package ipstat

import (
	"context"
	"time"
	"videoweb/pub/common/enum/redisconst"
	"videoweb/pub/common/log"
	"videoweb/pub/common/utils"
	"videoweb/pub/models/ipdailystatmod"
	"videoweb/pub/pubdef"
	"videoweb/pub/redis"
)

const syncInterval = 5 * time.Minute

// StartSync 启动后台协程，每隔 syncInterval 将当日和昨日的 Redis IP SET
// 数量同步写入 MongoDB（ip_daily_stat），供 web 端查询。
func StartSync() {
	go func() {
		// 启动时立即同步一次
		syncOnce()
		ticker := time.NewTicker(syncInterval)
		defer ticker.Stop()
		for range ticker.C {
			syncOnce()
		}
	}()
}

func syncOnce() {
	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()

	now := time.Now().In(utils.LocBJ)
	appId := int64(pubdef.AppId)

	for _, offset := range []int{0, -1} {
		date := now.AddDate(0, 0, offset).Format("20060102")
		key := redisconst.IpStatKey(appId, date)

		count, err := redis.SCard(key)
		if err != nil {
			log.Warn("ipstat sync: SCard failed",
				log.Any("date", date), log.E(err))
			continue
		}

		// 今日 Redis 为 0 时不覆盖 MongoDB，避免 key 丢失把已有数据写成 0。
		if offset == 0 && count == 0 {
			continue
		}

		if err := ipdailystatmod.UpsertCount(ctx, appId, date, count); err != nil {
			log.Warn("ipstat sync: UpsertCount failed",
				log.Any("appId", appId), log.Any("date", date), log.E(err))
		}
	}
}