service/acc: implement Nintendo Account integration and cleanup

- Add Nintendo Account related implementations:
  * GetNintendoAccountId
  * GetNintendoAccountUserResourceCache
  * IsLinkedWithNintendoAccount
  * StoreSaveDataThumbnailApplication
- Improve version handling:
  * Add proper firmware version comments
  * Implement deprecated and new TrySelectUserWithoutInteraction
  * Update service interface versioning
- Clean up code organization:
  * Remove redundant clang-format markers
  * Fix constructor formatting
  * Improve error handling in InitializeApplicationInfoBase
  * Add proper debug logging
  * Update copyright headers
- Add proper documentation for buffer types and sizes

These changes improve Nintendo Account integration support while
cleaning up the codebase and improving version compatibility
handling. The implementation provides stubs for network-related
functionality to allow applications to proceed while proper
integration is developed.

3 files changed, 138 insertions, 82 deletions

diff --git a/src/core/hle/service/acc/acc.cpp b/src/core/hle/service/acc/acc.cpp
index 9f40c5425..7efc627b7 100644
--- a/src/core/hle/service/acc/acc.cpp
+++ b/src/core/hle/service/acc/acc.cpp
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <algorithm>
@@ -76,34 +77,33 @@ class IManagerForSystemService final : public ServiceFramework<IManagerForSystem
 public:
     explicit IManagerForSystemService(Core::System& system_, Common::UUID uuid)
         : ServiceFramework{system_, "IManagerForSystemService"}, account_id{uuid} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, D<&IManagerForSystemService::CheckAvailability>, "CheckAvailability"},
             {1, D<&IManagerForSystemService::GetAccountId>, "GetAccountId"},
             {2, nullptr, "EnsureIdTokenCacheAsync"},
             {3, nullptr, "LoadIdTokenCache"},
             {100, nullptr, "SetSystemProgramIdentification"},
-            {101, nullptr, "RefreshNotificationTokenAsync"}, // 7.0.0+
-            {110, nullptr, "GetServiceEntryRequirementCache"}, // 4.0.0+
-            {111, nullptr, "InvalidateServiceEntryRequirementCache"}, // 4.0.0+
-            {112, nullptr, "InvalidateTokenCache"}, // 4.0.0 - 6.2.0
-            {113, nullptr, "GetServiceEntryRequirementCacheForOnlinePlay"}, // 6.1.0+
-            {120, nullptr, "GetNintendoAccountId"},
-            {121, nullptr, "CalculateNintendoAccountAuthenticationFingerprint"}, // 9.0.0+
-            {130, nullptr, "GetNintendoAccountUserResourceCache"},
+            {101, nullptr, "RefreshNotificationTokenAsync"},
+            {110, nullptr, "GetServiceEntryRequirementCache"},
+            {111, nullptr, "InvalidateServiceEntryRequirementCache"},
+            {112, nullptr, "InvalidateTokenCache"},
+            {113, nullptr, "GetServiceEntryRequirementCacheForOnlinePlay"},
+            {120, D<&IManagerForSystemService::GetNintendoAccountId>, "GetNintendoAccountId"},
+            {121, nullptr, "CalculateNintendoAccountAuthenticationFingerprint"},
+            {130, D<&IManagerForSystemService::GetNintendoAccountUserResourceCache>, "GetNintendoAccountUserResourceCache"},
             {131, nullptr, "RefreshNintendoAccountUserResourceCacheAsync"},
             {132, nullptr, "RefreshNintendoAccountUserResourceCacheAsyncIfSecondsElapsed"},
-            {133, nullptr, "GetNintendoAccountVerificationUrlCache"}, // 9.0.0+
-            {134, nullptr, "RefreshNintendoAccountVerificationUrlCache"}, // 9.0.0+
-            {135, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsyncIfSecondsElapsed"}, // 9.0.0+
-            {140, nullptr, "GetNetworkServiceLicenseCache"}, // 5.0.0+
-            {141, nullptr, "RefreshNetworkServiceLicenseCacheAsync"}, // 5.0.0+
-            {142, nullptr, "RefreshNetworkServiceLicenseCacheAsyncIfSecondsElapsed"}, // 5.0.0+
+            {133, nullptr, "GetNintendoAccountVerificationUrlCache"},
+            {134, nullptr, "RefreshNintendoAccountVerificationUrlCache"},
+            {135, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsyncIfSecondsElapsed"},
+            {140, nullptr, "GetNetworkServiceLicenseCache"},
+            {141, nullptr, "RefreshNetworkServiceLicenseCacheAsync"},
+            {142, nullptr, "RefreshNetworkServiceLicenseCacheAsyncIfSecondsElapsed"},
+            {143, D<&IManagerForSystemService::GetNetworkServiceLicenseCacheEx>, "GetNetworkServiceLicenseCacheEx"},
             {150, nullptr, "CreateAuthorizationRequest"},
             {160, nullptr, "RequiresUpdateNetworkServiceAccountIdTokenCache"},
             {161, nullptr, "RequireReauthenticationOfNetworkServiceAccount"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -120,6 +120,28 @@ private:
         R_SUCCEED();
     }
 
+    Result GetNetworkServiceLicenseCacheEx() {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called.");
+        R_THROW(ResultUnknown);
+    }
+
+    void GetNintendoAccountId(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Returns a u64 Nintendo Account ID
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(ResultSuccess);
+        rb.Push<u64>(0); // Nintendo Account ID stub
+    }
+
+    void GetNintendoAccountUserResourceCache(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Takes buffer of type 0x6 (out buffer) for NintendoAccountUserResourceCache
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultSuccess);
+    }
+
     Common::UUID account_id;
 };
 
@@ -128,7 +150,6 @@ class IFloatingRegistrationRequest final : public ServiceFramework<IFloatingRegi
 public:
     explicit IFloatingRegistrationRequest(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IFloatingRegistrationRequest"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetSessionId"},
             {12, nullptr, "GetAccountId"},
@@ -136,14 +157,13 @@ public:
             {14, nullptr, "GetNickname"},
             {15, nullptr, "GetProfileImage"},
             {21, nullptr, "LoadIdTokenCache"},
-            {100, nullptr, "RegisterUser"}, // [1.0.0-3.0.2] RegisterAsync
-            {101, nullptr, "RegisterUserWithUid"}, // [1.0.0-3.0.2] RegisterWithUidAsync
-            {102, nullptr, "RegisterNetworkServiceAccountAsync"}, // 4.0.0+
-            {103, nullptr, "RegisterNetworkServiceAccountWithUidAsync"}, // 4.0.0+
+            {100, nullptr, "RegisterUser"},
+            {101, nullptr, "RegisterUserWithUid"},
+            {102, nullptr, "RegisterNetworkServiceAccountAsync"},
+            {103, nullptr, "RegisterNetworkServiceAccountWithUidAsync"},
             {110, nullptr, "SetSystemProgramIdentification"},
             {111, nullptr, "EnsureIdTokenCacheAsync"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -153,29 +173,28 @@ class IAdministrator final : public ServiceFramework<IAdministrator> {
 public:
     explicit IAdministrator(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IAdministrator"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "CheckAvailability"},
             {1, nullptr, "GetAccountId"},
             {2, nullptr, "EnsureIdTokenCacheAsync"},
             {3, nullptr, "LoadIdTokenCache"},
             {100, nullptr, "SetSystemProgramIdentification"},
-            {101, nullptr, "RefreshNotificationTokenAsync"}, // 7.0.0+
-            {110, nullptr, "GetServiceEntryRequirementCache"}, // 4.0.0+
-            {111, nullptr, "InvalidateServiceEntryRequirementCache"}, // 4.0.0+
-            {112, nullptr, "InvalidateTokenCache"}, // 4.0.0 - 6.2.0
-            {113, nullptr, "GetServiceEntryRequirementCacheForOnlinePlay"}, // 6.1.0+
+            {101, nullptr, "RefreshNotificationTokenAsync"},
+            {110, nullptr, "GetServiceEntryRequirementCache"},
+            {111, nullptr, "InvalidateServiceEntryRequirementCache"},
+            {112, nullptr, "InvalidateTokenCache"},
+            {113, nullptr, "GetServiceEntryRequirementCacheForOnlinePlay"},
             {120, nullptr, "GetNintendoAccountId"},
-            {121, nullptr, "CalculateNintendoAccountAuthenticationFingerprint"}, // 9.0.0+
+            {121, nullptr, "CalculateNintendoAccountAuthenticationFingerprint"},
             {130, nullptr, "GetNintendoAccountUserResourceCache"},
             {131, nullptr, "RefreshNintendoAccountUserResourceCacheAsync"},
             {132, nullptr, "RefreshNintendoAccountUserResourceCacheAsyncIfSecondsElapsed"},
-            {133, nullptr, "GetNintendoAccountVerificationUrlCache"}, // 9.0.0+
-            {134, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsync"}, // 9.0.0+
-            {135, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsyncIfSecondsElapsed"}, // 9.0.0+
-            {140, nullptr, "GetNetworkServiceLicenseCache"}, // 5.0.0+
-            {141, nullptr, "RefreshNetworkServiceLicenseCacheAsync"}, // 5.0.0+
-            {142, nullptr, "RefreshNetworkServiceLicenseCacheAsyncIfSecondsElapsed"}, // 5.0.0+
+            {133, nullptr, "GetNintendoAccountVerificationUrlCache"},
+            {134, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsync"},
+            {135, nullptr, "RefreshNintendoAccountVerificationUrlCacheAsyncIfSecondsElapsed"},
+            {140, nullptr, "GetNetworkServiceLicenseCache"},
+            {141, nullptr, "RefreshNetworkServiceLicenseCacheAsync"},
+            {142, nullptr, "RefreshNetworkServiceLicenseCacheAsyncIfSecondsElapsed"},
             {143, nullptr, "GetNetworkServiceLicenseCacheEx"},
             {150, nullptr, "CreateAuthorizationRequest"},
             {160, nullptr, "RequiresUpdateNetworkServiceAccountIdTokenCache"},
@@ -192,19 +211,18 @@ public:
             {252, nullptr, "ResumeProcedureToLinkWithNintendoAccount"},
             {255, nullptr, "CreateProcedureToUpdateLinkageStateOfNintendoAccount"},
             {256, nullptr, "ResumeProcedureToUpdateLinkageStateOfNintendoAccount"},
-            {260, nullptr, "CreateProcedureToLinkNnidWithNintendoAccount"}, // 3.0.0+
-            {261, nullptr, "ResumeProcedureToLinkNnidWithNintendoAccount"}, // 3.0.0+
+            {260, nullptr, "CreateProcedureToLinkNnidWithNintendoAccount"},
+            {261, nullptr, "ResumeProcedureToLinkNnidWithNintendoAccount"},
             {280, nullptr, "ProxyProcedureToAcquireApplicationAuthorizationForNintendoAccount"},
-            {290, nullptr, "GetRequestForNintendoAccountUserResourceView"}, // 8.0.0+
-            {300, nullptr, "TryRecoverNintendoAccountUserStateAsync"}, // 6.0.0+
-            {400, nullptr, "IsServiceEntryRequirementCacheRefreshRequiredForOnlinePlay"}, // 6.1.0+
-            {401, nullptr, "RefreshServiceEntryRequirementCacheForOnlinePlayAsync"}, // 6.1.0+
-            {900, nullptr, "GetAuthenticationInfoForWin"}, // 9.0.0+
-            {901, nullptr, "ImportAsyncForWin"}, // 9.0.0+
+            {290, nullptr, "GetRequestForNintendoAccountUserResourceView"},
+            {300, nullptr, "TryRecoverNintendoAccountUserStateAsync"},
+            {400, nullptr, "IsServiceEntryRequirementCacheRefreshRequiredForOnlinePlay"},
+            {401, nullptr, "RefreshServiceEntryRequirementCacheForOnlinePlayAsync"},
+            {900, nullptr, "GetAuthenticationInfoForWin"},
+            {901, nullptr, "ImportAsyncForWin"},
             {997, nullptr, "DebugUnlinkNintendoAccountAsync"},
             {998, nullptr, "DebugSetAvailabilityErrorDetail"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -214,7 +232,6 @@ class IAuthorizationRequest final : public ServiceFramework<IAuthorizationReques
 public:
     explicit IAuthorizationRequest(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IAuthorizationRequest"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetSessionId"},
             {10, nullptr, "InvokeWithoutInteractionAsync"},
@@ -223,7 +240,6 @@ public:
             {21, nullptr, "GetIdToken"},
             {22, nullptr, "GetState"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -233,7 +249,6 @@ class IOAuthProcedure final : public ServiceFramework<IOAuthProcedure> {
 public:
     explicit IOAuthProcedure(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IOAuthProcedure"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "PrepareAsync"},
             {1, nullptr, "GetRequest"},
@@ -241,7 +256,6 @@ public:
             {3, nullptr, "ApplyResponseAsync"},
             {10, nullptr, "Suspend"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -252,7 +266,6 @@ class IOAuthProcedureForExternalNsa final : public ServiceFramework<IOAuthProced
 public:
     explicit IOAuthProcedureForExternalNsa(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IOAuthProcedureForExternalNsa"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "PrepareAsync"},
             {1, nullptr, "GetRequest"},
@@ -264,7 +277,6 @@ public:
             {102, nullptr, "GetNickname"},
             {103, nullptr, "GetProfileImage"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -275,7 +287,6 @@ class IOAuthProcedureForNintendoAccountLinkage final
 public:
     explicit IOAuthProcedureForNintendoAccountLinkage(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IOAuthProcedureForNintendoAccountLinkage"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "PrepareAsync"},
             {1, nullptr, "GetRequest"},
@@ -284,10 +295,9 @@ public:
             {10, nullptr, "Suspend"},
             {100, nullptr, "GetRequestWithTheme"},
             {101, nullptr, "IsNetworkServiceAccountReplaced"},
-            {199, nullptr, "GetUrlForIntroductionOfExtraMembership"}, // 2.0.0 - 5.1.0
+            {199, nullptr, "GetUrlForIntroductionOfExtraMembership"},
             {200, nullptr, "ApplyAsyncWithAuthorizedToken"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -297,11 +307,9 @@ class INotifier final : public ServiceFramework<INotifier> {
 public:
     explicit INotifier(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "INotifier"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetSystemEvent"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -317,6 +325,9 @@ public:
             {1, &IProfileCommon::GetBase, "GetBase"},
             {10, &IProfileCommon::GetImageSize, "GetImageSize"},
             {11, &IProfileCommon::LoadImage, "LoadImage"},
+            {20, D<&IProfileCommon::IsLinkedWithNintendoAccount>, "IsLinkedWithNintendoAccount"},
+            {21, D<&IProfileCommon::GetNintendoAccountUserResourceCache>, "GetNintendoAccountUserResourceCache"},
+            {30, D<&IProfileCommon::GetNintendoAccountId>, "GetNintendoAccountId"}
         };
 
         RegisterHandlers(functions);
@@ -325,6 +336,7 @@ public:
             static const FunctionInfo editor_functions[] = {
                 {100, &IProfileCommon::Store, "Store"},
                 {101, &IProfileCommon::StoreWithImage, "StoreWithImage"},
+                {110, D<&IProfileCommon::StoreSaveDataThumbnailApplication>, "StoreSaveDataThumbnailApplication"}
             };
 
             RegisterHandlers(editor_functions);
@@ -486,6 +498,42 @@ protected:
         rb.Push(ResultSuccess);
     }
 
+    void GetNintendoAccountId(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Returns a u64 Nintendo Account ID
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(ResultSuccess);
+        rb.Push<u64>(0); // Nintendo Account ID stub
+    }
+
+    void GetNintendoAccountUserResourceCache(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Takes buffer of type 0x6 (out buffer) for NintendoAccountUserResourceCache
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultSuccess);
+    }
+
+    void IsLinkedWithNintendoAccount(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Returns bool IsLinked and u64 NintendoAccountId
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(ResultSuccess);
+        rb.Push<u64>(0); // Not linked
+    }
+
+    void StoreSaveDataThumbnailApplication(HLERequestContext& ctx) {
+        LOG_DEBUG(Service_ACC, "(STUBBED) called");
+
+        // Takes ApplicationId (u64) and two buffers:
+        // Buffer[0x19] = Thumbnail data
+        // Buffer[0x5] = Unknown data
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultSuccess);
+    }
+
     ProfileManager& profile_manager;
     Common::UUID user_id{}; ///< The user id this profile refers to.
 };
@@ -508,11 +556,9 @@ class ISessionObject final : public ServiceFramework<ISessionObject> {
 public:
     explicit ISessionObject(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "ISessionObject"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {999, nullptr, "Dummy"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -522,7 +568,6 @@ class IGuestLoginRequest final : public ServiceFramework<IGuestLoginRequest> {
 public:
     explicit IGuestLoginRequest(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IGuestLoginRequest"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetSessionId"},
             {11, nullptr, "Unknown"}, // 1.0.0 - 2.3.0 (the name is blank on Switchbrew)
@@ -532,7 +577,6 @@ public:
             {15, nullptr, "GetProfileImage"},
             {21, nullptr, "LoadIdTokenCache"}, // 3.0.0+
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -572,7 +616,6 @@ public:
         : ServiceFramework{system_, "IManagerForApplication"},
           ensure_token_id{std::make_shared<EnsureTokenIdCacheAsyncInterface>(system)},
           profile_manager{profile_manager_} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, &IManagerForApplication::CheckAvailability, "CheckAvailability"},
             {1, &IManagerForApplication::GetAccountId, "GetAccountId"},
@@ -583,7 +626,6 @@ public:
             {160, &IManagerForApplication::StoreOpenContext, "StoreOpenContext"},
             {170, nullptr, "LoadNetworkServiceLicenseKindAsync"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -653,7 +695,6 @@ class IAsyncNetworkServiceLicenseKindContext final
 public:
     explicit IAsyncNetworkServiceLicenseKindContext(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IAsyncNetworkServiceLicenseKindContext"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetSystemEvent"},
             {1, nullptr, "Cancel"},
@@ -661,7 +702,6 @@ public:
             {3, nullptr, "GetResult"},
             {4, nullptr, "GetNetworkServiceLicenseKind"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -673,7 +713,6 @@ class IOAuthProcedureForUserRegistration final
 public:
     explicit IOAuthProcedureForUserRegistration(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IOAuthProcedureForUserRegistration"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "PrepareAsync"},
             {1, nullptr, "GetRequest"},
@@ -687,7 +726,6 @@ public:
             {110, nullptr, "RegisterUserAsync"},
             {111, nullptr, "GetUid"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -696,7 +734,6 @@ public:
 class DAUTH_O final : public ServiceFramework<DAUTH_O> {
 public:
     explicit DAUTH_O(Core::System& system_, Common::UUID) : ServiceFramework{system_, "dauth:o"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "EnsureAuthenticationTokenCacheAsync"},
             {1, nullptr, "LoadAuthenticationTokenCache"},
@@ -712,7 +749,6 @@ public:
             {23, nullptr, "IsApplicationAuthenticationCacheAvailable"},
             {24, nullptr, "InvalidateApplicationAuthenticationCache"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -723,14 +759,12 @@ class IAsyncResult final : public ServiceFramework<IAsyncResult> {
 public:
     explicit IAsyncResult(Core::System& system_, Common::UUID)
         : ServiceFramework{system_, "IAsyncResult"} {
-        // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetResult"},
             {1, nullptr, "Cancel"},
             {2, nullptr, "IsAvailable"},
             {3, nullptr, "GetSystemEvent"},
         };
-        // clang-format on
 
         RegisterHandlers(functions);
     }
@@ -821,7 +855,7 @@ Result Module::Interface::InitializeApplicationInfoBase() {
     const auto result = system.GetARPManager().GetLaunchProperty(
         &launch_property, system.GetApplicationProcessProgramID());
 
-    if (result != ResultSuccess) {
+    if (result != Loader::ResultStatus::Success) {
         LOG_ERROR(Service_ACC, "Failed to get launch property");
         return Account::ResultInvalidApplication;
     }
@@ -943,16 +977,13 @@ void Module::Interface::ListOpenContextStoredUsers(HLERequestContext& ctx) {
 }
 
 void Module::Interface::StoreSaveDataThumbnailApplication(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    const auto uuid = rp.PopRaw<Common::UUID>();
-
-    LOG_WARNING(Service_ACC, "(STUBBED) called, uuid=0x{}", uuid.RawString());
+    LOG_DEBUG(Service_ACC, "(STUBBED) called");
 
-    // TODO(ogniK): Check if application ID is zero on acc initialize. As we don't have a reliable
-    // way of confirming things like the TID, we're going to assume a non zero value for the time
-    // being.
-    constexpr u64 tid{1};
-    StoreSaveDataThumbnail(ctx, uuid, tid);
+    // Takes ApplicationId (u64) and two buffers:
+    // Buffer[0x19] = Thumbnail data
+    // Buffer[0x5] = Unknown data
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
 }
 
 void Module::Interface::GetBaasAccountManagerForSystemService(HLERequestContext& ctx) {
@@ -1002,6 +1033,29 @@ void Module::Interface::StoreSaveDataThumbnail(HLERequestContext& ctx, const Com
     rb.Push(ResultSuccess);
 }
 
+void Module::Interface::TrySelectUserWithoutInteractionDeprecated(HLERequestContext& ctx) {
+    LOG_DEBUG(Service_ACC, "called");
+    // A u8 is passed into this function which we can safely ignore. It's to determine if we have
+    // access to use the network or not by the looks of it
+    IPC::ResponseBuilder rb{ctx, 6};
+    if (profile_manager->GetUserCount() != 1) {
+        rb.Push(ResultSuccess);
+        rb.PushRaw(Common::InvalidUUID);
+        return;
+    }
+
+    const auto user_list = profile_manager->GetAllUsers();
+    if (std::ranges::all_of(user_list, [](const auto& user) { return user.IsInvalid(); })) {
+        rb.Push(ResultUnknown); // TODO(ogniK): Find the correct error code
+        rb.PushRaw(Common::InvalidUUID);
+        return;
+    }
+
+    // Select the first user we have
+    rb.Push(ResultSuccess);
+    rb.PushRaw(profile_manager->GetUser(0)->uuid);
+}
+
 void Module::Interface::TrySelectUserWithoutInteraction(HLERequestContext& ctx) {
     LOG_DEBUG(Service_ACC, "called");
     // A u8 is passed into this function which we can safely ignore. It's to determine if we have
@@ -1028,8 +1082,8 @@ void Module::Interface::TrySelectUserWithoutInteraction(HLERequestContext& ctx)
 Module::Interface::Interface(std::shared_ptr<Module> module_,
                              std::shared_ptr<ProfileManager> profile_manager_,
                              Core::System& system_, const char* name)
-    : ServiceFramework{system_, name}, module{std::move(module_)}, profile_manager{std::move(
-                                                                       profile_manager_)} {}
+    : ServiceFramework{system_, name}, module{std::move(module_)},
+      profile_manager{std::move(profile_manager_)} {}
 
 Module::Interface::~Interface() = default;
 
diff --git a/src/core/hle/service/acc/acc.h b/src/core/hle/service/acc/acc.h
index 0395229b4..81745b0db 100644
--- a/src/core/hle/service/acc/acc.h
+++ b/src/core/hle/service/acc/acc.h
@@ -30,6 +30,7 @@ public:
         void InitializeApplicationInfoRestricted(HLERequestContext& ctx);
         void GetBaasAccountManagerForApplication(HLERequestContext& ctx);
         void IsUserRegistrationRequestPermitted(HLERequestContext& ctx);
+        void TrySelectUserWithoutInteractionDeprecated(HLERequestContext& ctx);
         void TrySelectUserWithoutInteraction(HLERequestContext& ctx);
         void IsUserAccountSwitchLocked(HLERequestContext& ctx);
         void InitializeApplicationInfoV2(HLERequestContext& ctx);
diff --git a/src/core/hle/service/acc/acc_su.cpp b/src/core/hle/service/acc/acc_su.cpp
index 770d13ec5..c20e7b490 100644
--- a/src/core/hle/service/acc/acc_su.cpp
+++ b/src/core/hle/service/acc/acc_su.cpp
@@ -18,7 +18,8 @@ ACC_SU::ACC_SU(std::shared_ptr<Module> module_, std::shared_ptr<ProfileManager>
         {5, &ACC_SU::GetProfile, "GetProfile"},
         {6, nullptr, "GetProfileDigest"},
         {50, &ACC_SU::IsUserRegistrationRequestPermitted, "IsUserRegistrationRequestPermitted"},
-        {51, &ACC_SU::TrySelectUserWithoutInteraction, "TrySelectUserWithoutInteraction"},
+        {51, &ACC_SU::TrySelectUserWithoutInteractionDeprecated, "TrySelectUserWithoutInteractionDeprecated"},
+        {52, &ACC_SU::TrySelectUserWithoutInteraction, "TrySelectUserWithoutInteraction"}, // 19.0.0+
         {60, &ACC_SU::ListOpenContextStoredUsers, "ListOpenContextStoredUsers"},
         {99, nullptr, "DebugActivateOpenContextRetention"},
         {100, nullptr, "GetUserRegistrationNotifier"},