package refundOrderSer

import (
	"context"
	"errors"
	"fmt"
	"stat/api/proto"
	"stat/models/rechargemod"
	"stat/models/refundOrderMod"

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

// 只回填付款成功的订单。status=3 为付款成功,与 models/rechargemod/stat.go 中
// 各统计口径一致;付款失败(status=2)的订单不存在退款场景。
const rechargeStatusSuccess = 3

// List 退款订单查询,支持 appId / userId / cid / channelName / districtCode 任意组合
func List(ctx context.Context, req *proto.RefundOrderListReq) (*proto.RefundOrderListResp, error) {
	resp := &proto.RefundOrderListResp{
		Total: 0,
		List:  make(refundOrderMod.RefundOrderList, 0),
	}
	filter := bson.M{}
	if req.AppId != nil {
		filter[refundOrderMod.FN.RefundOrder.AppId] = *req.AppId
	}
	if req.UserId != nil {
		filter[refundOrderMod.FN.RefundOrder.UserId] = *req.UserId
	}
	if req.CID != nil && *req.CID != "" {
		filter[refundOrderMod.FN.RefundOrder.CID] = *req.CID
	}
	if req.ChannelName != nil && *req.ChannelName != "" {
		filter[refundOrderMod.FN.RefundOrder.ChannelName] = *req.ChannelName
	}
	if req.DistrictCode != nil && *req.DistrictCode != "" {
		filter[refundOrderMod.FN.RefundOrder.DistrictCode] = *req.DistrictCode
	}

	total, err := refundOrderMod.CountRefundOrders(ctx, filter)
	if err != nil {
		return nil, err
	}
	opt := &options.FindOptions{}
	opt.SetSort(bson.D{{Key: refundOrderMod.FN.RefundOrder.CreatedAt, Value: -1}})
	opt.SetSkip((req.PageNum - 1) * req.PageSize)
	opt.SetLimit(req.PageSize)
	list, err := refundOrderMod.FindManyRefundOrders(ctx, filter, opt)
	if err != nil {
		return nil, err
	}
	resp.Total = total
	resp.List = list
	return resp, nil
}

// Add 按单个 cid 回填
func Add(ctx context.Context, req *proto.AddRefundOrderReq) (*proto.AddRefundOrderResp, error) {
	return addByCids(ctx, []string{req.CID})
}

// BatchAdd 按多个 cid 批量回填
func BatchAdd(ctx context.Context, req *proto.BatchAddRefundOrderReq) (*proto.AddRefundOrderResp, error) {
	return addByCids(ctx, req.CIDs)
}

// addByCids 逐个 cid 查询 log_recharge 的成功订单,按 (appId, orderId) 判重后落库。
// 单个 cid 失败不影响其余 cid,错误直接返回由调用方决定。
func addByCids(ctx context.Context, cids []string) (*proto.AddRefundOrderResp, error) {
	resp := &proto.AddRefundOrderResp{
		Details: make([]proto.RefundCidStat, 0, len(cids)),
	}
	seen := make(map[string]bool, len(cids)) // 同一次请求里 cid 去重
	for _, cid := range cids {
		if cid == "" || seen[cid] {
			continue
		}
		seen[cid] = true

		stat, err := addOneCid(ctx, cid)
		if err != nil {
			return nil, fmt.Errorf("回填渠道[%s]失败: %w", cid, err)
		}
		resp.Matched += stat.Matched
		resp.Inserted += stat.Inserted
		resp.Skipped += stat.Skipped
		resp.Details = append(resp.Details, *stat)
	}
	return resp, nil
}

func addOneCid(ctx context.Context, cid string) (*proto.RefundCidStat, error) {
	stat := &proto.RefundCidStat{CID: cid}

	// cid 唯一标识一笔订单,只回填付款成功的那条
	src, err := rechargemod.FindOneRecharge(ctx, bson.M{
		"cid":    cid,
		"status": rechargeStatusSuccess,
	})
	if err != nil {
		if errors.Is(err, mongo.ErrNoDocuments) {
			return stat, nil // 该 cid 没有对应的成功订单,matched 记 0,不算失败
		}
		return nil, err
	}
	stat.Matched = 1

	// 按 (appId, orderId) 判重,已存在则跳过
	exist, err := refundOrderMod.FindOneRefundOrder(ctx, bson.M{
		refundOrderMod.FN.RefundOrder.AppId:   src.AppId,
		refundOrderMod.FN.RefundOrder.OrderId: src.OrderId,
	})
	if err != nil {
		return nil, err
	}
	if exist != nil && !exist.ID.IsZero() {
		stat.Skipped = 1
		return stat, nil
	}

	doc := &refundOrderMod.RefundOrder{
		AppId:        src.AppId,
		CID:          src.CID,
		DistrictCode: src.DistrictCode,
		Money:        src.Money,
		OrderId:      src.OrderId,
		UserId:       src.UserId,
		Type:         src.Type,
		ChannelName:  src.ChannelName,
		CreatedAt:    src.CreatedAt,
	}
	if err := refundOrderMod.InsertOneRefundOrder(ctx, doc); err != nil {
		// 并发下两个请求可能同时通过上面的判重检查,由唯一索引兜底。
		// 撞上即视为重复添加,与"重复跳过不报错"的口径一致。
		if refundOrderMod.IsDuplicateKey(err) {
			stat.Skipped = 1
			return stat, nil
		}
		return nil, err
	}
	stat.Inserted = 1
	return stat, nil
}

// Del 按 _id 删除单条
func Del(ctx context.Context, req *proto.DelRefundOrderReq) error {
	oid, err := primitive.ObjectIDFromHex(req.Id)
	if err != nil {
		return fmt.Errorf("id 格式错误: %w", err)
	}
	count, err := refundOrderMod.DelOneRefundOrder(ctx, bson.M{
		refundOrderMod.FN.RefundOrder.ID: oid,
	})
	if err != nil {
		return err
	}
	if count == 0 {
		return fmt.Errorf("记录不存在")
	}
	return nil
}