feat: add coupon support to orders and create user_coupons model

- Added CouponID field to Order model to track used coupons.
- Updated order query generation to include CouponID.
- Introduced UserCoupon model to manage user coupon associations.
- Implemented query methods for UserCoupon to facilitate CRUD operations.
- Updated query context and default query setup to include UserCoupon.

backend/app/services/coupon.go

@@ -0,0 +1,84 @@
+package services
+
+import (
+	"context"
+	"time"
+
+	"quyun/v2/app/errorx"
+	"quyun/v2/database/models"
+)
+
+// @provider
+type coupon struct{}
+
+// Validate checks if a coupon can be used for an order and returns the discount amount
+func (s *coupon) Validate(ctx context.Context, userID, userCouponID, amount int64) (int64, error) {
+	uc, err := models.UserCouponQuery.WithContext(ctx).Where(models.UserCouponQuery.ID.Eq(userCouponID)).First()
+	if err != nil {
+		return 0, errorx.ErrRecordNotFound.WithMsg("优惠券不存在")
+	}
+	if uc.UserID != userID {
+		return 0, errorx.ErrUnauthorized.WithMsg("无权使用该优惠券")
+	}
+	if uc.Status != "unused" {
+		return 0, errorx.ErrBusinessLogic.WithMsg("优惠券已使用或失效")
+	}
+
+	c, err := models.CouponQuery.WithContext(ctx).Where(models.CouponQuery.ID.Eq(uc.CouponID)).First()
+	if err != nil {
+		return 0, errorx.ErrRecordNotFound.WithMsg("优惠券信息缺失")
+	}
+
+	now := time.Now()
+	if !c.StartAt.IsZero() && now.Before(c.StartAt) {
+		return 0, errorx.ErrBusinessLogic.WithMsg("优惠券尚未生效")
+	}
+	if !c.EndAt.IsZero() && now.After(c.EndAt) {
+		return 0, errorx.ErrBusinessLogic.WithMsg("优惠券已过期")
+	}
+
+	if amount < c.MinOrderAmount {
+		return 0, errorx.ErrBusinessLogic.WithMsg("未达到优惠券使用门槛")
+	}
+
+	var discount int64
+	if c.Type == "fix_amount" {
+		discount = c.Value
+	} else if c.Type == "discount" {
+		discount = (amount * c.Value) / 100
+		if c.MaxDiscount > 0 && discount > c.MaxDiscount {
+			discount = c.MaxDiscount
+		}
+	}
+
+	// Discount cannot exceed order amount
+	if discount > amount {
+		discount = amount
+	}
+
+	return discount, nil
+}
+
+// MarkUsed marks a user coupon as used (intended to be called inside a transaction)
+func (s *coupon) MarkUsed(ctx context.Context, tx *models.Query, userCouponID, orderID int64) error {
+	now := time.Now()
+	// Update User Coupon
+	info, err := tx.UserCoupon.WithContext(ctx).Where(tx.UserCoupon.ID.Eq(userCouponID), tx.UserCoupon.Status.Eq("unused")).Updates(&models.UserCoupon{
+		Status:  "used",
+		OrderID: orderID,
+		UsedAt:  now,
+	})
+	if err != nil {
+		return err
+	}
+	if info.RowsAffected == 0 {
+		return errorx.ErrBusinessLogic.WithMsg("优惠券核销失败")
+	}
+
+	// Update Coupon used quantity (Optional, but good for stats)
+	// We need CouponID from uc
+	uc, _ := tx.UserCoupon.WithContext(ctx).Where(tx.UserCoupon.ID.Eq(userCouponID)).First()
+	_, _ = tx.Coupon.WithContext(ctx).Where(tx.Coupon.ID.Eq(uc.CouponID)).UpdateSimple(tx.Coupon.UsedQuantity.Add(1))
+
+	return nil
+}

backend/app/services/coupon_test.go

@@ -0,0 +1,111 @@
+package services
+
+import (
+	"context"
+	"database/sql"
+	"testing"
+
+	"quyun/v2/app/commands/testx"
+	order_dto "quyun/v2/app/http/v1/dto"
+	"quyun/v2/database"
+	"quyun/v2/database/models"
+	"quyun/v2/pkg/consts"
+	"quyun/v2/providers/storage"
+
+	. "github.com/smartystreets/goconvey/convey"
+	"github.com/spf13/cast"
+	"github.com/stretchr/testify/suite"
+	"go.ipao.vip/atom/contracts"
+	"go.uber.org/dig"
+)
+
+type CouponTestSuiteInjectParams struct {
+	dig.In
+
+	DB       *sql.DB
+	Initials []contracts.Initial `group:"initials"`
+}
+
+type CouponTestSuite struct {
+	suite.Suite
+	CouponTestSuiteInjectParams
+}
+
+func Test_Coupon(t *testing.T) {
+	providers := testx.Default().With(Provide).With(storage.Provide)
+
+	testx.Serve(providers, t, func(p CouponTestSuiteInjectParams) {
+		suite.Run(t, &CouponTestSuite{CouponTestSuiteInjectParams: p})
+	})
+}
+
+func (s *CouponTestSuite) Test_CouponFlow() {
+	Convey("Coupon Flow", s.T(), func() {
+		ctx := s.T().Context()
+		database.Truncate(ctx, s.DB, models.TableNameCoupon, models.TableNameUserCoupon, models.TableNameOrder, models.TableNameUser, models.TableNameContent, models.TableNameContentPrice)
+
+		user := &models.User{Username: "coupon_user", Phone: "13800000001"}
+		models.UserQuery.WithContext(ctx).Create(user)
+
+		// 1. Create Coupon (Fixed 5.00 CNY, Min 10.00 CNY)
+		cp := &models.Coupon{
+			Title:          "Save 5",
+			Type:           "fix_amount",
+			Value:          500,
+			MinOrderAmount: 1000,
+		}
+		models.CouponQuery.WithContext(ctx).Create(cp)
+
+		// 2. Give to User
+		uc := &models.UserCoupon{
+			UserID:   user.ID,
+			CouponID: cp.ID,
+			Status:   "unused",
+		}
+		models.UserCouponQuery.WithContext(ctx).Create(uc)
+
+		Convey("should validate coupon successfully", func() {
+			discount, err := Coupon.Validate(ctx, user.ID, uc.ID, 1500)
+			So(err, ShouldBeNil)
+			So(discount, ShouldEqual, 500)
+		})
+
+		Convey("should fail if below min amount", func() {
+			_, err := Coupon.Validate(ctx, user.ID, uc.ID, 800)
+			So(err, ShouldNotBeNil)
+		})
+
+		Convey("should apply in Order.Create", func() {
+			// Setup Content
+			c := &models.Content{UserID: 99, Title: "Test", Status: consts.ContentStatusPublished}
+			models.ContentQuery.WithContext(ctx).Create(c)
+			models.ContentPriceQuery.WithContext(ctx).Create(&models.ContentPrice{
+				ContentID:   c.ID,
+				PriceAmount: 2000, // 20.00 CNY
+				Currency:    "CNY",
+			})
+
+			form := &order_dto.OrderCreateForm{
+				ContentID:    cast.ToString(c.ID),
+				UserCouponID: cast.ToString(uc.ID),
+			}
+			// Simulate Auth context for Order service
+			authCtx := context.WithValue(ctx, consts.CtxKeyUser, user.ID)
+			res, err := Order.Create(authCtx, form)
+			So(err, ShouldBeNil)
+
+			// Verify Order
+			oid := cast.ToInt64(res.OrderID)
+			o, _ := models.OrderQuery.WithContext(ctx).Where(models.OrderQuery.ID.Eq(oid)).First()
+			So(o.AmountOriginal, ShouldEqual, 2000)
+			So(o.AmountDiscount, ShouldEqual, 500)
+			So(o.AmountPaid, ShouldEqual, 1500)
+			So(o.CouponID, ShouldEqual, cp.ID)
+
+			// Verify Coupon Status
+			ucReload, _ := models.UserCouponQuery.WithContext(ctx).Where(models.UserCouponQuery.ID.Eq(uc.ID)).First()
+			So(ucReload.Status, ShouldEqual, "used")
+			So(ucReload.OrderID, ShouldEqual, oid)
+		})
+	})
+}

backend/app/services/order.go

@@ -91,11 +91,30 @@ func (s *order) Create(ctx context.Context, form *transaction_dto.OrderCreateFor
 
 	price, err := models.ContentPriceQuery.WithContext(ctx).Where(models.ContentPriceQuery.ContentID.Eq(cid)).First()
 	if err != nil {
-		// If price missing, treat as error? Or maybe 0?
-		// Better to require price record.
 		return nil, errorx.ErrDataCorrupted.WithCause(err).WithMsg("价格信息缺失")
 	}
 
+	amountOriginal := price.PriceAmount
+	var amountDiscount int64 = 0
+	var couponID int64 = 0
+
+	// Validate Coupon
+	if form.UserCouponID != "" {
+		ucid := cast.ToInt64(form.UserCouponID)
+		discount, err := Coupon.Validate(ctx, uid, ucid, amountOriginal)
+		if err != nil {
+			return nil, err
+		}
+		amountDiscount = discount
+
+		uc, err := models.UserCouponQuery.WithContext(ctx).Where(models.UserCouponQuery.ID.Eq(ucid)).First()
+		if err == nil {
+			couponID = uc.CouponID
+		}
+	}
+
+	amountPaid := amountOriginal - amountDiscount
+
 	// 2. Create Order (Status: Created)
 	order := &models.Order{
 		TenantID:       content.TenantID,
@@ -103,27 +122,46 @@ func (s *order) Create(ctx context.Context, form *transaction_dto.OrderCreateFor
 		Type:           consts.OrderTypeContentPurchase,
 		Status:         consts.OrderStatusCreated,
 		Currency:       consts.Currency(price.Currency),
-		AmountOriginal: price.PriceAmount,
-		AmountDiscount: 0,
-		AmountPaid:     price.PriceAmount,
+		AmountOriginal: amountOriginal,
+		AmountDiscount: amountDiscount,
+		AmountPaid:     amountPaid,
+		CouponID:       couponID,
 		IdempotencyKey: uuid.NewString(),
 		Snapshot:       types.NewJSONType(fields.OrdersSnapshot{}),
 	}
 
-	if err := models.OrderQuery.WithContext(ctx).Create(order); err != nil {
-		return nil, errorx.ErrDatabaseError.WithCause(err)
-	}
+	err = models.Q.Transaction(func(tx *models.Query) error {
+		if err := tx.Order.WithContext(ctx).Create(order); err != nil {
+			return err
+		}
 
-	// 3. Create Order Item
-	item := &models.OrderItem{
-		TenantID:      content.TenantID,
-		UserID:        uid,
-		OrderID:       order.ID,
-		ContentID:     cid,
-		ContentUserID: content.UserID,
-		AmountPaid:    order.AmountPaid,
-	}
-	if err := models.OrderItemQuery.WithContext(ctx).Create(item); err != nil {
+		// 3. Create Order Item
+		item := &models.OrderItem{
+			TenantID:      content.TenantID,
+			UserID:        uid,
+			OrderID:       order.ID,
+			ContentID:     cid,
+			ContentUserID: content.UserID,
+			AmountPaid:    amountPaid,
+		}
+		if err := tx.OrderItem.WithContext(ctx).Create(item); err != nil {
+			return err
+		}
+
+		// Mark Coupon Used
+		if form.UserCouponID != "" {
+			if err := Coupon.MarkUsed(ctx, tx, cast.ToInt64(form.UserCouponID), order.ID); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		if _, ok := err.(*errorx.AppError); ok {
+			return nil, err
+		}
 		return nil, errorx.ErrDatabaseError.WithCause(err)
 	}
 

backend/app/services/provider.gen.go

@@ -38,6 +38,13 @@ func Provide(opts ...opt.Option) error {
 	}); err != nil {
 		return err
 	}
+	if err := container.Container.Provide(func() (*coupon, error) {
+		obj := &coupon{}
+
+		return obj, nil
+	}); err != nil {
+		return err
+	}
 	if err := container.Container.Provide(func() (*creator, error) {
 		obj := &creator{}
 
@@ -67,12 +74,11 @@ func Provide(opts ...opt.Option) error {
 		audit *audit,
 		common *common,
 		content *content,
+		coupon *coupon,
 		creator *creator,
 		db *gorm.DB,
-		job *job.Job,
 		notification *notification,
 		order *order,
-		storage *storage.Storage,
 		super *super,
 		tenant *tenant,
 		user *user,
@@ -82,12 +88,11 @@ func Provide(opts ...opt.Option) error {
 			audit:        audit,
 			common:       common,
 			content:      content,
+			coupon:       coupon,
 			creator:      creator,
 			db:           db,
-			job:          job,
 			notification: notification,
 			order:        order,
-			storage:      storage,
 			super:        super,
 			tenant:       tenant,
 			user:         user,

backend/app/services/services.gen.go

@@ -1,9 +1,6 @@
 package services
 
 import (
-	"quyun/v2/providers/job"
-	"quyun/v2/providers/storage"
-
 	"gorm.io/gorm"
 )
 
@@ -14,11 +11,10 @@ var (
 	Audit        *audit
 	Common       *common
 	Content      *content
+	Coupon       *coupon
 	Creator      *creator
-	Job          *job.Job
 	Notification *notification
 	Order        *order
-	Storage      *storage.Storage
 	Super        *super
 	Tenant       *tenant
 	User         *user
@@ -32,11 +28,10 @@ type services struct {
 	audit        *audit
 	common       *common
 	content      *content
+	coupon       *coupon
 	creator      *creator
-	job          *job.Job
 	notification *notification
 	order        *order
-	storage      *storage.Storage
 	super        *super
 	tenant       *tenant
 	user         *user
@@ -50,11 +45,10 @@ func (svc *services) Prepare() error {
 	Audit = svc.audit
 	Common = svc.common
 	Content = svc.content
+	Coupon = svc.coupon
 	Creator = svc.creator
-	Job = svc.job
 	Notification = svc.notification
 	Order = svc.order
-	Storage = svc.storage
 	Super = svc.super
 	Tenant = svc.tenant
 	User = svc.user