From 14d73851eaa23cbe9eb2adfa5e2e56ab8a603e6a Mon Sep 17 00:00:00 2001
From: Oliver Booth <git@olivr.me>
Date: Sat, 24 Feb 2024 15:37:39 +0000
Subject: [PATCH] refactor: delegate cookie writing to SessionService

---
 OliverBooth/Controllers/AdminController.cs |  4 +---
 OliverBooth/Services/ISessionService.cs    | 12 ++++++++++++
 OliverBooth/Services/SessionService.cs     | 14 ++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/OliverBooth/Controllers/AdminController.cs b/OliverBooth/Controllers/AdminController.cs
index 3040604..5fb65dd 100644
--- a/OliverBooth/Controllers/AdminController.cs
+++ b/OliverBooth/Controllers/AdminController.cs
@@ -60,9 +60,7 @@ public sealed class AdminController : ControllerBase
         }
 
         ISession session = _sessionService.CreateSession(Request, user);
-        Span<byte> sessionBytes = stackalloc byte[16];
-        session.Id.TryWriteBytes(sessionBytes);
-        Response.Cookies.Append("sid", Convert.ToBase64String(sessionBytes));
+        _sessionService.SaveSessionCookie(Response, session);
         return RedirectToPage("/admin/index");
     }
 
diff --git a/OliverBooth/Services/ISessionService.cs b/OliverBooth/Services/ISessionService.cs
index becaf5a..e40d56d 100644
--- a/OliverBooth/Services/ISessionService.cs
+++ b/OliverBooth/Services/ISessionService.cs
@@ -27,6 +27,18 @@ public interface ISessionService
     /// <exception cref="ArgumentNullException"><paramref name="session" /> is <see langword="null" />.</exception>
     void DeleteSession(ISession session);
 
+    /// <summary>
+    ///     Saves a session cookie to the client's browser.
+    /// </summary>
+    /// <param name="response">The response to edit.</param>
+    /// <param name="session">The session to write.</param>
+    /// <exception cref="ArgumentNullException">
+    ///     <para><paramref name="request" /> is <see langword="null" />.</para>
+    ///     -or-
+    ///     <para><paramref name="session" /> is <see langword="null" />.</para>
+    /// </exception>
+    void SaveSessionCookie(HttpResponse response, ISession session);
+    
     /// <summary>
     ///     Attempts to find a session with the specified ID.
     /// </summary>
diff --git a/OliverBooth/Services/SessionService.cs b/OliverBooth/Services/SessionService.cs
index e33b9aa..bd19a9d 100644
--- a/OliverBooth/Services/SessionService.cs
+++ b/OliverBooth/Services/SessionService.cs
@@ -63,6 +63,20 @@ internal sealed class SessionService : ISessionService
         context.SaveChanges();
     }
 
+    /// <inheritdoc />
+    public void SaveSessionCookie(HttpResponse response, ISession session)
+    {
+        if (response is null) throw new ArgumentNullException(nameof(response));
+        if (session is null) throw new ArgumentNullException(nameof(session));
+
+        Span<byte> buffer = stackalloc byte[16];
+        if (!session.Id.TryWriteBytes(buffer)) return;
+
+        IPAddress? remoteIpAddress = response.HttpContext.Connection.RemoteIpAddress;
+        _logger.LogDebug("Writing cookie 'sid' to HTTP response for {RemoteAddr}", remoteIpAddress);
+        response.Cookies.Append("sid", Convert.ToBase64String(buffer));
+    }
+
     /// <inheritdoc />
     public bool TryGetSession(Guid sessionId, [NotNullWhen(true)] out ISession? session)
     {