package search

import (
	"bytes"
	"context"
	"encoding/json"
	"math/rand"
	"os"
	"sort"
	"testing"
	"time"

	"github.com/stretchr/testify/mock"
	assert "github.com/stretchr/testify/require"
	"go.skia.org/infra/go/eventbus"
	"go.skia.org/infra/go/gcs/gcs_testutils"
	"go.skia.org/infra/go/sktest"
	"go.skia.org/infra/go/tiling"
	"go.skia.org/infra/golden/go/baseline/gcs_baseliner"
	"go.skia.org/infra/golden/go/diff"
	"go.skia.org/infra/golden/go/indexer"
	"go.skia.org/infra/golden/go/mocks"
	"go.skia.org/infra/golden/go/serialize"
	"go.skia.org/infra/golden/go/storage"
	"go.skia.org/infra/golden/go/types"
	"go.skia.org/infra/golden/go/warmer"
)

func checkQuery(t assert.TestingT, api *SearchAPI, idx *indexer.SearchIndex, qStr string, exp types.Expectations, buf *bytes.Buffer) int {
	q := &Query{}

	// We ignore incorrect queries. They are tested somewhere else.
	err := clearParseQuery(q, qStr)
	if err != nil {
		return 0
	}
	tile := idx.CpxTile().GetTile(q.IgnoreState())

	// TODO(stephana): Remove the lines below to also exercise the search for
	// issues. This requires to refresh the set of input queries.

	// Ignore queries for gerrit issues right now.
	if !types.IsMasterBranch(q.Issue) {
		return 0
	}

	// Ignore queries with blames since they are ephemeral.
	if q.BlameGroupID != "" {
		return 0
	}

	// Addjust the old default value for MaxRGBA
	if q.FRGBAMax < 0 {
		q.FRGBAMax = 255
	}

	resp, err := api.Search(context.Background(), q)
	assert.NoError(t, err)

	// Serialize the response to json.
	buf.Reset()
	assert.NoError(t, json.NewEncoder(buf).Encode(resp))

	expDigests := getTargetDigests(t, q, tile, exp)

	foundDigests := types.DigestSet{}
	for _, digestRec := range resp.Digests {
		foundDigests[digestRec.Digest] = true
	}

	set1 := expDigests.Keys()
	set2 := foundDigests.Keys()
	sort.Sort(set1)
	sort.Sort(set2)
	assert.Equal(t, set1, set2)
	return 1
}

func getTargetDigests(t assert.TestingT, q *Query, tile *tiling.Tile, exp types.Expectations) types.DigestSet {
	// Account for a given commit range.
	startIdx := 0
	endIdx := tile.LastCommitIndex()

	if q.FCommitBegin != "" {
		startIdx, _ = tiling.FindCommit(tile.Commits, q.FCommitBegin)
		assert.True(t, startIdx >= 0)
	}

	if q.FCommitEnd != "" {
		endIdx, _ = tiling.FindCommit(tile.Commits, q.FCommitEnd)
		assert.True(t, endIdx >= 0)
	}
	assert.True(t, startIdx <= endIdx)

	digestSet := types.DigestSet{}
	for _, trace := range tile.Traces {
		gTrace := trace.(*types.GoldenTrace)
		digestSet.AddLists(gTrace.Digests)
	}
	allDigests := map[types.Digest]int{}
	for idx, digest := range digestSet.Keys() {
		allDigests[digest] = idx
	}

	result := types.DigestSet{}
	lastIdx := endIdx - startIdx
	for _, trace := range tile.Traces {
		if tiling.Matches(trace, q.Query) {
			gTrace := trace.(*types.GoldenTrace)
			vals := gTrace.Digests[startIdx : endIdx+1]
			test := gTrace.TestName()

			relevantDigests := types.DigestSlice{}
			if q.Head {
				idx := lastIdx
				for (idx >= 0) && (vals[idx] == types.MISSING_DIGEST) {
					idx--
				}
				if idx >= 0 {
					relevantDigests = types.DigestSlice{vals[idx]}
				}
			} else {
				relevantDigests = vals
			}

			for _, digest := range relevantDigests {
				if !q.excludeClassification(exp.Classification(test, digest)) {
					result[digest] = true
				}
			}
		}
	}
	delete(result, types.MISSING_DIGEST)
	return result
}

func getStoragesIndexTile(t *testing.T, bucket, storagePath, outputPath string, randomize bool) (*storage.Storage, *indexer.SearchIndex, *tiling.Tile, *indexer.Indexer) {
	err := gcs_testutils.DownloadTestDataFile(t, bucket, storagePath, outputPath)
	assert.NoError(t, err, "Unable to download testdata.")
	return getStoragesAndIndexerFromTile(t, outputPath, randomize)
}

func getStoragesAndIndexerFromTile(t sktest.TestingT, path string, randomize bool) (*storage.Storage, *indexer.SearchIndex, *tiling.Tile, *indexer.Indexer) {
	sample := loadSample(t, path, randomize)

	mds := &mocks.DiffStore{}
	mes := &mocks.ExpectationsStore{}

	mes.On("Get").Return(sample.Expectations, nil)

	mds.On("UnavailableDigests").Return(map[types.Digest]*diff.DigestFailure{})
	mds.On("Get", mock.Anything, mock.Anything, mock.Anything).Return(mockDiffStoreGet, nil)

	tileBuilder := mocks.NewMockTileBuilderFromTile(t, sample.Tile)
	eventBus := eventbus.New()

	baseliner, err := gcs_baseliner.New(nil, mes, nil, nil)
	assert.NoError(t, err)

	storages := &storage.Storage{
		ExpectationsStore: mes,
		MasterTileBuilder: tileBuilder,
		EventBus:          eventBus,
		Baseliner:         baseliner,
		DiffStore:         mds,
	}

	ixr, err := indexer.New(storages, warmer.New(), 10*time.Minute)
	assert.NoError(t, err)
	idx := ixr.GetIndex()
	tile := idx.CpxTile().GetTile(types.ExcludeIgnoredTraces)

	return storages, idx, tile, ixr
}

// mockDiffStoreGet is a simple implementation of the diff comparison that
// makes some fake data for the given digest and slice of digests to compare to.
func mockDiffStoreGet(priority int64, dMain types.Digest, dRest types.DigestSlice) map[types.Digest]interface{} {
	result := map[types.Digest]interface{}{}
	for _, d := range dRest {
		if dMain != d {
			result[d] = &diff.DiffMetrics{
				NumDiffPixels:    10,
				PixelDiffPercent: 1.0,
				MaxRGBADiffs:     []int{5, 3, 4, 0},
				DimDiffer:        false,
				Diffs: map[string]float32{
					diff.METRIC_COMBINED: rand.Float32(),
					diff.METRIC_PERCENT:  rand.Float32(),
				},
			}
		}
	}
	return result
}

func loadSample(t assert.TestingT, fileName string, randomize bool) *serialize.Sample {
	file, err := os.Open(fileName)
	assert.NoError(t, err)

	sample, err := serialize.DeserializeSample(file)
	assert.NoError(t, err)

	if randomize {
		sample.Tile = randomizeTile(sample.Tile, sample.Expectations)
	}

	return sample
}

func randomizeTile(tile *tiling.Tile, testExp types.Expectations) *tiling.Tile {
	allDigestSet := types.DigestSet{}
	for _, digests := range testExp {
		for d := range digests {
			allDigestSet[d] = true
		}
	}
	allDigests := allDigestSet.Keys()

	tileLen := tile.LastCommitIndex() + 1
	ret := tile.Copy()
	for _, trace := range tile.Traces {
		gTrace := trace.(*types.GoldenTrace)
		for i := 0; i < tileLen; i++ {
			gTrace.Digests[i] = allDigests[int(rand.Uint32())%len(allDigests)]
		}
	}
	return ret
}