ES-DE/es-core/src/InputManager.cpp

//  SPDX-License-Identifier: MIT
//
//  EmulationStation Desktop Edition
//  InputManager.cpp
//
//  Low-level input handling.
//  Initiates and maps the keyboard and controllers.
//  Reads and writes the es_input.xml configuration file.
//

#include "InputManager.h"

#include "resources/ResourceManager.h"
#include "utils/FileSystemUtil.h"
#include "utils/StringUtil.h"
#include "CECInput.h"
#include "Log.h"
#include "Platform.h"
#include "Scripting.h"
#include "Window.h"

#include <iostream>
#include <pugixml.hpp>

#define KEYBOARD_GUID_STRING "-1"
#define CEC_GUID_STRING "-2"

int SDL_USER_CECBUTTONDOWN = -1;
int SDL_USER_CECBUTTONUP = -1;

// save button states for combo-button exit support and predefine exit option-function map
static bool altDown = false;
static bool lguiDown = false;

InputManager* InputManager::sInstance = nullptr;

InputManager::InputManager() : mKeyboardInputConfig(nullptr)
{
}

InputManager::~InputManager()
{
    deinit();
}

InputManager* InputManager::getInstance()
{
    if (!sInstance)
        sInstance = new InputManager();

    return sInstance;
}

void InputManager::init()
{
    if (initialized())
        deinit();

    mConfigFileExists = false;

    LOG(LogInfo) << "Setting up InputManager...";

    SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER);
    SDL_GameControllerEventState(SDL_ENABLE);

    if (!Utils::FileSystem::exists(getConfigPath())) {
        LOG(LogInfo) << "No input configuration file found, default mappings will be applied";
    }
    else {
        mConfigFileExists = true;
    }

    mKeyboardInputConfig = std::make_unique<InputConfig>(DEVICE_KEYBOARD,
            "Keyboard", KEYBOARD_GUID_STRING);

    bool customConfig = loadInputConfig(mKeyboardInputConfig.get());

    if (customConfig) {
        LOG(LogInfo) << "Added keyboard with custom configuration";
    }
    else {
        loadDefaultKBConfig();
        LOG(LogInfo) << "Added keyboard with default configuration";
    }

    // Load optional controller mappings. Normally the supported controllers should be compiled
    // into SDL as a header file, but if a user has a very rare controller that is not supported,
    // the bundled mapping is incorrect, or the SDL version is a bit older, it makes sense to be
    // able to customize this. If a controller GUID is present in the mappings file that is
    // already present inside SDL, the custom mapping will overwrite the bundled one.
    std::string mappingsFile = Utils::FileSystem::getHomePath() +
            "/.emulationstation/" + "es_controller_mappings.cfg";

    if (!Utils::FileSystem::exists(mappingsFile))
        mappingsFile = ResourceManager::getInstance()->
                getResourcePath(":/controllers/es_controller_mappings.cfg");

    int controllerMappings = SDL_GameControllerAddMappingsFromFile(mappingsFile.c_str());

    if (controllerMappings != -1 && controllerMappings != 0) {
        LOG(LogInfo) << "Loaded " << controllerMappings << " controller " <<
                (controllerMappings == 1 ? "mapping" : "mappings");
    }

    int numJoysticks = SDL_NumJoysticks();

    // Make sure that every joystick is actually supported by the GameController API.
    for (int i = 0; i < numJoysticks; i++)
        if (!SDL_IsGameController(i))
            numJoysticks--;

    for (int i = 0; i < numJoysticks; i++)
        addControllerByDeviceIndex(i);

    SDL_USER_CECBUTTONDOWN = SDL_RegisterEvents(2);
    SDL_USER_CECBUTTONUP = SDL_USER_CECBUTTONDOWN + 1;
    CECInput::init();
    mCECInputConfig = std::make_unique<InputConfig>(DEVICE_CEC, "CEC", CEC_GUID_STRING);
    loadInputConfig(mCECInputConfig.get());
}

void InputManager::deinit()
{
    if (!initialized())
        return;

    for (auto it = mControllers.cbegin(); it != mControllers.cend(); it++)
        SDL_GameControllerClose(it->second);

    mControllers.clear();
    mJoysticks.clear();
    mPrevAxisValues.clear();
    mPrevButtonValues.clear();
    mInputConfigs.clear();

    mKeyboardInputConfig.reset();
    mCECInputConfig.reset();

    CECInput::deinit();

    SDL_GameControllerEventState(SDL_DISABLE);
    SDL_QuitSubSystem(SDL_INIT_GAMECONTROLLER);

    if (sInstance) {
        delete sInstance;
        sInstance = nullptr;
    }
}

void InputManager::writeDeviceConfig(InputConfig* config)
{
    assert(initialized());

    std::string path = getConfigPath();

    LOG(LogDebug) << "InputManager::writeDeviceConfig(): "
            "Saving input configuration file to \"" << path << "\"";

    pugi::xml_document doc;

    if (Utils::FileSystem::exists(path)) {
        // Merge files.
        #if defined(_WIN64)
        pugi::xml_parse_result result =
                doc.load_file(Utils::String::stringToWideString(path).c_str());
        #else
        pugi::xml_parse_result result = doc.load_file(path.c_str());
        #endif
        if (!result) {
            LOG(LogError) << "Couldn't parse input configuration file: " << result.description();
        }
        else {
            // Successfully loaded, delete the old entry if it exists.
            pugi::xml_node root = doc.child("inputList");
            if (root) {
                // If inputAction @type=onfinish is set, let doOnFinish command take care of
                // creating input configuration. We just put the input configuration into a
                // temporary input config file.
                pugi::xml_node actionnode = root.find_child_by_attribute("inputAction",
                        "type", "onfinish");
                if (actionnode) {
                    path = getTemporaryConfigPath();
                    doc.reset();
                    root = doc.append_child("inputList");
                    root.append_copy(actionnode);
                }
                else {
                    pugi::xml_node oldEntry = root.find_child_by_attribute("inputConfig",
                            "deviceGUID", config->getDeviceGUIDString().c_str());
                    if (oldEntry)
                        root.remove_child(oldEntry);
                    oldEntry = root.find_child_by_attribute("inputConfig", "deviceName",
                            config->getDeviceName().c_str());
                    if (oldEntry)
                        root.remove_child(oldEntry);
                }
            }
        }
    }

    pugi::xml_node root = doc.child("inputList");
    if (!root)
        root = doc.append_child("inputList");

    config->writeToXML(root);

    #if defined(_WIN64)
    doc.save_file(Utils::String::stringToWideString(path).c_str());
    #else
    doc.save_file(path.c_str());
    #endif

    Scripting::fireEvent("config-changed");
    Scripting::fireEvent("controls-changed");

    // Execute any doOnFinish commands and reload the config for changes.
    doOnFinish();
    mConfigFileExists = true;
    loadInputConfig(config);
}

void InputManager::doOnFinish()
{
    assert(initialized());
    std::string path = getConfigPath();
    pugi::xml_document doc;

    if (Utils::FileSystem::exists(path)) {
        #if defined(_WIN64)
        pugi::xml_parse_result result =
                doc.load_file(Utils::String::stringToWideString(path).c_str());
        #else
        pugi::xml_parse_result result = doc.load_file(path.c_str());
        #endif

        if (!result) {
            LOG(LogError) << "Couldn't parse input configuration file: " << result.description();
        }
        else {
            pugi::xml_node root = doc.child("inputList");
            if (root) {
                root = root.find_child_by_attribute("inputAction", "type", "onfinish");
                if (root) {
                    for (pugi::xml_node command = root.child("command"); command;
                            command = command.next_sibling("command")) {
                        std::string tocall = command.text().get();

                        LOG(LogInfo) << "	" << tocall;
                        std::cout << "==============================================\n"
                                "input config finish command:\n";
                        int exitCode = runSystemCommand(tocall);
                        std::cout << "==============================================\n";

                        if (exitCode != 0) {
                            LOG(LogWarning) << "...launch terminated with nonzero exit code " <<
                                    exitCode << "!";
                        }
                    }
                }
            }
        }
    }
}

std::string InputManager::getConfigPath()
{
    std::string path = Utils::FileSystem::getHomePath();
    path += "/.emulationstation/es_input.xml";
    return path;
}

std::string InputManager::getTemporaryConfigPath()
{
    std::string path = Utils::FileSystem::getHomePath();
    path += "/.emulationstation/es_temporaryinput.xml";
    return path;
}

int InputManager::getNumJoysticks()
{
    int numJoysticks = 0;

    // This is a workaround to exclude the keyboard (ID -1) from the total joystick count.
    // It's incorrectly added when configuring the keyboard in GuiInputConfig, but I've
    // been unable to find a proper fix to not having it added to mJoysticks.
    for (auto it = mJoysticks.cbegin(); it != mJoysticks.cend(); it++) {
        if ((*it).first >= 0)
            numJoysticks += 1;
    }
    return numJoysticks;
}

int InputManager::getNumConfiguredDevices()
{
    int num = 0;
    for (auto it = mInputConfigs.cbegin(); it != mInputConfigs.cend(); it++)
        if (it->second->isConfigured())
            num++;

    if (mKeyboardInputConfig->isConfigured())
        num++;

    if (mCECInputConfig->isConfigured())
        num++;

    return num;
}

int InputManager::getAxisCountByDevice(SDL_JoystickID id)
{
    return SDL_JoystickNumAxes(mJoysticks[id]);
}

int InputManager::getButtonCountByDevice(SDL_JoystickID id)
{
    if (id == DEVICE_KEYBOARD)
        return -1;
    else if (id == DEVICE_CEC)
    #if defined(HAVE_CECLIB)
        return CEC::CEC_USER_CONTROL_CODE_MAX;
    #else
        return 0;
    #endif
    else
        return SDL_JoystickNumButtons(mJoysticks[id]);
}

std::string InputManager::getDeviceGUIDString(int deviceId)
{
    if (deviceId == DEVICE_KEYBOARD)
        return KEYBOARD_GUID_STRING;

    if (deviceId == DEVICE_CEC)
        return CEC_GUID_STRING;

    auto it = mJoysticks.find(deviceId);
    if (it == mJoysticks.cend()) {
        LOG(LogError) << "getDeviceGUIDString - deviceId " << deviceId << " not found!";
        return "Something went horribly wrong";
    }

    char guid[65];
    SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(it->second), guid, 65);
    return std::string(guid);
}

InputConfig* InputManager::getInputConfigByDevice(int device)
{
    if (device == DEVICE_KEYBOARD)
        return mKeyboardInputConfig.get();
    else if (device == DEVICE_CEC)
        return mCECInputConfig.get();
    else
        return mInputConfigs[device].get();
}

bool InputManager::parseEvent(const SDL_Event& event, Window* window)
{
    bool causedEvent = false;
    int32_t axisValue;

    switch (event.type) {
        case SDL_CONTROLLERAXISMOTION: {
        // Whether to only accept input from the first controller.
        if (Settings::getInstance()->getBool("InputOnlyFirstController"))
            if (mInputConfigs.begin()->first != event.cdevice.which)
                return false;

            // This is needed for a situation which sometimes occur when a game is launched,
            // some axis input is generated and then the controller is disconnected before
            // leaving the game. In this case, events for the old device index could be received
            // when returning from the game. If this happens we simply delete the configuration
            // map entry.
            if (!mInputConfigs[event.caxis.which]) {
                auto it = mInputConfigs.find(event.cdevice.which);
                mInputConfigs.erase(it);
                return false;
            }

            axisValue = event.caxis.value;
            int deadzone = 0;

            if (event.caxis.axis == SDL_CONTROLLER_AXIS_TRIGGERLEFT ||
                    event.caxis.axis == SDL_CONTROLLER_AXIS_TRIGGERRIGHT)
                deadzone = DEADZONE_TRIGGERS;
            else
                deadzone = DEADZONE_THUMBSTICKS;

            // Check if the input value switched boundaries.
            if ((abs(axisValue) > deadzone) != (abs(mPrevAxisValues[
                    std::make_pair(event.caxis.which, event.caxis.axis)]) > deadzone)) {
                int normValue;
                if (abs(axisValue) <= deadzone) {
                    normValue = 0;
                }
                else {
                    if (axisValue > 0)
                        normValue = 1;
                    else
                        normValue = -1;
                }

                window->input(getInputConfigByDevice(event.caxis.which), Input(event.caxis.which,
                        TYPE_AXIS, event.caxis.axis, normValue, false));
                causedEvent = true;
            }

            mPrevAxisValues[std::make_pair(event.caxis.which, event.caxis.axis)] = axisValue;
            return causedEvent;
        }
        case SDL_CONTROLLERBUTTONDOWN: {
        }
        case SDL_CONTROLLERBUTTONUP: {
        // Whether to only accept input from the first controller.
        if (Settings::getInstance()->getBool("InputOnlyFirstController"))
            if (mInputConfigs.begin()->first != event.cdevice.which)
                return false;

            // The event filtering below is required as some controllers send button presses
            // starting with the state 0 when using the D-pad. I consider this invalid behaviour
            // and the more popular controllers such as those from Microsoft and Sony do not show
            // this strange behavior.
            int buttonState = mPrevButtonValues[
                    std::make_pair(event.cbutton.which, event.cbutton.button)];

            if ((buttonState == -1 || buttonState == 0) && event.cbutton.state == 0)
                return false;

            mPrevButtonValues[std::make_pair(event.cbutton.which, event.cbutton.button)] =
                    event.cbutton.state;

            window->input(getInputConfigByDevice(event.cbutton.which), Input(event.cbutton.which,
                    TYPE_BUTTON, event.cbutton.button, event.cbutton.state == SDL_PRESSED, false));

            return true;
        }
        case SDL_KEYDOWN: {

            // save button states for alt and command
            if (event.key.keysym.sym == SDLK_LALT)
            {
                altDown = true;
            }
            if (event.key.keysym.sym == SDLK_LGUI)
            {
                lguiDown = true;
            }

            if (event.key.keysym.sym == SDLK_BACKSPACE && SDL_IsTextInputActive())
                window->textInput("\b");

            if (event.key.repeat)
                return false;

            // handle application exit
            bool exitState;
            std::string exitOption = Settings::getInstance()->getString("ExitButtonCombo");
            if (exitOption == "AltF4"){
                exitState = event.key.keysym.sym == SDLK_F4 && altDown;
            }else if (exitOption == "CmdQ"){
                exitState = event.key.keysym.sym == SDLK_q && lguiDown;
            }else if (exitOption == "AltQ"){
                exitState = event.key.keysym.sym == SDLK_q && altDown;
            }else{
                exitState = event.key.keysym.sym == SDLK_F4;
            }
            if (exitState) {
                SDL_Event quit;
                quit.type = SDL_QUIT;
                SDL_PushEvent(&quit);
                return false;
            }

            window->input(getInputConfigByDevice(DEVICE_KEYBOARD), Input(DEVICE_KEYBOARD,
                    TYPE_KEY, event.key.keysym.sym, 1, false));
            return true;
        }
        case SDL_KEYUP: {

            // release button states
            if (event.key.keysym.sym == SDLK_LALT)
            {
                altDown = false;
            }
            if (event.key.keysym.sym == SDLK_LGUI)
            {
                lguiDown = false;
            }

            window->input(getInputConfigByDevice(DEVICE_KEYBOARD), Input(DEVICE_KEYBOARD,
                    TYPE_KEY, event.key.keysym.sym, 0, false));
            return true;
        }
        case SDL_TEXTINPUT: {
            window->textInput(event.text.text);
            break;
        }
        case SDL_CONTROLLERDEVICEADDED: {
            addControllerByDeviceIndex(event.cdevice.which);
            return true;
        }
        case SDL_CONTROLLERDEVICEREMOVED: {
            removeControllerByJoystickID(event.cdevice.which);
            return false;
        }
    }

    if ((event.type == static_cast<unsigned int>(SDL_USER_CECBUTTONDOWN)) ||
            (event.type == static_cast<unsigned int>(SDL_USER_CECBUTTONUP))) {
        window->input(getInputConfigByDevice(DEVICE_CEC), Input(DEVICE_CEC,
                TYPE_CEC_BUTTON, event.user.code, event.type ==
                static_cast<unsigned int>(SDL_USER_CECBUTTONDOWN), false));
        return true;
    }

    return false;
}

bool InputManager::initialized() const
{
    return mKeyboardInputConfig != nullptr;
}

bool InputManager::loadInputConfig(InputConfig* config)
{
    if (!mConfigFileExists)
        return false;

    std::string path = getConfigPath();

    pugi::xml_document doc;
    #if defined(_WIN64)
    pugi::xml_parse_result res = doc.load_file(Utils::String::stringToWideString(path).c_str());
    #else
    pugi::xml_parse_result res = doc.load_file(path.c_str());
    #endif

    if (!res) {
        LOG(LogError) << "Couldn't parse the input configuration file: " << res.description();
        return false;
    }

    pugi::xml_node root = doc.child("inputList");
    if (!root)
        return false;

    pugi::xml_node configNode = root.find_child_by_attribute("inputConfig",
            "deviceGUID", config->getDeviceGUIDString().c_str());

    // Enabling this will match an entry in es_input.xml based on the device name if there
    // was no GUID match. This is probably not a good idea as many controllers share the same
    // name even though the GUID differ and potentially the button configuration could be
    // different between them. Keeping the code for now though.
//    if (!configNode)
//        configNode = root.find_child_by_attribute("inputConfig",
//                "deviceName", config->getDeviceName().c_str());

    // With the move to the SDL GameController API the button layout changed quite a lot, so
    // es_input.xml files generated using the old API will end up with a completely unusable
    // controller configuration. These older files had the configuration entry type set to
    // "joystick", so it's easy to ignore such entries by only accepting entries with the
    // type set to "controller" (which is now applied when saving the es_input.xml file).
    if (configNode && config->getDeviceName() != "Keyboard")
        if (!root.find_child_by_attribute("inputConfig", "type", "controller"))
            return false;

    if (!configNode)
        return false;

    config->loadFromXML(configNode);
    return true;
}

void InputManager::loadDefaultKBConfig()
{
    InputConfig* cfg = getInputConfigByDevice(DEVICE_KEYBOARD);

    if (cfg->isConfigured())
        return;

    cfg->clear();
    cfg->mapInput("Up", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_UP, 1, true));
    cfg->mapInput("Down", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_DOWN, 1, true));
    cfg->mapInput("Left", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_LEFT, 1, true));
    cfg->mapInput("Right", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_RIGHT, 1, true));

    cfg->mapInput("A", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_RETURN, 1, true));
    cfg->mapInput("B", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_BACKSPACE, 1, true));
    cfg->mapInput("X", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_DELETE, 1, true));
    #if defined(__APPLE__)
    cfg->mapInput("Y", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_PRINTSCREEN, 1, true));
    #else
    cfg->mapInput("Y", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_INSERT, 1, true));
    #endif
    cfg->mapInput("Start", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_ESCAPE, 1, true));
    cfg->mapInput("Back", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_F1, 1, true));

    cfg->mapInput("LeftShoulder", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_PAGEUP, 1, true));
    cfg->mapInput("RightShoulder", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_PAGEDOWN, 1, true));
    cfg->mapInput("LeftTrigger", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_HOME, 1, true));
    cfg->mapInput("RightTrigger", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_END, 1, true));

    cfg->mapInput("LeftThumbstickClick", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_F2, 1, true));
    cfg->mapInput("RightThumbstickClick", Input(DEVICE_KEYBOARD, TYPE_KEY, SDLK_F3, 1, true));
}

void InputManager::loadDefaultControllerConfig(SDL_JoystickID deviceIndex)
{
    InputConfig* cfg = getInputConfigByDevice(deviceIndex);

    if (cfg->isConfigured())
        return;

    cfg->mapInput("Up", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_DPAD_UP, 1, true));
    cfg->mapInput("Down", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_DPAD_DOWN, 1, true));
    cfg->mapInput("Left", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_DPAD_LEFT, 1, true));
    cfg->mapInput("Right", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_DPAD_RIGHT, 1, true));
    cfg->mapInput("Start", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_START, 1, true));
    cfg->mapInput("Back", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_BACK, 1, true));
    cfg->mapInput("A", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_A, 1, true));
    cfg->mapInput("B", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_B, 1, true));
    cfg->mapInput("X", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_X, 1, true));
    cfg->mapInput("Y", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_Y, 1, true));
    cfg->mapInput("LeftShoulder", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_LEFTSHOULDER, 1, true));
    cfg->mapInput("RightShoulder", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER, 1, true));
    cfg->mapInput("LeftTrigger", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_TRIGGERLEFT, 1, true));
    cfg->mapInput("RightTrigger", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_TRIGGERRIGHT, 1, true));
    cfg->mapInput("LeftThumbstickUp", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_LEFTY, -1, true));
    cfg->mapInput("LeftThumbstickDown", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_LEFTY, 1, true));
    cfg->mapInput("LeftThumbstickLeft", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_LEFTX, -1, true));
    cfg->mapInput("LeftThumbstickRight", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_LEFTX, 1, true));
    cfg->mapInput("LeftThumbstickClick", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_LEFTSTICK, 1, true));
    cfg->mapInput("RightThumbstickUp", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_RIGHTY, -1, true));
    cfg->mapInput("RightThumbstickDown", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_RIGHTY, 1, true));
    cfg->mapInput("RightThumbstickLeft", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_RIGHTX, -1, true));
    cfg->mapInput("RightThumbstickRight", Input(deviceIndex, TYPE_AXIS, SDL_CONTROLLER_AXIS_RIGHTX, 1, true));
    cfg->mapInput("RightThumbstickClick", Input(deviceIndex, TYPE_BUTTON, SDL_CONTROLLER_BUTTON_RIGHTSTICK, 1, true));
}

void InputManager::addControllerByDeviceIndex(int deviceIndex)
{
    // Open joystick and add it to our list.
    SDL_GameController* controller = SDL_GameControllerOpen(deviceIndex);
    SDL_Joystick* joy = SDL_GameControllerGetJoystick(controller);

    // Add it to our list so we can close it again later.
    SDL_JoystickID joyID = SDL_JoystickInstanceID(joy);
    mJoysticks[joyID] = joy;
    mControllers[joyID] = controller;

    char guid[65];
    SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(joy), guid, 65);

    mInputConfigs[joyID] = std::make_unique<InputConfig>(
            joyID, SDL_GameControllerName(mControllers[joyID]), guid);

    bool customConfig = loadInputConfig(mInputConfigs[joyID].get());

    if (customConfig) {
        LOG(LogInfo) << "Added controller with custom configuration: \"" <<
                SDL_GameControllerName(mControllers[joyID]) << "\" (GUID: " << guid <<
                ", instance ID: " << joyID << ", device index: " << deviceIndex << ")";
    }
    else {
        loadDefaultControllerConfig(joyID);
        LOG(LogInfo) << "Added controller with default configuration: \"" <<
                SDL_GameControllerName(mControllers[joyID]) << "\" (GUID: " << guid <<
                ", instance ID: " << joyID << ", device index: " << deviceIndex << ")";
    }

    int numAxes = SDL_JoystickNumAxes(joy);
    int numButtons = SDL_JoystickNumButtons(joy);

    for (int axis = 0; axis < numAxes; axis++)
        mPrevAxisValues[std::make_pair(joyID, axis)] = 0;

    for (int button = 0; button < numButtons; button++)
        mPrevButtonValues[std::make_pair(joyID, button)] = -1;
}

void InputManager::removeControllerByJoystickID(SDL_JoystickID joyID)
{
    assert(joyID != -1);

    char guid[65];
    SDL_Joystick* joy = SDL_JoystickFromInstanceID(joyID);
    SDL_JoystickGetGUIDString(SDL_JoystickGetGUID(joy), guid, 65);

    LOG(LogInfo) << "Removed controller \"" << SDL_GameControllerName(mControllers[joyID]) <<
            "\" (GUID: " << guid << ", instance ID: " << joyID << ")";

    // Delete mPrevAxisValues for the device.
    int axisEntries = static_cast<int>(mPrevAxisValues.size());
    for (int i = 0; i < axisEntries; i++) {
        auto entry = mPrevAxisValues.find(std::make_pair(joyID, i));
        if (entry != mPrevAxisValues.end()) {
            mPrevAxisValues.erase(entry);
        }
    }

    // Delete mPrevButtonValues for the device.
    int buttonEntries = static_cast<int>(mPrevButtonValues.size());
    for (int i = 0; i < buttonEntries; i++) {
        auto entry = mPrevButtonValues.find(std::make_pair(joyID, i));
        if (entry != mPrevButtonValues.end()) {
            mPrevButtonValues.erase(entry);
        }
    }

    auto it = mInputConfigs.find(joyID);
    mInputConfigs.erase(it);

    // Close the controllers.
    auto controllerIt = mControllers.find(joyID);
    if (controllerIt != mControllers.cend()) {
        SDL_GameControllerClose(controllerIt->second);
        mControllers.erase(controllerIt);
    }
    else {
        LOG(LogError) << "Couldn't find controller to close (instance ID: " << joyID << ")";
    }
}