using System;
using System.Globalization;
using Lucene.Net.Documents;
using Lucene.Net.Support;
using NUnit.Framework;

namespace Lucene.Net.Search
{
    using Analyzer = Lucene.Net.Analysis.Analyzer;
    using AtomicReaderContext = Lucene.Net.Index.AtomicReaderContext;
    using DefaultSimilarity = Lucene.Net.Search.Similarities.DefaultSimilarity;
    using Directory = Lucene.Net.Store.Directory;
    using DirectoryReader = Lucene.Net.Index.DirectoryReader;
    using Document = Documents.Document;

    /*
         * 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.
         */

    using Field = Field;
    using FieldInvertState = Lucene.Net.Index.FieldInvertState;
    using FieldType = FieldType;
    using IndexReader = Lucene.Net.Index.IndexReader;
    using IndexWriter = Lucene.Net.Index.IndexWriter;
    using IndexWriterConfig = Lucene.Net.Index.IndexWriterConfig;
    using LuceneTestCase = Lucene.Net.Util.LuceneTestCase;
    using MockAnalyzer = Lucene.Net.Analysis.MockAnalyzer;
    using RandomIndexWriter = Lucene.Net.Index.RandomIndexWriter;
    using Similarity = Lucene.Net.Search.Similarities.Similarity;
    using SlowCompositeReaderWrapper = Lucene.Net.Index.SlowCompositeReaderWrapper;
    using SpanQuery = Lucene.Net.Search.Spans.SpanQuery;
    using SpanTermQuery = Lucene.Net.Search.Spans.SpanTermQuery;
    using Term = Lucene.Net.Index.Term;
    using TextField = TextField;

    /// <summary>
    /// Test of the DisjunctionMaxQuery.
    ///
    /// </summary>
    [TestFixture]
    public class TestDisjunctionMaxQuery : LuceneTestCase
    {
        /// <summary>
        /// threshold for comparing floats </summary>
        public static readonly float SCORE_COMP_THRESH = 0.0000f;

        /// <summary>
        /// Similarity to eliminate tf, idf and lengthNorm effects to isolate test
        /// case.
        ///
        /// <p>
        /// same as TestRankingSimilarity in TestRanking.zip from
        /// http://issues.apache.org/jira/browse/LUCENE-323
        /// </p>
        /// </summary>
        private class TestSimilarity : DefaultSimilarity
        {
            public TestSimilarity()
            {
            }

            public override float Tf(float freq)
            {
                if (freq > 0.0f)
                {
                    return 1.0f;
                }
                else
                {
                    return 0.0f;
                }
            }

            public override float LengthNorm(FieldInvertState state)
            {
                // Disable length norm
                return state.Boost;
            }

            public override float Idf(long docFreq, long numDocs)
            {
                return 1.0f;
            }
        }

        public Similarity Sim = new TestSimilarity();
        public Directory Index;
        public IndexReader r;
        public IndexSearcher s;

        private static readonly FieldType NonAnalyzedType = new FieldType(TextField.TYPE_STORED);

        static TestDisjunctionMaxQuery()
        {
            NonAnalyzedType.IsTokenized = false;
        }

        [SetUp]
        public override void SetUp()
        {
            base.SetUp();

            Index = NewDirectory();
            RandomIndexWriter writer = new RandomIndexWriter(Random(), Index, NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random())).SetSimilarity(Sim).SetMergePolicy(NewLogMergePolicy()));

            // hed is the most important field, dek is secondary

            // d1 is an "ok" match for: albino elephant
            {
                Document d1 = new Document();
                d1.Add(NewField("id", "d1", NonAnalyzedType)); // Field.Keyword("id",
                // "d1"));
                d1.Add(NewTextField("hed", "elephant", Field.Store.YES)); // Field.Text("hed", "elephant"));
                d1.Add(NewTextField("dek", "elephant", Field.Store.YES)); // Field.Text("dek", "elephant"));
                writer.AddDocument(d1);
            }

            // d2 is a "good" match for: albino elephant
            {
                Document d2 = new Document();
                d2.Add(NewField("id", "d2", NonAnalyzedType)); // Field.Keyword("id",
                // "d2"));
                d2.Add(NewTextField("hed", "elephant", Field.Store.YES)); // Field.Text("hed", "elephant"));
                d2.Add(NewTextField("dek", "albino", Field.Store.YES)); // Field.Text("dek",
                // "albino"));
                d2.Add(NewTextField("dek", "elephant", Field.Store.YES)); // Field.Text("dek", "elephant"));
                writer.AddDocument(d2);
            }

            // d3 is a "better" match for: albino elephant
            {
                Document d3 = new Document();
                d3.Add(NewField("id", "d3", NonAnalyzedType)); // Field.Keyword("id",
                // "d3"));
                d3.Add(NewTextField("hed", "albino", Field.Store.YES)); // Field.Text("hed",
                // "albino"));
                d3.Add(NewTextField("hed", "elephant", Field.Store.YES)); // Field.Text("hed", "elephant"));
                writer.AddDocument(d3);
            }

            // d4 is the "best" match for: albino elephant
            {
                Document d4 = new Document();
                d4.Add(NewField("id", "d4", NonAnalyzedType)); // Field.Keyword("id",
                // "d4"));
                d4.Add(NewTextField("hed", "albino", Field.Store.YES)); // Field.Text("hed",
                // "albino"));
                d4.Add(NewField("hed", "elephant", NonAnalyzedType)); // Field.Text("hed", "elephant"));
                d4.Add(NewTextField("dek", "albino", Field.Store.YES)); // Field.Text("dek",
                // "albino"));
                writer.AddDocument(d4);
            }

            r = SlowCompositeReaderWrapper.Wrap(writer.Reader);
            writer.Dispose();
            s = NewSearcher(r);
            s.Similarity = Sim;
        }

        [TearDown]
        public override void TearDown()
        {
            r.Dispose();
            Index.Dispose();
            base.TearDown();
        }

        [Test]
        public virtual void TestSkipToFirsttimeMiss()
        {
            DisjunctionMaxQuery dq = new DisjunctionMaxQuery(0.0f);
            dq.Add(Tq("id", "d1"));
            dq.Add(Tq("dek", "DOES_NOT_EXIST"));

            QueryUtils.Check(Random(), dq, s, Similarity);
            Assert.IsTrue(s.TopReaderContext is AtomicReaderContext);
            Weight dw = s.CreateNormalizedWeight(dq);
            AtomicReaderContext context = (AtomicReaderContext)s.TopReaderContext;
            Scorer ds = dw.GetScorer(context, (context.AtomicReader).LiveDocs);
            bool skipOk = ds.Advance(3) != DocIdSetIterator.NO_MORE_DOCS;
            if (skipOk)
            {
                Assert.Fail("firsttime skipTo found a match? ... " + r.Document(ds.DocID).Get("id"));
            }
        }

        [Test]
        public virtual void TestSkipToFirsttimeHit()
        {
            DisjunctionMaxQuery dq = new DisjunctionMaxQuery(0.0f);
            dq.Add(Tq("dek", "albino"));
            dq.Add(Tq("dek", "DOES_NOT_EXIST"));
            Assert.IsTrue(s.TopReaderContext is AtomicReaderContext);
            QueryUtils.Check(Random(), dq, s, Similarity);
            Weight dw = s.CreateNormalizedWeight(dq);
            AtomicReaderContext context = (AtomicReaderContext)s.TopReaderContext;
            Scorer ds = dw.GetScorer(context, (context.AtomicReader).LiveDocs);
            Assert.IsTrue(ds.Advance(3) != DocIdSetIterator.NO_MORE_DOCS, "firsttime skipTo found no match");
            Assert.AreEqual("d4", r.Document(ds.DocID).Get("id"), "found wrong docid");
        }

        [Test]
        public virtual void TestSimpleEqualScores1()
        {
            DisjunctionMaxQuery q = new DisjunctionMaxQuery(0.0f);
            q.Add(Tq("hed", "albino"));
            q.Add(Tq("hed", "elephant"));
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(4, h.Length, "all docs should match " + q.ToString());

                float score = h[0].Score;
                for (int i = 1; i < h.Length; i++)
                {
                    Assert.AreEqual(score, h[i].Score, SCORE_COMP_THRESH, "score #" + i + " is not the same");
                }
            }
            catch (Exception e)
            {
                PrintHits("testSimpleEqualScores1", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestSimpleEqualScores2()
        {
            DisjunctionMaxQuery q = new DisjunctionMaxQuery(0.0f);
            q.Add(Tq("dek", "albino"));
            q.Add(Tq("dek", "elephant"));
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(3, h.Length, "3 docs should match " + q.ToString());
                float score = h[0].Score;
                for (int i = 1; i < h.Length; i++)
                {
                    Assert.AreEqual(score, h[i].Score, SCORE_COMP_THRESH, "score #" + i + " is not the same");
                }
            }
            catch (Exception e)
            {
                PrintHits("testSimpleEqualScores2", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestSimpleEqualScores3()
        {
            DisjunctionMaxQuery q = new DisjunctionMaxQuery(0.0f);
            q.Add(Tq("hed", "albino"));
            q.Add(Tq("hed", "elephant"));
            q.Add(Tq("dek", "albino"));
            q.Add(Tq("dek", "elephant"));
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(4, h.Length, "all docs should match " + q.ToString());
                float score = h[0].Score;
                for (int i = 1; i < h.Length; i++)
                {
                    Assert.AreEqual(score, h[i].Score, SCORE_COMP_THRESH, "score #" + i + " is not the same");
                }
            }
            catch (Exception e)
            {
                PrintHits("testSimpleEqualScores3", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestSimpleTiebreaker()
        {
            DisjunctionMaxQuery q = new DisjunctionMaxQuery(0.01f);
            q.Add(Tq("dek", "albino"));
            q.Add(Tq("dek", "elephant"));
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(3, h.Length, "3 docs should match " + q.ToString());
                Assert.AreEqual("d2", s.Doc(h[0].Doc).Get("id"), "wrong first");
                float score0 = h[0].Score;
                float score1 = h[1].Score;
                float score2 = h[2].Score;
                Assert.IsTrue(score0 > score1, "d2 does not have better score then others: " + score0 + " >? " + score1);
                Assert.AreEqual(score1, score2, SCORE_COMP_THRESH, "d4 and d1 don't have equal scores");
            }
            catch (Exception e)
            {
                PrintHits("testSimpleTiebreaker", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestBooleanRequiredEqualScores()
        {
            BooleanQuery q = new BooleanQuery();
            {
                DisjunctionMaxQuery q1 = new DisjunctionMaxQuery(0.0f);
                q1.Add(Tq("hed", "albino"));
                q1.Add(Tq("dek", "albino"));
                q.Add(q1, Occur.MUST); // true,false);
                QueryUtils.Check(Random(), q1, s, Similarity);
            }
            {
                DisjunctionMaxQuery q2 = new DisjunctionMaxQuery(0.0f);
                q2.Add(Tq("hed", "elephant"));
                q2.Add(Tq("dek", "elephant"));
                q.Add(q2, Occur.MUST); // true,false);
                QueryUtils.Check(Random(), q2, s, Similarity);
            }

            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(3, h.Length, "3 docs should match " + q.ToString());
                float score = h[0].Score;
                for (int i = 1; i < h.Length; i++)
                {
                    Assert.AreEqual(score, h[i].Score, SCORE_COMP_THRESH, "score #" + i + " is not the same");
                }
            }
            catch (Exception e)
            {
                PrintHits("testBooleanRequiredEqualScores1", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestBooleanOptionalNoTiebreaker()
        {
            BooleanQuery q = new BooleanQuery();
            {
                DisjunctionMaxQuery q1 = new DisjunctionMaxQuery(0.0f);
                q1.Add(Tq("hed", "albino"));
                q1.Add(Tq("dek", "albino"));
                q.Add(q1, Occur.SHOULD); // false,false);
            }
            {
                DisjunctionMaxQuery q2 = new DisjunctionMaxQuery(0.0f);
                q2.Add(Tq("hed", "elephant"));
                q2.Add(Tq("dek", "elephant"));
                q.Add(q2, Occur.SHOULD); // false,false);
            }
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(4, h.Length, "4 docs should match " + q.ToString());
                float score = h[0].Score;
                for (int i = 1; i < h.Length - 1; i++) // note: -1
                {
                    Assert.AreEqual(score, h[i].Score, SCORE_COMP_THRESH, "score #" + i + " is not the same");
                }
                Assert.AreEqual("d1", s.Doc(h[h.Length - 1].Doc).Get("id"), "wrong last");
                float score1 = h[h.Length - 1].Score;
                Assert.IsTrue(score > score1, "d1 does not have worse score then others: " + score + " >? " + score1);
            }
            catch (Exception e)
            {
                PrintHits("testBooleanOptionalNoTiebreaker", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestBooleanOptionalWithTiebreaker()
        {
            BooleanQuery q = new BooleanQuery();
            {
                DisjunctionMaxQuery q1 = new DisjunctionMaxQuery(0.01f);
                q1.Add(Tq("hed", "albino"));
                q1.Add(Tq("dek", "albino"));
                q.Add(q1, Occur.SHOULD); // false,false);
            }
            {
                DisjunctionMaxQuery q2 = new DisjunctionMaxQuery(0.01f);
                q2.Add(Tq("hed", "elephant"));
                q2.Add(Tq("dek", "elephant"));
                q.Add(q2, Occur.SHOULD); // false,false);
            }
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(4, h.Length, "4 docs should match " + q.ToString());

                float score0 = h[0].Score;
                float score1 = h[1].Score;
                float score2 = h[2].Score;
                float score3 = h[3].Score;

                string doc0 = s.Doc(h[0].Doc).Get("id");
                string doc1 = s.Doc(h[1].Doc).Get("id");
                string doc2 = s.Doc(h[2].Doc).Get("id");
                string doc3 = s.Doc(h[3].Doc).Get("id");

                Assert.IsTrue(doc0.Equals("d2") || doc0.Equals("d4"), "doc0 should be d2 or d4: " + doc0);
                Assert.IsTrue(doc1.Equals("d2") || doc1.Equals("d4"), "doc1 should be d2 or d4: " + doc0);
                Assert.AreEqual(score0, score1, SCORE_COMP_THRESH, "score0 and score1 should match");
                Assert.AreEqual("d3", doc2, "wrong third");
                Assert.IsTrue(score1 > score2, "d3 does not have worse score then d2 and d4: " + score1 + " >? " + score2);

                Assert.AreEqual("d1", doc3, "wrong fourth");
                Assert.IsTrue(score2 > score3, "d1 does not have worse score then d3: " + score2 + " >? " + score3);
            }
            catch (Exception e)
            {
                PrintHits("testBooleanOptionalWithTiebreaker", h, s);
                throw e;
            }
        }

        [Test]
        public virtual void TestBooleanOptionalWithTiebreakerAndBoost()
        {
            BooleanQuery q = new BooleanQuery();
            {
                DisjunctionMaxQuery q1 = new DisjunctionMaxQuery(0.01f);
                q1.Add(Tq("hed", "albino", 1.5f));
                q1.Add(Tq("dek", "albino"));
                q.Add(q1, Occur.SHOULD); // false,false);
            }
            {
                DisjunctionMaxQuery q2 = new DisjunctionMaxQuery(0.01f);
                q2.Add(Tq("hed", "elephant", 1.5f));
                q2.Add(Tq("dek", "elephant"));
                q.Add(q2, Occur.SHOULD); // false,false);
            }
            QueryUtils.Check(Random(), q, s, Similarity);

            ScoreDoc[] h = s.Search(q, null, 1000).ScoreDocs;

            try
            {
                Assert.AreEqual(4, h.Length, "4 docs should match " + q.ToString());

                float score0 = h[0].Score;
                float score1 = h[1].Score;
                float score2 = h[2].Score;
                float score3 = h[3].Score;

                string doc0 = s.Doc(h[0].Doc).Get("id");
                string doc1 = s.Doc(h[1].Doc).Get("id");
                string doc2 = s.Doc(h[2].Doc).Get("id");
                string doc3 = s.Doc(h[3].Doc).Get("id");

                Assert.AreEqual("d4", doc0, "doc0 should be d4: ");
                Assert.AreEqual("d3", doc1, "doc1 should be d3: ");
                Assert.AreEqual("d2", doc2, "doc2 should be d2: ");
                Assert.AreEqual("d1", doc3, "doc3 should be d1: ");

                Assert.IsTrue(score0 > score1, "d4 does not have a better score then d3: " + score0 + " >? " + score1);
                Assert.IsTrue(score1 > score2, "d3 does not have a better score then d2: " + score1 + " >? " + score2);
                Assert.IsTrue(score2 > score3, "d3 does not have a better score then d1: " + score2 + " >? " + score3);
            }
            catch (Exception e)
            {
                PrintHits("TestBooleanOptionalWithTiebreakerAndBoost", h, s);
                throw e;
            }
        }

        // LUCENE-4477 / LUCENE-4401:
        [Test]
        public virtual void TestBooleanSpanQuery()
        {
            int hits = 0;
            Directory directory = NewDirectory();
            Analyzer indexerAnalyzer = new MockAnalyzer(Random());

            IndexWriterConfig config = new IndexWriterConfig(TEST_VERSION_CURRENT, indexerAnalyzer);
            IndexWriter writer = new IndexWriter(directory, config);
            string FIELD = "content";
            Document d = new Document();
            d.Add(new TextField(FIELD, "clockwork orange", Field.Store.YES));
            writer.AddDocument(d);
            writer.Dispose();

            IndexReader indexReader = DirectoryReader.Open(directory);
            IndexSearcher searcher = NewSearcher(indexReader);

            DisjunctionMaxQuery query = new DisjunctionMaxQuery(1.0f);
            SpanQuery sq1 = new SpanTermQuery(new Term(FIELD, "clockwork"));
            SpanQuery sq2 = new SpanTermQuery(new Term(FIELD, "clckwork"));
            query.Add(sq1);
            query.Add(sq2);
            TopScoreDocCollector collector = TopScoreDocCollector.Create(1000, true);
            searcher.Search(query, collector);
            hits = collector.GetTopDocs().ScoreDocs.Length;
            foreach (ScoreDoc scoreDoc in collector.GetTopDocs().ScoreDocs)
            {
                Console.WriteLine(scoreDoc.Doc);
            }
            indexReader.Dispose();
            Assert.AreEqual(hits, 1);
            directory.Dispose();
        }

        /// <summary>
        /// macro </summary>
        protected internal virtual Query Tq(string f, string t)
        {
            return new TermQuery(new Term(f, t));
        }

        /// <summary>
        /// macro </summary>
        protected internal virtual Query Tq(string f, string t, float b)
        {
            Query q = Tq(f, t);
            q.Boost = b;
            return q;
        }

        protected internal virtual void PrintHits(string test, ScoreDoc[] h, IndexSearcher searcher)
        {
            Console.Error.WriteLine("------- " + test + " -------");

            //DecimalFormat f = new DecimalFormat("0.000000000", DecimalFormatSymbols.getInstance(Locale.ROOT));

            NumberFormatInfo f = new NumberFormatInfo();
            f.NumberDecimalSeparator = ".";

            for (int i = 0; i < h.Length; i++)
            {
                Document d = searcher.Doc(h[i].Doc);
                decimal score = (decimal)h[i].Score;
                Console.Error.WriteLine("#" + i + ": " + score.ToString(f) + " - " + d.Get("id"));
            }
        }
    }
}