package videoupdater

import (
	"context"
	"math/rand"
	"time"
	"videoweb/pub/common/log"
	"videoweb/pub/models/videocategorymod"
	"videoweb/pub/models/videoinformationmod"
	"videoweb/pub/pubdef"

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

const _topN = 20

// RefreshTopVideosUpdatedAt 遍历所有启用的分类，取排名靠前的20个资源，
// 将 PageUpdatedAt 更新为前一个小时内的随机时间
func RefreshTopVideosUpdatedAt() {
	ctx := context.Background()
	log.Info("videoupdater RefreshTopVideosUpdatedAt start")
	defer log.Info("videoupdater RefreshTopVideosUpdatedAt end")

	// 查询所有启用的分类
	catFilter := bson.M{
		videocategorymod.FN.VideoCategory.Status: true,
	}
	catOpts := &options.FindOptions{}
	catOpts.SetLimit(500)
	categories, serr := videocategorymod.FindManyVideoCategorys(ctx, catFilter, catOpts)
	if serr != nil {
		log.Error("videoupdater FindManyVideoCategorys failed", log.Any("err", serr))
		return
	}

	now := time.Now()
	oneHourAgo := now.Add(-1 * time.Hour)

	for _, cat := range categories {
		updateCategoryTopVideos(ctx, cat, oneHourAgo, now)
	}
}

func updateCategoryTopVideos(ctx context.Context, cat *videocategorymod.VideoCategory, rangeStart, rangeEnd time.Time) {
	// mdcom 的 VideoInformation.CategoryId 是单值，直接按等值匹配
	videoFilter := bson.M{
		videoinformationmod.FN.VideoInformation.Status:     pubdef.InformationStatusVerifyOK,
		videoinformationmod.FN.VideoInformation.AddedTime:  bson.M{"$lt": rangeEnd},
		videoinformationmod.FN.VideoInformation.CategoryId: cat.Id,
	}

	videoOpt := &options.FindOptions{}
	videoOpt.SetSort(bson.D{
		{Key: videoinformationmod.FN.VideoInformation.Sort, Value: -1},
		{Key: videoinformationmod.FN.VideoInformation.AddedTime, Value: -1},
	})
	videoOpt.SetLimit(_topN)

	videos, serr := videoinformationmod.FindManyVideoInformations(ctx, videoFilter, videoOpt)
	if serr != nil {
		log.Warn("videoupdater FindManyVideoInformations failed",
			log.Any("categoryId", cat.Id), log.Any("err", serr))
		return
	}

	rangeDuration := rangeEnd.Sub(rangeStart)
	for _, v := range videos {
		randomOffset := time.Duration(rand.Int63n(int64(rangeDuration)))
		randomTime := rangeStart.Add(randomOffset)

		filter := bson.M{videoinformationmod.FN.VideoInformation.Id: v.Id}
		update := bson.M{"$set": bson.M{videoinformationmod.FN.VideoInformation.PageUpdatedAt: randomTime}}
		if err := videoinformationmod.UpdateOneVideoInformation(ctx, filter, update); err != nil {
			log.Warn("videoupdater UpdateOneVideoInformation failed",
				log.Any("videoId", v.Id), log.Any("err", err))
		}
	}

	if len(videos) > 0 {
		log.Info("videoupdater updated category top videos",
			log.Any("categoryId", cat.Id), log.Any("categoryName", cat.Name), log.Any("count", len(videos)))
	}
}