处理无法播放的问题

处理无法播放的问题

internal/config/config_test.go

@@ -40,15 +40,15 @@ func TestLoadDefaults(t *testing.T) {
 	if cfg.Database.MaxOpenConns != defaultDatabaseMaxOpenConns {
 		t.Fatalf("expected default MaxOpenConns %d, got %d", defaultDatabaseMaxOpenConns, cfg.Database.MaxOpenConns)
 	}
-		if cfg.Cache.RedisPrefix != "mmtl" {
-			t.Fatalf("expected default redis prefix, got %q", cfg.Cache.RedisPrefix)
-		}
-		if cfg.Cache.MediaTTLSeconds != 15 {
-			t.Fatalf("expected default media cache ttl 15, got %d", cfg.Cache.MediaTTLSeconds)
-		}
-		if cfg.Search.Index != "mmtl_media" {
-			t.Fatalf("expected default search index, got %q", cfg.Search.Index)
-		}
+	if cfg.Cache.RedisPrefix != "mmtl" {
+		t.Fatalf("expected default redis prefix, got %q", cfg.Cache.RedisPrefix)
+	}
+	if cfg.Cache.MediaTTLSeconds != 15 {
+		t.Fatalf("expected default media cache ttl 15, got %d", cfg.Cache.MediaTTLSeconds)
+	}
+	if cfg.Search.Index != "mmtl_media" {
+		t.Fatalf("expected default search index, got %q", cfg.Search.Index)
+	}
 	if cfg.Database.MaxIdleConns != defaultDatabaseMaxIdleConns {
 		t.Fatalf("expected default MaxIdleConns %d, got %d", defaultDatabaseMaxIdleConns, cfg.Database.MaxIdleConns)
 	}

internal/handler/api_config_handler.go

@@ -177,7 +177,7 @@ func (h *ApiConfigHandler) TestApiConfig(c *gin.Context) {
 	_ = h.svc.ApiConfig.UpdateTestResult(c.Request.Context(), provider, result)
 
 	c.JSON(http.StatusOK, gin.H{
-		"code": 0,
+		"code":    0,
 		"message": "ok",
 		"data": gin.H{
 			"result": result,

internal/handler/danmaku.go

@@ -30,4 +30,4 @@ func getDanmakuConfigHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		c.JSON(http.StatusOK, svc.Danmaku.Config(c.Request.Context()))
 	}
-}
+}

internal/handler/emby_authed_loop_test.go

@@ -144,4 +144,4 @@ func TestEmbyLoginWithAuthorizationHeaderToken(t *testing.T) {
 	if w.Code != http.StatusOK {
 		t.Fatalf("Authorization-token request = %d body=%s", w.Code, w.Body.String())
 	}
-}
+}

internal/handler/routes_authenticated_test.go

@@ -23,16 +23,16 @@ func TestAuthenticatedRouteSurfacesAreRegistered(t *testing.T) {
 		routes[route.Method+" "+route.Path] = true
 	}
 
-		for _, want := range []string{
-			"GET /api/me",
-			"GET /api/auth/permissions",
-			"GET /api/libraries",
-			"GET /api/media",
-			"GET /api/stream/:id",
-			"GET /api/storage",
-			"GET /api/watch-history",
-			"GET /api/playback/:id/info",
-		} {
+	for _, want := range []string{
+		"GET /api/me",
+		"GET /api/auth/permissions",
+		"GET /api/libraries",
+		"GET /api/media",
+		"GET /api/stream/:id",
+		"GET /api/storage",
+		"GET /api/watch-history",
+		"GET /api/playback/:id/info",
+	} {
 		if !routes[want] {
 			t.Fatalf("%s route is not registered", want)
 		}

internal/handler/stats_user.go

@@ -26,9 +26,9 @@ func statsUserHandler(svc *service.Container) gin.HandlerFunc {
 		_ = svc.Repo.DB.Model(&model.PlaybackHistory{}).
 			Where("user_id = ?", uid).Count(&total).Error
 		c.JSON(http.StatusOK, gin.H{
-			"user_id":      uid,
-			"watched_ms":   watched,
-			"plays":        total,
+			"user_id":       uid,
+			"watched_ms":    watched,
+			"plays":         total,
 			"watched_hours": float64(watched) / 1000.0 / 3600.0,
 		})
 	}

internal/handler/strm.go

@@ -410,7 +410,11 @@ func cancelPendingDownloadsHandler(svc *service.Container) gin.HandlerFunc {
 func strmPlayHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		provider := strings.TrimSpace(c.Param("provider"))
-		result, err := svc.Strm.ResolvePlay(c.Request.Context(), provider, url.Values(c.Request.URL.Query()))
+		q := url.Values(c.Request.URL.Query())
+		if userAgent := c.GetHeader("User-Agent"); userAgent != "" {
+			q.Set("__ua", userAgent)
+		}
+		result, err := svc.Strm.ResolvePlay(c.Request.Context(), provider, q)
 		if err != nil {
 			if errors.Is(err, service.ErrStrmPlayNotFound) {
 				c.Status(http.StatusNotFound)

internal/handler/system_extra.go

@@ -58,12 +58,12 @@ func schemaHandler(_ *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		c.JSON(http.StatusOK, gin.H{
 			"groups": []gin.H{
-					{
-						"key":   "general",
-						"label": "常规",
-						"items": []gin.H{
-							{"key": "tmdb.language", "type": "select", "label": "TMDb 元数据语言"},
-							{"key": "transcode.enabled", "type": "toggle", "label": "启用转码"},
+				{
+					"key":   "general",
+					"label": "常规",
+					"items": []gin.H{
+						{"key": "tmdb.language", "type": "select", "label": "TMDb 元数据语言"},
+						{"key": "transcode.enabled", "type": "toggle", "label": "启用转码"},
 						{"key": "transcode.hw_accel", "type": "select", "label": "硬件编码器"},
 						{"key": "transcode.hw_enabled", "type": "toggle", "label": "启用硬件加速"},
 						{"key": "transcode.max_jobs", "type": "number", "label": "最大并发"},
@@ -120,10 +120,10 @@ func schemaHandler(_ *service.Container) gin.HandlerFunc {
 						{"key": "qbittorrent.password", "type": "text"},
 						{"key": "qbittorrent.savepath", "type": "text"},
 					},
-},
-					{
-						"key":   "system-update",
-						"label": "系统更新",
+				},
+				{
+					"key":   "system-update",
+					"label": "系统更新",
 					"items": []gin.H{
 						{"key": "system.update.image", "type": "text", "label": "应用镜像"},
 						{"key": "system.update.compose_dir", "type": "text", "label": "Docker Compose 安装目录"},

internal/handler/task_helpers.go

@@ -7,4 +7,4 @@ func finishHTTPTask(task *service.TaskHandle, err error, stage, message string,
 		return
 	}
 	task.Finish(err, service.TaskUpdate{Stage: stage, Message: message, Metrics: metrics, Details: details})
-}
+}

internal/middleware/emby_auth.go

@@ -42,14 +42,14 @@ func EmbyAuthRequired(secret string) gin.HandlerFunc {
 			return []byte(secret), nil
 		})
 
-if err != nil || !parsed.Valid || claims.UserID == "" {
-		c.JSON(http.StatusUnauthorized, gin.H{
-			"Code":    40101,
-			"Message": "Invalid token",
-		})
-		c.Abort()
-		return
-	}
+		if err != nil || !parsed.Valid || claims.UserID == "" {
+			c.JSON(http.StatusUnauthorized, gin.H{
+				"Code":    40101,
+				"Message": "Invalid token",
+			})
+			c.Abort()
+			return
+		}
 
 		c.Set(EmbyCtxUserID, claims.UserID)
 		c.Set(CtxUserID, claims.UserID)

internal/middleware/middleware_test.go

@@ -106,13 +106,13 @@ func TestAuthRequiredSyncsAccessTokenCookieFromBearer(t *testing.T) {
 		},
 	})
 
-		router := gin.New()
-		router.Use(AuthRequired(secret))
-		router.GET("/api/test-auth-cookie", func(c *gin.Context) {
-			c.JSON(http.StatusOK, gin.H{"ok": true})
-		})
+	router := gin.New()
+	router.Use(AuthRequired(secret))
+	router.GET("/api/test-auth-cookie", func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"ok": true})
+	})
 
-		req := httptest.NewRequest(http.MethodGet, "/api/test-auth-cookie", nil)
+	req := httptest.NewRequest(http.MethodGet, "/api/test-auth-cookie", nil)
 	req.Header.Set("Authorization", "Bearer "+token)
 	w := httptest.NewRecorder()
 	router.ServeHTTP(w, req)

internal/model/api_config.go

@@ -39,7 +39,7 @@ func PredefinedProviders() []ApiProvider {
 		{ID: "openai", Name: "OpenAI", Description: "GPT 系列模型", HasAPIKey: true, HasBaseURL: true},
 		{ID: "deepseek", Name: "DeepSeek", Description: "DeepSeek 大模型", HasAPIKey: true, HasBaseURL: true},
 		{ID: "siliconflow", Name: "SiliconFlow", Description: "AI 模型聚合 API", HasAPIKey: true, HasBaseURL: true},
-			{ID: "adult", Name: "Adult / 番号", Description: "JavDB/JavBus 成人内容元数据与 Cookie 凭据", HasAPIKey: true, HasBaseURL: true},
-			{ID: "metatube", Name: "MetaTube", Description: "MetaTube Server 番号元数据后端服务", HasAPIKey: true, HasBaseURL: true},
-		}
+		{ID: "adult", Name: "Adult / 番号", Description: "JavDB/JavBus 成人内容元数据与 Cookie 凭据", HasAPIKey: true, HasBaseURL: true},
+		{ID: "metatube", Name: "MetaTube", Description: "MetaTube Server 番号元数据后端服务", HasAPIKey: true, HasBaseURL: true},
+	}
 }

internal/model/permission.go

@@ -16,7 +16,7 @@ type UserPermission struct {
 	UserID string `gorm:"uniqueIndex;size:36;not null" json:"user_id"`
 
 	// 默认开启（6项）- Basic
-	CanViewDashboard   bool `gorm:"default:true" json:"can_view_dashboard"`
+	CanViewDashboard  bool `gorm:"default:true" json:"can_view_dashboard"`
 	CanPlayMedia      bool `gorm:"default:true" json:"can_play_media"`
 	CanCast           bool `gorm:"default:true" json:"can_cast"`
 	CanExternalPlayer bool `gorm:"default:true" json:"can_external_player"`
@@ -24,18 +24,18 @@ type UserPermission struct {
 	CanViewHistory    bool `gorm:"default:true" json:"can_view_history"`
 
 	// 默认关闭（13项）- Advanced
-	CanEditMedia             bool `gorm:"default:false" json:"can_edit_media"`
-	CanRescrape              bool `gorm:"default:false" json:"can_rescrape"`
-	CanUseAI                 bool `gorm:"default:false" json:"can_use_ai"`
-	CanCaptureFrames         bool `gorm:"default:false" json:"can_capture_frames"`
-		CanManageDownloads       bool `gorm:"default:false" json:"can_manage_downloads"`
-		CanManageSubscriptions   bool `gorm:"default:false" json:"can_manage_subscriptions"`
-	CanManageSites           bool `gorm:"default:false" json:"can_manage_sites"`
-	CanUseAIAssistant        bool `gorm:"default:false" json:"can_use_ai_assistant"`
-	CanManageUsers           bool `gorm:"default:false" json:"can_manage_users"`
-	CanManageFiles           bool `gorm:"default:false" json:"can_manage_files"`
-	CanManageStrm            bool `gorm:"default:false" json:"can_manage_strm"`
-	CanAccessSettings        bool `gorm:"default:false" json:"can_access_settings"`
+	CanEditMedia           bool `gorm:"default:false" json:"can_edit_media"`
+	CanRescrape            bool `gorm:"default:false" json:"can_rescrape"`
+	CanUseAI               bool `gorm:"default:false" json:"can_use_ai"`
+	CanCaptureFrames       bool `gorm:"default:false" json:"can_capture_frames"`
+	CanManageDownloads     bool `gorm:"default:false" json:"can_manage_downloads"`
+	CanManageSubscriptions bool `gorm:"default:false" json:"can_manage_subscriptions"`
+	CanManageSites         bool `gorm:"default:false" json:"can_manage_sites"`
+	CanUseAIAssistant      bool `gorm:"default:false" json:"can_use_ai_assistant"`
+	CanManageUsers         bool `gorm:"default:false" json:"can_manage_users"`
+	CanManageFiles         bool `gorm:"default:false" json:"can_manage_files"`
+	CanManageStrm          bool `gorm:"default:false" json:"can_manage_strm"`
+	CanAccessSettings      bool `gorm:"default:false" json:"can_access_settings"`
 
 	CreatedAt time.Time `json:"created_at"`
 	UpdatedAt time.Time `json:"updated_at"`
@@ -52,26 +52,26 @@ func (p *UserPermission) BeforeCreate(_ *gorm.DB) error {
 // NewDefaultPermission 创建带有默认权限的 UserPermission。
 func NewDefaultPermission(userID string) *UserPermission {
 	return &UserPermission{
-		ID:                    uuid.NewString(),
-		UserID:                userID,
-		CanViewDashboard:      true,
-		CanPlayMedia:          true,
-		CanCast:               true,
-		CanExternalPlayer:     true,
-		CanFavorite:           true,
-		CanViewHistory:        true,
-		CanEditMedia:          false,
-		CanRescrape:           false,
-		CanUseAI:              false,
-		CanCaptureFrames:      false,
-			CanManageDownloads:    false,
-			CanManageSubscriptions: false,
-		CanManageSites:        false,
-		CanUseAIAssistant:     false,
-		CanManageUsers:        false,
-		CanManageFiles:        false,
-		CanManageStrm:         false,
-		CanAccessSettings:     false,
+		ID:                     uuid.NewString(),
+		UserID:                 userID,
+		CanViewDashboard:       true,
+		CanPlayMedia:           true,
+		CanCast:                true,
+		CanExternalPlayer:      true,
+		CanFavorite:            true,
+		CanViewHistory:         true,
+		CanEditMedia:           false,
+		CanRescrape:            false,
+		CanUseAI:               false,
+		CanCaptureFrames:       false,
+		CanManageDownloads:     false,
+		CanManageSubscriptions: false,
+		CanManageSites:         false,
+		CanUseAIAssistant:      false,
+		CanManageUsers:         false,
+		CanManageFiles:         false,
+		CanManageStrm:          false,
+		CanAccessSettings:      false,
 	}
 }
 
@@ -88,13 +88,13 @@ func (p *UserPermission) PermissionMap() map[string]bool {
 		"can_rescrape":             p.CanRescrape,
 		"can_use_ai":               p.CanUseAI,
 		"can_capture_frames":       p.CanCaptureFrames,
-			"can_manage_downloads":     p.CanManageDownloads,
-			"can_manage_subscriptions":  p.CanManageSubscriptions,
+		"can_manage_downloads":     p.CanManageDownloads,
+		"can_manage_subscriptions": p.CanManageSubscriptions,
 		"can_manage_sites":         p.CanManageSites,
-		"can_use_ai_assistant":      p.CanUseAIAssistant,
+		"can_use_ai_assistant":     p.CanUseAIAssistant,
 		"can_manage_users":         p.CanManageUsers,
 		"can_manage_files":         p.CanManageFiles,
 		"can_manage_strm":          p.CanManageStrm,
-		"can_access_settings":     p.CanAccessSettings,
+		"can_access_settings":      p.CanAccessSettings,
 	}
 }

internal/repository/storage_config_repo.go

@@ -66,7 +66,6 @@ func (r *StorageConfigRepository) Upsert(ctx context.Context, c *model.StorageCo
 	}).Error
 }
 
-
 // Delete removes a storage config by ID.
 func (r *StorageConfigRepository) Delete(ctx context.Context, id string) error {
 	return r.db.WithContext(ctx).Where("id = ?", id).Delete(&model.StorageConfig{}).Error

internal/service/cloud/pan115_openapi.go

@@ -77,7 +77,11 @@ func (p *openAPI115Provider) List(ctx context.Context, dirID string) ([]FileEntr
 }
 
 func (p *openAPI115Provider) Resolve(ctx context.Context, fileRef string) (*DirectLink, error) {
-	url, err := p.c.GetDownloadURL(ctx, fileRef)
+	return p.ResolveWithUA(ctx, fileRef, "")
+}
+
+func (p *openAPI115Provider) ResolveWithUA(ctx context.Context, fileRef, ua string) (*DirectLink, error) {
+	url, err := p.c.GetDownloadURLWithUA(ctx, fileRef, ua)
 	if err != nil {
 		return nil, err
 	}

internal/service/cloud115/client.go

@@ -90,11 +90,15 @@ type RespBase struct {
 }
 
 // doJSON 执行 HTTP 请求并解析为统一响应；带 AccessToken（access=true 时）。
-func (c *OpenClient) doJSON(ctx context.Context, method, rawURL string, form map[string]string, access bool, retries int) (*RespBase, error) {
+func (c *OpenClient) doJSON(ctx context.Context, method, rawURL string, form map[string]string, access bool, retries int, uas ...string) (*RespBase, error) {
 	executor := c.executor
 	if executor == nil {
 		executor = GetGlobalExecutor()
 	}
+	ua := ""
+	if len(uas) > 0 {
+		ua = uas[0]
+	}
 
 	var lastErr error
 	for attempt := 0; attempt <= retries; attempt++ {
@@ -103,7 +107,7 @@ func (c *OpenClient) doJSON(ctx context.Context, method, rawURL string, form map
 			return nil, err
 		}
 
-		req, err := c.buildRequest(ctx, method, rawURL, form, access)
+		req, err := c.buildRequestWithUA(ctx, method, rawURL, form, access, ua)
 		if err != nil {
 			return nil, err
 		}
@@ -187,6 +191,10 @@ func (c *OpenClient) doJSON(ctx context.Context, method, rawURL string, form map
 }
 
 func (c *OpenClient) buildRequest(ctx context.Context, method, rawURL string, form map[string]string, access bool) (*http.Request, error) {
+	return c.buildRequestWithUA(ctx, method, rawURL, form, access, "")
+}
+
+func (c *OpenClient) buildRequestWithUA(ctx context.Context, method, rawURL string, form map[string]string, access bool, ua string) (*http.Request, error) {
 	method = strings.ToUpper(method)
 	var body io.Reader
 	if method == http.MethodPost && len(form) > 0 {
@@ -211,7 +219,11 @@ func (c *OpenClient) buildRequest(ctx context.Context, method, rawURL string, fo
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", DefaultUA)
+	targetUA := DefaultUA
+	if strings.TrimSpace(ua) != "" {
+		targetUA = strings.TrimSpace(ua)
+	}
+	req.Header.Set("User-Agent", targetUA)
 	if method == http.MethodPost && len(form) > 0 {
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	}
@@ -226,6 +238,11 @@ func (c *OpenClient) doAuthJSON(ctx context.Context, method, rawURL string, form
 	return c.doJSON(ctx, method, rawURL, form, true, retries)
 }
 
+// doAuthJSONWithUA 带自定义 User-Agent 的业务请求（换取直链等防盗链接口使用）。
+func (c *OpenClient) doAuthJSONWithUA(ctx context.Context, method, rawURL string, form map[string]string, retries int, ua string) (*RespBase, error) {
+	return c.doJSON(ctx, method, rawURL, form, true, retries, ua)
+}
+
 // IsThrottleCode 判断是否为限流错误码。
 func IsThrottleCode(code int) bool {
 	return code == RequestMaxLimitCode || code == RequestRateLimitCode

internal/service/cloud115/open.go

@@ -127,11 +127,17 @@ type downloadURLData struct {
 // GetDownloadURL 获取下载直链（pickcode）。命中缓存直接返回，
 // 避免对同一文件反复换取直链触发 115 风控。
 func (c *OpenClient) GetDownloadURL(ctx context.Context, pickCode string) (string, error) {
-	if cached := GetDownloadURLCache(pickCode); cached != "" {
+	return c.GetDownloadURLWithUA(ctx, pickCode, "")
+}
+
+// GetDownloadURLWithUA 支持按调用方/播放器 User-Agent 换取对应的 115 CDN 直链（用于 115 防盗链白名单校验）。
+func (c *OpenClient) GetDownloadURLWithUA(ctx context.Context, pickCode, ua string) (string, error) {
+	ua = strings.TrimSpace(ua)
+	if cached := GetDownloadURLCache(pickCode, ua); cached != "" {
 		return cached, nil
 	}
 	params := map[string]string{"pick_code": pickCode}
-	resp, err := c.doAuthJSON(ctx, "POST", ProAPIBase+"/open/ufile/downurl", params, 1)
+	resp, err := c.doAuthJSONWithUA(ctx, "POST", ProAPIBase+"/open/ufile/downurl", params, 1, ua)
 	if err != nil {
 		return "", err
 	}
@@ -143,7 +149,7 @@ func (c *OpenClient) GetDownloadURL(ctx context.Context, pickCode string) (strin
 	if first.URL.URL == "" {
 		return "", fmt.Errorf("115: 下载地址为空（文件可能未上传完成或已被删除）")
 	}
-	SetDownloadURLCache(pickCode, first.URL.URL)
+	SetDownloadURLCache(pickCode, first.URL.URL, ua)
 	return first.URL.URL, nil
 }
 

internal/service/cloud115/url_cache.go

@@ -7,6 +7,7 @@
 package cloud115
 
 import (
+	"strings"
 	"sync"
 	"time"
 )
@@ -28,17 +29,30 @@ var (
 	urlCache   = map[string]urlCacheEntry{}
 )
 
+// urlCacheKey 构造缓存键名（pickCode + UA，实现直链防盗链按客户端 UA 独立缓存）。
+func urlCacheKey(pickCode, ua string) string {
+	if ua == "" {
+		return pickCode
+	}
+	return pickCode + "@" + ua
+}
+
 // GetDownloadURLCache 返回未过期的缓存直链；不存在或已过期返回空串。
-func GetDownloadURLCache(pickCode string) string {
+func GetDownloadURLCache(pickCode string, uas ...string) string {
 	if pickCode == "" {
 		return ""
 	}
+	ua := ""
+	if len(uas) > 0 {
+		ua = uas[0]
+	}
+	key := urlCacheKey(pickCode, ua)
 	urlCacheMu.Lock()
 	defer urlCacheMu.Unlock()
-	entry, ok := urlCache[pickCode]
+	entry, ok := urlCache[key]
 	if !ok || time.Now().After(entry.expiresAt) {
 		if ok {
-			delete(urlCache, pickCode)
+			delete(urlCache, key)
 		}
 		return ""
 	}
@@ -46,10 +60,14 @@ func GetDownloadURLCache(pickCode string) string {
 }
 
 // SetDownloadURLCache 写入直链缓存。
-func SetDownloadURLCache(pickCode, url string) {
+func SetDownloadURLCache(pickCode string, url string, uas ...string) {
 	if pickCode == "" || url == "" {
 		return
 	}
+	ua := ""
+	if len(uas) > 0 {
+		ua = uas[0]
+	}
 	urlCacheMu.Lock()
 	defer urlCacheMu.Unlock()
 	if len(urlCache) >= maxCachedURLs {
@@ -60,15 +78,20 @@ func SetDownloadURLCache(pickCode, url string) {
 			}
 		}
 	}
-	urlCache[pickCode] = urlCacheEntry{url: url, expiresAt: time.Now().Add(downloadURLCacheTTL)}
+	key := urlCacheKey(pickCode, ua)
+	urlCache[key] = urlCacheEntry{url: url, expiresAt: time.Now().Add(downloadURLCacheTTL)}
 }
 
-// ClearDownloadURLCache 删除指定 pickcode 的缓存（下载得到非 2xx 时调用）。
+// ClearDownloadURLCache 删除指定 pickcode 的所有缓存（下载得到非 2xx 时调用）。
 func ClearDownloadURLCache(pickCode string) {
 	if pickCode == "" {
 		return
 	}
 	urlCacheMu.Lock()
 	defer urlCacheMu.Unlock()
-	delete(urlCache, pickCode)
+	for k := range urlCache {
+		if k == pickCode || strings.HasPrefix(k, pickCode+"@") {
+			delete(urlCache, k)
+		}
+	}
 }

internal/service/strm_play.go

@@ -66,7 +66,15 @@ func (s *StrmService) resolveCloudPlay(ctx context.Context, provider string, q u
 	if err != nil {
 		return nil, err
 	}
-	link, err := p.Resolve(ctx, ref)
+	var link *cloud.DirectLink
+	ua := q.Get("__ua")
+	if uaProvider, ok := p.(interface {
+		ResolveWithUA(ctx context.Context, fileRef, ua string) (*cloud.DirectLink, error)
+	}); ok && ua != "" {
+		link, err = uaProvider.ResolveWithUA(ctx, ref, ua)
+	} else {
+		link, err = p.Resolve(ctx, ref)
+	}
 	if err != nil {
 		return nil, err
 	}