9 files changed, 320 insertions, 0 deletions

diff --git a/src/input_common/CMakeLists.txt b/src/input_common/CMakeLists.txt
index 4b91b88ce..2cf9eb97f 100644
--- a/src/input_common/CMakeLists.txt
+++ b/src/input_common/CMakeLists.txt
@@ -18,6 +18,8 @@ add_library(input_common STATIC
     drivers/touch_screen.h
     drivers/udp_client.cpp
     drivers/udp_client.h
+    drivers/virtual_amiibo.cpp
+    drivers/virtual_amiibo.h
     helpers/stick_from_buttons.cpp
     helpers/stick_from_buttons.h
     helpers/touch_from_buttons.cpp
diff --git a/src/input_common/drivers/virtual_amiibo.cpp b/src/input_common/drivers/virtual_amiibo.cpp
new file mode 100644
index 000000000..0cd5129da
--- /dev/null
+++ b/src/input_common/drivers/virtual_amiibo.cpp
@@ -0,0 +1,101 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <cstring>
+#include <fmt/format.h>
+
+#include "common/fs/file.h"
+#include "common/fs/fs.h"
+#include "common/fs/path_util.h"
+#include "common/logging/log.h"
+#include "common/settings.h"
+#include "input_common/drivers/virtual_amiibo.h"
+
+namespace InputCommon {
+constexpr PadIdentifier identifier = {
+    .guid = Common::UUID{},
+    .port = 0,
+    .pad = 0,
+};
+
+VirtualAmiibo::VirtualAmiibo(std::string input_engine_) : InputEngine(std::move(input_engine_)) {}
+
+VirtualAmiibo::~VirtualAmiibo() = default;
+
+Common::Input::PollingError VirtualAmiibo::SetPollingMode(
+    [[maybe_unused]] const PadIdentifier& identifier_,
+    const Common::Input::PollingMode polling_mode_) {
+    polling_mode = polling_mode_;
+
+    if (polling_mode == Common::Input::PollingMode::NFC) {
+        if (state == State::Initialized) {
+            state = State::WaitingForAmiibo;
+        }
+    } else {
+        if (state == State::AmiiboIsOpen) {
+            CloseAmiibo();
+        }
+    }
+
+    return Common::Input::PollingError::None;
+}
+
+Common::Input::NfcState VirtualAmiibo::SupportsNfc(
+    [[maybe_unused]] const PadIdentifier& identifier_) const {
+    return Common::Input::NfcState::Success;
+}
+
+Common::Input::NfcState VirtualAmiibo::WriteNfcData(
+    [[maybe_unused]] const PadIdentifier& identifier_, const std::vector<u8>& data) {
+    const Common::FS::IOFile amiibo_file{file_path, Common::FS::FileAccessMode::ReadWrite,
+                                         Common::FS::FileType::BinaryFile};
+
+    if (!amiibo_file.IsOpen()) {
+        LOG_ERROR(Core, "Amiibo is already on use");
+        return Common::Input::NfcState::WriteFailed;
+    }
+
+    if (!amiibo_file.Write(data)) {
+        LOG_ERROR(Service_NFP, "Error writting to file");
+        return Common::Input::NfcState::WriteFailed;
+    }
+
+    return Common::Input::NfcState::Success;
+}
+
+VirtualAmiibo::State VirtualAmiibo::GetCurrentState() const {
+    return state;
+}
+
+VirtualAmiibo::Info VirtualAmiibo::LoadAmiibo(const std::string& filename) {
+    const Common::FS::IOFile amiibo_file{filename, Common::FS::FileAccessMode::Read,
+                                         Common::FS::FileType::BinaryFile};
+
+    if (state != State::WaitingForAmiibo) {
+        return Info::WrongDeviceState;
+    }
+
+    if (!amiibo_file.IsOpen()) {
+        return Info::UnableToLoad;
+    }
+
+    amiibo_data.resize(amiibo_size);
+
+    if (amiibo_file.Read(amiibo_data) < amiibo_size_without_password) {
+        return Info::NotAnAmiibo;
+    }
+
+    file_path = filename;
+    state = State::AmiiboIsOpen;
+    SetNfc(identifier, {Common::Input::NfcState::NewAmiibo, amiibo_data});
+    return Info::Success;
+}
+
+VirtualAmiibo::Info VirtualAmiibo::CloseAmiibo() {
+    state = polling_mode == Common::Input::PollingMode::NFC ? State::WaitingForAmiibo
+                                                            : State::Initialized;
+    SetNfc(identifier, {Common::Input::NfcState::AmiiboRemoved, {}});
+    return Info::Success;
+}
+
+} // namespace InputCommon
diff --git a/src/input_common/drivers/virtual_amiibo.h b/src/input_common/drivers/virtual_amiibo.h
new file mode 100644
index 000000000..9eac07544
--- /dev/null
+++ b/src/input_common/drivers/virtual_amiibo.h
@@ -0,0 +1,61 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <array>
+#include <string>
+#include <vector>
+
+#include "common/common_types.h"
+#include "input_common/input_engine.h"
+
+namespace Common::FS {
+class IOFile;
+}
+
+namespace InputCommon {
+
+class VirtualAmiibo final : public InputEngine {
+public:
+    enum class State {
+        Initialized,
+        WaitingForAmiibo,
+        AmiiboIsOpen,
+    };
+
+    enum class Info {
+        Success,
+        UnableToLoad,
+        NotAnAmiibo,
+        WrongDeviceState,
+        Unknown,
+    };
+
+    explicit VirtualAmiibo(std::string input_engine_);
+    ~VirtualAmiibo() override;
+
+    // Sets polling mode to a controller
+    Common::Input::PollingError SetPollingMode(
+        const PadIdentifier& identifier_, const Common::Input::PollingMode polling_mode_) override;
+
+    Common::Input::NfcState SupportsNfc(const PadIdentifier& identifier_) const override;
+
+    Common::Input::NfcState WriteNfcData(const PadIdentifier& identifier_,
+                                         const std::vector<u8>& data) override;
+
+    State GetCurrentState() const;
+
+    Info LoadAmiibo(const std::string& amiibo_file);
+    Info CloseAmiibo();
+
+private:
+    static constexpr std::size_t amiibo_size = 0x21C;
+    static constexpr std::size_t amiibo_size_without_password = amiibo_size - 0x8;
+
+    std::string file_path{};
+    State state{State::Initialized};
+    std::vector<u8> amiibo_data;
+    Common::Input::PollingMode polling_mode{Common::Input::PollingMode::Pasive};
+};
+} // namespace InputCommon
diff --git a/src/input_common/input_engine.cpp b/src/input_common/input_engine.cpp
index 6ede0e4b0..61cfd0911 100644
--- a/src/input_common/input_engine.cpp
+++ b/src/input_common/input_engine.cpp
@@ -102,6 +102,17 @@ void InputEngine::SetCamera(const PadIdentifier& identifier,
     TriggerOnCameraChange(identifier, value);
 }
 
+void InputEngine::SetNfc(const PadIdentifier& identifier, const Common::Input::NfcStatus& value) {
+    {
+        std::scoped_lock lock{mutex};
+        ControllerData& controller = controller_list.at(identifier);
+        if (!configuring) {
+            controller.nfc = value;
+        }
+    }
+    TriggerOnNfcChange(identifier, value);
+}
+
 bool InputEngine::GetButton(const PadIdentifier& identifier, int button) const {
     std::scoped_lock lock{mutex};
     const auto controller_iter = controller_list.find(identifier);
@@ -189,6 +200,18 @@ Common::Input::CameraStatus InputEngine::GetCamera(const PadIdentifier& identifi
     return controller.camera;
 }
 
+Common::Input::NfcStatus InputEngine::GetNfc(const PadIdentifier& identifier) const {
+    std::scoped_lock lock{mutex};
+    const auto controller_iter = controller_list.find(identifier);
+    if (controller_iter == controller_list.cend()) {
+        LOG_ERROR(Input, "Invalid identifier guid={}, pad={}, port={}", identifier.guid.RawString(),
+                  identifier.pad, identifier.port);
+        return {};
+    }
+    const ControllerData& controller = controller_iter->second;
+    return controller.nfc;
+}
+
 void InputEngine::ResetButtonState() {
     for (const auto& controller : controller_list) {
         for (const auto& button : controller.second.buttons) {
@@ -355,6 +378,20 @@ void InputEngine::TriggerOnCameraChange(const PadIdentifier& identifier,
     }
 }
 
+void InputEngine::TriggerOnNfcChange(const PadIdentifier& identifier,
+                                     [[maybe_unused]] const Common::Input::NfcStatus& value) {
+    std::scoped_lock lock{mutex_callback};
+    for (const auto& poller_pair : callback_list) {
+        const InputIdentifier& poller = poller_pair.second;
+        if (!IsInputIdentifierEqual(poller, identifier, EngineInputType::Nfc, 0)) {
+            continue;
+        }
+        if (poller.callback.on_change) {
+            poller.callback.on_change();
+        }
+    }
+}
+
 bool InputEngine::IsInputIdentifierEqual(const InputIdentifier& input_identifier,
                                          const PadIdentifier& identifier, EngineInputType type,
                                          int index) const {
diff --git a/src/input_common/input_engine.h b/src/input_common/input_engine.h
index f6b3c4610..cfbdb26bd 100644
--- a/src/input_common/input_engine.h
+++ b/src/input_common/input_engine.h
@@ -42,6 +42,7 @@ enum class EngineInputType {
     Camera,
     HatButton,
     Motion,
+    Nfc,
 };
 
 namespace std {
@@ -127,6 +128,18 @@ public:
         return Common::Input::CameraError::NotSupported;
     }
 
+    // Request nfc data from a controller
+    virtual Common::Input::NfcState SupportsNfc(
+        [[maybe_unused]] const PadIdentifier& identifier) const {
+        return Common::Input::NfcState::NotSupported;
+    }
+
+    // Writes data to an nfc tag
+    virtual Common::Input::NfcState WriteNfcData([[maybe_unused]] const PadIdentifier& identifier,
+                                                 [[maybe_unused]] const std::vector<u8>& data) {
+        return Common::Input::NfcState::NotSupported;
+    }
+
     // Returns the engine name
     [[nodiscard]] const std::string& GetEngineName() const;
 
@@ -183,6 +196,7 @@ public:
     Common::Input::BatteryLevel GetBattery(const PadIdentifier& identifier) const;
     BasicMotion GetMotion(const PadIdentifier& identifier, int motion) const;
     Common::Input::CameraStatus GetCamera(const PadIdentifier& identifier) const;
+    Common::Input::NfcStatus GetNfc(const PadIdentifier& identifier) const;
 
     int SetCallback(InputIdentifier input_identifier);
     void SetMappingCallback(MappingCallback callback);
@@ -195,6 +209,7 @@ protected:
     void SetBattery(const PadIdentifier& identifier, Common::Input::BatteryLevel value);
     void SetMotion(const PadIdentifier& identifier, int motion, const BasicMotion& value);
     void SetCamera(const PadIdentifier& identifier, const Common::Input::CameraStatus& value);
+    void SetNfc(const PadIdentifier& identifier, const Common::Input::NfcStatus& value);
 
     virtual std::string GetHatButtonName([[maybe_unused]] u8 direction_value) const {
         return "Unknown";
@@ -208,6 +223,7 @@ private:
         std::unordered_map<int, BasicMotion> motions;
         Common::Input::BatteryLevel battery{};
         Common::Input::CameraStatus camera{};
+        Common::Input::NfcStatus nfc{};
     };
 
     void TriggerOnButtonChange(const PadIdentifier& identifier, int button, bool value);
@@ -218,6 +234,7 @@ private:
                                const BasicMotion& value);
     void TriggerOnCameraChange(const PadIdentifier& identifier,
                                const Common::Input::CameraStatus& value);
+    void TriggerOnNfcChange(const PadIdentifier& identifier, const Common::Input::NfcStatus& value);
 
     bool IsInputIdentifierEqual(const InputIdentifier& input_identifier,
                                 const PadIdentifier& identifier, EngineInputType type,
diff --git a/src/input_common/input_poller.cpp b/src/input_common/input_poller.cpp
index ffb9b945e..75705b67e 100644
--- a/src/input_common/input_poller.cpp
+++ b/src/input_common/input_poller.cpp
@@ -705,6 +705,47 @@ private:
     InputEngine* input_engine;
 };
 
+class InputFromNfc final : public Common::Input::InputDevice {
+public:
+    explicit InputFromNfc(PadIdentifier identifier_, InputEngine* input_engine_)
+        : identifier(identifier_), input_engine(input_engine_) {
+        UpdateCallback engine_callback{[this]() { OnChange(); }};
+        const InputIdentifier input_identifier{
+            .identifier = identifier,
+            .type = EngineInputType::Nfc,
+            .index = 0,
+            .callback = engine_callback,
+        };
+        callback_key = input_engine->SetCallback(input_identifier);
+    }
+
+    ~InputFromNfc() override {
+        input_engine->DeleteCallback(callback_key);
+    }
+
+    Common::Input::NfcStatus GetStatus() const {
+        return input_engine->GetNfc(identifier);
+    }
+
+    void ForceUpdate() override {
+        OnChange();
+    }
+
+    void OnChange() {
+        const Common::Input::CallbackStatus status{
+            .type = Common::Input::InputType::Nfc,
+            .nfc_status = GetStatus(),
+        };
+
+        TriggerOnChange(status);
+    }
+
+private:
+    const PadIdentifier identifier;
+    int callback_key;
+    InputEngine* input_engine;
+};
+
 class OutputFromIdentifier final : public Common::Input::OutputDevice {
 public:
     explicit OutputFromIdentifier(PadIdentifier identifier_, InputEngine* input_engine_)
@@ -727,6 +768,14 @@ public:
         return input_engine->SetCameraFormat(identifier, camera_format);
     }
 
+    Common::Input::NfcState SupportsNfc() const override {
+        return input_engine->SupportsNfc(identifier);
+    }
+
+    Common::Input::NfcState WriteNfcData(const std::vector<u8>& data) override {
+        return input_engine->WriteNfcData(identifier, data);
+    }
+
 private:
     const PadIdentifier identifier;
     InputEngine* input_engine;
@@ -978,6 +1027,18 @@ std::unique_ptr<Common::Input::InputDevice> InputFactory::CreateCameraDevice(
     return std::make_unique<InputFromCamera>(identifier, input_engine.get());
 }
 
+std::unique_ptr<Common::Input::InputDevice> InputFactory::CreateNfcDevice(
+    const Common::ParamPackage& params) {
+    const PadIdentifier identifier = {
+        .guid = Common::UUID{params.Get("guid", "")},
+        .port = static_cast<std::size_t>(params.Get("port", 0)),
+        .pad = static_cast<std::size_t>(params.Get("pad", 0)),
+    };
+
+    input_engine->PreSetController(identifier);
+    return std::make_unique<InputFromNfc>(identifier, input_engine.get());
+}
+
 InputFactory::InputFactory(std::shared_ptr<InputEngine> input_engine_)
     : input_engine(std::move(input_engine_)) {}
 
@@ -989,6 +1050,9 @@ std::unique_ptr<Common::Input::InputDevice> InputFactory::Create(
     if (params.Has("camera")) {
         return CreateCameraDevice(params);
     }
+    if (params.Has("nfc")) {
+        return CreateNfcDevice(params);
+    }
     if (params.Has("button") && params.Has("axis")) {
         return CreateTriggerDevice(params);
     }
diff --git a/src/input_common/input_poller.h b/src/input_common/input_poller.h
index 4410a8415..d7db13ce4 100644
--- a/src/input_common/input_poller.h
+++ b/src/input_common/input_poller.h
@@ -222,6 +222,16 @@ private:
     std::unique_ptr<Common::Input::InputDevice> CreateCameraDevice(
         const Common::ParamPackage& params);
 
+    /**
+     * Creates a nfc device from the parameters given.
+     * @param params contains parameters for creating the device:
+     *               - "guid": text string for identifying controllers
+     *               - "port": port of the connected device
+     *               - "pad": slot of the connected controller
+     * @returns a unique input device with the parameters specified
+     */
+    std::unique_ptr<Common::Input::InputDevice> CreateNfcDevice(const Common::ParamPackage& params);
+
     std::shared_ptr<InputEngine> input_engine;
 };
 } // namespace InputCommon
diff --git a/src/input_common/main.cpp b/src/input_common/main.cpp
index 75a57b9fc..b2064ef95 100644
--- a/src/input_common/main.cpp
+++ b/src/input_common/main.cpp
@@ -11,6 +11,7 @@
 #include "input_common/drivers/tas_input.h"
 #include "input_common/drivers/touch_screen.h"
 #include "input_common/drivers/udp_client.h"
+#include "input_common/drivers/virtual_amiibo.h"
 #include "input_common/helpers/stick_from_buttons.h"
 #include "input_common/helpers/touch_from_buttons.h"
 #include "input_common/input_engine.h"
@@ -87,6 +88,15 @@ struct InputSubsystem::Impl {
         Common::Input::RegisterFactory<Common::Input::OutputDevice>(camera->GetEngineName(),
                                                                     camera_output_factory);
 
+        virtual_amiibo = std::make_shared<VirtualAmiibo>("virtual_amiibo");
+        virtual_amiibo->SetMappingCallback(mapping_callback);
+        virtual_amiibo_input_factory = std::make_shared<InputFactory>(virtual_amiibo);
+        virtual_amiibo_output_factory = std::make_shared<OutputFactory>(virtual_amiibo);
+        Common::Input::RegisterFactory<Common::Input::InputDevice>(virtual_amiibo->GetEngineName(),
+                                                                   virtual_amiibo_input_factory);
+        Common::Input::RegisterFactory<Common::Input::OutputDevice>(virtual_amiibo->GetEngineName(),
+                                                                    virtual_amiibo_output_factory);
+
 #ifdef HAVE_SDL2
         sdl = std::make_shared<SDLDriver>("sdl");
         sdl->SetMappingCallback(mapping_callback);
@@ -327,6 +337,7 @@ struct InputSubsystem::Impl {
     std::shared_ptr<TasInput::Tas> tas_input;
     std::shared_ptr<CemuhookUDP::UDPClient> udp_client;
     std::shared_ptr<Camera> camera;
+    std::shared_ptr<VirtualAmiibo> virtual_amiibo;
 
     std::shared_ptr<InputFactory> keyboard_factory;
     std::shared_ptr<InputFactory> mouse_factory;
@@ -335,6 +346,7 @@ struct InputSubsystem::Impl {
     std::shared_ptr<InputFactory> udp_client_input_factory;
     std::shared_ptr<InputFactory> tas_input_factory;
     std::shared_ptr<InputFactory> camera_input_factory;
+    std::shared_ptr<InputFactory> virtual_amiibo_input_factory;
 
     std::shared_ptr<OutputFactory> keyboard_output_factory;
     std::shared_ptr<OutputFactory> mouse_output_factory;
@@ -342,6 +354,7 @@ struct InputSubsystem::Impl {
     std::shared_ptr<OutputFactory> udp_client_output_factory;
     std::shared_ptr<OutputFactory> tas_output_factory;
     std::shared_ptr<OutputFactory> camera_output_factory;
+    std::shared_ptr<OutputFactory> virtual_amiibo_output_factory;
 
 #ifdef HAVE_SDL2
     std::shared_ptr<SDLDriver> sdl;
@@ -402,6 +415,14 @@ const Camera* InputSubsystem::GetCamera() const {
     return impl->camera.get();
 }
 
+VirtualAmiibo* InputSubsystem::GetVirtualAmiibo() {
+    return impl->virtual_amiibo.get();
+}
+
+const VirtualAmiibo* InputSubsystem::GetVirtualAmiibo() const {
+    return impl->virtual_amiibo.get();
+}
+
 std::vector<Common::ParamPackage> InputSubsystem::GetInputDevices() const {
     return impl->GetInputDevices();
 }
diff --git a/src/input_common/main.h b/src/input_common/main.h
index 9a969e747..ced252383 100644
--- a/src/input_common/main.h
+++ b/src/input_common/main.h
@@ -33,6 +33,7 @@ class Camera;
 class Keyboard;
 class Mouse;
 class TouchScreen;
+class VirtualAmiibo;
 struct MappingData;
 } // namespace InputCommon
 
@@ -101,6 +102,12 @@ public:
     /// Retrieves the underlying camera input device.
     [[nodiscard]] const Camera* GetCamera() const;
 
+    /// Retrieves the underlying virtual amiibo input device.
+    [[nodiscard]] VirtualAmiibo* GetVirtualAmiibo();
+
+    /// Retrieves the underlying virtual amiibo input device.
+    [[nodiscard]] const VirtualAmiibo* GetVirtualAmiibo() const;
+
     /**
      * Returns all available input devices that this Factory can create a new device with.
      * Each returned ParamPackage should have a `display` field used for display, a `engine` field