Fix custom filename formats for paid messages and posts, and fix creator config empty strings

OF DL.Core/Models/Config/Config.cs

@@ -115,22 +115,22 @@ public class Config : IFileNameFormatConfig
 
         if (CreatorConfigs.TryGetValue(username, out CreatorConfig? creatorConfig))
         {
-            if (creatorConfig.PaidPostFileNameFormat != null)
+            if (!string.IsNullOrEmpty(creatorConfig.PaidPostFileNameFormat))
             {
                 combinedFilenameFormatConfig.PaidPostFileNameFormat = creatorConfig.PaidPostFileNameFormat;
             }
 
-            if (creatorConfig.PostFileNameFormat != null)
+            if (!string.IsNullOrEmpty(creatorConfig.PostFileNameFormat))
             {
                 combinedFilenameFormatConfig.PostFileNameFormat = creatorConfig.PostFileNameFormat;
             }
 
-            if (creatorConfig.PaidMessageFileNameFormat != null)
+            if (!string.IsNullOrEmpty(creatorConfig.PaidMessageFileNameFormat))
             {
                 combinedFilenameFormatConfig.PaidMessageFileNameFormat = creatorConfig.PaidMessageFileNameFormat;
             }
 
-            if (creatorConfig.MessageFileNameFormat != null)
+            if (!string.IsNullOrEmpty(creatorConfig.MessageFileNameFormat))
             {
                 combinedFilenameFormatConfig.MessageFileNameFormat = creatorConfig.MessageFileNameFormat;
             }

OF DL.Core/Services/DownloadService.cs

@@ -1363,11 +1363,12 @@ public class DownloadService(
             PurchasedEntities.ListItem? messageInfo = paidMessageCollection.PaidMessageObjects.FirstOrDefault(p =>
                 p.Media?.Any(m => m.Id == kvpEntry.Key) == true);
             string filenameFormat =
-                configService.CurrentConfig.GetCreatorFileNameFormatConfig(username).MessageFileNameFormat ?? "";
+                configService.CurrentConfig.GetCreatorFileNameFormatConfig(username).PaidMessageFileNameFormat ?? "";
             string paidMsgPath = configService.CurrentConfig.FolderPerPaidMessage && messageInfo != null &&
                                  messageInfo.Id != 0 && messageInfo.CreatedAt is not null
                 ? $"/Messages/Paid/{messageInfo.Id} {messageInfo.CreatedAt.Value:yyyy-MM-dd HH-mm-ss}"
                 : "/Messages/Paid";
+            object? messageAuthor = messageInfo?.FromUser ?? (object?)messageInfo?.Author;
 
             if (kvpEntry.Value.Contains("cdn3.onlyfans.com/dash/files"))
             {
@@ -1383,12 +1384,12 @@ public class DownloadService(
                 isNew = await DownloadDrmVideo(parsed[1], parsed[2], parsed[3], parsed[0],
                     drmInfo.Value.decryptionKey, path, drmInfo.Value.lastModified, kvpEntry.Key, "Messages",
                     progressReporter, paidMsgPath + "/Videos", filenameFormat,
-                    messageInfo, mediaInfo, messageInfo?.FromUser, users);
+                    messageInfo, mediaInfo, messageAuthor, users);
             }
             else
             {
                 isNew = await DownloadMedia(kvpEntry.Value, path, kvpEntry.Key, "Messages", progressReporter,
-                    paidMsgPath, filenameFormat, messageInfo, mediaInfo, messageInfo?.FromUser, users);
+                    paidMsgPath, filenameFormat, messageInfo, mediaInfo, messageAuthor, users);
             }
 
             if (isNew)
@@ -1640,11 +1641,12 @@ public class DownloadService(
             PurchasedEntities.ListItem? postInfo =
                 purchasedPosts.PaidPostObjects.FirstOrDefault(p => p.Media?.Any(m => m.Id == postKvp.Key) == true);
             string filenameFormat =
-                configService.CurrentConfig.GetCreatorFileNameFormatConfig(username).PostFileNameFormat ?? "";
+                configService.CurrentConfig.GetCreatorFileNameFormatConfig(username).PaidPostFileNameFormat ?? "";
             string paidPostPath = configService.CurrentConfig.FolderPerPaidPost && postInfo != null &&
                                   postInfo.Id != 0 && postInfo.PostedAt is not null
                 ? $"/Posts/Paid/{postInfo.Id} {postInfo.PostedAt.Value:yyyy-MM-dd HH-mm-ss}"
                 : "/Posts/Paid";
+            object? postAuthor = postInfo?.FromUser ?? (object?)postInfo?.Author;
 
             if (postKvp.Value.Contains("cdn3.onlyfans.com/dash/files"))
             {
@@ -1660,12 +1662,12 @@ public class DownloadService(
                 isNew = await DownloadDrmVideo(parsed[1], parsed[2], parsed[3], parsed[0],
                     drmInfo.Value.decryptionKey, path, drmInfo.Value.lastModified, postKvp.Key, "Posts",
                     progressReporter, paidPostPath + "/Videos", filenameFormat,
-                    postInfo, mediaInfo, postInfo?.FromUser, users);
+                    postInfo, mediaInfo, postAuthor, users);
             }
             else
             {
                 isNew = await DownloadMedia(postKvp.Value, path, postKvp.Key, "Posts", progressReporter,
-                    paidPostPath, filenameFormat, postInfo, mediaInfo, postInfo?.FromUser, users);
+                    paidPostPath, filenameFormat, postInfo, mediaInfo, postAuthor, users);
             }
 
             if (isNew)
@@ -1729,6 +1731,7 @@ public class DownloadService(
                                   postInfo.Id != 0 && postInfo.PostedAt is not null
                 ? $"/Posts/Paid/{postInfo.Id} {postInfo.PostedAt.Value:yyyy-MM-dd HH-mm-ss}"
                 : "/Posts/Paid";
+            object? postAuthor = postInfo?.FromUser ?? (object?)postInfo?.Author;
 
             if (purchasedPostKvp.Value.Contains("cdn3.onlyfans.com/dash/files"))
             {
@@ -1744,13 +1747,13 @@ public class DownloadService(
                 isNew = await DownloadDrmVideo(parsed[1], parsed[2], parsed[3], parsed[0],
                     drmInfo.Value.decryptionKey, path, drmInfo.Value.lastModified, purchasedPostKvp.Key,
                     "Posts", progressReporter, paidPostPath + "/Videos", filenameFormat,
-                    postInfo, mediaInfo, postInfo?.FromUser, users);
+                    postInfo, mediaInfo, postAuthor, users);
             }
             else
             {
                 isNew = await DownloadMedia(purchasedPostKvp.Value, path,
                     purchasedPostKvp.Key, "Posts", progressReporter,
-                    paidPostPath, filenameFormat, postInfo, mediaInfo, postInfo?.FromUser, users);
+                    paidPostPath, filenameFormat, postInfo, mediaInfo, postAuthor, users);
             }
 
             if (isNew)
@@ -1813,6 +1816,7 @@ public class DownloadService(
                                  messageInfo.Id != 0 && messageInfo.CreatedAt is not null
                 ? $"/Messages/Paid/{messageInfo.Id} {messageInfo.CreatedAt.Value:yyyy-MM-dd HH-mm-ss}"
                 : "/Messages/Paid";
+            object? messageAuthor = messageInfo?.FromUser ?? (object?)messageInfo?.Author;
 
             if (paidMessageKvp.Value.Contains("cdn3.onlyfans.com/dash/files"))
             {
@@ -1828,13 +1832,13 @@ public class DownloadService(
                 isNew = await DownloadDrmVideo(parsed[1], parsed[2], parsed[3], parsed[0],
                     drmInfo.Value.decryptionKey, path, drmInfo.Value.lastModified, paidMessageKvp.Key,
                     "Messages", progressReporter, paidMsgPath + "/Videos", filenameFormat,
-                    messageInfo, mediaInfo, messageInfo?.FromUser, users);
+                    messageInfo, mediaInfo, messageAuthor, users);
             }
             else
             {
                 isNew = await DownloadMedia(paidMessageKvp.Value, path,
                     paidMessageKvp.Key, "Messages", progressReporter,
-                    paidMsgPath, filenameFormat, messageInfo, mediaInfo, messageInfo?.FromUser, users);
+                    paidMsgPath, filenameFormat, messageInfo, mediaInfo, messageAuthor, users);
             }
 
             if (isNew)

OF DL.Core/Services/FileNameService.cs

@@ -200,8 +200,18 @@ public class FileNameService(IAuthService authService) : IFileNameService
         object? value = source;
         foreach (string propertyName in propertyPath.Split('.'))
         {
-            PropertyInfo property = value?.GetType().GetProperty(propertyName) ??
+            if (value == null)
-                                    throw new ArgumentException($"Property '{propertyName}' not found.");
+            {
+                return null;
+            }
+
+            PropertyInfo? property = value.GetType().GetProperty(propertyName,
+                BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
+            if (property == null)
+            {
+                return null;
+            }
+
             value = property.GetValue(value);
         }
 

OF DL.Tests/Models/Config/ConfigTests.cs

@@ -0,0 +1,122 @@
+using OF_DL.Models.Config;
+
+namespace OF_DL.Tests.Models.Config;
+
+public class ConfigTests
+{
+    [Fact]
+    public void GetCreatorFileNameFormatConfig_UsesCreatorFormatWhenDefined()
+    {
+        OF_DL.Models.Config.Config config = new()
+        {
+            PaidPostFileNameFormat = "global-paid-post",
+            PostFileNameFormat = "global-post",
+            PaidMessageFileNameFormat = "global-paid-message",
+            MessageFileNameFormat = "global-message",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new()
+                {
+                    PaidPostFileNameFormat = "creator-paid-post",
+                    PostFileNameFormat = "creator-post",
+                    PaidMessageFileNameFormat = "creator-paid-message",
+                    MessageFileNameFormat = "creator-message"
+                }
+            }
+        };
+
+        IFileNameFormatConfig result = config.GetCreatorFileNameFormatConfig("creator");
+
+        Assert.Equal("creator-paid-post", result.PaidPostFileNameFormat);
+        Assert.Equal("creator-post", result.PostFileNameFormat);
+        Assert.Equal("creator-paid-message", result.PaidMessageFileNameFormat);
+        Assert.Equal("creator-message", result.MessageFileNameFormat);
+    }
+
+    [Fact]
+    public void GetCreatorFileNameFormatConfig_FallsBackToGlobalWhenCreatorFormatIsNullOrEmpty()
+    {
+        OF_DL.Models.Config.Config config = new()
+        {
+            PaidPostFileNameFormat = "global-paid-post",
+            PostFileNameFormat = "global-post",
+            PaidMessageFileNameFormat = "global-paid-message",
+            MessageFileNameFormat = "global-message",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new()
+                {
+                    PaidPostFileNameFormat = null,
+                    PostFileNameFormat = "",
+                    PaidMessageFileNameFormat = null,
+                    MessageFileNameFormat = ""
+                }
+            }
+        };
+
+        IFileNameFormatConfig result = config.GetCreatorFileNameFormatConfig("creator");
+
+        Assert.Equal("global-paid-post", result.PaidPostFileNameFormat);
+        Assert.Equal("global-post", result.PostFileNameFormat);
+        Assert.Equal("global-paid-message", result.PaidMessageFileNameFormat);
+        Assert.Equal("global-message", result.MessageFileNameFormat);
+    }
+
+    [Fact]
+    public void GetCreatorFileNameFormatConfig_UsesGlobalWhenCreatorConfigDoesNotExist()
+    {
+        OF_DL.Models.Config.Config config = new()
+        {
+            PaidPostFileNameFormat = "global-paid-post",
+            PostFileNameFormat = "global-post",
+            PaidMessageFileNameFormat = "global-paid-message",
+            MessageFileNameFormat = "global-message",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["other-creator"] = new()
+                {
+                    PaidPostFileNameFormat = "other-paid-post",
+                    PostFileNameFormat = "other-post",
+                    PaidMessageFileNameFormat = "other-paid-message",
+                    MessageFileNameFormat = "other-message"
+                }
+            }
+        };
+
+        IFileNameFormatConfig result = config.GetCreatorFileNameFormatConfig("creator");
+
+        Assert.Equal("global-paid-post", result.PaidPostFileNameFormat);
+        Assert.Equal("global-post", result.PostFileNameFormat);
+        Assert.Equal("global-paid-message", result.PaidMessageFileNameFormat);
+        Assert.Equal("global-message", result.MessageFileNameFormat);
+    }
+
+    [Fact]
+    public void GetCreatorFileNameFormatConfig_ReturnsEmptyFormatsWhenCreatorAndGlobalAreUndefined()
+    {
+        OF_DL.Models.Config.Config config = new()
+        {
+            PaidPostFileNameFormat = "",
+            PostFileNameFormat = "",
+            PaidMessageFileNameFormat = "",
+            MessageFileNameFormat = "",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new()
+                {
+                    PaidPostFileNameFormat = "",
+                    PostFileNameFormat = null,
+                    PaidMessageFileNameFormat = "",
+                    MessageFileNameFormat = null
+                }
+            }
+        };
+
+        IFileNameFormatConfig result = config.GetCreatorFileNameFormatConfig("creator");
+
+        Assert.True(string.IsNullOrEmpty(result.PaidPostFileNameFormat));
+        Assert.True(string.IsNullOrEmpty(result.PostFileNameFormat));
+        Assert.True(string.IsNullOrEmpty(result.PaidMessageFileNameFormat));
+        Assert.True(string.IsNullOrEmpty(result.MessageFileNameFormat));
+    }
+}

OF DL.Tests/Services/DownloadServiceTests.cs

@@ -1,5 +1,9 @@
 using OF_DL.Models.Config;
 using OF_DL.Models.Downloads;
+using OF_DL.Models;
+using PostEntities = OF_DL.Models.Entities.Posts;
+using PurchasedEntities = OF_DL.Models.Entities.Purchased;
+using MessageEntities = OF_DL.Models.Entities.Messages;
 using OF_DL.Services;
 
 namespace OF_DL.Tests.Services;
@@ -150,11 +154,218 @@ public class DownloadServiceTests
         Assert.Equal(2, progress.Total);
     }
 
-    private static DownloadService CreateService(FakeConfigService configService, MediaTrackingDbService dbService,
+    [Fact]
-        StaticApiService? apiService = null) =>
+    public async Task DownloadFreePosts_UsesDefaultFilenameWhenNoGlobalOrCreatorFormatIsDefined()
-        new(new FakeAuthService(), configService, dbService, new FakeFileNameService(),
+    {
-            apiService ?? new StaticApiService());
+        using TempFolder temp = new();
+        string folder = NormalizeFolder(Path.Combine(temp.Path, "creator"));
+        const string serverFilename = "server-name";
+        string existingFilePath = $"{folder}/Posts/Free/Images/{serverFilename}.jpg";
+        Directory.CreateDirectory(Path.GetDirectoryName(existingFilePath) ?? throw new InvalidOperationException());
+        await File.WriteAllTextAsync(existingFilePath, "abc");
 
-    private static string NormalizeFolder(string folder) => folder.Replace("\\", "/");
+        Config config = new()
+        {
+            ShowScrapeSize = false,
+            PostFileNameFormat = "",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new() { PostFileNameFormat = "" }
+            }
+        };
+
+        MediaTrackingDbService dbService = new() { CheckDownloadedResult = false };
+        DownloadService service = CreateService(new FakeConfigService(config), dbService);
+        ProgressRecorder progress = new();
+        PostEntities.PostCollection posts = new()
+        {
+            Posts = new Dictionary<long, string> { { 1, $"https://example.com/{serverFilename}.jpg" } }
+        };
+
+        DownloadResult result = await service.DownloadFreePosts("creator", 1, folder, new Dictionary<string, long>(),
+            false, false, posts, progress);
+
+        Assert.Equal(1, result.TotalCount);
+        Assert.Equal(0, result.NewDownloads);
+        Assert.Equal(1, result.ExistingDownloads);
+        Assert.NotNull(dbService.LastUpdateMedia);
+        Assert.Equal($"{serverFilename}.jpg", dbService.LastUpdateMedia.Value.filename);
+        Assert.Equal(1, progress.Total);
     }
 
+    [Fact]
+    public async Task DownloadFreePosts_UsesGlobalCustomFormatWhenCreatorCustomFormatNotDefined()
+    {
+        using TempFolder temp = new();
+        string folder = NormalizeFolder(Path.Combine(temp.Path, "creator"));
+        const string serverFilename = "server-name";
+        string existingFilePath = $"{folder}/Posts/Free/Images/{serverFilename}.jpg";
+        Directory.CreateDirectory(Path.GetDirectoryName(existingFilePath) ?? throw new InvalidOperationException());
+        await File.WriteAllTextAsync(existingFilePath, "abc");
+
+        Config config = new()
+        {
+            ShowScrapeSize = false,
+            PostFileNameFormat = "global-custom-name",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new() { PostFileNameFormat = "" }
+            }
+        };
+
+        MediaTrackingDbService dbService = new() { CheckDownloadedResult = false };
+        DownloadService service = CreateService(new FakeConfigService(config), dbService,
+            fileNameService: new DeterministicFileNameService());
+        ProgressRecorder progress = new();
+        PostEntities.PostCollection posts = CreatePostCollection(1, serverFilename);
+
+        DownloadResult result = await service.DownloadFreePosts("creator", 1, folder, new Dictionary<string, long>(),
+            false, false, posts, progress);
+
+        string renamedPath = $"{folder}/Posts/Free/Images/global-custom-name.jpg";
+        Assert.Equal(1, result.TotalCount);
+        Assert.Equal(0, result.NewDownloads);
+        Assert.Equal(1, result.ExistingDownloads);
+        Assert.False(File.Exists(existingFilePath));
+        Assert.True(File.Exists(renamedPath));
+        Assert.NotNull(dbService.LastUpdateMedia);
+        Assert.Equal("global-custom-name.jpg", dbService.LastUpdateMedia.Value.filename);
+        Assert.Equal(1, progress.Total);
+    }
+
+    [Fact]
+    public async Task DownloadFreePosts_UsesCreatorCustomFormatWhenGlobalAndCreatorFormatsAreDefined()
+    {
+        using TempFolder temp = new();
+        string folder = NormalizeFolder(Path.Combine(temp.Path, "creator"));
+        const string serverFilename = "server-name";
+        string existingFilePath = $"{folder}/Posts/Free/Images/{serverFilename}.jpg";
+        Directory.CreateDirectory(Path.GetDirectoryName(existingFilePath) ?? throw new InvalidOperationException());
+        await File.WriteAllTextAsync(existingFilePath, "abc");
+
+        Config config = new()
+        {
+            ShowScrapeSize = false,
+            PostFileNameFormat = "global-custom-name",
+            CreatorConfigs = new Dictionary<string, CreatorConfig>
+            {
+                ["creator"] = new() { PostFileNameFormat = "creator-custom-name" }
+            }
+        };
+
+        MediaTrackingDbService dbService = new() { CheckDownloadedResult = false };
+        DownloadService service = CreateService(new FakeConfigService(config), dbService,
+            fileNameService: new DeterministicFileNameService());
+        ProgressRecorder progress = new();
+        PostEntities.PostCollection posts = CreatePostCollection(1, serverFilename);
+
+        DownloadResult result = await service.DownloadFreePosts("creator", 1, folder, new Dictionary<string, long>(),
+            false, false, posts, progress);
+
+        string renamedPath = $"{folder}/Posts/Free/Images/creator-custom-name.jpg";
+        Assert.Equal(1, result.TotalCount);
+        Assert.Equal(0, result.NewDownloads);
+        Assert.Equal(1, result.ExistingDownloads);
+        Assert.False(File.Exists(existingFilePath));
+        Assert.True(File.Exists(renamedPath));
+        Assert.NotNull(dbService.LastUpdateMedia);
+        Assert.Equal("creator-custom-name.jpg", dbService.LastUpdateMedia.Value.filename);
+        Assert.Equal(1, progress.Total);
+    }
+
+    [Fact]
+    public async Task DownloadPaidPosts_AppliesPaidCustomFormatForDrm_WhenAuthorExistsButFromUserMissing()
+    {
+        using TempFolder temp = new();
+        string folder = NormalizeFolder(Path.Combine(temp.Path, "creator"));
+        const string customName = "paid-custom-name";
+        const string drmBaseFilename = "video-file";
+        string basePath = $"{folder}/Posts/Paid/Videos";
+        Directory.CreateDirectory(basePath);
+        await File.WriteAllTextAsync($"{basePath}/{customName}.mp4", "custom");
+        await File.WriteAllTextAsync($"{basePath}/{drmBaseFilename}_source.mp4", "server");
+
+        Config config = new() { ShowScrapeSize = false, PaidPostFileNameFormat = customName, PostFileNameFormat = "" };
+
+        MediaTrackingDbService dbService = new() { CheckDownloadedResult = false };
+        StaticApiService apiService = new();
+        FakeAuthService authService = new()
+        {
+            CurrentAuth = new Auth { Cookie = "sess=test;", UserAgent = "unit-test-agent" }
+        };
+
+        DownloadService service = CreateService(new FakeConfigService(config), dbService,
+            apiService, new DeterministicFileNameService(), authService);
+        ProgressRecorder progress = new();
+        PurchasedEntities.PaidPostCollection posts = CreatePaidPostCollectionForDrm(1,
+            $"https://cdn3.onlyfans.com/dash/files/{drmBaseFilename}.mpd,policy,signature,kvp,1,2");
+
+        DownloadResult result = await service.DownloadPaidPosts("creator", 1, folder, new Dictionary<string, long>(),
+            false, false, posts, progress);
+
+        Assert.Equal(1, result.TotalCount);
+        Assert.Equal(0, result.NewDownloads);
+        Assert.Equal(1, result.ExistingDownloads);
+        Assert.NotNull(dbService.LastUpdateMedia);
+        Assert.Equal($"{customName}.mp4", dbService.LastUpdateMedia.Value.filename);
+        Assert.Equal(1, progress.Total);
+    }
+
+    private static DownloadService CreateService(FakeConfigService configService, MediaTrackingDbService dbService,
+        StaticApiService? apiService = null, IFileNameService? fileNameService = null,
+        IAuthService? authService = null) =>
+        new(authService ?? new FakeAuthService(), configService, dbService,
+            fileNameService ?? new FakeFileNameService(),
+            apiService ?? new StaticApiService());
+
+    private static PostEntities.PostCollection CreatePostCollection(long mediaId, string serverFilename)
+    {
+        PostEntities.Medium media = new() { Id = mediaId };
+        PostEntities.ListItem post = new()
+        {
+            Id = 10,
+            PostedAt = new DateTime(2024, 1, 1),
+            Author = new OF_DL.Models.Entities.Common.Author { Id = 99 },
+            Media = [media]
+        };
+
+        return new PostEntities.PostCollection
+        {
+            Posts = new Dictionary<long, string> { { mediaId, $"https://example.com/{serverFilename}.jpg" } },
+            PostMedia = [media],
+            PostObjects = [post]
+        };
+    }
+
+    private static PurchasedEntities.PaidPostCollection CreatePaidPostCollectionForDrm(long mediaId, string drmUrl)
+    {
+        MessageEntities.Medium media = new() { Id = mediaId };
+        PurchasedEntities.ListItem post = new()
+        {
+            Id = 20,
+            PostedAt = new DateTime(2024, 1, 1),
+            Author = new OF_DL.Models.Entities.Common.Author { Id = 99 },
+            FromUser = null,
+            Media = [media]
+        };
+
+        return new PurchasedEntities.PaidPostCollection
+        {
+            PaidPosts = new Dictionary<long, string> { { mediaId, drmUrl } },
+            PaidPostMedia = [media],
+            PaidPostObjects = [post]
+        };
+    }
+
+    private static string NormalizeFolder(string folder) => folder.Replace("\\", "/");
+
+    private sealed class DeterministicFileNameService : IFileNameService
+    {
+        public Task<string> BuildFilename(string fileFormat, Dictionary<string, string> values) =>
+            Task.FromResult(fileFormat);
+
+        public Task<Dictionary<string, string>> GetFilename(object info, object media, object author,
+            List<string> selectedProperties, string username, Dictionary<string, long>? users = null) =>
+            Task.FromResult(new Dictionary<string, string>());
+    }
+}

OF DL.Tests/Services/FileNameServiceTestModels.cs

@@ -20,7 +20,7 @@ internal sealed class TestMedia
 
 internal sealed class TestMediaFiles
 {
-    public TestMediaFull Full { get; set; } = new();
+    public TestMediaFull? Full { get; set; } = new();
     public object? Drm { get; set; }
 }
 

OF DL.Tests/Services/FileNameServiceTests.cs

@@ -76,4 +76,24 @@ public class FileNameServiceTests
 
         Assert.Equal("creator_99", result);
     }
+
+    [Fact]
+    public async Task GetFilename_UsesDrmFilenameWhenFullUrlMissing()
+    {
+        TestMedia media = new()
+        {
+            Id = 99,
+            Files = new TestMediaFiles
+            {
+                Full = null,
+                Drm = new { Manifest = new { Dash = "https://cdn.test/drm-name.mpd" } }
+            }
+        };
+        FileNameService service = new(new FakeAuthService());
+
+        Dictionary<string, string> values =
+            await service.GetFilename(new TestInfo(), media, new TestAuthor(), ["filename"], "creator");
+
+        Assert.Equal("drm-name_source", values["filename"]);
+    }
 }