package configser

import (
	"context"
	"time"
	"videoweb/pub/common/log"
	"videoweb/pub/models/videofavoritemod"
	"videoweb/pub/models/videoinformationmod"

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

// favoriteCountResult 收藏聚合结果
type favoriteCountResult struct {
	Id    int64 `bson:"_id"`
	Count int64 `bson:"count"`
}

// UpdateAllFavoriteDataCount 统计视频收藏量并写回DB
func UpdateAllFavoriteDataCount() {
	updateVideoFavoriteDataCount(context.Background())
}

// buildFavoritePipeline 构建按时间窗口统计收藏量的聚合 pipeline
// contentIdField: favorite表中内容ID字段名（如 videoId）
// since: 统计起始时间，零值表示统计全量
func buildFavoritePipeline(contentIdField string, since time.Time) []bson.M {
	matchStage := bson.M{}
	if !since.IsZero() {
		matchStage["createdAt"] = bson.M{"$gte": since}
	}
	pipeline := []bson.M{}
	if len(matchStage) > 0 {
		pipeline = append(pipeline, bson.M{"$match": matchStage})
	}
	pipeline = append(pipeline,
		bson.M{"$group": bson.M{
			"_id":   "$" + contentIdField,
			"count": bson.M{"$sum": 1},
		}},
	)
	return pipeline
}

// updateVideoFavoriteDataCount 统计视频收藏量，更新 Likes/WeekLikes/MonthLikes/YearLikes
func updateVideoFavoriteDataCount(ctx context.Context) {
	now := time.Now()
	type period struct {
		field string
		since time.Time
	}
	periods := []period{
		{videoinformationmod.FN.VideoInformation.Real.Likes, time.Time{}},
		{videoinformationmod.FN.VideoInformation.Real.WeekLikes, now.AddDate(0, 0, -7)},
		{videoinformationmod.FN.VideoInformation.Real.MonthLikes, now.AddDate(0, 0, -30)},
		{videoinformationmod.FN.VideoInformation.Real.YearLikes, now.AddDate(0, 0, -365)},
	}
	idField := videofavoritemod.FN.VideoFavorite.VideoID
	for _, p := range periods {
		var results []favoriteCountResult
		pipeline := buildFavoritePipeline(idField, p.since)
		if serr := videofavoritemod.AggregateVideoFavorite(ctx, &results, pipeline); serr != nil {
			log.Warn("updateVideoFavoriteDataCount aggregate failed", log.Any("field", p.field))
			continue
		}
		if len(results) == 0 {
			continue
		}
		writes := make([]mongo.WriteModel, 0, len(results))
		for _, r := range results {
			writes = append(writes, mongo.NewUpdateOneModel().
				SetFilter(bson.M{videoinformationmod.FN.VideoInformation.Id: r.Id}).
				SetUpdate(bson.M{"$set": bson.M{p.field: r.Count}}),
			)
		}
		if _, serr := videoinformationmod.BulkWriteVideoInformation(ctx, writes); serr != nil {
			log.Warn("updateVideoFavoriteDataCount bulk update failed", log.Any("field", p.field))
		}
	}
}

// RankPeriod 排行榜时间维度
type RankPeriod int

const (
	RankPeriodTotal RankPeriod = 0 // 总榜
	RankPeriodWeek  RankPeriod = 1 // 周榜
	RankPeriodMonth RankPeriod = 2 // 月榜
	RankPeriodYear  RankPeriod = 3 // 年榜
)