package srv_viporder

import (
	"context"
	"strings"
	"time"
	"videoweb/pub/common/srvdef"
	"videoweb/pub/models/usermod"
	"videoweb/pub/models/vipordermod"

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

// GetVipOrders 分页查询会员购买记录（固定 OrderType=会员）
func GetVipOrders(ctx context.Context, req *VipOrderReq) (*VipOrderResp, *srvdef.SrvErr) {
	orderType := vipordermod.OrderTypeVip
	reqCopy := *req
	reqCopy.OrderType = &orderType
	return GetOrders(ctx, &reqCopy)
}

// GetOrders 分页查询充值订单，支持按 OrderType 筛选（不传则查全部类型）
func GetOrders(ctx context.Context, req *VipOrderReq) (*VipOrderResp, *srvdef.SrvErr) {
	filter := bson.M{}
	if req.OrderType != nil {
		filter[vipordermod.FN.VipOrder.OrderType] = *req.OrderType
	}
	if req.UserId != nil && *req.UserId > 0 {
		filter[vipordermod.FN.VipOrder.UserId] = *req.UserId
	}
	if req.Status != nil {
		filter[vipordermod.FN.VipOrder.Status] = *req.Status
	}
	if req.TradeNo != nil && *req.TradeNo != "" {
		filter[vipordermod.FN.VipOrder.TradeNo] = *req.TradeNo
	}
	if districtCode := strings.TrimSpace(req.DistrictCode); districtCode != "" {
		filter[vipordermod.FN.VipOrder.DistrictCode] = districtCode
	}

	timeFilter := bson.M{}
	if req.StartTime != nil && *req.StartTime != "" {
		if t, ok := parseTime(*req.StartTime); ok {
			timeFilter["$gte"] = t
		}
	}
	if req.EndTime != nil && *req.EndTime != "" {
		if t, ok := parseTime(*req.EndTime); ok {
			timeFilter["$lte"] = t
		}
	}
	if len(timeFilter) > 0 {
		filter[vipordermod.FN.VipOrder.CreatedAt] = timeFilter
	}

	total, serr := vipordermod.CountVipOrder(ctx, filter)
	if serr != nil {
		return nil, serr
	}
	resp := &VipOrderResp{Total: total}
	if total == 0 {
		resp.List = vipordermod.VipOrderList{}
		return resp, nil
	}

	opt := options.Find().
		SetSort(bson.D{{Key: vipordermod.FN.VipOrder.CreatedAt, Value: -1}}).
		SetSkip((req.PageNum - 1) * req.PageSize).
		SetLimit(req.PageSize)

	list, serr := vipordermod.FindManyVipOrder(ctx, filter, opt)
	if serr != nil {
		return nil, serr
	}
	resp.List = list
	return resp, nil
}

const (
	syncDistrictDefaultSize = int64(500)
	syncDistrictMaxSize     = int64(2000)
	syncDistrictBatchSize   = int64(200)
)

// SyncDistrictCode 将历史订单中空的渠道码，按用户当前 districtCode 回填。
func SyncDistrictCode(ctx context.Context, req *SyncDistrictCodeReq) (*SyncDistrictCodeResp, *srvdef.SrvErr) {
	maxSize := syncDistrictDefaultSize
	if req != nil && req.MaxSize > 0 {
		maxSize = req.MaxSize
	}
	if maxSize > syncDistrictMaxSize {
		maxSize = syncDistrictMaxSize
	}

	resp := &SyncDistrictCodeResp{}
	lastId := int64(0)
	updatedUsers := make(map[int64]struct{})
	skippedUsers := make(map[int64]struct{})

	for resp.Scanned < maxSize {
		limit := syncDistrictBatchSize
		if remain := maxSize - resp.Scanned; remain < limit {
			limit = remain
		}
		filter := emptyDistrictSyncFilter(lastId, skippedUsers)
		list, serr := vipordermod.FindManyVipOrder(ctx, filter, options.Find().
			SetProjection(bson.D{
				{Key: vipordermod.FN.VipOrder.Id, Value: 1},
				{Key: vipordermod.FN.VipOrder.UserId, Value: 1},
			}).
			SetSort(bson.D{{Key: vipordermod.FN.VipOrder.Id, Value: 1}}).
			SetLimit(limit))
		if serr != nil {
			return nil, serr
		}
		if len(list) == 0 {
			break
		}
		resp.Scanned += int64(len(list))
		lastId = list[len(list)-1].Id
		if int64(len(list)) == limit && resp.Scanned >= maxSize {
			resp.HasMore = true
		}

		userIds := make([]int64, 0, len(list))
		seen := make(map[int64]struct{}, len(list))
		for _, order := range list {
			if order == nil || order.UserId <= 0 {
				continue
			}
			if _, ok := seen[order.UserId]; ok {
				continue
			}
			seen[order.UserId] = struct{}{}
			userIds = append(userIds, order.UserId)
		}
		if len(userIds) == 0 {
			continue
		}

		users, serr := usermod.FindManyUser(ctx, bson.M{
			usermod.FN.User.Id: bson.M{"$in": userIds},
		}, options.Find().SetProjection(bson.D{
			{Key: usermod.FN.User.Id, Value: 1},
			{Key: usermod.FN.User.DistrictCode, Value: 1},
		}))
		if serr != nil {
			return nil, serr
		}
		userMap := make(map[int64]*usermod.User, len(users))
		for _, user := range users {
			if user != nil {
				userMap[user.Id] = user
			}
		}

		now := time.Now()
		for _, userId := range userIds {
			user := userMap[userId]
			code := ""
			if user != nil {
				code = strings.TrimSpace(user.DistrictCode)
			}
			if code == "" {
				skippedUsers[userId] = struct{}{}
				continue
			}
			modified, serr := vipordermod.UpdateManyVipOrder(ctx,
				mergeEmptyDistrictFilter(bson.M{vipordermod.FN.VipOrder.UserId: userId}),
				bson.M{"$set": bson.M{
					vipordermod.FN.VipOrder.DistrictCode: code,
					vipordermod.FN.VipOrder.UpdatedAt:    now,
				}},
			)
			if serr != nil {
				return nil, serr
			}
			if modified > 0 {
				updatedUsers[userId] = struct{}{}
				resp.OrderUpdated += modified
			}
		}
	}

	resp.UserUpdated = int64(len(updatedUsers))
	resp.UserSkipped = int64(len(skippedUsers))
	if !resp.HasMore {
		remain, serr := vipordermod.FindManyVipOrder(ctx, emptyDistrictSyncFilter(lastId, skippedUsers),
			options.Find().SetProjection(bson.D{{Key: vipordermod.FN.VipOrder.Id, Value: 1}}).SetLimit(1))
		if serr != nil {
			return nil, serr
		}
		resp.HasMore = len(remain) > 0
	}
	return resp, nil
}

func emptyDistrictSyncFilter(lastId int64, skippedUsers map[int64]struct{}) bson.M {
	conds := []bson.M{vipordermod.EmptyDistrictFilter()}
	if lastId > 0 {
		conds = append(conds, bson.M{vipordermod.FN.VipOrder.Id: bson.M{"$gt": lastId}})
	}
	if skipIds := mapKeys(skippedUsers); len(skipIds) > 0 {
		conds = append(conds, bson.M{vipordermod.FN.VipOrder.UserId: bson.M{"$nin": skipIds}})
	}
	if len(conds) == 1 {
		return conds[0]
	}
	return bson.M{"$and": conds}
}

func mergeEmptyDistrictFilter(extra bson.M) bson.M {
	filter := vipordermod.EmptyDistrictFilter()
	if len(extra) == 0 {
		return filter
	}
	conds := []bson.M{filter}
	for key, value := range extra {
		conds = append(conds, bson.M{key: value})
	}
	return bson.M{"$and": conds}
}

func mapKeys(m map[int64]struct{}) []int64 {
	if len(m) == 0 {
		return nil
	}
	keys := make([]int64, 0, len(m))
	for id := range m {
		keys = append(keys, id)
	}
	return keys
}