fix(order): prevent duplicate subscriptions and repair invite gifts

internal/logic/common/newUserEligibility.go

@@ -76,7 +76,10 @@ func CountScopedSubscribePurchaseOrders(
 	var count int64
 	query := db.WithContext(ctx).
 		Model(&modelOrder.Order{}).
-		Where("user_id IN ? AND subscribe_id = ? AND type IN ? AND amount > 0", scopeUserIDs, subscribeID, []int64{1, 2})
+		Where("user_id IN ? AND type IN ?", scopeUserIDs, []int64{1, 2})
+	if subscribeID > 0 {
+		query = query.Where("subscribe_id = ?", subscribeID)
+	}
 	if len(statuses) > 0 {
 		query = query.Where("status IN ?", statuses)
 	}

internal/logic/common/subscribeModeRoute.go

@@ -52,12 +52,8 @@ func ResolvePurchaseRoute(
 		return decision, nil
 	}
 
-	if requestedSubscribeID != anchorSub.SubscribeId {
-		return nil, ErrSingleModePlanMismatch
-	}
-
 	decision.Route = PurchaseRoutePurchaseToRenewal
-	decision.ResolvedSubscribeID = anchorSub.SubscribeId
+	decision.ResolvedSubscribeID = requestedSubscribeID
 	decision.Anchor = anchorSub
 	return decision, nil
 }

internal/logic/common/subscribeModeRoute_test.go

@@ -0,0 +1,36 @@
+package common
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/perfect-panel/server/internal/model/user"
+	"github.com/stretchr/testify/require"
+)
+
+func TestResolvePurchaseRoute_AllowsPlanChangeForExistingSubscription(t *testing.T) {
+	anchor := &user.Subscribe{
+		Id:          10,
+		UserId:      20,
+		OrderId:     30,
+		SubscribeId: 1,
+		Token:       "existing-token",
+		ExpireTime:  time.Now().Add(time.Hour),
+	}
+
+	decision, err := ResolvePurchaseRoute(
+		context.Background(),
+		true,
+		anchor.UserId,
+		2,
+		func(context.Context, int64) (*user.Subscribe, error) {
+			return anchor, nil
+		},
+	)
+
+	require.NoError(t, err)
+	require.Equal(t, PurchaseRoutePurchaseToRenewal, decision.Route)
+	require.Equal(t, int64(2), decision.ResolvedSubscribeID)
+	require.Equal(t, anchor, decision.Anchor)
+}