libvirtualhid/tests/fixtures/windows_backend_test_hooks.cpp

/**
 * @file tests/fixtures/windows_backend_test_hooks.cpp
 * @brief Windows backend test hook definitions.
 */

// local includes
#include "fixtures/windows_backend_test_hooks.hpp"

// lib includes
#include <lizardbyte/common/env.h>

#define create_platform_backend create_platform_backend_for_windows_backend_test_hooks
#include "../../src/platform/windows/windows_backend.cpp"
#undef create_platform_backend

// standard includes
#include <bit>

namespace lvh::detail {
  namespace {

    class FakeWindowsControlChannelState {
    public:
      FakeWindowsControlChannelState() = default;

      FakeWindowsControlChannelState(std::string path, std::string response_device_path):
          path_ {std::move(path)},
          response_device_path_ {std::move(response_device_path)} {}

      const std::string &path() const {
        return path_;
      }

      void set_create_transport_status(OperationStatus status) {
        std::lock_guard lock {mutex_};
        create_transport_status_ = std::move(status);
      }

      void set_create_protocol_status(std::uint32_t status) {
        std::lock_guard lock {mutex_};
        create_protocol_status_ = status;
      }

      OperationStatus create_device(
        const LvhWindowsCreateDeviceRequest &request,
        LvhWindowsCreateDeviceResponse &response
      ) {
        std::lock_guard lock {mutex_};
        create_requests_.push_back(request);
        if (!create_transport_status_.ok()) {
          return create_transport_status_;
        }

        response.version = LVH_WINDOWS_CONTROL_PROTOCOL_VERSION;
        response.size = sizeof(response);
        response.status = create_protocol_status_;
        response.driver_device_id = next_driver_id_++;
        response.session_token = session_token_;
        windows::copy_string(response.device_path, response_device_path_);
        if (response.status == LVH_WINDOWS_STATUS_SUCCESS && request.device_type == LVH_WINDOWS_DEVICE_GAMEPAD && request.gamepad_kind == LVH_WINDOWS_GAMEPAD_XBOX_360) {
          response.transport_handle = reinterpret_cast<std::uintptr_t>(
            ::CreateEventW(nullptr, TRUE, FALSE, nullptr)
          );
        }
        return protocol_status(response.status, "Windows driver rejected virtual HID device creation");
      }

      OperationStatus destroy_device(
        std::uint64_t driver_device_id,
        const LvhWindowsSessionToken &session_token
      ) {
        std::lock_guard lock {mutex_};
        if (!session_token_matches(session_token)) {
          return OperationStatus::failure(ErrorCode::backend_failure, "unexpected destroy session token");
        }
        destroyed_ids_.push_back(driver_device_id);
        return destroy_status_;
      }

      OperationStatus submit_input_report(
        const LvhWindowsSessionToken &session_token,
        const std::vector<std::uint8_t> &report
      ) {
        using enum ErrorCode;

        if (report.size() > LVH_WINDOWS_MAX_INPUT_REPORT_SIZE) {
          return OperationStatus::failure(invalid_argument, "input report exceeds Windows control protocol limit");
        }

        std::lock_guard lock {mutex_};
        if (!session_token_matches(session_token)) {
          return OperationStatus::failure(backend_failure, "unexpected submit session token");
        }
        submit_reports_.push_back(report);
        return submit_status_;
      }

      std::optional<LvhWindowsOutputReportEvent> pop_output_event() {
        std::lock_guard lock {mutex_};
        if (output_events_.empty()) {
          return std::nullopt;
        }

        auto event = output_events_.front();
        output_events_.erase(output_events_.begin());
        return event;
      }

      bool output_events_empty() const {
        std::lock_guard lock {mutex_};
        return output_events_.empty();
      }

      std::uint64_t last_created_driver_id() const {
        std::lock_guard lock {mutex_};
        return next_driver_id_ - 1U;
      }

      void enqueue_output_event(const LvhWindowsOutputReportEvent &event) {
        std::lock_guard lock {mutex_};
        output_events_.push_back(event);
      }

      std::size_t create_request_count() const {
        std::lock_guard lock {mutex_};
        return create_requests_.size();
      }

      std::size_t submit_report_count() const {
        std::lock_guard lock {mutex_};
        return submit_reports_.size();
      }

      std::size_t destroy_request_count() const {
        std::lock_guard lock {mutex_};
        return destroyed_ids_.size();
      }

      std::vector<LvhWindowsCreateDeviceRequest> create_requests() const {
        std::lock_guard lock {mutex_};
        return create_requests_;
      }

      std::vector<std::vector<std::uint8_t>> submit_reports() const {
        std::lock_guard lock {mutex_};
        return submit_reports_;
      }

    private:
      bool session_token_matches(const LvhWindowsSessionToken &session_token) const {
        return std::ranges::equal(session_token.bytes, session_token_.bytes);
      }

      static LvhWindowsSessionToken make_session_token() {
        LvhWindowsSessionToken session_token {};
        for (std::uint8_t index = 0; index < LVH_WINDOWS_SESSION_TOKEN_SIZE; ++index) {
          session_token.bytes[index] = static_cast<std::uint8_t>(0x10U + index);
        }

        return session_token;
      }

      mutable std::mutex mutex_;
      std::string path_ = R"(\\.\LibVirtualHid)";
      std::string response_device_path_ = R"(\\.\LibVirtualHid#100)";
      std::uint64_t next_driver_id_ = 100;
      LvhWindowsSessionToken session_token_ = make_session_token();
      OperationStatus create_transport_status_ = OperationStatus::success();
      std::uint32_t create_protocol_status_ = LVH_WINDOWS_STATUS_SUCCESS;
      OperationStatus submit_status_ = OperationStatus::success();
      OperationStatus destroy_status_ = OperationStatus::success();
      std::vector<LvhWindowsCreateDeviceRequest> create_requests_;
      std::vector<std::vector<std::uint8_t>> submit_reports_;
      std::vector<std::uint64_t> destroyed_ids_;
      std::vector<LvhWindowsOutputReportEvent> output_events_;
    };

    class FakeWindowsControlChannel final: public WindowsControlChannel {
    public:
      explicit FakeWindowsControlChannel(std::shared_ptr<FakeWindowsControlChannelState> state):
          state_ {std::move(state)} {}

      const std::string &path() const override {
        return state_->path();
      }

      OperationStatus create_device(
        const LvhWindowsCreateDeviceRequest &request,
        LvhWindowsCreateDeviceResponse &response
      ) const override {
        return state_->create_device(request, response);
      }

      OperationStatus destroy_device(
        std::uint64_t driver_device_id,
        const LvhWindowsSessionToken &session_token
      ) const override {
        return state_->destroy_device(driver_device_id, session_token);
      }

      OperationStatus submit_input_report(
        std::uint64_t /*driver_device_id*/,
        const LvhWindowsSessionToken &session_token,
        const std::vector<std::uint8_t> &report
      ) const override {
        return state_->submit_input_report(session_token, report);
      }

      std::optional<LvhWindowsOutputReportEvent> read_output_report(HANDLE stop_event) const override {
        if (auto event = state_->pop_output_event(); event.has_value()) {
          return event;
        }

        static_cast<void>(::WaitForSingleObject(stop_event, 1U));
        return std::nullopt;
      }

    private:
      std::shared_ptr<FakeWindowsControlChannelState> state_;
    };

    std::unique_ptr<WindowsBackend> make_fake_windows_backend(
      std::shared_ptr<FakeWindowsControlChannelState> command_state,
      std::shared_ptr<FakeWindowsControlChannelState> event_state
    ) {
      return std::make_unique<WindowsBackend>(
        std::make_unique<FakeWindowsControlChannel>(std::move(command_state)),
        std::make_unique<FakeWindowsControlChannel>(std::move(event_state))
      );
    }

    template<typename Predicate>
    bool wait_until(Predicate predicate) {
      const auto deadline = std::chrono::steady_clock::now() + std::chrono::milliseconds {250};
      while (std::chrono::steady_clock::now() < deadline) {
        if (predicate()) {
          return true;
        }

        std::this_thread::sleep_for(std::chrono::milliseconds {1});
      }

      return predicate();
    }

    void wait_for_output_events_to_drain(const std::shared_ptr<FakeWindowsControlChannelState> &state) {
      static_cast<void>(wait_until([&state] {
        return state->output_events_empty();
      }));
    }

    std::uint64_t last_created_driver_id(const std::shared_ptr<FakeWindowsControlChannelState> &state) {
      return state->last_created_driver_id();
    }

    void capture_created_hid_device(
      const std::shared_ptr<FakeWindowsControlChannelState> &state,
      test::WindowsHidCreatedDevice &device
    ) {
      const auto requests = state->create_requests();
      if (requests.empty()) {
        return;
      }

      const auto &request = requests.front();
      device.device_type = request.device_type;
      device.bus_type = request.bus_type;
      device.flags = request.flags;
      device.vendor_id = request.hardware_ids.vendor_id;
      device.product_id = request.hardware_ids.product_id;
      device.version = request.hardware_ids.device_version;
      device.report_id = request.hardware_ids.report_id;
      device.input_report_size = request.report_sizes.input_report_size;
      device.output_report_size = request.report_sizes.output_report_size;
      device.name = request.name.data();
      device.manufacturer = request.manufacturer.data();
      device.stable_id = request.stable_id.data();
    }

    void enqueue_output_report(
      const std::shared_ptr<FakeWindowsControlChannelState> &state,
      std::uint64_t driver_id,
      const DeviceProfile &profile
    ) {
      LvhWindowsOutputReportEvent event {};
      event.version = LVH_WINDOWS_CONTROL_PROTOCOL_VERSION;
      event.size = sizeof(event);
      event.driver_device_id = driver_id;
      event.report_size = static_cast<std::uint32_t>(profile.output_report_size);
      if (profile.gamepad_kind == GamepadProfileKind::xbox_one || profile.gamepad_kind == GamepadProfileKind::xbox_series) {
        event.report[0] = 0x03;
        event.report[3] = 75;
        event.report[4] = 100;
        event.report[5] = 10;
      } else {
        event.report[0] = profile.report_id;
        event.report[1] = 0x78;
        event.report[2] = 0x56;
        event.report[3] = 0x34;
        event.report[4] = 0x12;
      }

      state->enqueue_output_event(event);
    }

    OperationStatus create_gamepad_with_protocol_status(std::uint32_t protocol_status_code) {
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      command_state->set_create_protocol_status(protocol_status_code);
      auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

      CreateGamepadOptions options;
      options.profile = profiles::xbox_series();
      return backend->create_gamepad(1, options).status;
    }

    struct FakeSendInputState {
      std::vector<test::WindowsSendInputRecord> sent_inputs;
      std::optional<UINT> forced_sent_count;
    };

    test::WindowsSendInputRecord make_send_input_record(const INPUT &input) {
      test::WindowsSendInputRecord record;
      record.type = input.type;
      if (input.type == INPUT_KEYBOARD) {
        record.virtual_key = input.ki.wVk;
        record.scan_code = input.ki.wScan;
        record.key_flags = input.ki.dwFlags;
      } else if (input.type == INPUT_MOUSE) {
        record.mouse_x = input.mi.dx;
        record.mouse_y = input.mi.dy;
        record.mouse_data = input.mi.mouseData;
        record.mouse_flags = input.mi.dwFlags;
      }

      return record;
    }

    UINT fake_send_input(FakeSendInputState &state, std::span<INPUT> inputs) {
      for (const auto &input : inputs) {
        state.sent_inputs.push_back(make_send_input_record(input));
      }

      if (state.forced_sent_count.has_value()) {
        ::SetLastError(ERROR_ACCESS_DENIED);
        return *state.forced_sent_count;
      }

      return static_cast<UINT>(inputs.size());
    }

    class ScopedFakeSendInput {
    public:
      explicit ScopedFakeSendInput(FakeSendInputState &state) {
        previous_function_ = send_input_function();
        previous_sync_function_ = sync_thread_desktop_function();
        send_input_function() = [&state](std::span<INPUT> inputs) {
          return fake_send_input(state, inputs);
        };
        sync_thread_desktop_function() = [] {
          return static_cast<HDESK>(nullptr);
        };
      }

      ScopedFakeSendInput(const ScopedFakeSendInput &) = delete;
      ScopedFakeSendInput &operator=(const ScopedFakeSendInput &) = delete;
      ScopedFakeSendInput(ScopedFakeSendInput &&) noexcept = delete;
      ScopedFakeSendInput &operator=(ScopedFakeSendInput &&) noexcept = delete;

      ~ScopedFakeSendInput() {
        send_input_function() = std::move(previous_function_);
        sync_thread_desktop_function() = std::move(previous_sync_function_);
      }

    private:
      SendInputFunction previous_function_ = send_input_with_win32;
      SyncThreadDesktopFunction previous_sync_function_ = sync_thread_desktop_with_win32;
    };

    struct FakeSyntheticPointerState {
      std::vector<test::WindowsSyntheticPointerRecord> injected_pointers;
      std::vector<POINTER_INPUT_TYPE> created_types;
      std::size_t destroyed_devices = 0;
      std::optional<BOOL> forced_inject_result;
      bool force_create_failure = false;
      std::uintptr_t next_device = 1;
    };

    test::WindowsSyntheticPointerRecord make_synthetic_pointer_record(const POINTER_TYPE_INFO &pointer, UINT32 count) {
      test::WindowsSyntheticPointerRecord record;
      record.type = pointer.type;
      record.count = count;
      if (pointer.type == PT_TOUCH) {
        const auto &touch = pointer.touchInfo;
        record.pointer_flags = touch.pointerInfo.pointerFlags;
        record.pointer_id = touch.pointerInfo.pointerId;
        record.x = touch.pointerInfo.ptPixelLocation.x;
        record.y = touch.pointerInfo.ptPixelLocation.y;
        record.touch_mask = touch.touchMask;
        record.touch_pressure = touch.pressure;
        record.touch_orientation = touch.orientation;
      } else if (pointer.type == PT_PEN) {
        const auto &pen = pointer.penInfo;
        record.pointer_flags = pen.pointerInfo.pointerFlags;
        record.pointer_id = pen.pointerInfo.pointerId;
        record.x = pen.pointerInfo.ptPixelLocation.x;
        record.y = pen.pointerInfo.ptPixelLocation.y;
        record.pen_mask = pen.penMask;
        record.pen_flags = pen.penFlags;
        record.pen_tilt_x = pen.tiltX;
        record.pen_tilt_y = pen.tiltY;
      }

      return record;
    }

    HSYNTHETICPOINTERDEVICE fake_create_synthetic_pointer_device(
      FakeSyntheticPointerState &state,
      POINTER_INPUT_TYPE type,
      ULONG /*max_count*/,
      POINTER_FEEDBACK_MODE /*mode*/
    ) {
      if (state.force_create_failure) {
        ::SetLastError(ERROR_ACCESS_DENIED);
        return nullptr;
      }

      static_assert(sizeof(HSYNTHETICPOINTERDEVICE) == sizeof(state.next_device));

      state.created_types.push_back(type);
      return std::bit_cast<HSYNTHETICPOINTERDEVICE>(state.next_device++);
    }

    BOOL fake_inject_synthetic_pointer_input(
      FakeSyntheticPointerState &state,
      HSYNTHETICPOINTERDEVICE /*device*/,
      const POINTER_TYPE_INFO *pointer_info,
      UINT32 count
    ) {
      for (UINT32 index = 0; index < count; ++index) {
        state.injected_pointers.push_back(make_synthetic_pointer_record(pointer_info[index], count));
      }

      if (state.forced_inject_result.has_value()) {
        ::SetLastError(ERROR_ACCESS_DENIED);
        return *state.forced_inject_result;
      }

      return TRUE;
    }

    void fake_destroy_synthetic_pointer_device(FakeSyntheticPointerState &state, HSYNTHETICPOINTERDEVICE /*device*/) {
      ++state.destroyed_devices;
    }

    class ScopedFakeSyntheticPointerApi {
    public:
      explicit ScopedFakeSyntheticPointerApi(FakeSyntheticPointerState &state) {
        previous_api_ = synthetic_pointer_api();
        synthetic_pointer_api() = SyntheticPointerApi {
          .create = [&state](POINTER_INPUT_TYPE type, ULONG max_count, POINTER_FEEDBACK_MODE mode) {
            return fake_create_synthetic_pointer_device(state, type, max_count, mode);
          },
          .inject = [&state](HSYNTHETICPOINTERDEVICE device, const POINTER_TYPE_INFO *pointer_info, UINT32 count) {
            return fake_inject_synthetic_pointer_input(state, device, pointer_info, count);
          },
          .destroy = [&state](HSYNTHETICPOINTERDEVICE device) {
            fake_destroy_synthetic_pointer_device(state, device);
          },
        };
      }

      ScopedFakeSyntheticPointerApi(const ScopedFakeSyntheticPointerApi &) = delete;
      ScopedFakeSyntheticPointerApi &operator=(const ScopedFakeSyntheticPointerApi &) = delete;
      ScopedFakeSyntheticPointerApi(ScopedFakeSyntheticPointerApi &&) noexcept = delete;
      ScopedFakeSyntheticPointerApi &operator=(ScopedFakeSyntheticPointerApi &&) noexcept = delete;

      ~ScopedFakeSyntheticPointerApi() {
        synthetic_pointer_api() = std::move(previous_api_);
      }

    private:
      SyntheticPointerApi previous_api_;
    };

  }  // namespace

  namespace test {

    WindowsBackendLifecycleResult windows_backend_fake_channel_lifecycle() {
      WindowsBackendLifecycleResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto event_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, event_state);
      result.capabilities = backend->capabilities();

      CreateGamepadOptions options;
      options.profile = profiles::xbox_series();
      auto created = backend->create_gamepad(7, options);
      result.create_status = created.status;
      if (created) {
        result.device_nodes = created.gamepad->device_nodes();
        std::vector<std::uint8_t> report(options.profile.input_report_size, 0x7A);
        result.submit_status = created.gamepad->submit({}, report);

        const auto driver_id = last_created_driver_id(command_state);
        enqueue_output_report(event_state, driver_id, options.profile);
        wait_for_output_events_to_drain(event_state);

        std::atomic_bool output_seen {false};
        created.gamepad->set_output_callback([&result, &output_seen](const GamepadOutput &output) {
          if (output.kind == GamepadOutputKind::rumble) {
            result.last_output = output;
            result.saw_output = true;
            output_seen.store(true);
          }
        });
        enqueue_output_report(event_state, driver_id, options.profile);
        static_cast<void>(wait_until([&output_seen] {
          return output_seen.load();
        }));

        result.close_status = created.gamepad->close();
        enqueue_output_report(event_state, driver_id, options.profile);
        wait_for_output_events_to_drain(event_state);
        result.second_close_status = created.gamepad->close();
        result.submit_after_close_status = created.gamepad->submit({}, report);

        result.create_requests = command_state->create_request_count();
        result.submit_requests = command_state->submit_report_count();
        result.destroy_requests = command_state->destroy_request_count();
      }

      return result;
    }

    WindowsSwitchReportStreamResult windows_backend_switch_report_stream() {
      WindowsSwitchReportStreamResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

      CreateGamepadOptions options;
      options.profile = profiles::switch_pro();
      auto created = backend->create_gamepad(8, options);
      result.create_status = created.status;
      if (created) {
        result.expected_report.assign(options.profile.input_report_size, 0x5AU);
        result.expected_report[0] = 0x30U;
        result.submit_status = created.gamepad->submit({}, result.expected_report);
        result.repeated_report = wait_until([&command_state] {
          return command_state->submit_report_count() >= 2U;
        });
        result.close_status = created.gamepad->close();
        result.submitted_reports = command_state->submit_reports();
      }

      return result;
    }

    WindowsXboxInputDeduplicationResult windows_backend_xbox_input_deduplication(GamepadProfileKind kind) {
      WindowsXboxInputDeduplicationResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

      CreateGamepadOptions options;
      options.profile = kind == GamepadProfileKind::xbox_one ? profiles::xbox_one() : profiles::xbox_series();
      auto created = backend->create_gamepad(9, options);
      result.create_status = created.status;
      if (created) {
        auto report = std::vector<std::uint8_t>(options.profile.input_report_size, 0U);
        report[12] = 0x10U;
        result.left_shoulder_status = created.gamepad->submit({}, report);
        result.repeated_left_shoulder_status = created.gamepad->submit({}, report);

        report[12] = 0x20U;
        result.right_shoulder_status = created.gamepad->submit({}, report);
        result.repeated_right_shoulder_status = created.gamepad->submit({}, report);

        report[12] = 0U;
        result.release_status = created.gamepad->submit({}, report);
        result.close_status = created.gamepad->close();
        result.submitted_reports = command_state->submit_reports();
      }

      return result;
    }

    WindowsHidMouseResult windows_backend_hid_mouse() {
      using enum MouseEventKind;

      WindowsHidMouseResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

      CreateMouseOptions options;
      options.profile = profiles::mouse();
      options.profile.bus_type = BusType::bluetooth;
      options.profile.vendor_id = 0x1234;
      options.profile.product_id = 0x5678;
      options.profile.version = 0x4321;
      options.profile.name = "Configured mouse";
      options.profile.manufacturer = "Configured manufacturer";
      options.stable_id = "configured-mouse";

      auto created = backend->create_mouse(8U, options);
      result.operations.create_status = created.status;
      if (created) {
        result.operations.motion_status = created.mouse->submit(MouseEvent {
          .kind = relative_motion,
          .x = 70000,
          .y = -70000,
        });
        result.operations.large_scroll_status = created.mouse->submit(MouseEvent {
          .kind = vertical_scroll,
          .high_resolution_scroll = 120 * 132,
        });
        result.operations.partial_scroll_status = created.mouse->submit(MouseEvent {
          .kind = horizontal_scroll,
          .high_resolution_scroll = 60,
        });
        result.operations.completed_scroll_status = created.mouse->submit(MouseEvent {
          .kind = horizontal_scroll,
          .high_resolution_scroll = 60,
        });
        result.operations.close_status = created.mouse->close();
      }

      capture_created_hid_device(command_state, result.device);
      result.observations.reports = command_state->submit_reports();
      result.observations.destroy_requests = command_state->destroy_request_count();

      {
        auto failure_state = std::make_shared<FakeWindowsControlChannelState>();
        failure_state->set_create_protocol_status(LVH_WINDOWS_STATUS_BACKEND_FAILURE);
        auto failure_backend = make_fake_windows_backend(
          failure_state,
          std::make_shared<FakeWindowsControlChannelState>()
        );
        result.operations.protocol_failure_status = failure_backend->create_mouse(9U, options).status;
      }

      {
        FakeSendInputState send_input_state;
        ScopedFakeSendInput fake_send_input {send_input_state};
        auto license_state = std::make_shared<FakeWindowsControlChannelState>();
        license_state->set_create_transport_status(
          OperationStatus::failure(ErrorCode::license_required, "license required")
        );
        auto license_backend = make_fake_windows_backend(
          license_state,
          std::make_shared<FakeWindowsControlChannelState>()
        );
        auto fallback = license_backend->create_mouse(10U, options);
        result.operations.license_fallback_create_status = fallback.status;
        if (fallback) {
          result.operations.license_fallback_submit_status = fallback.mouse->submit(MouseEvent {
            .kind = relative_motion,
            .x = 1,
            .y = 2,
          });
        }
        result.observations.license_create_requests = license_state->create_request_count();
        result.observations.license_fallback_send_inputs = send_input_state.sent_inputs.size();
      }

      return result;
    }

    WindowsHidKeyboardResult windows_backend_hid_keyboard() {
      WindowsHidKeyboardResult result;
      CreateKeyboardOptions options;
      options.profile = profiles::keyboard();
      options.profile.bus_type = BusType::usb;
      options.profile.vendor_id = 0x1234;
      options.profile.product_id = 0x5678;
      options.profile.version = 0x4321;
      options.profile.name = "Configured keyboard";
      options.profile.manufacturer = "Configured manufacturer";
      options.stable_id = "configured-keyboard";

      {
        FakeSendInputState send_input_state;
        ScopedFakeSendInput fake_send_input {send_input_state};
        auto command_state = std::make_shared<FakeWindowsControlChannelState>();
        auto backend = make_fake_windows_backend(
          command_state,
          std::make_shared<FakeWindowsControlChannelState>()
        );

        auto created = backend->create_keyboard(18U, options);
        result.operations.create_status = created.status;
        if (created) {
          result.operations.letter_press_status = created.keyboard->submit({
            .key_code = 'A',
            .pressed = true,
            .uses_normalized_key_code = true,
            .prefer_native_scan_code = true,
          });
          result.operations.modifier_press_status =
            created.keyboard->submit({.key_code = VK_LSHIFT, .pressed = true});
          result.operations.extended_press_status = created.keyboard->submit({
            .key_code = VK_RIGHT,
            .pressed = true,
            .scan_code = 0x4DU,
          });
          result.operations.letter_release_status = created.keyboard->submit({.key_code = 'A', .pressed = false});
          result.operations.unmapped_submit_status =
            created.keyboard->submit({.key_code = VK_BROWSER_BACK, .pressed = true});
          result.operations.text_status = created.keyboard->type_text({.text = "A"});
          result.operations.close_status = created.keyboard->close();
        }

        capture_created_hid_device(command_state, result.device);
        result.observations.reports = command_state->submit_reports();
        result.observations.destroy_requests = command_state->destroy_request_count();
        result.observations.fallback_send_inputs = send_input_state.sent_inputs.size();
      }

      {
        auto failure_state = std::make_shared<FakeWindowsControlChannelState>();
        failure_state->set_create_protocol_status(LVH_WINDOWS_STATUS_BACKEND_FAILURE);
        auto failure_backend = make_fake_windows_backend(
          failure_state,
          std::make_shared<FakeWindowsControlChannelState>()
        );
        result.operations.protocol_failure_status = failure_backend->create_keyboard(19U, options).status;
      }

      {
        FakeSendInputState send_input_state;
        ScopedFakeSendInput fake_send_input {send_input_state};
        auto license_state = std::make_shared<FakeWindowsControlChannelState>();
        license_state->set_create_transport_status(
          OperationStatus::failure(ErrorCode::license_required, "license required")
        );
        auto license_backend = make_fake_windows_backend(
          license_state,
          std::make_shared<FakeWindowsControlChannelState>()
        );
        auto fallback = license_backend->create_keyboard(20U, options);
        result.operations.license_fallback_create_status = fallback.status;
        if (fallback) {
          result.operations.license_fallback_submit_status =
            fallback.keyboard->submit({.key_code = 'B', .pressed = true});
        }
        result.observations.license_create_requests = license_state->create_request_count();
        result.observations.license_fallback_send_inputs = send_input_state.sent_inputs.size();
      }

      return result;
    }

    WindowsPlayStationTransportResult windows_backend_playstation_transport() {
      WindowsPlayStationTransportResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto event_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, event_state);

      CreateGamepadOptions options;
      options.profile = profiles::dualshock4();
      auto dualshock4 = backend->create_gamepad(40, options);
      result.dualshock4_status = dualshock4.status;
      if (dualshock4.effective_profile.has_value()) {
        result.dualshock4_effective_profile = std::move(*dualshock4.effective_profile);
      }
      if (dualshock4.gamepad) {
        static_cast<void>(dualshock4.gamepad->close());
      }

      options.profile = profiles::dualsense();
      auto dualsense = backend->create_gamepad(41, options);
      result.dualsense_status = dualsense.status;
      if (dualsense.effective_profile.has_value()) {
        result.dualsense_effective_profile = std::move(*dualsense.effective_profile);
      }
      if (dualsense.gamepad) {
        static_cast<void>(dualsense.gamepad->close());
      }

      return result;
    }

    WindowsGenericPidOrderingResult windows_backend_generic_pid_callback_ordering() {
      WindowsGenericPidOrderingResult result;
      auto command_state = std::make_shared<FakeWindowsControlChannelState>();
      auto event_state = std::make_shared<FakeWindowsControlChannelState>();
      auto backend = make_fake_windows_backend(command_state, event_state);

      CreateGamepadOptions options;
      options.profile = profiles::generic_gamepad();
      auto created = backend->create_gamepad(30, options);
      if (!created) {
        return result;
      }

      std::mutex gate_mutex;
      std::condition_variable gate_ready;
      bool zero_waiting = false;
      bool release_zero = false;
      std::mutex strengths_mutex;
      created.gamepad->set_output_callback([&gate_mutex,
                                            &gate_ready,
                                            &zero_waiting,
                                            &release_zero,
                                            &strengths_mutex,
                                            &result](const GamepadOutput &output) {
        if (output.kind != GamepadOutputKind::rumble) {
          return;
        }
        if (output.low_frequency_rumble == 0U) {
          std::unique_lock lock {gate_mutex};
          zero_waiting = true;
          gate_ready.notify_all();
          gate_ready.wait(lock, [&release_zero] {
            return release_zero;
          });
        }
        std::lock_guard lock {strengths_mutex};
        result.strengths.push_back(output.low_frequency_rumble);
      });

      const auto driver_id = last_created_driver_id(command_state);
      const auto enqueue_report = [&](std::span<const std::uint8_t> report) {
        LvhWindowsOutputReportEvent event {};
        event.version = LVH_WINDOWS_CONTROL_PROTOCOL_VERSION;
        event.size = sizeof(event);
        event.driver_device_id = driver_id;
        event.report_size = static_cast<std::uint32_t>(report.size());
        std::ranges::copy(report, event.report.begin());
        event_state->enqueue_output_event(event);
      };

      std::array<std::uint8_t, windows::generic_pid_output_report_size> set_effect {};
      set_effect[0] = windows::generic_pid_set_effect_report_id;
      set_effect[1] = 1;
      set_effect[2] = 1;
      set_effect[3] = 10;  // Ten millisecond duration.
      set_effect[11] = 255;
      std::array<std::uint8_t, windows::generic_pid_output_report_size> set_magnitude {};
      set_magnitude[0] = windows::generic_pid_set_constant_force_report_id;
      set_magnitude[1] = 1;
      set_magnitude[2] = 0x10;
      set_magnitude[3] = 0x27;
      std::array<std::uint8_t, windows::generic_pid_output_report_size> start_effect {};
      start_effect[0] = windows::generic_pid_effect_operation_report_id;
      start_effect[1] = 1;
      start_effect[2] = 1;
      start_effect[3] = 1;

      enqueue_report(set_effect);
      enqueue_report(set_magnitude);
      enqueue_report(start_effect);
      const auto saw_start = wait_until([&strengths_mutex, &result] {
        std::lock_guard lock {strengths_mutex};
        return !result.strengths.empty() && result.strengths.front() > 0U;
      });
      bool saw_expiry = false;
      if (saw_start) {
        std::unique_lock lock {gate_mutex};
        saw_expiry = gate_ready.wait_for(lock, std::chrono::milliseconds {250}, [&zero_waiting] {
          return zero_waiting;
        });
      }

      if (saw_expiry) {
        enqueue_report(start_effect);
        wait_for_output_events_to_drain(event_state);
      }
      {
        std::lock_guard lock {gate_mutex};
        release_zero = true;
      }
      gate_ready.notify_all();

      result.completed = saw_expiry && wait_until([&strengths_mutex, &result] {
                           std::lock_guard lock {strengths_mutex};
                           return result.strengths.size() >= 3U;
                         });
      static_cast<void>(created.gamepad->close());
      return result;
    }

    WindowsBackendFailureResult windows_backend_fake_channel_failures() {
      WindowsBackendFailureResult result;
      result.invalid_argument_status = create_gamepad_with_protocol_status(LVH_WINDOWS_STATUS_INVALID_ARGUMENT);
      result.unsupported_profile_status = create_gamepad_with_protocol_status(LVH_WINDOWS_STATUS_UNSUPPORTED_PROFILE);
      result.device_closed_status = create_gamepad_with_protocol_status(LVH_WINDOWS_STATUS_DEVICE_NOT_FOUND);
      result.backend_failure_status = create_gamepad_with_protocol_status(LVH_WINDOWS_STATUS_BACKEND_FAILURE);

      {
        auto command_state = std::make_shared<FakeWindowsControlChannelState>();
        command_state->set_create_transport_status(
          OperationStatus::failure(ErrorCode::backend_failure, "transport failed")
        );
        auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

        CreateGamepadOptions options;
        options.profile = profiles::xbox_series();
        result.transport_failure_status = backend->create_gamepad(2, options).status;
      }

      {
        WindowsBackend backend {nullptr, nullptr};

        CreateGamepadOptions options;
        options.profile = profiles::xbox_series();
        result.unavailable_status = backend.create_gamepad(3, options).status;

        auto oversized_descriptor_options = options;
        oversized_descriptor_options.profile.report_descriptor.assign(LVH_WINDOWS_MAX_REPORT_DESCRIPTOR_SIZE + 1U, 0x01);
        result.oversized_descriptor_status = backend.create_gamepad(17, oversized_descriptor_options).status;

        auto oversized_input_options = options;
        oversized_input_options.profile.input_report_size = LVH_WINDOWS_MAX_INPUT_REPORT_SIZE + 1U;
        result.oversized_input_report_status = backend.create_gamepad(18, oversized_input_options).status;

        auto oversized_output_options = options;
        oversized_output_options.profile.output_report_size = LVH_WINDOWS_MAX_OUTPUT_REPORT_SIZE + 1U;
        result.oversized_output_report_status = backend.create_gamepad(19, oversized_output_options).status;
      }

      {
        auto backend = make_fake_windows_backend(
          std::make_shared<FakeWindowsControlChannelState>(),
          std::make_shared<FakeWindowsControlChannelState>()
        );

        CreateGamepadOptions options;
        options.profile = profiles::xbox_360();
        result.xbox_360_create_status = backend->create_gamepad(20, options).status;
      }

      {
        auto command_state = std::make_shared<FakeWindowsControlChannelState>("", "");
        auto backend = make_fake_windows_backend(command_state, std::make_shared<FakeWindowsControlChannelState>());

        CreateGamepadOptions options;
        options.profile = profiles::xbox_series();
        auto created = backend->create_gamepad(4, options);
        result.empty_nodes_create_status = created.status;
        if (created) {
          result.empty_device_nodes = created.gamepad->device_nodes();
          result.oversized_submit_status = created.gamepad->submit(
            {},
            std::vector<std::uint8_t>(LVH_WINDOWS_MAX_INPUT_REPORT_SIZE + 1U, 0x7B)
          );
        }
      }

      return result;
    }

    WindowsBackendUtilityResult windows_backend_fake_channel_utilities() {
      WindowsBackendUtilityResult result;
      result.default_device_paths = resolve_control_device_paths();

      constexpr auto environment_name = "LIBVIRTUALHID_WINDOWS_CONTROL_DEVICE";
      constexpr auto custom_path = R"(\\.\LibVirtualHid-Test)";
      std::string original_value;
      const auto had_original_value = lizardbyte::common::get_env(environment_name, original_value);
      static_cast<void>(lizardbyte::common::set_env(environment_name, custom_path));
      result.custom_device_paths = resolve_control_device_paths();
      if (had_original_value) {
        static_cast<void>(lizardbyte::common::set_env(environment_name, original_value));
      } else {
        static_cast<void>(lizardbyte::common::unset_env(environment_name));
      }

      result.formatted_error_status =
        windows_failure(ErrorCode::backend_failure, "format known Windows error", ERROR_FILE_NOT_FOUND);
      result.fallback_error_status =
        windows_failure(ErrorCode::backend_failure, "format unknown Windows error", 0xE0000001U);

      {
        WindowsBackend backend {nullptr, nullptr};

        CreateKeyboardOptions keyboard_options;
        keyboard_options.profile = profiles::keyboard();
        auto keyboard = backend.create_keyboard(8, keyboard_options);
        result.keyboard_create_status = keyboard.status;
        if (keyboard) {
          result.keyboard_close_status = keyboard.keyboard->close();
          result.keyboard_submit_after_close_status =
            keyboard.keyboard->submit({.key_code = 0x41, .pressed = true});
        }

        CreateMouseOptions mouse_options;
        mouse_options.profile = profiles::mouse();
        auto mouse = backend.create_mouse(9, mouse_options);
        result.mouse_create_status = mouse.status;
        if (mouse) {
          result.mouse_close_status = mouse.mouse->close();
          MouseEvent mouse_event;
          mouse_event.kind = MouseEventKind::relative_motion;
          mouse_event.x = 1;
          result.mouse_submit_after_close_status = mouse.mouse->submit(mouse_event);
        }
      }

      auto invalid_context = std::make_shared<WindowsBackendContext>(
        std::unique_ptr<WindowsControlChannel> {},
        std::unique_ptr<WindowsControlChannel> {}
      );
      invalid_context->start();

      auto context = std::make_shared<WindowsBackendContext>(
        std::make_unique<FakeWindowsControlChannel>(std::make_shared<FakeWindowsControlChannelState>()),
        std::make_unique<FakeWindowsControlChannel>(std::make_shared<FakeWindowsControlChannelState>())
      );
      context->start();
      context->start();
      context->stop();

      result.timeout_result = wait_until([] {
        return false;
      });

      return result;
    }

    WindowsOverlappedIoResult windows_backend_overlapped_device_io() {
      WindowsOverlappedIoResult result;

      DWORD bytes_returned = 0;
      result.immediate_status = run_overlapped_device_io(
        "complete immediate test operation",
        &bytes_returned,
        [&result](const OVERLAPPED &overlapped, DWORD *result_size) {
          result.immediate_saw_event = overlapped.hEvent != nullptr;
          *result_size = 7U;
          return TRUE;
        },
        [&result](OVERLAPPED &, DWORD *, BOOL) {
          result.immediate_called_completion = true;
          return TRUE;
        }
      );
      result.immediate_bytes_returned = bytes_returned;

      bytes_returned = 0;
      result.pending_status = run_overlapped_device_io(
        "complete pending test operation",
        &bytes_returned,
        [&result](const OVERLAPPED &overlapped, DWORD *) {
          result.pending_saw_event = overlapped.hEvent != nullptr;
          ::SetLastError(ERROR_IO_PENDING);
          return FALSE;
        },
        [&result](OVERLAPPED &, DWORD *result_size, BOOL wait) {
          result.pending_waited = wait != FALSE;
          *result_size = 11U;
          return TRUE;
        }
      );
      result.pending_bytes_returned = bytes_returned;

      OVERLAPPED canceled {};
      cancel_and_drain_overlapped_io(
        canceled,
        &bytes_returned,
        [&result](OVERLAPPED &) {
          result.cancellation_called = true;
          return TRUE;
        },
        [&result](OVERLAPPED &, DWORD *, BOOL wait) {
          result.cancellation_drained_after_cancel = result.cancellation_called;
          result.cancellation_waited = wait != FALSE;
          ::SetLastError(ERROR_OPERATION_ABORTED);
          return FALSE;
        }
      );

      result.start_failure_status = run_overlapped_device_io(
        "fail test operation start",
        &bytes_returned,
        [](OVERLAPPED &, DWORD *) {
          ::SetLastError(ERROR_ACCESS_DENIED);
          return FALSE;
        },
        [](OVERLAPPED &, DWORD *, BOOL) {
          return TRUE;
        }
      );

      result.completion_failure_status = run_overlapped_device_io(
        "fail pending test operation",
        &bytes_returned,
        [](OVERLAPPED &, DWORD *) {
          ::SetLastError(ERROR_IO_PENDING);
          return FALSE;
        },
        [](OVERLAPPED &, DWORD *, BOOL) {
          ::SetLastError(ERROR_OPERATION_ABORTED);
          return FALSE;
        }
      );

      return result;
    }

    WindowsBackendSendInputResult windows_backend_send_input_devices() {
      using enum MouseEventKind;

      WindowsBackendSendInputResult result;
      FakeSendInputState fake_send_input;
      ScopedFakeSendInput scoped_send_input {fake_send_input};
      FakeSyntheticPointerState fake_synthetic_pointer;
      ScopedFakeSyntheticPointerApi scoped_synthetic_pointer {fake_synthetic_pointer};
      WindowsBackend backend {nullptr, nullptr};
      result.synthetic.capabilities = backend.capabilities();

      CreateKeyboardOptions keyboard_options;
      keyboard_options.profile = profiles::keyboard();
      if (auto keyboard = backend.create_keyboard(10, keyboard_options); keyboard) {
        result.keyboard.down_status = keyboard.keyboard->submit({.key_code = 0x41, .pressed = true});
        result.keyboard.up_status = keyboard.keyboard->submit({.key_code = 0x41, .pressed = false});
        result.keyboard.text_status = keyboard.keyboard->type_text({.text = "Az"});
        result.keyboard.empty_text_status = keyboard.keyboard->type_text({.text = ""});
        result.keyboard.invalid_text_status =
          keyboard.keyboard->type_text({.text = std::string(1U, static_cast<char>(0xFF))});

        fake_send_input.forced_sent_count = 0U;
        result.keyboard.failure_status = keyboard.keyboard->submit({.key_code = 0x42, .pressed = true});
        fake_send_input.forced_sent_count.reset();

        const auto prior_input_count = fake_send_input.sent_inputs.size();
        result.keyboard.normalized_status =
          keyboard.keyboard->submit({.key_code = 0x41, .pressed = true, .uses_normalized_key_code = true});
        if (fake_send_input.sent_inputs.size() > prior_input_count) {
          result.keyboard.normalized_input = fake_send_input.sent_inputs.back();
          fake_send_input.sent_inputs.resize(prior_input_count);
        }
      } else {
        result.keyboard.down_status = keyboard.status;
      }

      CreateMouseOptions mouse_options;
      mouse_options.profile = profiles::mouse();
      if (auto mouse = backend.create_mouse(11, mouse_options); mouse) {
        result.mouse.relative_status = mouse.mouse->submit({.kind = relative_motion, .x = 11, .y = -12});
        result.mouse.absolute_status =
          mouse.mouse->submit({.kind = absolute_motion, .x = 50, .y = 25, .width = 100, .height = 50});
        result.mouse.degenerate_absolute_status =
          mouse.mouse->submit({.kind = absolute_motion, .x = 99, .y = 99, .width = 1, .height = 0});

        MouseEvent button_event;
        button_event.kind = button;
        button_event.button = MouseButton::left;
        button_event.pressed = true;
        result.mouse.left_button_status = mouse.mouse->submit(button_event);
        button_event.button = MouseButton::middle;
        button_event.pressed = false;
        result.mouse.middle_button_status = mouse.mouse->submit(button_event);
        button_event.button = MouseButton::right;
        button_event.pressed = true;
        result.mouse.right_button_status = mouse.mouse->submit(button_event);
        button_event.button = MouseButton::side;
        result.mouse.side_button_status = mouse.mouse->submit(button_event);
        button_event.button = MouseButton::extra;
        button_event.pressed = false;
        result.mouse.extra_button_status = mouse.mouse->submit(button_event);

        result.mouse.vertical_scroll_status = mouse.mouse->submit({.kind = vertical_scroll, .high_resolution_scroll = 120});
        result.mouse.horizontal_scroll_status =
          mouse.mouse->submit({.kind = horizontal_scroll, .high_resolution_scroll = -240});

        fake_send_input.forced_sent_count = 0U;
        result.mouse.failure_status = mouse.mouse->submit({.kind = relative_motion, .x = 1, .y = 1});
        fake_send_input.forced_sent_count.reset();
      } else {
        result.mouse.relative_status = mouse.status;
      }

      CreateKeyboardOptions invalid_keyboard_options;
      invalid_keyboard_options.profile = profiles::mouse();
      result.keyboard.invalid_profile_status = backend.create_keyboard(12, invalid_keyboard_options).status;

      CreateMouseOptions invalid_mouse_options;
      invalid_mouse_options.profile = profiles::keyboard();
      result.mouse.invalid_profile_status = backend.create_mouse(13, invalid_mouse_options).status;

      CreateTouchscreenOptions touchscreen_options;
      touchscreen_options.profile = profiles::touchscreen();
      if (auto touchscreen = backend.create_touchscreen(14, touchscreen_options); touchscreen) {
        result.synthetic.touchscreen_create_status = touchscreen.status;
        result.synthetic.touchscreen_place_status = touchscreen.touchscreen->place_contact({
          .id = 7,
          .x = 0.25F,
          .y = 0.5F,
          .pressure = 0.75F,
          .orientation = 30,
          .viewport = {.offset_x = 100, .offset_y = 200, .width = 400, .height = 300},
          .contact_major_axis = 20.0F,
          .contact_minor_axis = 10.0F,
        });
        result.synthetic.touchscreen_release_status =
          touchscreen.touchscreen->release_contact(7, PointerTransition::release);

        fake_synthetic_pointer.forced_inject_result = FALSE;
        result.synthetic.touchscreen_failure_status = touchscreen.touchscreen->place_contact({
          .id = 8,
          .x = 0.1F,
          .y = 0.2F,
          .viewport = {.offset_x = 0, .offset_y = 0, .width = 100, .height = 100},
        });
        fake_synthetic_pointer.forced_inject_result.reset();
      } else {
        result.synthetic.touchscreen_create_status = touchscreen.status;
      }

      CreateTrackpadOptions trackpad_options;
      trackpad_options.profile = profiles::trackpad();
      result.unsupported.trackpad_status = backend.create_trackpad(15, trackpad_options).status;

      CreatePenTabletOptions pen_tablet_options;
      pen_tablet_options.profile = profiles::pen_tablet();
      if (auto pen_tablet = backend.create_pen_tablet(16, pen_tablet_options); pen_tablet) {
        result.synthetic.pen_tablet_create_status = pen_tablet.status;
        result.synthetic.pen_tablet_button_status = pen_tablet.pen_tablet->button(PenButton::secondary, true);
        result.synthetic.pen_tablet_tool_status = pen_tablet.pen_tablet->place_tool({
          .tool = PenToolType::eraser,
          .x = 0.5F,
          .y = 0.75F,
          .pressure = 0.5F,
          .distance = -1.0F,
          .tilt_x = 10.0F,
          .tilt_y = -20.0F,
          .viewport = {.offset_x = 10, .offset_y = 20, .width = 200, .height = 100},
        });
      } else {
        result.synthetic.pen_tablet_create_status = pen_tablet.status;
      }

      CreateTouchscreenOptions invalid_touchscreen_options;
      invalid_touchscreen_options.profile = profiles::pen_tablet();
      result.synthetic.touchscreen_invalid_profile_status = backend.create_touchscreen(17, invalid_touchscreen_options).status;

      CreatePenTabletOptions invalid_pen_tablet_options;
      invalid_pen_tablet_options.profile = profiles::touchscreen();
      result.synthetic.pen_tablet_invalid_profile_status = backend.create_pen_tablet(18, invalid_pen_tablet_options).status;

      result.sent_inputs = std::move(fake_send_input.sent_inputs);
      result.synthetic.created_devices = fake_synthetic_pointer.created_types.size();
      result.synthetic.destroyed_devices = fake_synthetic_pointer.destroyed_devices;
      result.synthetic.injected_pointers = std::move(fake_synthetic_pointer.injected_pointers);
      return result;
    }

  }  // namespace test

}  // namespace lvh::detail