Initial commit

Infrastructure/Auth/SessionTokenCredential.cs

@@ -0,0 +1,25 @@
+using Azure.Core;
+using SharepointToolbox.Web.Services;
+
+namespace SharepointToolbox.Web.Infrastructure.Auth;
+
+/// <summary>
+/// TokenCredential backed by the circuit's ISessionManager.
+/// Lets GraphServiceClient call GetTokenAsync transparently using our refresh-token flow.
+/// </summary>
+public class SessionTokenCredential : TokenCredential
+{
+    private readonly ISessionManager _sessionManager;
+
+    public SessionTokenCredential(ISessionManager sessionManager) { _sessionManager = sessionManager; }
+
+    public override async ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken ct)
+    {
+        var scope = requestContext.Scopes.FirstOrDefault() ?? "https://graph.microsoft.com/.default";
+        var (token, expiresAt) = await _sessionManager.GetAccessTokenWithExpiryAsync(scope, ct);
+        return new AccessToken(token, expiresAt);
+    }
+
+    public override AccessToken GetToken(TokenRequestContext requestContext, CancellationToken ct)
+        => GetTokenAsync(requestContext, ct).AsTask().GetAwaiter().GetResult();
+}