feat: remove auth method

Foxnouns.Backend/Controllers/Authentication/AuthController.cs

@@ -1,3 +1,4 @@
+using System.Net;
 using System.Web;
 using Foxnouns.Backend.Database;
 using Foxnouns.Backend.Database.Models;
@@ -15,7 +16,7 @@ namespace Foxnouns.Backend.Controllers.Authentication;
 public class AuthController(
     Config config,
     DatabaseContext db,
-    KeyCacheService keyCache,
+    KeyCacheService keyCacheService,
     ILogger logger
 ) : ApiControllerBase
 {
@@ -31,7 +32,7 @@ public class AuthController(
             config.GoogleAuth.Enabled,
             config.TumblrAuth.Enabled
         );
-        var state = HttpUtility.UrlEncode(await keyCache.GenerateAuthStateAsync(ct));
+        var state = HttpUtility.UrlEncode(await keyCacheService.GenerateAuthStateAsync(ct));
         string? discord = null;
         if (config.DiscordAuth is { ClientId: not null, ClientSecret: not null })
             discord =
@@ -75,6 +76,52 @@ public class AuthController(
 
         return NoContent();
     }
+
+    [HttpGet("methods/{id}")]
+    [Authorize("*")]
+    [ProducesResponseType<UserRendererService.AuthMethodResponse>(
+        statusCode: StatusCodes.Status200OK
+    )]
+    public async Task<IActionResult> GetAuthMethodAsync(Snowflake id)
+    {
+        var authMethod = await db
+            .AuthMethods.Include(a => a.FediverseApplication)
+            .FirstOrDefaultAsync(a => a.UserId == CurrentUser!.Id && a.Id == id);
+        if (authMethod == null)
+            throw new ApiError.NotFound("No authentication method with that ID found.");
+
+        return Ok(UserRendererService.RenderAuthMethod(authMethod));
+    }
+
+    [HttpDelete("methods/{id}")]
+    [Authorize("*")]
+    public async Task<IActionResult> DeleteAuthMethodAsync(Snowflake id)
+    {
+        var authMethods = await db
+            .AuthMethods.Where(a => a.UserId == CurrentUser!.Id)
+            .ToListAsync();
+        if (authMethods.Count < 2)
+            throw new ApiError(
+                "You cannot remove your last authentication method.",
+                HttpStatusCode.BadRequest,
+                ErrorCode.LastAuthMethod
+            );
+
+        var authMethod = authMethods.FirstOrDefault(a => a.Id == id);
+        if (authMethod == null)
+            throw new ApiError.NotFound("No authentication method with that ID found.");
+
+        _logger.Debug(
+            "Deleting auth method {AuthMethodId} for user {UserId}",
+            authMethod.Id,
+            CurrentUser!.Id
+        );
+
+        db.Remove(authMethod);
+        await db.SaveChangesAsync();
+
+        return NoContent();
+    }
 }
 
 public record CallbackResponse(

Foxnouns.Backend/ExpectedError.cs

@@ -148,6 +148,7 @@ public enum ErrorCode
     UserNotFound,
     MemberNotFound,
     AccountAlreadyLinked,
+    LastAuthMethod,
 }
 
 public class ValidationError

Foxnouns.Backend/Services/UserRendererService.cs

@@ -67,22 +67,23 @@ public class UserRendererService(
             renderMembers
                 ? members.Select(m => memberRenderer.RenderPartialMember(m, tokenHidden))
                 : null,
-            renderAuthMethods
-                ? authMethods.Select(a => new AuthenticationMethodResponse(
-                    a.Id,
-                    a.AuthType,
-                    a.RemoteId,
-                    a.FediverseApplication != null
-                        ? $"@{a.RemoteUsername}@{a.FediverseApplication.Domain}"
-                        : a.RemoteUsername
-                ))
-                : null,
+            renderAuthMethods ? authMethods.Select(RenderAuthMethod) : null,
             tokenHidden ? user.ListHidden : null,
             tokenHidden ? user.LastActive : null,
             tokenHidden ? user.LastSidReroll : null
         );
     }
 
+    public static AuthMethodResponse RenderAuthMethod(AuthMethod a) =>
+        new(
+            a.Id,
+            a.AuthType,
+            a.RemoteId,
+            a.FediverseApplication != null
+                ? $"@{a.RemoteUsername}@{a.FediverseApplication.Domain}"
+                : a.RemoteUsername
+        );
+
     public PartialUser RenderPartialUser(User user) =>
         new(
             user.Id,
@@ -118,7 +119,7 @@ public class UserRendererService(
         [property: JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
             IEnumerable<MemberRendererService.PartialMember>? Members,
         [property: JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
-            IEnumerable<AuthenticationMethodResponse>? AuthMethods,
+            IEnumerable<AuthMethodResponse>? AuthMethods,
         [property: JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
             bool? MemberListHidden,
         [property: JsonProperty(NullValueHandling = NullValueHandling.Ignore)] Instant? LastActive,
@@ -126,7 +127,7 @@ public class UserRendererService(
             Instant? LastSidReroll
     );
 
-    public record AuthenticationMethodResponse(
+    public record AuthMethodResponse(
         Snowflake Id,
         [property: JsonConverter(typeof(ScreamingSnakeCaseEnumConverter))] AuthType Type,
         string RemoteId,