Implemented complete oauth2 flow with modular providers

The local oauth2 provider still needs A LOT of love. But the general oauth2 workflow works. The http api client needs an option to disable the authentication things and we need to switch to the local storage for storing access, refresh and timestamp for the client

Moonlight.ApiServer/Http/Controllers/OAuth2/OAuth2Controller.cs

@@ -7,6 +7,7 @@ using MoonCore.Services;
 using Moonlight.ApiServer.Configuration;
 using Moonlight.ApiServer.Database.Entities;
 using Moonlight.ApiServer.Services;
+using Moonlight.Shared.Http.Responses.OAuth2;
 
 namespace Moonlight.ApiServer.Http.Controllers.OAuth2;
 
@@ -88,7 +89,7 @@ public class OAuth2Controller : Controller
         [FromForm(Name = "redirect_uri")] string redirectUri,
         [FromForm(Name = "grant_type")] string grantType,
         [FromForm(Name = "code")] string code
-        )
+    )
     {
         if (grantType != "authorization_code")
             throw new HttpApiException("Invalid grant type", 400);
@@ -106,14 +107,56 @@ public class OAuth2Controller : Controller
             user = UserRepository.Get().FirstOrDefault(x => x.Id == userId);
 
             return user != null;
-        }, data =>
-        {
-            data.Add("userId", user!.Id.ToString());
-        });
+        }, data => { data.Add("userId", user!.Id.ToString()); });
 
         if (access == null)
             throw new HttpApiException("Unable to validate access", 400);
 
         return access;
     }
+
+    [HttpGet("info")]
+    public async Task<InfoResponse> Info()
+    {
+        if (!Request.Headers.ContainsKey("Authorization"))
+            throw new HttpApiException("Authorization header is missing", 400);
+
+        var authHeader = Request.Headers["Authorization"].First() ?? "";
+
+        if (string.IsNullOrEmpty(authHeader))
+            throw new HttpApiException("Authorization header is missing", 400);
+
+        User? currentUser = null;
+        
+        var isValid = await OAuth2Service.IsValidAccessToken(
+            authHeader,
+            data =>
+            {
+                // Check if the userId is present in the access token
+                if (!data.TryGetValue("userId", out var userIdStr) || !int.TryParse(userIdStr, out var userId))
+                    return false;
+
+                currentUser = UserRepository
+                    .Get()
+                    .FirstOrDefault(x => x.Id == userId);
+
+                if (currentUser == null)
+                    return false;
+
+                return true;
+            }
+        );
+
+        if (!isValid)
+            throw new HttpApiException("Invalid access token", 401);
+        
+        if(currentUser == null)
+            throw new HttpApiException("Invalid access token", 401);
+
+        return new InfoResponse()
+        {
+            Username = currentUser.Username,
+            Email = currentUser.Email
+        };
+    }
 }