repo(viewer): add UDID lookup, anonymous register, Steam link helpers

Extracts the default-loadout body into a private BuildDefaultViewer
helper shared by the existing Steam-import path and a new
RegisterAnonymousViewer for /tool/signup. LinkSteamToViewer is the
seam SteamSessionAuthenticationHandler will call on first-Steam-touch
of a UDID-keyed viewer.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.Database/Repositories/Viewer/IViewerRepository.cs

@@ -7,7 +7,10 @@ public interface IViewerRepository
     Task<Models.Viewer?> GetViewerBySocialConnection(SocialAccountType accountType, ulong socialId);
     Task<Models.Viewer?> GetViewerWithSocials(long id);
     Task<Models.Viewer?> GetViewerByShortUdid(long shortUdid);
+    Task<Models.Viewer?> GetViewerByUdid(Guid udid);
 
     Task<Models.Viewer> RegisterViewer(string displayName, SocialAccountType socialType,
         ulong socialAccountIdentifier, ulong? shortUdid = null);
+    Task<Models.Viewer> RegisterAnonymousViewer(Guid udid);
+    Task LinkSteamToViewer(long viewerId, ulong steamId);
 }

SVSim.Database/Repositories/Viewer/ViewerRepository.cs

@@ -70,6 +70,58 @@ public class ViewerRepository : IViewerRepository
 
     public async Task<Models.Viewer> RegisterViewer(string displayName, SocialAccountType socialType,
         ulong socialAccountIdentifier, ulong? shortUdid = null)
+    {
+        var viewer = await BuildDefaultViewer(displayName);
+        viewer.SocialAccountConnections.Add(new SocialAccountConnection
+        {
+            AccountId = socialAccountIdentifier,
+            AccountType = socialType
+        });
+        _dbContext.Set<Models.Viewer>().Add(viewer);
+        await _dbContext.SaveChangesAsync();
+        return viewer;
+    }
+
+    public async Task<Models.Viewer?> GetViewerByUdid(Guid udid)
+    {
+        if (udid == Guid.Empty) return null;
+        return await _dbContext.Set<Models.Viewer>()
+            .AsNoTracking()
+            .FirstOrDefaultAsync(v => v.Udid == udid);
+    }
+
+    public async Task<Models.Viewer> RegisterAnonymousViewer(Guid udid)
+    {
+        if (udid == Guid.Empty)
+            throw new InvalidOperationException("Cannot register viewer for empty UDID.");
+
+        var viewer = await BuildDefaultViewer("Player");
+        viewer.Udid = udid;
+        _dbContext.Set<Models.Viewer>().Add(viewer);
+        await _dbContext.SaveChangesAsync();
+        return viewer;
+    }
+
+    public async Task LinkSteamToViewer(long viewerId, ulong steamId)
+    {
+        var viewer = await _dbContext.Set<Models.Viewer>()
+            .Include(v => v.SocialAccountConnections)
+            .FirstOrDefaultAsync(v => v.Id == viewerId)
+            ?? throw new InvalidOperationException($"Viewer {viewerId} not found for Steam link.");
+
+        bool alreadyLinked = viewer.SocialAccountConnections.Any(sac =>
+            sac.AccountType == SocialAccountType.Steam && sac.AccountId == steamId);
+        if (alreadyLinked) return;
+
+        viewer.SocialAccountConnections.Add(new SocialAccountConnection
+        {
+            AccountId = steamId,
+            AccountType = SocialAccountType.Steam
+        });
+        await _dbContext.SaveChangesAsync();
+    }
+
+    private async Task<Models.Viewer> BuildDefaultViewer(string displayName)
     {
         Models.Viewer viewer = new Models.Viewer
         {
@@ -79,12 +131,6 @@ public class ViewerRepository : IViewerRepository
         var grants = _config.Get<DefaultGrantsConfig>();
         var loadout = _config.Get<DefaultLoadoutConfig>();
 
-        viewer.SocialAccountConnections.Add(new SocialAccountConnection
-        {
-            AccountId = socialAccountIdentifier,
-            AccountType = socialType
-        });
-
         viewer.Info.MaxFriends = player.MaxFriends;
         viewer.Info.CountryCode = "KOR";
         viewer.Info.BirthDate = DateTime.UtcNow;
@@ -124,8 +170,6 @@ public class ViewerRepository : IViewerRepository
         if (defaultEmblem is not null) viewer.Emblems.Add(defaultEmblem);
         if (defaultBg is not null) viewer.MyPageBackgrounds.Add(defaultBg);
 
-        // Grant one of each class's default leader skin. Filter out the synthetic placeholders
-        // (Id=0) and dedupe — skins are many-to-many via SleeveEntryViewer-style join.
         var grantedSkins = viewer.Classes
             .Select(vcd => vcd.LeaderSkin)
             .Where(s => s.Id != 0)
@@ -133,8 +177,6 @@ public class ViewerRepository : IViewerRepository
             .ToList();
         viewer.LeaderSkins.AddRange(grantedSkins);
 
-        _dbContext.Set<Models.Viewer>().Add(viewer);
-        await _dbContext.SaveChangesAsync();
         return viewer;
     }
 }

SVSim.UnitTests/Repositories/ViewerRepositoryTests.cs

@@ -71,4 +71,99 @@ public class ViewerRepositoryTests
         Assert.That(viewer.LeaderSkins, Is.Not.Empty,
             "Viewer should own at least one leader skin from class defaults.");
     }
+
+    [Test]
+    public async Task RegisterAnonymousViewer_creates_viewer_with_udid_and_no_socials()
+    {
+        using var factory = new SVSimTestFactory();
+        var udid = Guid.NewGuid();
+
+        long viewerId;
+        using (var scope = factory.Services.CreateScope())
+        {
+            var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+            var v = await repo.RegisterAnonymousViewer(udid);
+            viewerId = v.Id;
+        }
+
+        using var verifyScope = factory.Services.CreateScope();
+        var db = verifyScope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var loaded = await db.Viewers
+            .Include(v => v.Classes)
+            .Include(v => v.SocialAccountConnections)
+            .FirstAsync(v => v.Id == viewerId);
+
+        Assert.That(loaded.Udid, Is.EqualTo(udid));
+        Assert.That(loaded.SocialAccountConnections, Is.Empty);
+        Assert.That(loaded.Classes, Is.Not.Empty,
+            "Default-loadout body should populate Classes (smoke-test the shared BuildDefaultViewer helper).");
+    }
+
+    [Test]
+    public async Task RegisterAnonymousViewer_with_empty_udid_throws()
+    {
+        using var factory = new SVSimTestFactory();
+        using var scope = factory.Services.CreateScope();
+        var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+
+        Assert.ThrowsAsync<InvalidOperationException>(async () =>
+            await repo.RegisterAnonymousViewer(Guid.Empty));
+    }
+
+    [Test]
+    public async Task GetViewerByUdid_returns_viewer_or_null()
+    {
+        using var factory = new SVSimTestFactory();
+        var udid = Guid.NewGuid();
+
+        long createdId;
+        using (var scope = factory.Services.CreateScope())
+        {
+            var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+            createdId = (await repo.RegisterAnonymousViewer(udid)).Id;
+        }
+
+        using (var scope = factory.Services.CreateScope())
+        {
+            var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+            var hit = await repo.GetViewerByUdid(udid);
+            var miss = await repo.GetViewerByUdid(Guid.NewGuid());
+
+            Assert.That(hit, Is.Not.Null);
+            Assert.That(hit!.Id, Is.EqualTo(createdId));
+            Assert.That(miss, Is.Null);
+        }
+    }
+
+    [Test]
+    public async Task LinkSteamToViewer_appends_steam_social_connection()
+    {
+        using var factory = new SVSimTestFactory();
+        var udid = Guid.NewGuid();
+        const ulong steamId = 76_561_198_900_000_001UL;
+
+        long viewerId;
+        using (var scope = factory.Services.CreateScope())
+        {
+            var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+            viewerId = (await repo.RegisterAnonymousViewer(udid)).Id;
+        }
+
+        using (var scope = factory.Services.CreateScope())
+        {
+            var repo = scope.ServiceProvider.GetRequiredService<IViewerRepository>();
+            await repo.LinkSteamToViewer(viewerId, steamId);
+        }
+
+        using var verifyScope = factory.Services.CreateScope();
+        var db = verifyScope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+        var loaded = await db.Viewers
+            .Include(v => v.SocialAccountConnections)
+            .FirstAsync(v => v.Id == viewerId);
+
+        Assert.That(loaded.SocialAccountConnections, Has.Count.EqualTo(1));
+        Assert.That(loaded.SocialAccountConnections[0].AccountType,
+            Is.EqualTo(SocialAccountType.Steam));
+        Assert.That(loaded.SocialAccountConnections[0].AccountId, Is.EqualTo(steamId));
+    }
 }