq, termsEnum.docFreq());
      assertEquals(termFreqs.get(term.utf8ToString()).totalTermFreq, termsEnum.totalTermFreq());
      if (supportsOrds) {
        long ord;
        try {
          ord = termsEnum.ord();
        } catch (
            @SuppressWarnings("unused")
            UnsupportedOperationException uoe) {
          supportsOrds = false;
          ord = -1;
        }
        if (ord != -1) {
          assertEquals(termCount, ord);
        }
      }
      termCount++;
    }
    assertEquals(termFreqs.size(), termCount);

    r.close();
    dir.close();
  }

  protected void assertReused(String field, PostingsEnum p1, PostingsEnum p2) {
    // if its not DirectPF, we should always reuse. This one has trouble.
    if (!"Direct".equals(TestUtil.getPostingsFormat(field))) {
      assertSame(p1, p2);
    }
  }

  public void testPostingsEnumDocsOnly() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = new IndexWriterConfig(null);
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    doc.add(new StringField("foo", "bar", Field.Store.NO));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(1, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(1, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // asking for any flags: ok
    for (int flag : new int[] {NONE, FREQS, POSITIONS, PAYLOADS, OFFSETS, ALL}) {
      postings = termsEnum.postings(null, flag);
      assertEquals(-1, postings.docID());
      assertEquals(0, postings.nextDoc());
      assertEquals(1, postings.freq());
      assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());
      // reuse that too
      postings2 = termsEnum.postings(postings, flag);
      assertNotNull(postings2);
      assertReused("foo", postings, postings2);
      // and it had better work
      assertEquals(-1, postings2.docID());
      assertEquals(0, postings2.nextDoc());
      assertEquals(1, postings2.freq());
      assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());
    }

    iw.close();
    reader.close();
    dir.close();
  }

  public void testPostingsEnumFreqs() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc =
        new IndexWriterConfig(
            new Analyzer() {
              @Override
              protected TokenStreamComponents createComponents(String fieldName) {
                return new TokenStreamComponents(new MockTokenizer());
              }
            });
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    FieldType ft = new FieldType(TextField.TYPE_NOT_STORED);
    ft.setIndexOptions(IndexOptions.DOCS_AND_FREQS);
    doc.add(new Field("foo", "bar bar", ft));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(2, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings2.docID());
    assertEquals(0, postings2.nextDoc());
    assertEquals(2, postings2.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());

    // asking for docs only: ok
    PostingsEnum docsOnly = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(-1, docsOnly.docID());
    assertEquals(0, docsOnly.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly.nextDoc());
    // reuse that too
    PostingsEnum docsOnly2 = termsEnum.postings(docsOnly, PostingsEnum.NONE);
    assertNotNull(docsOnly2);
    assertReused("foo", docsOnly, docsOnly2);
    // and it had better work
    assertEquals(-1, docsOnly2.docID());
    assertEquals(0, docsOnly2.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly2.nextDoc());

    // asking for any flags: ok
    for (int flag : new int[] {NONE, FREQS, POSITIONS, PAYLOADS, OFFSETS, ALL}) {
      postings = termsEnum.postings(null, flag);
      assertEquals(-1, postings.docID());
      assertEquals(0, postings.nextDoc());
      if (flag != NONE) {
        assertEquals(2, postings.freq());
      }
      assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());
      // reuse that too
      postings2 = termsEnum.postings(postings, flag);
      assertNotNull(postings2);
      assertReused("foo", postings, postings2);
      // and it had better work
      assertEquals(-1, postings2.docID());
      assertEquals(0, postings2.nextDoc());
      if (flag != NONE) {
        assertEquals(2, postings2.freq());
      }
      assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());
    }

    iw.close();
    reader.close();
    dir.close();
  }

  public void testPostingsEnumPositions() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc =
        new IndexWriterConfig(
            new Analyzer() {
              @Override
              protected TokenStreamComponents createComponents(String fieldName) {
                return new TokenStreamComponents(new MockTokenizer());
              }
            });
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    doc.add(new TextField("foo", "bar bar", Field.Store.NO));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(2, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings2.docID());
    assertEquals(0, postings2.nextDoc());
    assertEquals(2, postings2.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());

    // asking for docs only: ok
    PostingsEnum docsOnly = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(-1, docsOnly.docID());
    assertEquals(0, docsOnly.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly.nextDoc());
    // reuse that too
    PostingsEnum docsOnly2 = termsEnum.postings(docsOnly, PostingsEnum.NONE);
    assertNotNull(docsOnly2);
    assertReused("foo", docsOnly, docsOnly2);
    // and it had better work
    assertEquals(-1, docsOnly2.docID());
    assertEquals(0, docsOnly2.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly2.freq() == 1 || docsOnly2.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly2.nextDoc());

    // asking for positions, ok
    PostingsEnum docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.POSITIONS);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());

    // now reuse the positions
    PostingsEnum docsAndPositionsEnum2 =
        termsEnum.postings(docsAndPositionsEnum, PostingsEnum.POSITIONS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    // payloads, offsets, etc don't cause an error if they aren't there
    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.PAYLOADS);
    assertNotNull(docsAndPositionsEnum);
    // but make sure they work
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.PAYLOADS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.OFFSETS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.OFFSETS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.ALL);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.ALL);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    iw.close();
    reader.close();
    dir.close();
  }

  public void testPostingsEnumOffsets() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc =
        new IndexWriterConfig(
            new Analyzer() {
              @Override
              protected TokenStreamComponents createComponents(String fieldName) {
                return new TokenStreamComponents(new MockTokenizer());
              }
            });
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    FieldType ft = new FieldType(TextField.TYPE_NOT_STORED);
    ft.setIndexOptions(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS);
    doc.add(new Field("foo", "bar bar", ft));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(2, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings2.docID());
    assertEquals(0, postings2.nextDoc());
    assertEquals(2, postings2.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());

    // asking for docs only: ok
    PostingsEnum docsOnly = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(-1, docsOnly.docID());
    assertEquals(0, docsOnly.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly.nextDoc());
    // reuse that too
    PostingsEnum docsOnly2 = termsEnum.postings(docsOnly, PostingsEnum.NONE);
    assertNotNull(docsOnly2);
    assertReused("foo", docsOnly, docsOnly2);
    // and it had better work
    assertEquals(-1, docsOnly2.docID());
    assertEquals(0, docsOnly2.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly2.freq() == 1 || docsOnly2.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly2.nextDoc());

    // asking for positions, ok
    PostingsEnum docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.POSITIONS);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 0);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 3);
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 4);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 7);
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());

    // now reuse the positions
    PostingsEnum docsAndPositionsEnum2 =
        termsEnum.postings(docsAndPositionsEnum, PostingsEnum.POSITIONS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 0);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 3);
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 4);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 7);
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    // payloads don't cause an error if they aren't there
    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.PAYLOADS);
    assertNotNull(docsAndPositionsEnum);
    // but make sure they work
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 0);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 3);
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 4);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 7);
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.PAYLOADS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 0);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 3);
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 4);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 7);
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.OFFSETS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(0, docsAndPositionsEnum.startOffset());
    assertEquals(3, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(4, docsAndPositionsEnum.startOffset());
    assertEquals(7, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.OFFSETS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(0, docsAndPositionsEnum2.startOffset());
    assertEquals(3, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(4, docsAndPositionsEnum2.startOffset());
    assertEquals(7, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.ALL);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(0, docsAndPositionsEnum.startOffset());
    assertEquals(3, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(4, docsAndPositionsEnum.startOffset());
    assertEquals(7, docsAndPositionsEnum.endOffset());
    assertNull(docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.ALL);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(0, docsAndPositionsEnum2.startOffset());
    assertEquals(3, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(4, docsAndPositionsEnum2.startOffset());
    assertEquals(7, docsAndPositionsEnum2.endOffset());
    assertNull(docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    iw.close();
    reader.close();
    dir.close();
  }

  public void testPostingsEnumPayloads() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = new IndexWriterConfig(null);
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    Token token1 = new Token("bar", 0, 3);
    token1.setPayload(new BytesRef("pay1"));
    Token token2 = new Token("bar", 4, 7);
    token2.setPayload(new BytesRef("pay2"));
    doc.add(new TextField("foo", new CannedTokenStream(token1, token2)));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(2, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings2.docID());
    assertEquals(0, postings2.nextDoc());
    assertEquals(2, postings2.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());

    // asking for docs only: ok
    PostingsEnum docsOnly = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(-1, docsOnly.docID());
    assertEquals(0, docsOnly.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly.nextDoc());
    // reuse that too
    PostingsEnum docsOnly2 = termsEnum.postings(docsOnly, PostingsEnum.NONE);
    assertNotNull(docsOnly2);
    assertReused("foo", docsOnly, docsOnly2);
    // and it had better work
    assertEquals(-1, docsOnly2.docID());
    assertEquals(0, docsOnly2.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly2.freq() == 1 || docsOnly2.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly2.nextDoc());

    // asking for positions, ok
    PostingsEnum docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.POSITIONS);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());

    // now reuse the positions
    PostingsEnum docsAndPositionsEnum2 =
        termsEnum.postings(docsAndPositionsEnum, PostingsEnum.POSITIONS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    // payloads
    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.PAYLOADS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.PAYLOADS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.OFFSETS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.OFFSETS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.ALL);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(-1, docsAndPositionsEnum.startOffset());
    assertEquals(-1, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.ALL);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(-1, docsAndPositionsEnum2.startOffset());
    assertEquals(-1, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    iw.close();
    reader.close();
    dir.close();
  }

  public void testPostingsEnumAll() throws Exception {
    Directory dir = newDirectory();
    IndexWriterConfig iwc = new IndexWriterConfig(null);
    IndexWriter iw = new IndexWriter(dir, iwc);
    Document doc = new Document();
    Token token1 = new Token("bar", 0, 3);
    token1.setPayload(new BytesRef("pay1"));
    Token token2 = new Token("bar", 4, 7);
    token2.setPayload(new BytesRef("pay2"));
    FieldType ft = new FieldType(TextField.TYPE_NOT_STORED);
    ft.setIndexOptions(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS);
    doc.add(new Field("foo", new CannedTokenStream(token1, token2), ft));
    iw.addDocument(doc);
    DirectoryReader reader = DirectoryReader.open(iw);

    // sugar method (FREQS)
    PostingsEnum postings = getOnlyLeafReader(reader).postings(new Term("foo", "bar"));
    assertEquals(-1, postings.docID());
    assertEquals(0, postings.nextDoc());
    assertEquals(2, postings.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings.nextDoc());

    // termsenum reuse (FREQS)
    TermsEnum termsEnum = getOnlyLeafReader(reader).terms("foo").iterator();
    termsEnum.seekExact(new BytesRef("bar"));
    PostingsEnum postings2 = termsEnum.postings(postings);
    assertNotNull(postings2);
    assertReused("foo", postings, postings2);
    // and it had better work
    assertEquals(-1, postings2.docID());
    assertEquals(0, postings2.nextDoc());
    assertEquals(2, postings2.freq());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, postings2.nextDoc());

    // asking for docs only: ok
    PostingsEnum docsOnly = termsEnum.postings(null, PostingsEnum.NONE);
    assertEquals(-1, docsOnly.docID());
    assertEquals(0, docsOnly.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly.freq() == 1 || docsOnly.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly.nextDoc());
    // reuse that too
    PostingsEnum docsOnly2 = termsEnum.postings(docsOnly, PostingsEnum.NONE);
    assertNotNull(docsOnly2);
    assertReused("foo", docsOnly, docsOnly2);
    // and it had better work
    assertEquals(-1, docsOnly2.docID());
    assertEquals(0, docsOnly2.nextDoc());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsOnly2.freq() == 1 || docsOnly2.freq() == 2);
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsOnly2.nextDoc());

    // asking for positions, ok
    PostingsEnum docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.POSITIONS);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 0);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 3);
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 4);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 7);
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());

    // now reuse the positions
    PostingsEnum docsAndPositionsEnum2 =
        termsEnum.postings(docsAndPositionsEnum, PostingsEnum.POSITIONS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 0);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 3);
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 4);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 7);
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    // payloads
    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.PAYLOADS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 0);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 3);
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(docsAndPositionsEnum.startOffset() == -1 || docsAndPositionsEnum.startOffset() == 4);
    assertTrue(docsAndPositionsEnum.endOffset() == -1 || docsAndPositionsEnum.endOffset() == 7);
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.PAYLOADS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 0);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 3);
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.startOffset() == -1 || docsAndPositionsEnum2.startOffset() == 4);
    assertTrue(docsAndPositionsEnum2.endOffset() == -1 || docsAndPositionsEnum2.endOffset() == 7);
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.OFFSETS);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(0, docsAndPositionsEnum.startOffset());
    assertEquals(3, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(4, docsAndPositionsEnum.startOffset());
    assertEquals(7, docsAndPositionsEnum.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    // reuse
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.OFFSETS);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(0, docsAndPositionsEnum2.startOffset());
    assertEquals(3, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay1").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(4, docsAndPositionsEnum2.startOffset());
    assertEquals(7, docsAndPositionsEnum2.endOffset());
    // we don't define what it is, but if its something else, we should look into it?
    assertTrue(
        docsAndPositionsEnum2.getPayload() == null
            || new BytesRef("pay2").equals(docsAndPositionsEnum2.getPayload()));
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    docsAndPositionsEnum =
        getOnlyLeafReader(reader).postings(new Term("foo", "bar"), PostingsEnum.ALL);
    assertNotNull(docsAndPositionsEnum);
    assertEquals(-1, docsAndPositionsEnum.docID());
    assertEquals(0, docsAndPositionsEnum.nextDoc());
    assertEquals(2, docsAndPositionsEnum.freq());
    assertEquals(0, docsAndPositionsEnum.nextPosition());
    assertEquals(0, docsAndPositionsEnum.startOffset());
    assertEquals(3, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum.getPayload());
    assertEquals(1, docsAndPositionsEnum.nextPosition());
    assertEquals(4, docsAndPositionsEnum.startOffset());
    assertEquals(7, docsAndPositionsEnum.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum.nextDoc());
    docsAndPositionsEnum2 = termsEnum.postings(docsAndPositionsEnum, PostingsEnum.ALL);
    assertReused("foo", docsAndPositionsEnum, docsAndPositionsEnum2);
    assertEquals(-1, docsAndPositionsEnum2.docID());
    assertEquals(0, docsAndPositionsEnum2.nextDoc());
    assertEquals(2, docsAndPositionsEnum2.freq());
    assertEquals(0, docsAndPositionsEnum2.nextPosition());
    assertEquals(0, docsAndPositionsEnum2.startOffset());
    assertEquals(3, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay1"), docsAndPositionsEnum2.getPayload());
    assertEquals(1, docsAndPositionsEnum2.nextPosition());
    assertEquals(4, docsAndPositionsEnum2.startOffset());
    assertEquals(7, docsAndPositionsEnum2.endOffset());
    assertEquals(new BytesRef("pay2"), docsAndPositionsEnum2.getPayload());
    assertEquals(DocIdSetIterator.NO_MORE_DOCS, docsAndPositionsEnum2.nextDoc());

    iw.close();
    reader.close();
    dir.close();
  }

  @Override
  protected void addRandomFields(Document doc) {
    for (IndexOptions opts : IndexOptions.values()) {
      if (opts == IndexOptions.NONE || opts == IndexOptions.DOCS_AND_CUSTOM_FREQS) {
        continue;
      }
      FieldType ft = new FieldType();
      ft.setIndexOptions(opts);
      ft.freeze();
      final int numFields = random().nextInt(5);
      for (int j = 0; j < numFields; ++j) {
        doc.add(new Field("f_" + opts, TestUtil.randomSimpleString(random(), 2), ft));
      }
    }
  }

  /** Test realistic data, which is often better at uncovering real bugs. */
  @Nightly // this test takes a few seconds
  public void testLineFileDocs() throws IOException {
    // Use a FS dir and a non-randomized IWC to not slow down indexing
    try (Directory dir = newFSDirectory(createTempDir())) {
      try (LineFileDocs docs = new LineFileDocs(random());
          IndexWriter w = new IndexWriter(dir, new IndexWriterConfig())) {
        final int numDocs = atLeast(10_000);
        for (int i = 0; i < numDocs; ++i) {
          // Only keep the body field, and don't index term vectors on it, we only care about
          // postings
          Document doc = docs.nextDoc();
          IndexableField body = doc.getField("body");
          assertNotNull(body);
          assertNotNull(body.stringValue());
          assertNotEquals(IndexOptions.NONE, body.fieldType().indexOptions());
          body = new TextField("body", body.stringValue(), Store.NO);
          w.addDocument(Collections.singletonList(body));
        }
        w.forceMerge(1);
      }
      TestUtil.checkIndex(dir);
    }
  }

  public void testMismatchedFields() throws Exception {
    Directory dir1 = newDirectory();
    IndexWriter w1 = new IndexWriter(dir1, newIndexWriterConfig());
    Document doc = new Document();
    doc.add(new StringField("f", "a", Store.NO));
    doc.add(new StringField("g", "b", Store.NO));
    w1.addDocument(doc);

    Directory dir2 = newDirectory();
    IndexWriter w2 =
        new IndexWriter(dir2, newIndexWriterConfig().setMergeScheduler(new SerialMergeScheduler()));
    w2.addDocument(doc);
    w2.commit();

    DirectoryReader reader = DirectoryReader.open(w1);
    w1.close();
    w2.addIndexes(new MismatchedCodecReader((CodecReader) getOnlyLeafReader(reader), random()));
    reader.close();
    w2.forceMerge(1);
    reader = DirectoryReader.open(w2);
    w2.close();

    LeafReader leafReader = getOnlyLeafReader(reader);

    TermsEnum te = leafReader.terms("f").iterator();
    assertEquals("a", te.next().utf8ToString());
    assertEquals(2, te.docFreq());
    assertNull(te.next());

    te = leafReader.terms("g").iterator();
    assertEquals("b", te.next().utf8ToString());
    assertEquals(2, te.docFreq());
    assertNull(te.next());

    IOUtils.close(reader, w2, dir1, dir2);
  }

  public void testDocIDRunEnd() throws Exception {
    Directory dir = newDirectory();
    for (int iter = 0; iter < 100; ++iter) {
      IndexWriterConfig iwc = newIndexWriterConfig(null).setOpenMode(OpenMode.CREATE);
      iwc.setCodec(getCodec());
      // Prevent randomization from slowing down indexing too much
      if (iwc.getMaxBufferedDocs() < 1_000) {
        iwc.setMaxBufferedDocs(1_000);
      }
      IndexWriter iw = new IndexWriter(dir, iwc);
      Document emptyDoc = new Document();
      Document doc = new Document();
      doc.add(new StringField("", "something", Field.Store.NO));
      int numEmptyDocs = TestUtil.nextInt(random(), 0, 5_000);
      int numDocs = TestUtil.nextInt(random(), 4096, 20_000);
      for (int i = 0; i < numEmptyDocs; ++i) {
        iw.addDocument(emptyDoc);
      }
      for (int i = 0; i < numDocs; ++i) {
        iw.addDocument(doc);
      }
      iw.forceMerge(1);
      DirectoryReader ir = DirectoryReader.open(iw);
      LeafReader ar = getOnlyLeafReader(ir);
      TestUtil.checkReader(ar);
      ir.close();
      iw.close();
    }
    dir.close();
  }
}
