feat: implement coupon management and receive flow

backend/pkg/consts/coupon.go

@@ -0,0 +1,57 @@
+package consts
+
+import "quyun/v2/app/requests"
+
+// swagger:enum CouponType
+// ENUM( fix_amount, discount )
+type CouponType string
+
+// Description returns the Chinese label for the specific enum value.
+func (t CouponType) Description() string {
+	switch t {
+	case CouponTypeFixAmount:
+		return "满减"
+	case CouponTypeDiscount:
+		return "折扣"
+	default:
+		return "未知类型"
+	}
+}
+
+// CouponTypeItems returns the KV list for FE dropdowns.
+func CouponTypeItems() []requests.KV {
+	values := CouponTypeValues()
+	items := make([]requests.KV, 0, len(values))
+	for _, v := range values {
+		items = append(items, requests.NewKV(string(v), v.Description()))
+	}
+	return items
+}
+
+// swagger:enum UserCouponStatus
+// ENUM( unused, used, expired )
+type UserCouponStatus string
+
+// Description returns the Chinese label for the specific enum value.
+func (t UserCouponStatus) Description() string {
+	switch t {
+	case UserCouponStatusUnused:
+		return "未使用"
+	case UserCouponStatusUsed:
+		return "已使用"
+	case UserCouponStatusExpired:
+		return "已过期"
+	default:
+		return "未知状态"
+	}
+}
+
+// UserCouponStatusItems returns the KV list for FE dropdowns.
+func UserCouponStatusItems() []requests.KV {
+	values := UserCouponStatusValues()
+	items := make([]requests.KV, 0, len(values))
+	for _, v := range values {
+		items = append(items, requests.NewKV(string(v), v.Description()))
+	}
+	return items
+}