package hotsearchmod

import (
	"context"
	"fmt"
	"hkdj-web-server/pub/common/log"
	"hkdj-web-server/pub/common/srvdef"
	"hkdj-web-server/pub/mongos"
	"strings"
	"time"
	"unicode"
	"unicode/utf8"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

var db *mongos.Collection

func Init(ctx context.Context) {
	db = mongos.Shop.Coll(TN.HotSearch)
	indexes := []mongo.IndexModel{
		{
			Keys:    bson.D{{Key: FN.HotSearch.Keyword, Value: 1}},
			Options: options.Index().SetUnique(true),
		},
		{
			Keys: bson.D{
				{Key: FN.HotSearch.Count, Value: -1},
				{Key: FN.HotSearch.UpdatedAt, Value: -1},
			},
		},
	}
	if _, err := db.CreateIndex(ctx, indexes); err != nil {
		panic(fmt.Sprintf("(hotsearchmod:Init) Create HotSearch Index failed! err:%+v:", err))
	}
}

// NormalizeKeyword 去掉首尾空白、压缩中间空格，并限制长度。
func NormalizeKeyword(raw string) string {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return ""
	}
	fields := strings.FieldsFunc(raw, unicode.IsSpace)
	raw = strings.Join(fields, " ")
	if utf8.RuneCountInString(raw) > MaxKeywordRunes {
		raw = string([]rune(raw)[:MaxKeywordRunes])
	}
	return raw
}

// IncrByKeyword 按搜索词累加次数，不存在则插入。
func IncrByKeyword(ctx context.Context, keyword string) *srvdef.SrvErr {
	keyword = NormalizeKeyword(keyword)
	if keyword == "" {
		return nil
	}
	now := time.Now()
	filter := bson.M{FN.HotSearch.Keyword: keyword}
	update := bson.M{
		"$inc": bson.M{FN.HotSearch.Count: 1},
		"$set": bson.M{FN.HotSearch.UpdatedAt: now},
		"$setOnInsert": bson.M{
			FN.HotSearch.Id:        mongos.Lid.HotSearch.Get(),
			FN.HotSearch.Keyword:   keyword,
			FN.HotSearch.CreatedAt: now,
		},
	}
	if _, err := db.UpsertOne(ctx, filter, update); err != nil {
		if _, retryErr := db.UpdateOne(ctx, filter, bson.M{
			"$inc": bson.M{FN.HotSearch.Count: 1},
			"$set": bson.M{FN.HotSearch.UpdatedAt: now},
		}); retryErr != nil {
			log.Warn("hotsearchmod:IncrByKeyword failed", log.E(err), log.E(retryErr), log.Any("keyword", keyword))
			return srvdef.New(srvdef.ErrDbUpdateError, "", "")
		}
	}
	return nil
}

func FindTopHotSearch(ctx context.Context, limit int64) (HotSearchList, *srvdef.SrvErr) {
	if limit <= 0 {
		limit = TopLimit
	}
	opts := options.Find().
		SetSort(bson.D{
			{Key: FN.HotSearch.Count, Value: -1},
			{Key: FN.HotSearch.UpdatedAt, Value: -1},
			{Key: FN.HotSearch.Id, Value: -1},
		}).
		SetLimit(limit).
		SetProjection(bson.D{
			{Key: FN.HotSearch.Id, Value: 1},
			{Key: FN.HotSearch.Keyword, Value: 1},
			{Key: FN.HotSearch.Count, Value: 1},
		})
	data := make(HotSearchList, 0)
	if err := db.Find(ctx, &data, bson.M{}, opts); err != nil {
		log.Warn("hotsearchmod:FindTopHotSearch db.Find failed", log.E(err))
		return nil, srvdef.New(srvdef.ErrDbQueryError, "", "")
	}
	return data, nil
}