//  Copyright (c) 2014 Couchbase, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 		http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package searcher

import (
	"context"
	"testing"

	"github.com/blevesearch/bleve/v2/search"
	index "github.com/blevesearch/bleve_index_api"
)

func TestBooleanSearch(t *testing.T) {
	if twoDocIndex == nil {
		t.Fatal("its null")
	}
	twoDocIndexReader, err := twoDocIndex.Reader()
	if err != nil {
		t.Error(err)
	}
	defer func() {
		err := twoDocIndexReader.Close()
		if err != nil {
			t.Fatal(err)
		}
	}()

	explainTrue := search.SearcherOptions{Explain: true}

	// test 0
	beerTermSearcher, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	martyTermSearcher, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	dustinTermSearcher, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "dustin", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	shouldSearcher, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{martyTermSearcher, dustinTermSearcher}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	steveTermSearcher, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher, shouldSearcher, mustNotSearcher, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 1
	martyTermSearcher2, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	dustinTermSearcher2, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "dustin", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	shouldSearcher2, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{martyTermSearcher2, dustinTermSearcher2}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	steveTermSearcher2, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher2, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher2}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher2, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, nil, shouldSearcher2, mustNotSearcher2, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 2
	steveTermSearcher3, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher3, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher3}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher3, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, nil, nil, mustNotSearcher3, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 3
	beerTermSearcher4, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher4, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher4}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	steveTermSearcher4, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher4, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher4}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher4, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher4, nil, mustNotSearcher4, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 4
	beerTermSearcher5, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher5, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher5}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	steveTermSearcher5, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	martyTermSearcher5, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher5, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher5, martyTermSearcher5}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher5, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher5, nil, mustNotSearcher5, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 5
	beerTermSearcher6, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher6, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher6}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	martyTermSearcher6, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	dustinTermSearcher6, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "dustin", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	shouldSearcher6, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{martyTermSearcher6, dustinTermSearcher6}, 2, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher6, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher6, shouldSearcher6, nil, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 6
	beerTermSearcher7, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher7, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher7}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher7, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher7, nil, nil, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	martyTermSearcher7, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 5.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	conjunctionSearcher7, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{martyTermSearcher7, booleanSearcher7}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	// test 7
	beerTermSearcher8, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "beer", "desc", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustSearcher8, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{beerTermSearcher8}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	martyTermSearcher8, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "marty", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	dustinTermSearcher8, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "dustin", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	shouldSearcher8, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{martyTermSearcher8, dustinTermSearcher8}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	steveTermSearcher8, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "steve", "name", 1.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	mustNotSearcher8, err := NewDisjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{steveTermSearcher8}, 0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	booleanSearcher8, err := NewBooleanSearcher(context.TODO(), twoDocIndexReader, mustSearcher8, shouldSearcher8, mustNotSearcher8, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	dustinTermSearcher8a, err := NewTermSearcher(context.TODO(), twoDocIndexReader, "dustin", "name", 5.0, explainTrue)
	if err != nil {
		t.Fatal(err)
	}
	conjunctionSearcher8, err := NewConjunctionSearcher(context.TODO(), twoDocIndexReader, []search.Searcher{booleanSearcher8, dustinTermSearcher8a}, explainTrue)
	if err != nil {
		t.Fatal(err)
	}

	tests := []struct {
		searcher search.Searcher
		results  []*search.DocumentMatch
	}{
		{
			searcher: booleanSearcher,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("1"),
					Score:           0.9818005051949021,
				},
				{
					IndexInternalID: index.IndexInternalID("3"),
					Score:           0.808709699395535,
				},
				{
					IndexInternalID: index.IndexInternalID("4"),
					Score:           0.34618161159873423,
				},
			},
		},
		{
			searcher: booleanSearcher2,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("1"),
					Score:           0.6775110856165737,
				},
				{
					IndexInternalID: index.IndexInternalID("3"),
					Score:           0.6775110856165737,
				},
			},
		},
		// no MUST or SHOULD clauses yields no results
		{
			searcher: booleanSearcher3,
			results:  []*search.DocumentMatch{},
		},
		{
			searcher: booleanSearcher4,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("1"),
					Score:           1.0,
				},
				{
					IndexInternalID: index.IndexInternalID("3"),
					Score:           0.5,
				},
				{
					IndexInternalID: index.IndexInternalID("4"),
					Score:           1.0,
				},
			},
		},
		{
			searcher: booleanSearcher5,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("3"),
					Score:           0.5,
				},
				{
					IndexInternalID: index.IndexInternalID("4"),
					Score:           1.0,
				},
			},
		},
		{
			searcher: booleanSearcher6,
			results:  []*search.DocumentMatch{},
		},
		// test a conjunction query with a nested boolean
		{
			searcher: conjunctionSearcher7,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("1"),
					Score:           2.0097428702814377,
				},
			},
		},
		{
			searcher: conjunctionSearcher8,
			results: []*search.DocumentMatch{
				{
					IndexInternalID: index.IndexInternalID("3"),
					Score:           2.0681575785068107,
				},
			},
		},
	}

	for testIndex, test := range tests {
		defer func() {
			err := test.searcher.Close()
			if err != nil {
				t.Fatal(err)
			}
		}()

		ctx := &search.SearchContext{
			DocumentMatchPool: search.NewDocumentMatchPool(test.searcher.DocumentMatchPoolSize(), 0),
		}
		next, err := test.searcher.Next(ctx)
		i := 0
		for err == nil && next != nil {
			if i < len(test.results) {
				if !next.IndexInternalID.Equals(test.results[i].IndexInternalID) {
					t.Errorf("expected result %d to have id %s got %s for test %d", i, test.results[i].IndexInternalID, next.IndexInternalID, testIndex)
				}
				if !scoresCloseEnough(next.Score, test.results[i].Score) {
					t.Errorf("expected result %d to have score %v got  %v for test %d", i, test.results[i].Score, next.Score, testIndex)
					t.Logf("scoring explanation: %s", next.Expl)
				}
			}
			ctx.DocumentMatchPool.Put(next)
			next, err = test.searcher.Next(ctx)
			i++
		}
		if err != nil {
			t.Fatalf("error iterating searcher: %v for test %d", err, testIndex)
		}
		if len(test.results) != i {
			t.Errorf("expected %d results got %d for test %d", len(test.results), i, testIndex)
		}
	}
}
