herald.go/server/search.go

package server

import (
	"context"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"github.com/btcsuite/btcutil/base58"
	"log"
	"math"
	"reflect"
	"strconv"
	"strings"
	"time"

	//"github.com/lbryio/hub/schema"

	pb "github.com/lbryio/hub/protobuf/go"
	"github.com/lbryio/lbry.go/v2/extras/util"
	"github.com/olivere/elastic/v7"
	"golang.org/x/text/cases"
	"golang.org/x/text/language"
	"google.golang.org/protobuf/encoding/protojson"
	"gopkg.in/karalabe/cookiejar.v1/collections/deque"
)

const DefaultSearchSize = 1000

type record struct {
	Txid               string  `json:"tx_id"`
	Nout               uint32  `json:"tx_nout"`
	Height             uint32  `json:"height"`
	ClaimId            string  `json:"claim_id"`
	ChannelId          string  `json:"channel_id"`
	RepostedClaimId    string  `json:"reposted_claim_id"`
	CensorType         uint32  `json:"censor_type"`
	CensoringChannelId string  `json:"censoring_channel_id"`
	ShortUrl           string  `json:"short_url"`
	CanonicalUrl       string  `json:"canonical_url"`
	IsControlling      bool    `json:"is_controlling"`
	TakeOverHeight     uint32  `json:"last_take_over_height"`
	CreationHeight     uint32  `json:"creation_height"`
	ActivationHeight   uint32  `json:"activation_height"`
	ExpirationHeight   uint32  `json:"expiration_height"`
	ClaimsInChannel    uint32  `json:"claims_in_channel"`
	RepostCount        uint32  `json:"repost_count"`
	EffectiveAmount    uint64  `json:"effective_amount"`
	SupportAmount      uint64  `json:"support_amount"`
	TrendingScore      float64 `json:"TrendingScore"`
	ClaimName          string  `json:"claim_name"`
}

type orderField struct {
	Field string
	IsAsc bool
}

func StrArrToInterface(arr []string) []interface{} {
	searchVals := make([]interface{}, len(arr))
	for i := 0; i < len(arr); i++ {
		searchVals[i] = arr[i]
	}
	return searchVals
}

func AddTermsField(q *elastic.BoolQuery, arr []string, name string) *elastic.BoolQuery {
	if len(arr) == 0 {
		return q
	}
	searchVals := StrArrToInterface(arr)
	return q.Must(elastic.NewTermsQuery(name, searchVals...))
}

func AddTermField(q *elastic.BoolQuery, value string, name string) *elastic.BoolQuery {
	if value != "" {
		return q.Must(elastic.NewTermQuery(name, value))
	}
	return q
}

func AddIndividualTermFields(q *elastic.BoolQuery, arr []string, name string, invert bool) *elastic.BoolQuery {
	for _, x := range arr {
		if invert {
			q = q.MustNot(elastic.NewTermQuery(name, x))
		} else {
			q = q.Must(elastic.NewTermQuery(name, x))
		}
	}
	return q
}

func AddRangeField(q *elastic.BoolQuery, rq *pb.RangeField, name string) *elastic.BoolQuery {
	if rq == nil {
		return q
	}
	if len(rq.Value) > 1 {
		if rq.Op != pb.RangeField_EQ {
			return q
		}
		return AddTermsField(q, rq.Value, name)
	}
	if rq.Op == pb.RangeField_EQ {
		return q.Must(elastic.NewTermQuery(name, rq.Value[0]))
	} else if rq.Op == pb.RangeField_LT {
		return q.Must(elastic.NewRangeQuery(name).Lt(rq.Value[0]))
	} else if rq.Op == pb.RangeField_LTE {
		return q.Must(elastic.NewRangeQuery(name).Lte(rq.Value[0]))
	} else if rq.Op == pb.RangeField_GT {
		return q.Must(elastic.NewRangeQuery(name).Gt(rq.Value[0]))
	} else { // pb.RangeField_GTE
		return q.Must(elastic.NewRangeQuery(name).Gte(rq.Value[0]))
	}
}

func AddInvertibleField(q *elastic.BoolQuery, field *pb.InvertibleField, name string) *elastic.BoolQuery {
	if field == nil {
		return q
	}
	searchVals := StrArrToInterface(field.Value)
	if field.Invert {
		q = q.MustNot(elastic.NewTermsQuery(name, searchVals...))
		if name == "channel_id.keyword" {
			q = q.MustNot(elastic.NewTermsQuery("_id", searchVals...))
		}
		return q
	} else {
		return q.Must(elastic.NewTermsQuery(name, searchVals...))
	}
}
func (s *Server) recordErrorAndReturn(err error, typ string) (interface{}, error) {
	// TODO record metric
	log.Println(err)
	return nil, err
}

func (s *Server) recordErrorAndDie(err error) {
	// TODO record metric fatal_error_counter
	log.Fatalln(err)
}

func RoundUpReleaseTime(q *elastic.BoolQuery, rq *pb.RangeField, name string) *elastic.BoolQuery {
	if rq == nil {
		return q
	}
	releaseTimeInt, err := strconv.ParseInt(rq.Value[0], 10, 32)
	if err != nil {
		return q
	}
	if releaseTimeInt < 0 {
		releaseTimeInt *= - 1
	}
	releaseTime := strconv.Itoa(int(((releaseTimeInt / 360) + 1) * 360))
	if rq.Op == pb.RangeField_EQ {
		return q.Must(elastic.NewTermQuery(name, releaseTime))
	} else if rq.Op == pb.RangeField_LT {
		return q.Must(elastic.NewRangeQuery(name).Lt(releaseTime))
	} else if rq.Op == pb.RangeField_LTE {
		return q.Must(elastic.NewRangeQuery(name).Lte(releaseTime))
	} else if rq.Op == pb.RangeField_GT {
		return q.Must(elastic.NewRangeQuery(name).Gt(releaseTime))
	} else { // pb.RangeField_GTE
		return q.Must(elastic.NewRangeQuery(name).Gte(releaseTime))
	}
}

// Search /*
// Search logic is as follows:
// 1) Setup query with params given
// 2) Do query with limit of 1000
// 3) remove blocked content (these are returned separately)
// 4) remove duplicates (these are not returned)
// 5) limit claims per channel logic
// 6) get claims referenced by reposts
// 7) get channels references by claims and repost claims
// 8) return streams referenced by repost and all channel referenced in extra_txos
//*/
func (s *Server) Search(ctx context.Context, in *pb.SearchRequest) (*pb.Outputs, error) {
	// TODO record metric search_counter
	t0 := time.Now()

	var from = 0
	var pageSize = 10
	var orderBy []orderField
	var searchIndices []string
	var searchResult *elastic.SearchResult = nil
	client := s.EsClient
	searchIndices = make([]string, 0, 1)
	//searchIndices = append(searchIndices, s.Args.EsIndex)

	indices, _ := client.IndexNames()
	for _, index := range indices {
		if index != "claims" {
			log.Println(index)
			searchIndices = append(searchIndices, index)
		}
	}

	//cacheHit := false
	var records []*record

	cacheKey := s.serializeSearchRequest(in)

	/*
			cache based on search request params
			include from value and number of results.
			When another search request comes in with same search params
			and same or increased offset (which we currently don't even use?)
			that will be a cache hit.
			FIXME: For now the cache is turned off when in debugging mode
				(for unit tests) because it breaks on some of them.
			FIXME: Currently the cache just skips the initial search,
				the mgets and post processing are still done. There's probably
				a more efficient way to store the final result.
	*/

	if val, err := s.QueryCache.Get(cacheKey); err != nil || s.Args.Debug {

		q := elastic.NewBoolQuery()

		err := s.checkQuery(in)
		if err != nil {
			return nil, err
		}
		q = s.setupEsQuery(q, in, &pageSize, &from, &orderBy)

		fsc := elastic.NewFetchSourceContext(true).Exclude("description", "title")
		search := client.Search().
			Index(searchIndices...).
			FetchSourceContext(fsc).
			Query(q). // specify the query
			From(0).Size(DefaultSearchSize)

		for _, x := range orderBy {
			search = search.Sort(x.Field, x.IsAsc)
		}

		searchResult, err = search.Do(ctx) // execute
		if err != nil && elastic.IsNotFound(err) {
			log.Println("Index returned 404! Check writer. Index: ", searchIndices)
			return &pb.Outputs{}, nil

		} else if err != nil {
			s.recordErrorAndReturn(err, "search_errors")
			log.Println("Error executing query: ", err)
			return nil, err
		}

		log.Printf("%s: found %d results in %dms\n", in.Text, len(searchResult.Hits.Hits), searchResult.TookInMillis)

		records = s.searchResultToRecords(searchResult)
		err = s.QueryCache.Set(cacheKey, records)
		if err != nil {
			//FIXME: Should this be fatal?
			log.Println("Error storing records in cache: ", err)
		}
	} else {
		records = val.([]*record)
	}

	txos, extraTxos, blocked := s.postProcessResults(ctx, client, records, in, pageSize, from, searchIndices)

	t1 := time.Now()

	delta := t1.Unix() - t0.Unix()
	log.Printf("delta: %d\n", delta)
	// TODO record metric query_time

	if in.NoTotals {
		return &pb.Outputs{
			Txos:      txos,
			ExtraTxos: extraTxos,
			Offset:    uint32(int64(from) + searchResult.TotalHits()),
			Blocked:   blocked,
		}, nil
	}

	var blockedTotal uint32 = 0
	for _, b := range blocked {
		blockedTotal += b.Count
	}
	return &pb.Outputs{
		Txos:         txos,
		ExtraTxos:    extraTxos,
		Total:        uint32(searchResult.TotalHits()),
		Offset:       uint32(int64(from) + searchResult.TotalHits()),
		Blocked:      blocked,
		BlockedTotal: blockedTotal,
	}, nil
}

func (s *Server) normalizeTag(tag string) string {
	c := cases.Lower(language.English)
	res := s.MultiSpaceRe.ReplaceAll(
		s.WeirdCharsRe.ReplaceAll(
			[]byte(strings.TrimSpace(strings.Replace(c.String(tag), "'", "", -1))),
			[]byte(" ")),
		[]byte(" "))

	return string(res)
}

func (s *Server) cleanTags(tags []string) []string {
	cleanedTags := make([]string, len(tags))
	for i, tag := range tags {
		cleanedTags[i] = s.normalizeTag(tag)
	}
	return cleanedTags
}

func (s *Server) searchResultToRecords(
	searchResult *elastic.SearchResult) []*record {
	records := make([]*record, 0, searchResult.TotalHits())

	var r record
	for _, item := range searchResult.Each(reflect.TypeOf(r)) {
		if t, ok := item.(record); ok {
			records = append(records, &t)
		}
	}

	return records
}

func (s *Server) postProcessResults(
	ctx context.Context,
	client *elastic.Client,
	records []*record,
	in *pb.SearchRequest,
	pageSize int,
	from int,
	searchIndices []string) ([]*pb.Output, []*pb.Output, []*pb.Blocked) {
	var txos []*pb.Output
	var blockedRecords []*record
	var blocked []*pb.Blocked
	var blockedMap map[string]*pb.Blocked

	//printJsonFullResults(searchResult)
	records, blockedRecords, blockedMap = removeBlocked(records)

	if in.RemoveDuplicates {
		records = removeDuplicates(records)
	}

	if in.LimitClaimsPerChannel > 0 {
		records = searchAhead(records, pageSize, int(in.LimitClaimsPerChannel))
	}

	finalLength := int(math.Min(float64(len(records)), float64(pageSize)))
	txos = make([]*pb.Output, 0, finalLength)
	var j = 0
	for i := from; i < from+finalLength && i < len(records) && j < finalLength; i++ {
		t := records[i]
		res := t.recordToOutput()
		txos = append(txos, res)
		j += 1
	}
	//Get claims for reposts
	repostClaims, repostRecords, repostedMap := s.getClaimsForReposts(ctx, client, records, searchIndices)
	//get all unique channels
	channels, channelMap := s.getUniqueChannels(append(append(records, repostRecords...), blockedRecords...), client, ctx, searchIndices)
	//add these to extra txos
	extraTxos := append(repostClaims, channels...)

	//Fill in channel / repost data for txos and blocked
	for i, txo := range txos {
		channel, cOk := channelMap[records[i].ChannelId]
		repostClaim, rOk := repostedMap[records[i].RepostedClaimId]
		if cOk {
			txo.GetClaim().Channel = channel
		}
		if rOk {
			txo.GetClaim().Repost = repostClaim
		}
	}

	blocked = make([]*pb.Blocked, 0, len(blockedMap))
	for k, v := range blockedMap {
		if channel, ok := channelMap[k]; ok {
			v.Channel = channel
		}
		blocked = append(blocked, v)
	}

	return txos, extraTxos, blocked
}

func (s *Server) checkQuery(in *pb.SearchRequest) error {
	limit := 2048
	checks := map[string]bool{
		"claim_ids":       in.ClaimId != nil && !in.ClaimId.Invert && len(in.ClaimId.Value) > limit,
		"not_claim_ids":   in.ClaimId != nil && in.ClaimId.Invert && len(in.ClaimId.Value) > limit,
		"channel_ids":     in.ChannelId != nil && !in.ChannelId.Invert && len(in.ChannelId.Value) > limit,
		"not_channel_ids": in.ChannelId != nil && in.ChannelId.Invert && len(in.ChannelId.Value) > limit,
		"not_tags":        len(in.NotTags) > limit,
		"all_tags":        len(in.AllTags) > limit,
		"any_tags":        len(in.AnyTags) > limit,
		"any_languages":   len(in.AnyLanguages) > limit,
	}
	for name, failed := range checks {
		if failed {
			time.Sleep(2) // throttle
			return fmt.Errorf("%s cant have more than %d items", name, limit)
		}
	}
	return nil
}

func (s *Server) setupEsQuery(
	q *elastic.BoolQuery,
	in *pb.SearchRequest,
	pageSize *int,
	from *int,
	orderBy *[]orderField) *elastic.BoolQuery {
	claimTypes := map[string]int{
		"stream":     1,
		"channel":    2,
		"repost":     3,
		"collection": 4,
	}

	streamTypes := map[string]int{
		"video":    1,
		"audio":    2,
		"image":    3,
		"document": 4,
		"binary":   5,
		"model":    6,
	}

	replacements := map[string]string{
		"name":       "normalized_name",
		"normalized": "normalized_name",
		"claim_name": "normalized_name",
		"txid":       "tx_id",
		"nout":	      "tx_nout",
		"reposted":   "repost_count",
		"valid_channel_signature": "is_signature_valid",
		"claim_id":   "_id",
		"signature_digest": "signature",
	}

	textFields := map[string]bool{
		"author":            true,
		"canonical_url":     true,
		"channel_id":        true,
		"claim_name":        true,
		"description":       true,
		"claim_id":          true,
		"media_type":        true,
		"normalized_name":   true,
		"public_key_bytes":  true,
		"public_key_id":     true,
		"short_url":         true,
		"signature":         true,
		"stream_type":       true,
		"title":             true,
		"tx_id":             true,
		"fee_currency":      true,
		"reposted_claim_id": true,
		"tags":              true,
	}

	if in.IsControlling {
		q = q.Must(elastic.NewTermQuery("is_controlling", in.IsControlling))
	}

	if in.Limit > 0 {
		*pageSize = int(in.Limit)
	}

	if in.Offset > 0 {
		*from = int(in.Offset)
	}

	if len(in.ClaimName) > 0 {
		in.NormalizedName = util.NormalizeName(in.ClaimName)
	}

	if len(in.OrderBy) > 0 {
		for _, x := range in.OrderBy {
			var toAppend string
			var isAsc = false
			if x[0] == '^' {
				isAsc = true
				x = x[1:]
			}
			if _, ok := replacements[x]; ok {
				toAppend = replacements[x]
			} else {
				toAppend = x
			}

			if _, ok := textFields[toAppend]; ok {
				toAppend = toAppend + ".keyword"
			}
			*orderBy = append(*orderBy, orderField{toAppend, isAsc})
		}
	}

	if len(in.ClaimType) > 0 {
		searchVals := make([]interface{}, len(in.ClaimType))
		for i := 0; i < len(in.ClaimType); i++ {
			searchVals[i] = claimTypes[in.ClaimType[i]]
		}
		q = q.Must(elastic.NewTermsQuery("claim_type", searchVals...))
	}

	if len(in.StreamType) > 0 {
		searchVals := make([]interface{}, len(in.StreamType))
		for i := 0; i < len(in.StreamType); i++ {
			searchVals[i] = streamTypes[in.StreamType[i]]
		}
		q = q.Must(elastic.NewTermsQuery("stream_type", searchVals...))
	}

	if in.ClaimId != nil {
		searchVals := StrArrToInterface(in.ClaimId.Value)
		if len(in.ClaimId.Value) == 1 && len(in.ClaimId.Value[0]) < 20 {
			if in.ClaimId.Invert {
				q = q.MustNot(elastic.NewPrefixQuery("claim_id.keyword", in.ClaimId.Value[0]))
			} else {
				q = q.Must(elastic.NewPrefixQuery("claim_id.keyword", in.ClaimId.Value[0]))
			}
		} else {
			if in.ClaimId.Invert {
				q = q.MustNot(elastic.NewTermsQuery("claim_id.keyword", searchVals...))
			} else {
				q = q.Must(elastic.NewTermsQuery("claim_id.keyword", searchVals...))
			}
		}
	}

	if in.PublicKeyId != "" {
		value := hex.EncodeToString(base58.Decode(in.PublicKeyId)[1:21])
		q = q.Must(elastic.NewTermQuery("public_key_id.keyword", value))
		// q = q.Must(elastic.NewTermQuery("public_key_id.keyword", in.PublicKeyId))
	}

	if in.HasChannelSignature {
		q = q.Must(elastic.NewExistsQuery("signature"))
		if in.IsSignatureValid != nil {
			q = q.Must(elastic.NewTermQuery("is_signature_valid", in.IsSignatureValid.Value))
		}
	} else if in.IsSignatureValid != nil {
		q = q.MinimumNumberShouldMatch(1)
		q = q.Should(elastic.NewBoolQuery().MustNot(elastic.NewExistsQuery("signature")))
		q = q.Should(elastic.NewTermQuery("is_signature_valid", in.IsSignatureValid.Value))
	}

	if in.HasSource != nil {
		q = q.MinimumNumberShouldMatch(1)
		isStreamOrRepost := elastic.NewTermsQuery("claim_type", claimTypes["stream"], claimTypes["repost"])
		q = q.Should(elastic.NewBoolQuery().Must(isStreamOrRepost, elastic.NewMatchQuery("has_source", in.HasSource.Value)))
		q = q.Should(elastic.NewBoolQuery().MustNot(isStreamOrRepost))
		q = q.Should(elastic.NewBoolQuery().Must(elastic.NewTermQuery("reposted_claim_type", claimTypes["channel"])))
	}

	if in.TxNout != nil {
		q = q.Must(elastic.NewTermQuery("tx_nout", in.TxNout.Value))
	}

	q = AddTermField(q, in.Author, "author.keyword")
	q = AddTermField(q, in.Title, "title.keyword")
	q = AddTermField(q, in.CanonicalUrl, "canonical_url.keyword")
	q = AddTermField(q, in.ClaimName, "claim_name.keyword")
	q = AddTermField(q, in.Description, "description.keyword")
	q = AddTermsField(q, in.MediaType, "media_type.keyword")
	q = AddTermField(q, in.NormalizedName, "normalized_name.keyword")
	q = AddTermField(q, in.ShortUrl, "short_url.keyword")
	q = AddTermField(q, in.Signature, "signature.keyword")
	q = AddTermField(q, in.TxId, "tx_id.keyword")
	// q = AddTermField(q, strings.ToUpper(in.FeeCurrency), "fee_currency.keyword")
	q = AddTermField(q, in.FeeCurrency, "fee_currency.keyword")
	q = AddTermField(q, in.RepostedClaimId, "reposted_claim_id.keyword")

	q = AddTermsField(q, s.cleanTags(in.AnyTags), "tags.keyword")
	q = AddIndividualTermFields(q, s.cleanTags(in.AllTags), "tags.keyword", false)
	q = AddIndividualTermFields(q, s.cleanTags(in.NotTags), "tags.keyword", true)
	q = AddTermsField(q, in.AnyLanguages, "languages")
	q = AddIndividualTermFields(q, in.AllLanguages, "languages", false)

	q = AddInvertibleField(q, in.ChannelId, "channel_id.keyword")

	q = AddRangeField(q, in.TxPosition, "tx_position")
	q = AddRangeField(q, in.Amount, "amount")
	q = AddRangeField(q, in.Timestamp, "timestamp")
	q = AddRangeField(q, in.CreationTimestamp, "creation_timestamp")
	q = AddRangeField(q, in.Height, "height")
	q = AddRangeField(q, in.CreationHeight, "creation_height")
	q = AddRangeField(q, in.ActivationHeight, "activation_height")
	q = AddRangeField(q, in.ExpirationHeight, "expiration_height")
	q = RoundUpReleaseTime(q, in.ReleaseTime, "release_time")
	q = AddRangeField(q, in.RepostCount, "repost_count")
	q = AddRangeField(q, in.FeeAmount, "fee_amount")
	q = AddRangeField(q, in.Duration, "duration")
	q = AddRangeField(q, in.CensorType, "censor_type")
	q = AddRangeField(q, in.ChannelJoin, "channel_join")
	q = AddRangeField(q, in.EffectiveAmount, "effective_amount")
	q = AddRangeField(q, in.SupportAmount, "support_amount")
	q = AddRangeField(q, in.TrendingScore, "trending_score")

	if in.Text != "" {
		textQuery := elastic.NewSimpleQueryStringQuery(in.Text).
			FieldWithBoost("claim_name", 4).
			FieldWithBoost("channel_name", 8).
			FieldWithBoost("title", 1).
			FieldWithBoost("description", 0.5).
			FieldWithBoost("author", 1).
			FieldWithBoost("tags", 0.5)

		q = q.Must(textQuery)
	}

	return q
}

func (s *Server) getUniqueChannels(records []*record, client *elastic.Client, ctx context.Context, searchIndices []string) ([]*pb.Output, map[string]*pb.Output) {
	channels := make(map[string]*pb.Output)
	channelsSet := make(map[string]bool)
	var mget = client.Mget()
	var totalChannels = 0
	for _, r := range records {
		for _, searchIndex := range searchIndices {
			if r.ChannelId != "" && !channelsSet[r.ChannelId] {
				channelsSet[r.ChannelId] = true
				nmget := elastic.NewMultiGetItem().Id(r.ChannelId).Index(searchIndex)
				mget = mget.Add(nmget)
				totalChannels++
			}
			if r.CensorType != 0 && !channelsSet[r.CensoringChannelId] {
				channelsSet[r.CensoringChannelId] = true
				nmget := elastic.NewMultiGetItem().Id(r.CensoringChannelId).Index(searchIndex)
				mget = mget.Add(nmget)
				totalChannels++
			}
		}
	}
	if totalChannels == 0 {
		s.recordErrorAndReturn(nil, "zero_channels_counter")
		return []*pb.Output{}, make(map[string]*pb.Output)
	}

	res, err := mget.Do(ctx)
	if err != nil {
		s.recordErrorAndReturn(err, "get_unique_channels_errors")
		return []*pb.Output{}, make(map[string]*pb.Output)
	}

	channelTxos := make([]*pb.Output, totalChannels)
	//repostedRecords := make([]*record, totalReposted)

	//log.Println("total channel", totalChannels)
	for i, doc := range res.Docs {
		var r record
		err := json.Unmarshal(doc.Source, &r)
		if err != nil {
			s.recordErrorAndReturn(err, "json_errors")
			return []*pb.Output{}, make(map[string]*pb.Output)
		}
		channelTxos[i] = r.recordToOutput()
		channels[r.ClaimId] = channelTxos[i]
		//log.Println(r)
		//repostedRecords[i] = &r
	}

	return channelTxos, channels
}

func (s *Server) getClaimsForReposts(ctx context.Context, client *elastic.Client, records []*record, searchIndices []string) ([]*pb.Output, []*record, map[string]*pb.Output) {

	var totalReposted = 0
	var mget = client.Mget() //.StoredFields("_id")
	/*
		var nmget = elastic.NewMultiGetItem()
		for _, index := range searchIndices {
			nmget = nmget.Index(index)
		}
	*/
	for _, r := range records {
		for _, searchIndex := range searchIndices {
			if r.RepostedClaimId != "" {
				var nmget = elastic.NewMultiGetItem().Id(r.RepostedClaimId).Index(searchIndex)
				//nmget = nmget.Id(r.RepostedClaimId)
				mget = mget.Add(nmget)
				totalReposted++
			}
		}
	}
	//mget = mget.Add(nmget)
	if totalReposted == 0 {
		// TODO record metric no_reposted_counter
		return []*pb.Output{}, []*record{}, make(map[string]*pb.Output)
	}

	res, err := mget.Do(ctx)
	if err != nil {
		s.recordErrorAndReturn(err, "mget_error_counter")
		return []*pb.Output{}, []*record{}, make(map[string]*pb.Output)
	}

	claims := make([]*pb.Output, totalReposted)
	repostedRecords := make([]*record, totalReposted)
	respostedMap := make(map[string]*pb.Output)

	//log.Println("reposted records", totalReposted)
	for i, doc := range res.Docs {
		var r record
		err := json.Unmarshal(doc.Source, &r)
		if err != nil {
			s.recordErrorAndReturn(err, "json_error_counter")
			return []*pb.Output{}, []*record{}, make(map[string]*pb.Output)
		}
		claims[i] = r.recordToOutput()
		repostedRecords[i] = &r
		respostedMap[r.ClaimId] = claims[i]
	}

	return claims, repostedRecords, respostedMap
}

/*
	Takes a search request and serializes into a string for use as a key into the
	internal cache for the hub.
*/
func (s *Server) serializeSearchRequest(request *pb.SearchRequest) string {
	bytes, err := protojson.Marshal(request)
	if err != nil {
		return ""
	}
	str := string((*s.S256).Sum(bytes))
	log.Println(str)
	return str
}

func searchAhead(searchHits []*record, pageSize int, perChannelPerPage int) []*record {
	finalHits := make([]*record, 0, len(searchHits))
	var channelCounters map[string]int
	channelCounters = make(map[string]int)
	nextPageHitsMaybeCheckLater := deque.New()
	searchHitsQ := deque.New()
	for _, rec := range searchHits {
		searchHitsQ.PushRight(rec)
	}
	for !searchHitsQ.Empty() || !nextPageHitsMaybeCheckLater.Empty() {
		if len(finalHits) > 0 && len(finalHits)%pageSize == 0 {
			channelCounters = make(map[string]int)
		} else if len(finalHits) != 0 {
			// means last page was incomplete and we are left with bad replacements
			break
		}

		for i := 0; i < nextPageHitsMaybeCheckLater.Size(); i++ {
			rec := nextPageHitsMaybeCheckLater.PopLeft().(*record)
			if perChannelPerPage > 0 && channelCounters[rec.ChannelId] < perChannelPerPage {
				finalHits = append(finalHits, rec)
				channelCounters[rec.ChannelId] = channelCounters[rec.ChannelId] + 1
			}
		}
		for !searchHitsQ.Empty() {
			hit := searchHitsQ.PopLeft().(*record)
			if hit.ChannelId == "" || perChannelPerPage < 0 {
				finalHits = append(finalHits, hit)
			} else if channelCounters[hit.ChannelId] < perChannelPerPage {
				finalHits = append(finalHits, hit)
				channelCounters[hit.ChannelId] = channelCounters[hit.ChannelId] + 1
				if len(finalHits)%pageSize == 0 {
					break
				}
			} else {
				nextPageHitsMaybeCheckLater.PushRight(hit)
			}
		}
	}
	return finalHits
}

func (r *record) recordToOutput() *pb.Output {
	return &pb.Output{
		TxHash: util.TxIdToTxHash(r.Txid),
		Nout:   r.Nout,
		Height: r.Height,
		Meta: &pb.Output_Claim{
			Claim: &pb.ClaimMeta{
				//Channel:
				//Repost:
				ShortUrl:         r.ShortUrl,
				CanonicalUrl:     r.CanonicalUrl,
				IsControlling:    r.IsControlling,
				TakeOverHeight:   r.TakeOverHeight,
				CreationHeight:   r.CreationHeight,
				ActivationHeight: r.ActivationHeight,
				ExpirationHeight: r.ExpirationHeight,
				ClaimsInChannel:  r.ClaimsInChannel,
				Reposted:         r.RepostCount,
				EffectiveAmount:  r.EffectiveAmount,
				SupportAmount:    r.SupportAmount,
				TrendingScore:    r.TrendingScore,
			},
		},
	}
}

func (r *record) getHitId() string {
	if r.RepostedClaimId != "" {
		return r.RepostedClaimId
	} else {
		return r.ClaimId
	}
}

func removeDuplicates(searchHits []*record) []*record {
	dropped := make(map[*record]bool)
	// claim_id -> (creation_height, hit_id), where hit_id is either reposted claim id or original
	knownIds := make(map[string]*record)

	for _, hit := range searchHits {
		hitHeight := hit.Height
		hitId := hit.getHitId()

		if knownIds[hitId] == nil {
			knownIds[hitId] = hit
		} else {
			prevHit := knownIds[hitId]
			if hitHeight < prevHit.Height {
				knownIds[hitId] = hit
				dropped[prevHit] = true
			} else {
				dropped[hit] = true
			}
		}
	}

	deduped := make([]*record, len(searchHits)-len(dropped))

	var i = 0
	for _, hit := range searchHits {
		if !dropped[hit] {
			deduped[i] = hit
			i++
		}
	}

	return deduped
}

func removeBlocked(searchHits []*record) ([]*record, []*record, map[string]*pb.Blocked) {
	newHits := make([]*record, 0, len(searchHits))
	blockedHits := make([]*record, 0, len(searchHits))
	blockedChannels := make(map[string]*pb.Blocked)
	for _, r := range searchHits {
		if r.CensorType != 0 {
			if blockedChannels[r.CensoringChannelId] == nil {
				blockedObj := &pb.Blocked{
					Count:   1,
					Channel: nil,
				}
				blockedChannels[r.CensoringChannelId] = blockedObj
				blockedHits = append(blockedHits, r)
			} else {
				blockedChannels[r.CensoringChannelId].Count += 1
			}
		} else {
			newHits = append(newHits, r)
		}
	}

	return newHits, blockedHits, blockedChannels
}