实现已发放优惠券的管理接口

web/core/scopes.go

@@ -53,6 +53,11 @@ const (
 	ScopeCouponWrite       = string("coupon:write")        // 写入优惠券
 	ScopeCouponWriteAssign = string("coupon:write:assign") // 发放优惠券
 
+	ScopeCouponUser           = string("coupon_user")              // 用户优惠券
+	ScopeCouponUserRead       = string("coupon_user:read")         // 读取用户优惠券列表
+	ScopeCouponUserReadOfUser = string("coupon_user:read:of_user") // 读取指定用户的用户优惠券列表
+	ScopeCouponUserWrite      = string("coupon_user:write")        // 写入用户优惠券
+
 	ScopeBatch           = string("batch")              // 批次
 	ScopeBatchRead       = string("batch:read")         // 读取批次列表
 	ScopeBatchReadOfUser = string("batch:read:of_user") // 读取指定用户的批次列表

web/handlers/coupon_user.go

@@ -0,0 +1,330 @@
+package handlers
+
+import (
+	"errors"
+	"platform/pkg/u"
+	"platform/web/auth"
+	"platform/web/core"
+	g "platform/web/globals"
+	m "platform/web/models"
+	q "platform/web/queries"
+	s "platform/web/services"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"gorm.io/gen"
+	"gorm.io/gen/field"
+	"gorm.io/gorm"
+)
+
+// PageCouponUser 分页查询当前用户已发放优惠券
+func PageCouponUser(c *fiber.Ctx) error {
+	authCtx, err := auth.GetAuthCtx(c).PermitUser()
+	if err != nil {
+		return err
+	}
+
+	var req PageCouponUserReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	conds := couponUserPageConditions(req.CouponUserPageFilter)
+	conds = append(conds, q.CouponUser.UserID.Eq(authCtx.User.ID))
+
+	list, total, err := q.CouponUser.
+		Joins(q.CouponUser.Coupon).
+		Select(couponUserSelect(false)...).
+		Where(conds...).
+		Order(q.CouponUser.CreatedAt.Desc()).
+		FindByPage(req.GetOffset(), req.GetLimit())
+	if err != nil {
+		return core.NewBizErr("获取数据失败", err)
+	}
+
+	return c.JSON(core.PageResp{
+		List:  list,
+		Total: int(total),
+		Page:  req.GetPage(),
+		Size:  req.GetSize(),
+	})
+}
+
+type PageCouponUserReq struct {
+	core.PageReq
+	CouponUserPageFilter
+}
+
+// GetCouponUser 获取当前用户已发放优惠券详情
+func GetCouponUser(c *fiber.Ctx) error {
+	authCtx, err := auth.GetAuthCtx(c).PermitUser()
+	if err != nil {
+		return err
+	}
+
+	var req core.IdReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	item, err := q.CouponUser.
+		Joins(q.CouponUser.Coupon).
+		Select(couponUserSelect(false)...).
+		Where(
+			q.CouponUser.ID.Eq(req.Id),
+			q.CouponUser.UserID.Eq(authCtx.User.ID),
+		).
+		Take()
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return core.NewBizErr("已发放优惠券不存在")
+	}
+	if err != nil {
+		return core.NewBizErr("获取数据失败", err)
+	}
+
+	return c.JSON(item)
+}
+
+// PageCouponUserByAdmin 分页查询全部已发放优惠券
+func PageCouponUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserRead)
+	if err != nil {
+		return err
+	}
+
+	var req PageCouponUserByAdminReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	conds := couponUserPageConditions(req.CouponUserPageFilter)
+	if req.UserID != nil {
+		conds = append(conds, q.CouponUser.UserID.Eq(*req.UserID))
+	}
+	if req.UserPhone != nil {
+		conds = append(conds, q.User.As("User").Phone.Eq(*req.UserPhone))
+	}
+
+	list, total, err := q.CouponUser.
+		Joins(q.CouponUser.Coupon, q.CouponUser.User).
+		Select(couponUserSelect(true)...).
+		Where(conds...).
+		Order(q.CouponUser.CreatedAt.Desc()).
+		FindByPage(req.GetOffset(), req.GetLimit())
+	if err != nil {
+		return core.NewBizErr("获取数据失败", err)
+	}
+
+	return c.JSON(core.PageResp{
+		List:  list,
+		Total: int(total),
+		Page:  req.GetPage(),
+		Size:  req.GetSize(),
+	})
+}
+
+type PageCouponUserByAdminReq struct {
+	core.PageReq
+	CouponUserPageFilter
+	UserID    *int32  `json:"user_id,omitempty"`
+	UserPhone *string `json:"user_phone,omitempty"`
+}
+
+// PageCouponUserOfUserByAdmin 分页查询指定用户已发放优惠券
+func PageCouponUserOfUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserReadOfUser)
+	if err != nil {
+		return err
+	}
+
+	var req PageCouponUserOfUserByAdminReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	conds := couponUserPageConditions(req.CouponUserPageFilter)
+	conds = append(conds, q.CouponUser.UserID.Eq(req.UserID))
+
+	list, total, err := q.CouponUser.
+		Joins(q.CouponUser.Coupon, q.CouponUser.User).
+		Select(couponUserSelect(true)...).
+		Where(conds...).
+		Order(q.CouponUser.CreatedAt.Desc()).
+		FindByPage(req.GetOffset(), req.GetLimit())
+	if err != nil {
+		return core.NewBizErr("获取数据失败", err)
+	}
+
+	return c.JSON(core.PageResp{
+		List:  list,
+		Total: int(total),
+		Page:  req.GetPage(),
+		Size:  req.GetSize(),
+	})
+}
+
+type PageCouponUserOfUserByAdminReq struct {
+	core.PageReq
+	CouponUserPageFilter
+	UserID int32 `json:"user_id" validate:"required"`
+}
+
+// GetCouponUserByAdmin 获取已发放优惠券详情
+func GetCouponUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserRead)
+	if err != nil {
+		return err
+	}
+
+	var req core.IdReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	item, err := q.CouponUser.
+		Joins(q.CouponUser.Coupon, q.CouponUser.User).
+		Select(couponUserSelect(true)...).
+		Where(q.CouponUser.ID.Eq(req.Id)).
+		Take()
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return core.NewBizErr("已发放优惠券不存在")
+	}
+	if err != nil {
+		return core.NewBizErr("获取数据失败", err)
+	}
+
+	return c.JSON(item)
+}
+
+func CreateCouponUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
+	if err != nil {
+		return err
+	}
+
+	var req s.CreateCouponUserData
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	if err := s.CouponUser.Create(req); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func UpdateCouponUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
+	if err != nil {
+		return err
+	}
+
+	var req s.UpdateCouponUserData
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	if err := s.CouponUser.Update(req); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func DeleteCouponUserByAdmin(c *fiber.Ctx) error {
+	_, err := auth.GetAuthCtx(c).PermitAdmin(core.ScopeCouponUserWrite)
+	if err != nil {
+		return err
+	}
+
+	var req core.IdReq
+	if err := g.Validator.ParseBody(c, &req); err != nil {
+		return err
+	}
+
+	if err := s.CouponUser.Delete(req.Id); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type CouponUserPageFilter struct {
+	CouponID       *int32              `json:"coupon_id,omitempty"`
+	CouponName     *string             `json:"coupon_name,omitempty"`
+	Status         *m.CouponUserStatus `json:"status,omitempty"`
+	Expired        *bool               `json:"expired,omitempty"`
+	CreatedAtStart *time.Time          `json:"created_at_start,omitempty"`
+	CreatedAtEnd   *time.Time          `json:"created_at_end,omitempty"`
+	ExpireAtStart  *time.Time          `json:"expire_at_start,omitempty"`
+	ExpireAtEnd    *time.Time          `json:"expire_at_end,omitempty"`
+	UsedAtStart    *time.Time          `json:"used_at_start,omitempty"`
+	UsedAtEnd      *time.Time          `json:"used_at_end,omitempty"`
+}
+
+func couponUserPageConditions(req CouponUserPageFilter) []gen.Condition {
+	conds := make([]gen.Condition, 0)
+	if req.CouponID != nil {
+		conds = append(conds, q.CouponUser.CouponID.Eq(*req.CouponID))
+	}
+	if req.CouponName != nil {
+		conds = append(conds, q.Coupon.As("Coupon").Name.Like("%"+*req.CouponName+"%"))
+	}
+	if req.Status != nil {
+		conds = append(conds, q.CouponUser.Status.Eq(int(*req.Status)))
+	}
+	if req.Expired != nil {
+		if *req.Expired {
+			conds = append(conds, q.CouponUser.ExpireAt.IsNotNull(), q.CouponUser.ExpireAt.Lte(time.Now()))
+		} else {
+			conds = append(conds, q.CouponUser.Where(q.CouponUser.ExpireAt.IsNull()).Or(q.CouponUser.ExpireAt.Gt(time.Now())))
+		}
+	}
+	if req.CreatedAtStart != nil {
+		conds = append(conds, q.CouponUser.CreatedAt.Gte(u.DateHead(*req.CreatedAtStart)))
+	}
+	if req.CreatedAtEnd != nil {
+		conds = append(conds, q.CouponUser.CreatedAt.Lte(u.DateTail(*req.CreatedAtEnd)))
+	}
+	if req.ExpireAtStart != nil {
+		conds = append(conds, q.CouponUser.ExpireAt.Gte(u.DateHead(*req.ExpireAtStart)))
+	}
+	if req.ExpireAtEnd != nil {
+		conds = append(conds, q.CouponUser.ExpireAt.Lte(u.DateTail(*req.ExpireAtEnd)))
+	}
+	if req.UsedAtStart != nil {
+		conds = append(conds, q.CouponUser.UsedAt.Gte(u.DateHead(*req.UsedAtStart)))
+	}
+	if req.UsedAtEnd != nil {
+		conds = append(conds, q.CouponUser.UsedAt.Lte(u.DateTail(*req.UsedAtEnd)))
+	}
+	return conds
+}
+
+func couponUserSelect(includeUser bool) []field.Expr {
+	cols := []field.Expr{
+		q.CouponUser.ALL,
+		q.Coupon.As("Coupon").ID.As("Coupon__id"),
+		q.Coupon.As("Coupon").Name.As("Coupon__name"),
+		q.Coupon.As("Coupon").Amount.As("Coupon__amount"),
+		q.Coupon.As("Coupon").MinAmount.As("Coupon__min_amount"),
+		q.Coupon.As("Coupon").Count_.As("Coupon__count"),
+		q.Coupon.As("Coupon").Status.As("Coupon__status"),
+		q.Coupon.As("Coupon").ExpireType.As("Coupon__expire_type"),
+		q.Coupon.As("Coupon").ExpireAt.As("Coupon__expire_at"),
+		q.Coupon.As("Coupon").ExpireIn.As("Coupon__expire_in"),
+		q.Coupon.As("Coupon").CreatedAt.As("Coupon__created_at"),
+		q.Coupon.As("Coupon").UpdatedAt.As("Coupon__updated_at"),
+	}
+
+	if includeUser {
+		cols = append(cols,
+			q.User.As("User").ID.As("User__id"),
+			q.User.As("User").Phone.As("User__phone"),
+			q.User.As("User").Name.As("User__name"),
+		)
+	}
+
+	return cols
+}

web/models/coupon_user.go

@@ -20,6 +20,7 @@ type CouponUser struct {
 type CouponUserStatus int
 
 const (
-	CouponUserStatusUnused CouponUserStatus = 0 // 未使用
-	CouponUserStatusUsed   CouponUserStatus = 1 // 已使用
+	CouponUserStatusUnused   CouponUserStatus = 0 // 未使用
+	CouponUserStatusUsed     CouponUserStatus = 1 // 已使用
+	CouponUserStatusDisabled CouponUserStatus = 2 // 已禁用
 )

web/routes.go

@@ -95,6 +95,11 @@ func userRouter(api fiber.Router) {
 	balance := api.Group("/balance")
 	balance.Post("/page", handlers.PageBalanceActivity)
 
+	// 已发放优惠券
+	couponUser := api.Group("/coupon-user")
+	couponUser.Post("/page", handlers.PageCouponUser)
+	couponUser.Post("/get", handlers.GetCouponUser)
+
 	// 公告
 	announcement := api.Group("/announcement")
 	announcement.Post("/list", handlers.ListAnnouncements)
@@ -254,4 +259,13 @@ func adminRouter(api fiber.Router) {
 	coupon.Post("/update", handlers.UpdateCoupon)
 	coupon.Post("/remove", handlers.DeleteCoupon)
 	coupon.Post("/update/assign", handlers.AssignCoupon)
+
+	// coupon-user 已发放优惠券
+	var couponUser = api.Group("/coupon-user")
+	couponUser.Post("/page", handlers.PageCouponUserByAdmin)
+	couponUser.Post("/page/of-user", handlers.PageCouponUserOfUserByAdmin)
+	couponUser.Post("/get", handlers.GetCouponUserByAdmin)
+	couponUser.Post("/create", handlers.CreateCouponUserByAdmin)
+	couponUser.Post("/update", handlers.UpdateCouponUserByAdmin)
+	couponUser.Post("/remove", handlers.DeleteCouponUserByAdmin)
 }

web/services/coupon.go

@@ -108,54 +108,11 @@ func (s *couponService) Delete(id int32) error {
 	return err
 }
 
-// 发放优惠券
 func (s *couponService) Assign(couponID int32, userID int32) error {
-	// 获取优惠券信息
-	coupon, err := q.Coupon.Where(q.Coupon.ID.Eq(couponID)).Take()
-	if errors.Is(err, gorm.ErrRecordNotFound) {
-		return core.NewBizErr("优惠券不存在")
-	}
-	if err != nil {
-		return core.NewBizErr("获取优惠券数据失败", err)
-	}
-
-	// 检查优惠券是否可用
-	// 1. 状态必须为正常
-	if coupon.Status != m.CouponStatusEnabled {
-		return core.NewBizErr("优惠券不可用")
-	}
-	// 2. 数量必须大于0
-	if coupon.Count <= 0 {
-		return core.NewBizErr("优惠券已发放完")
-	}
-
-	// 发放优惠券
-	err = q.Q.Transaction(func(q *q.Query) error {
-		// 创建用户优惠券记录
-		err := q.CouponUser.Create(&m.CouponUser{
-			UserID:   userID,
-			CouponID: couponID,
-			Status:   m.CouponUserStatusUnused,
-		})
-		if err != nil {
-			return err
-		}
-
-		// 扣减优惠券数量
-		_, err = q.Coupon.
-			Where(q.Coupon.ID.Eq(couponID), q.Coupon.Count_.Eq(coupon.Count)).
-			UpdateSimple(q.Coupon.Count_.Value(coupon.Count - 1))
-		if err != nil {
-			return err
-		}
-
-		return nil
+	return CouponUser.Create(CreateCouponUserData{
+		CouponID: couponID,
+		UserID:   userID,
 	})
-	if err != nil {
-		return core.NewBizErr("发放优惠券失败", err)
-	}
-
-	return nil
 }
 
 // GetUserCoupon 获取用户的指定优惠券
@@ -165,7 +122,7 @@ func (s *couponService) GetUserCoupon(uid int32, cuid int32, amount decimal.Deci
 		q.CouponUser.ID.Eq(cuid),
 		q.CouponUser.UserID.Eq(uid),
 		q.CouponUser.Status.Eq(int(m.CouponUserStatusUnused)),
-		q.CouponUser.ExpireAt.Gt(time.Now()),
+		q.CouponUser.Where(q.CouponUser.ExpireAt.IsNull()).Or(q.CouponUser.ExpireAt.Gt(time.Now())),
 	).Take()
 	if errors.Is(err, gorm.ErrRecordNotFound) {
 		return nil, core.NewBizErr("优惠券不存在或已失效")

web/services/coupon_user.go

@@ -0,0 +1,255 @@
+package services
+
+import (
+	"errors"
+	"platform/pkg/u"
+	"platform/web/core"
+	m "platform/web/models"
+	q "platform/web/queries"
+	"time"
+
+	"gorm.io/gen/field"
+	"gorm.io/gorm"
+)
+
+var CouponUser = &couponUserService{}
+
+type couponUserService struct{}
+
+func (s *couponUserService) Create(data CreateCouponUserData) error {
+	now := time.Now()
+	status := u.Else(data.Status, m.CouponUserStatusUnused)
+	if err := validateCouponUserStatus(status); err != nil {
+		return err
+	}
+
+	return q.Q.Transaction(func(tx *q.Query) error {
+		coupon, err := tx.Coupon.Where(tx.Coupon.ID.Eq(data.CouponID)).Take()
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return core.NewBizErr("优惠券不存在")
+		}
+		if err != nil {
+			return core.NewServErr("获取优惠券数据失败", err)
+		}
+		if coupon.Status != m.CouponStatusEnabled {
+			return core.NewBizErr("优惠券不可用")
+		}
+		if coupon.Count <= 0 {
+			return core.NewBizErr("优惠券已发放完")
+		}
+
+		_, err = tx.User.Where(tx.User.ID.Eq(data.UserID)).Take()
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return core.NewBizErr("用户不存在")
+		}
+		if err != nil {
+			return core.NewServErr("获取用户数据失败", err)
+		}
+
+		expireAt := data.ExpireAt
+		if expireAt == nil {
+			expireAt = couponUserExpireAt(coupon, now)
+		}
+
+		usedAt := data.UsedAt
+		if status == m.CouponUserStatusUsed && usedAt == nil {
+			usedAt = &now
+		}
+		if status == m.CouponUserStatusUnused {
+			usedAt = nil
+		}
+
+		err = tx.CouponUser.Create(&m.CouponUser{
+			UserID:   data.UserID,
+			CouponID: data.CouponID,
+			Status:   status,
+			ExpireAt: expireAt,
+			UsedAt:   usedAt,
+		})
+		if err != nil {
+			return core.NewServErr("发放优惠券失败", err)
+		}
+
+		return adjustCouponCount(tx, coupon.ID, -1)
+	})
+}
+
+type CreateCouponUserData struct {
+	CouponID int32               `json:"coupon_id" validate:"required"`
+	UserID   int32               `json:"user_id" validate:"required"`
+	Status   *m.CouponUserStatus `json:"status"`
+	ExpireAt *time.Time          `json:"expire_at"`
+	UsedAt   *time.Time          `json:"used_at"`
+}
+
+func (s *couponUserService) Update(data UpdateCouponUserData) error {
+	return q.Q.Transaction(func(tx *q.Query) error {
+		current, err := tx.CouponUser.Where(tx.CouponUser.ID.Eq(data.ID)).Take()
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return core.NewBizErr("已发放优惠券不存在")
+		}
+		if err != nil {
+			return core.NewServErr("获取已发放优惠券失败", err)
+		}
+
+		do := make([]field.AssignExpr, 0)
+		if data.ExpireAtClear != nil && *data.ExpireAtClear {
+			do = append(do, tx.CouponUser.ExpireAt.Null())
+		} else if data.ExpireAt != nil {
+			do = append(do, tx.CouponUser.ExpireAt.Value(*data.ExpireAt))
+		}
+
+		if data.UsedAtClear != nil && *data.UsedAtClear {
+			do = append(do, tx.CouponUser.UsedAt.Null())
+		} else if data.UsedAt != nil {
+			do = append(do, tx.CouponUser.UsedAt.Value(*data.UsedAt))
+		}
+
+		if data.Status != nil {
+			if err := validateCouponUserStatus(*data.Status); err != nil {
+				return err
+			}
+			if current.Status != *data.Status {
+				if current.Status == m.CouponUserStatusUsed {
+					return core.NewBizErr("已使用的优惠券不能修改状态")
+				}
+				if current.Status == m.CouponUserStatusDisabled && *data.Status == m.CouponUserStatusUsed {
+					return core.NewBizErr("已禁用的优惠券不能标记为已使用")
+				}
+
+				switch *data.Status {
+				case m.CouponUserStatusUnused:
+					if current.Status == m.CouponUserStatusDisabled {
+						if err := adjustCouponCount(tx, current.CouponID, -1); err != nil {
+							return err
+						}
+					}
+					if data.UsedAt == nil && (data.UsedAtClear == nil || !*data.UsedAtClear) {
+						do = append(do, tx.CouponUser.UsedAt.Null())
+					}
+
+				case m.CouponUserStatusUsed:
+					if data.UsedAt == nil && (data.UsedAtClear == nil || !*data.UsedAtClear) {
+						do = append(do, tx.CouponUser.UsedAt.Value(time.Now()))
+					}
+
+				case m.CouponUserStatusDisabled:
+					if current.Status == m.CouponUserStatusUnused {
+						if err := adjustCouponCount(tx, current.CouponID, 1); err != nil {
+							return err
+						}
+					}
+				}
+				do = append(do, tx.CouponUser.Status.Value(int(*data.Status)))
+			}
+		}
+
+		if len(do) == 0 {
+			return nil
+		}
+
+		result, err := tx.CouponUser.
+			Where(
+				tx.CouponUser.ID.Eq(data.ID),
+				tx.CouponUser.Status.Eq(int(current.Status)),
+			).
+			UpdateSimple(do...)
+		if err != nil {
+			return core.NewServErr("更新已发放优惠券失败", err)
+		}
+		if result.RowsAffected == 0 {
+			return core.NewBizErr("已发放优惠券状态已变化，请重试")
+		}
+		return nil
+	})
+}
+
+type UpdateCouponUserData struct {
+	ID            int32               `json:"id" validate:"required"`
+	Status        *m.CouponUserStatus `json:"status"`
+	ExpireAt      *time.Time          `json:"expire_at"`
+	ExpireAtClear *bool               `json:"expire_at_clear"`
+	UsedAt        *time.Time          `json:"used_at"`
+	UsedAtClear   *bool               `json:"used_at_clear"`
+}
+
+func (s *couponUserService) Delete(id int32) error {
+	status := m.CouponUserStatusDisabled
+	return s.Update(UpdateCouponUserData{
+		ID:     id,
+		Status: &status,
+	})
+}
+
+func (s *couponUserService) DeleteOfUser(id int32, userID int32) error {
+	assigned, err := q.CouponUser.Where(
+		q.CouponUser.ID.Eq(id),
+		q.CouponUser.UserID.Eq(userID),
+	).Take()
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return core.NewBizErr("已发放优惠券不存在")
+	}
+	if err != nil {
+		return core.NewServErr("获取已发放优惠券失败", err)
+	}
+	if assigned.Status != m.CouponUserStatusUnused {
+		return core.NewBizErr("只能撤销未使用的优惠券")
+	}
+
+	return s.Delete(id)
+}
+
+func couponUserExpireAt(coupon *m.Coupon, now time.Time) *time.Time {
+	if coupon == nil {
+		return nil
+	}
+
+	switch coupon.ExpireType {
+	case m.CouponExpireTypeFixed:
+		return coupon.ExpireAt
+	case m.CouponExpireTypeRelative:
+		if coupon.ExpireIn == nil {
+			return nil
+		}
+		expireAt := now.Add(time.Duration(*coupon.ExpireIn) * 24 * time.Hour)
+		return &expireAt
+	default:
+		return nil
+	}
+}
+
+func validateCouponUserStatus(status m.CouponUserStatus) error {
+	switch status {
+	case m.CouponUserStatusUnused, m.CouponUserStatusUsed, m.CouponUserStatusDisabled:
+		return nil
+	default:
+		return core.NewBizErr("优惠券发放状态无效")
+	}
+}
+
+func adjustCouponCount(tx *q.Query, couponID int32, delta int32) error {
+	coupon, err := tx.Coupon.Where(tx.Coupon.ID.Eq(couponID)).Take()
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return core.NewBizErr("优惠券不存在")
+	}
+	if err != nil {
+		return core.NewServErr("获取优惠券数据失败", err)
+	}
+
+	next := coupon.Count + delta
+	if next < 0 {
+		return core.NewBizErr("优惠券已发放完")
+	}
+
+	result, err := tx.Coupon.
+		Where(tx.Coupon.ID.Eq(couponID), tx.Coupon.Count_.Eq(coupon.Count)).
+		UpdateSimple(tx.Coupon.Count_.Value(next))
+	if err != nil {
+		return core.NewServErr("更新优惠券数量失败", err)
+	}
+	if result.RowsAffected == 0 {
+		return core.NewBizErr("优惠券库存已变化，请重试")
+	}
+
+	return nil
+}