feat: add platform type filter to subscription management page

Add a platform filter dropdown to the admin subscriptions view, allowing
filtering subscriptions by platform (Anthropic, OpenAI, Gemini, etc.)
through the group association.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/internal/handler/admin/subscription_handler.go

@@ -77,12 +77,13 @@ func (h *SubscriptionHandler) List(c *gin.Context) {
 		}
 	}
 	status := c.Query("status")
+	platform := c.Query("platform")
 
 	// Parse sorting parameters
 	sortBy := c.DefaultQuery("sort_by", "created_at")
 	sortOrder := c.DefaultQuery("sort_order", "desc")
 
-	subscriptions, pagination, err := h.subscriptionService.List(c.Request.Context(), page, pageSize, userID, groupID, status, sortBy, sortOrder)
+	subscriptions, pagination, err := h.subscriptionService.List(c.Request.Context(), page, pageSize, userID, groupID, status, platform, sortBy, sortOrder)
 	if err != nil {
 		response.ErrorFrom(c, err)
 		return

backend/internal/repository/user_subscription_repo.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	dbent "github.com/Wei-Shaw/sub2api/ent"
+	"github.com/Wei-Shaw/sub2api/ent/group"
 	"github.com/Wei-Shaw/sub2api/ent/usersubscription"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
 	"github.com/Wei-Shaw/sub2api/internal/service"
@@ -190,7 +191,7 @@ func (r *userSubscriptionRepository) ListByGroupID(ctx context.Context, groupID
 	return userSubscriptionEntitiesToService(subs), paginationResultFromTotal(int64(total), params), nil
 }
 
-func (r *userSubscriptionRepository) List(ctx context.Context, params pagination.PaginationParams, userID, groupID *int64, status, sortBy, sortOrder string) ([]service.UserSubscription, *pagination.PaginationResult, error) {
+func (r *userSubscriptionRepository) List(ctx context.Context, params pagination.PaginationParams, userID, groupID *int64, status, platform, sortBy, sortOrder string) ([]service.UserSubscription, *pagination.PaginationResult, error) {
 	client := clientFromContext(ctx, r.client)
 	q := client.UserSubscription.Query()
 	if userID != nil {
@@ -199,6 +200,9 @@ func (r *userSubscriptionRepository) List(ctx context.Context, params pagination
 	if groupID != nil {
 		q = q.Where(usersubscription.GroupIDEQ(*groupID))
 	}
+	if platform != "" {
+		q = q.Where(usersubscription.HasGroupWith(group.PlatformEQ(platform)))
+	}
 
 	// Status filtering with real-time expiration check
 	now := time.Now()

backend/internal/service/subscription_assign_idempotency_test.go

@@ -92,7 +92,7 @@ func (userSubRepoNoop) ListActiveByUserID(context.Context, int64) ([]UserSubscri
 func (userSubRepoNoop) ListByGroupID(context.Context, int64, pagination.PaginationParams) ([]UserSubscription, *pagination.PaginationResult, error) {
 	panic("unexpected ListByGroupID call")
 }
-func (userSubRepoNoop) List(context.Context, pagination.PaginationParams, *int64, *int64, string, string, string) ([]UserSubscription, *pagination.PaginationResult, error) {
+func (userSubRepoNoop) List(context.Context, pagination.PaginationParams, *int64, *int64, string, string, string, string) ([]UserSubscription, *pagination.PaginationResult, error) {
 	panic("unexpected List call")
 }
 func (userSubRepoNoop) ExistsByUserIDAndGroupID(context.Context, int64, int64) (bool, error) {

backend/internal/service/subscription_service.go

@@ -634,9 +634,9 @@ func (s *SubscriptionService) ListGroupSubscriptions(ctx context.Context, groupI
 }
 
 // List 获取所有订阅（分页，支持筛选和排序）
-func (s *SubscriptionService) List(ctx context.Context, page, pageSize int, userID, groupID *int64, status, sortBy, sortOrder string) ([]UserSubscription, *pagination.PaginationResult, error) {
+func (s *SubscriptionService) List(ctx context.Context, page, pageSize int, userID, groupID *int64, status, platform, sortBy, sortOrder string) ([]UserSubscription, *pagination.PaginationResult, error) {
 	params := pagination.PaginationParams{Page: page, PageSize: pageSize}
-	subs, pag, err := s.userSubRepo.List(ctx, params, userID, groupID, status, sortBy, sortOrder)
+	subs, pag, err := s.userSubRepo.List(ctx, params, userID, groupID, status, platform, sortBy, sortOrder)
 	if err != nil {
 		return nil, nil, err
 	}

backend/internal/service/user_subscription_port.go

@@ -18,7 +18,7 @@ type UserSubscriptionRepository interface {
 	ListByUserID(ctx context.Context, userID int64) ([]UserSubscription, error)
 	ListActiveByUserID(ctx context.Context, userID int64) ([]UserSubscription, error)
 	ListByGroupID(ctx context.Context, groupID int64, params pagination.PaginationParams) ([]UserSubscription, *pagination.PaginationResult, error)
-	List(ctx context.Context, params pagination.PaginationParams, userID, groupID *int64, status, sortBy, sortOrder string) ([]UserSubscription, *pagination.PaginationResult, error)
+	List(ctx context.Context, params pagination.PaginationParams, userID, groupID *int64, status, platform, sortBy, sortOrder string) ([]UserSubscription, *pagination.PaginationResult, error)
 
 	ExistsByUserIDAndGroupID(ctx context.Context, userID, groupID int64) (bool, error)
 	ExtendExpiry(ctx context.Context, subscriptionID int64, newExpiresAt time.Time) error

frontend/src/api/admin/subscriptions.ts

@@ -27,6 +27,7 @@ export async function list(
     status?: 'active' | 'expired' | 'revoked'
     user_id?: number
     group_id?: number
+    platform?: string
     sort_by?: string
     sort_order?: 'asc' | 'desc'
   },

frontend/src/i18n/locales/en.ts

@@ -1694,6 +1694,7 @@ export default {
       revokeSubscription: 'Revoke Subscription',
       allStatus: 'All Status',
       allGroups: 'All Groups',
+      allPlatforms: 'All Platforms',
       daily: 'Daily',
       weekly: 'Weekly',
       monthly: 'Monthly',

frontend/src/i18n/locales/zh.ts

@@ -1774,6 +1774,7 @@ export default {
       revokeSubscription: '撤销订阅',
       allStatus: '全部状态',
       allGroups: '全部分组',
+      allPlatforms: '全部平台',
       daily: '每日',
       weekly: '每周',
       monthly: '每月',

frontend/src/views/admin/SubscriptionsView.vue

@@ -81,6 +81,14 @@
                 @change="applyFilters"
               />
             </div>
+            <div class="w-full sm:w-40">
+              <Select
+                v-model="filters.platform"
+                :options="platformFilterOptions"
+                :placeholder="t('admin.subscriptions.allPlatforms')"
+                @change="applyFilters"
+              />
+            </div>
           </div>
 
           <!-- Right: Actions -->
@@ -813,6 +821,7 @@ let userSearchTimeout: ReturnType<typeof setTimeout> | null = null
 const filters = reactive({
   status: 'active',
   group_id: '',
+  platform: '',
   user_id: null as number | null
 })
 
@@ -855,6 +864,15 @@ const groupOptions = computed(() => [
   ...groups.value.map((g) => ({ value: g.id.toString(), label: g.name }))
 ])
 
+const platformFilterOptions = computed(() => [
+  { value: '', label: t('admin.subscriptions.allPlatforms') },
+  { value: 'anthropic', label: 'Anthropic' },
+  { value: 'openai', label: 'OpenAI' },
+  { value: 'gemini', label: 'Gemini' },
+  { value: 'antigravity', label: 'Antigravity' },
+  { value: 'sora', label: 'Sora' }
+])
+
 // Group options for assign (only subscription type groups)
 const subscriptionGroupOptions = computed(() =>
   groups.value
@@ -890,6 +908,7 @@ const loadSubscriptions = async () => {
       {
         status: (filters.status as any) || undefined,
         group_id: filters.group_id ? parseInt(filters.group_id) : undefined,
+        platform: filters.platform || undefined,
         user_id: filters.user_id || undefined,
         sort_by: sortState.sort_by,
         sort_order: sortState.sort_order