//
//  ViveControllerManager.cpp
//  input-plugins/src/input-plugins
//
//  Created by Sam Gondelman on 6/29/15.
//  Copyright 2013 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "ViveControllerManager.h"
#include <algorithm>

#include <PerfStat.h>
#include <PathUtils.h>
#include <GeometryCache.h>
#include <gpu/Batch.h>
#include <gpu/Context.h>
#include <DeferredLightingEffect.h>
#include <NumericalConstants.h>
#include <ui-plugins/PluginContainer.h>
#include <UserActivityLogger.h>
#include <NumericalConstants.h>
#include <OffscreenUi.h>
#include <GLMHelpers.h>
#include <glm/ext.hpp>
#include <glm/gtc/quaternion.hpp>


#include <controllers/UserInputMapper.h>

#include <controllers/StandardControls.h>

#include "OpenVrHelpers.h"

extern PoseData _nextSimPoseData;

vr::IVRSystem* acquireOpenVrSystem();
void releaseOpenVrSystem();


static const char* CONTROLLER_MODEL_STRING = "vr_controller_05_wireless_b";
const quint64 CALIBRATION_TIMELAPSE = 2 * USECS_PER_SECOND;

static const char* MENU_PARENT = "Avatar";
static const char* MENU_NAME = "Vive Controllers";
static const char* MENU_PATH = "Avatar" ">" "Vive Controllers";
static const char* RENDER_CONTROLLERS = "Render Hand Controllers";
static const int MIN_PUCK_COUNT = 2;
static const int MIN_FEET_AND_HIPS = 3;
static const int MIN_FEET_HIPS_CHEST = 4;
static const int FIRST_FOOT = 0;
static const int SECOND_FOOT = 1;
static const int HIP = 2;
static const int CHEST = 3;

const char* ViveControllerManager::NAME { "OpenVR" };

static glm::mat4 computeOffset(glm::mat4 defaultToReferenceMat, glm::mat4 defaultJointMat, controller::Pose puckPose) {
    glm::mat4 poseMat = createMatFromQuatAndPos(puckPose.rotation, puckPose.translation);
    glm::mat4 referenceJointMat = defaultToReferenceMat * defaultJointMat;
    return glm::inverse(poseMat) * referenceJointMat;
}

static bool sortPucksYPosition(std::pair<uint32_t, controller::Pose> firstPuck, std::pair<uint32_t, controller::Pose> secondPuck) {
    return (firstPuck.second.translation.y < firstPuck.second.translation.y);
}

bool ViveControllerManager::isSupported() const {
    return openVrSupported();
}

bool ViveControllerManager::activate() {
    InputPlugin::activate();

    _container->addMenu(MENU_PATH);
    _container->addMenuItem(PluginType::INPUT_PLUGIN, MENU_PATH, RENDER_CONTROLLERS,
        [this] (bool clicked) { this->setRenderControllers(clicked); },
        true, true);

    if (!_system) {
        _system = acquireOpenVrSystem();
    }
    Q_ASSERT(_system);

    enableOpenVrKeyboard(_container);

    // register with UserInputMapper
    auto userInputMapper = DependencyManager::get<controller::UserInputMapper>();
    userInputMapper->registerDevice(_inputDevice);
    _registeredWithInputMapper = true;
    return true;
}

void ViveControllerManager::deactivate() {
    InputPlugin::deactivate();

    disableOpenVrKeyboard();

    _container->removeMenuItem(MENU_NAME, RENDER_CONTROLLERS);
    _container->removeMenu(MENU_PATH);

    if (_system) {
        _container->makeRenderingContextCurrent();
        releaseOpenVrSystem();
        _system = nullptr;
    }

    _inputDevice->_poseStateMap.clear();

    // unregister with UserInputMapper
    auto userInputMapper = DependencyManager::get<controller::UserInputMapper>();
    userInputMapper->removeDevice(_inputDevice->_deviceID);
    _registeredWithInputMapper = false;
}

void ViveControllerManager::pluginUpdate(float deltaTime, const controller::InputCalibrationData& inputCalibrationData) {

    if (!_system) {
        return;
    }

    auto userInputMapper = DependencyManager::get<controller::UserInputMapper>();
    handleOpenVrEvents();
    if (openVrQuitRequested()) {
        deactivate();
        return;
    }

    // because update mutates the internal state we need to lock
    userInputMapper->withLock([&, this]() {
        _inputDevice->update(deltaTime, inputCalibrationData);
    });

    if (_inputDevice->_trackedControllers == 0 && _registeredWithInputMapper) {
        userInputMapper->removeDevice(_inputDevice->_deviceID);
        _registeredWithInputMapper = false;
        _inputDevice->_poseStateMap.clear();
    }

    if (!_registeredWithInputMapper && _inputDevice->_trackedControllers > 0) {
        userInputMapper->registerDevice(_inputDevice);
        _registeredWithInputMapper = true;
    }
}

void ViveControllerManager::InputDevice::update(float deltaTime, const controller::InputCalibrationData& inputCalibrationData) {
    _poseStateMap.clear();
    _buttonPressedMap.clear();
    _validTrackedObjects.clear();

    // While the keyboard is open, we defer strictly to the keyboard values
    if (isOpenVrKeyboardShown()) {
        _axisStateMap.clear();
        return;
    }

    PerformanceTimer perfTimer("ViveControllerManager::update");

    auto leftHandDeviceIndex = _system->GetTrackedDeviceIndexForControllerRole(vr::TrackedControllerRole_LeftHand);
    auto rightHandDeviceIndex = _system->GetTrackedDeviceIndexForControllerRole(vr::TrackedControllerRole_RightHand);

    handleHandController(deltaTime, leftHandDeviceIndex, inputCalibrationData, true);
    handleHandController(deltaTime, rightHandDeviceIndex, inputCalibrationData, false);

    // collect poses for all generic trackers
    for (int i = 0; i < vr::k_unMaxTrackedDeviceCount; i++) {
        handleTrackedObject(i, inputCalibrationData);
        handleHmd(i, inputCalibrationData);
    }

    // handle haptics
    {
        Locker locker(_lock);
        if (_leftHapticDuration > 0.0f) {
            hapticsHelper(deltaTime, true);
        }
        if (_rightHapticDuration > 0.0f) {
            hapticsHelper(deltaTime, false);
        }
    }

    int numTrackedControllers = 0;
    if (leftHandDeviceIndex != vr::k_unTrackedDeviceIndexInvalid) {
        numTrackedControllers++;
    }
    if (rightHandDeviceIndex != vr::k_unTrackedDeviceIndexInvalid) {
        numTrackedControllers++;
    }
    _trackedControllers = numTrackedControllers;

    if (checkForCalibrationEvent()) {
        quint64 currentTime = usecTimestampNow();
        if (!_timeTilCalibrationSet) {
            _timeTilCalibrationSet = true;
            _timeTilCalibration = currentTime + CALIBRATION_TIMELAPSE;
        }

        if (currentTime > _timeTilCalibration && !_triggersPressedHandled) {
            _triggersPressedHandled = true;
            calibrateOrUncalibrate(inputCalibrationData);
        }
    } else {
        _triggersPressedHandled = false;
        _timeTilCalibrationSet = false;
    }

    updateCalibratedLimbs();
}

void ViveControllerManager::InputDevice::handleTrackedObject(uint32_t deviceIndex, const controller::InputCalibrationData& inputCalibrationData) {
    uint32_t poseIndex = controller::TRACKED_OBJECT_00 + deviceIndex;

    if (_system->IsTrackedDeviceConnected(deviceIndex) &&
        _system->GetTrackedDeviceClass(deviceIndex) == vr::TrackedDeviceClass_GenericTracker &&
        _nextSimPoseData.vrPoses[deviceIndex].bPoseIsValid &&
        poseIndex <= controller::TRACKED_OBJECT_15) {

        // process pose
        const mat4& mat = _nextSimPoseData.poses[deviceIndex];
        const vec3 linearVelocity = _nextSimPoseData.linearVelocities[deviceIndex];
        const vec3 angularVelocity = _nextSimPoseData.angularVelocities[deviceIndex];

        controller::Pose pose(extractTranslation(mat), glmExtractRotation(mat), linearVelocity, angularVelocity);

        // transform into avatar frame
        glm::mat4 controllerToAvatar = glm::inverse(inputCalibrationData.avatarMat) * inputCalibrationData.sensorToWorldMat;
        _poseStateMap[poseIndex] = pose.transform(controllerToAvatar);
        _validTrackedObjects.push_back(std::make_pair(poseIndex, _poseStateMap[poseIndex]));
    } else {
        controller::Pose invalidPose;
        _poseStateMap[poseIndex] = invalidPose;
    }
}

void ViveControllerManager::InputDevice::calibrateOrUncalibrate(const controller::InputCalibrationData& inputCalibration) {
    if (!_calibrated) {
        calibrate(inputCalibration);
    } else {
        uncalibrate();
    }
}

void ViveControllerManager::InputDevice::calibrate(const controller::InputCalibrationData& inputCalibration) {
    // convert the hmd head from sensor space to avatar space
    glm::mat4 hmdSensorFlippedMat = inputCalibration.hmdSensorMat * Matrices::Y_180;
    glm::mat4 sensorToAvatarMat = glm::inverse(inputCalibration.avatarMat) * inputCalibration.sensorToWorldMat;
    glm::mat4 hmdAvatarMat = sensorToAvatarMat * hmdSensorFlippedMat;

    // cancel the roll and pitch for the hmd head
    glm::quat hmdRotation = cancelOutRollAndPitch(glmExtractRotation(hmdAvatarMat));
    glm::vec3 hmdTranslation = extractTranslation(hmdAvatarMat);
    glm::mat4 currentHmd = createMatFromQuatAndPos(hmdRotation, hmdTranslation);

    // calculate the offset from the centerOfEye to defaultHeadMat
    glm::mat4 defaultHeadOffset = glm::inverse(inputCalibration.defaultCenterEyeMat) * inputCalibration.defaultHeadMat;

    glm::mat4 currentHead  = currentHmd * defaultHeadOffset;

    // calculate the defaultToRefrenceXform
    glm::mat4 defaultToReferenceMat = currentHead * glm::inverse(inputCalibration.defaultHeadMat);

    int puckCount = (int)_validTrackedObjects.size();
    if (puckCount == MIN_PUCK_COUNT) {
        _config = Config::Feet;
    } else if (puckCount == MIN_FEET_AND_HIPS) {
        _config = Config::FeetAndHips;
    } else if (puckCount >= MIN_FEET_HIPS_CHEST) {
        _config = Config::FeetHipsAndChest;
    } else {
        return;
    }

    std::sort(_validTrackedObjects.begin(), _validTrackedObjects.end(), sortPucksYPosition);



    auto& firstFoot = _validTrackedObjects[FIRST_FOOT];
    auto& secondFoot = _validTrackedObjects[SECOND_FOOT];
    controller::Pose& firstFootPose = firstFoot.second;
    controller::Pose& secondFootPose = secondFoot.second;

    if (firstFootPose.translation.x < secondFootPose.translation.x) {
        _jointToPuckMap[controller::LEFT_FOOT] = firstFoot.first;
        _pucksOffset[firstFoot.first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultLeftFoot, firstFootPose);
        _jointToPuckMap[controller::RIGHT_FOOT] = secondFoot.first;
        _pucksOffset[secondFoot.first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultRightFoot, secondFootPose);

    } else {
        _jointToPuckMap[controller::LEFT_FOOT] = secondFoot.first;
        _pucksOffset[secondFoot.first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultLeftFoot, secondFootPose);
        _jointToPuckMap[controller::RIGHT_FOOT] = firstFoot.first;
        _pucksOffset[firstFoot.first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultRightFoot, firstFootPose);
    }

    if (_config == Config::Feet) {
        // done
    } else if (_config == Config::FeetAndHips) {
        _jointToPuckMap[controller::HIPS] = _validTrackedObjects[HIP].first;
        _pucksOffset[_validTrackedObjects[HIP].first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultHips, _validTrackedObjects[HIP].second);
    } else if (_config == Config::FeetHipsAndChest) {
        _jointToPuckMap[controller::HIPS] = _validTrackedObjects[HIP].first;
        _pucksOffset[_validTrackedObjects[HIP].first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultHips, _validTrackedObjects[HIP].second);
        _jointToPuckMap[controller::SPINE2] = _validTrackedObjects[CHEST].first;
        _pucksOffset[_validTrackedObjects[CHEST].first] = computeOffset(defaultToReferenceMat, inputCalibration.defaultSpine2, _validTrackedObjects[CHEST].second);
    }
    _calibrated = true;
}

void ViveControllerManager::InputDevice::uncalibrate() {
    _pucksOffset.clear();
    _jointToPuckMap.clear();
    _calibrated = false;
}

void ViveControllerManager::InputDevice::updateCalibratedLimbs() {
    _poseStateMap[controller::LEFT_FOOT] = addOffsetToPuckPose(controller::LEFT_FOOT);
    _poseStateMap[controller::RIGHT_FOOT] = addOffsetToPuckPose(controller::RIGHT_FOOT);
    _poseStateMap[controller::HIPS] = addOffsetToPuckPose(controller::HIPS);
    _poseStateMap[controller::SPINE2] = addOffsetToPuckPose(controller::SPINE2);
}

controller::Pose ViveControllerManager::InputDevice::addOffsetToPuckPose(int joint) const {
    auto puck = _jointToPuckMap.find(joint);
    if (puck != _jointToPuckMap.end()) {
        uint32_t puckIndex = puck->second;
        auto puckPose = _poseStateMap.find(puckIndex);
        auto puckOffset = _pucksOffset.find(puckIndex);

        if ((puckPose != _poseStateMap.end()) && (puckOffset != _pucksOffset.end())) {
            return puckPose->second.postTransform(puckOffset->second);
        }
    }
    return controller::Pose();
}

void ViveControllerManager::InputDevice::handleHmd(uint32_t deviceIndex, const controller::InputCalibrationData& inputCalibrationData) {
     uint32_t poseIndex = controller::TRACKED_OBJECT_00 + deviceIndex;

     if (_system->IsTrackedDeviceConnected(deviceIndex) &&
         _system->GetTrackedDeviceClass(deviceIndex) == vr::TrackedDeviceClass_HMD &&
         _nextSimPoseData.vrPoses[deviceIndex].bPoseIsValid) {

         const mat4& mat = _nextSimPoseData.poses[deviceIndex];
         const vec3 linearVelocity = _nextSimPoseData.linearVelocities[deviceIndex];
         const vec3 angularVelocity = _nextSimPoseData.angularVelocities[deviceIndex];

         handleHeadPoseEvent(inputCalibrationData, mat, linearVelocity, angularVelocity);
     }
}

void ViveControllerManager::InputDevice::handleHandController(float deltaTime, uint32_t deviceIndex, const controller::InputCalibrationData& inputCalibrationData, bool isLeftHand) {

    if (_system->IsTrackedDeviceConnected(deviceIndex) &&
        _system->GetTrackedDeviceClass(deviceIndex) == vr::TrackedDeviceClass_Controller &&
        _nextSimPoseData.vrPoses[deviceIndex].bPoseIsValid) {

        // process pose
        const mat4& mat = _nextSimPoseData.poses[deviceIndex];
        const vec3 linearVelocity = _nextSimPoseData.linearVelocities[deviceIndex];
        const vec3 angularVelocity = _nextSimPoseData.angularVelocities[deviceIndex];
        handlePoseEvent(deltaTime, inputCalibrationData, mat, linearVelocity, angularVelocity, isLeftHand);

        vr::VRControllerState_t controllerState = vr::VRControllerState_t();
        if (_system->GetControllerState(deviceIndex, &controllerState, sizeof(vr::VRControllerState_t))) {
            // process each button
            for (uint32_t i = 0; i < vr::k_EButton_Max; ++i) {
                auto mask = vr::ButtonMaskFromId((vr::EVRButtonId)i);
                bool pressed = 0 != (controllerState.ulButtonPressed & mask);
                bool touched = 0 != (controllerState.ulButtonTouched & mask);
                handleButtonEvent(deltaTime, i, pressed, touched, isLeftHand);
            }

            // process each axis
            for (uint32_t i = 0; i < vr::k_unControllerStateAxisCount; i++) {
                handleAxisEvent(deltaTime, i, controllerState.rAxis[i].x, controllerState.rAxis[i].y, isLeftHand);
            }

            // pseudo buttons the depend on both of the above for-loops
            partitionTouchpad(controller::LS, controller::LX, controller::LY, controller::LS_CENTER, controller::LS_X, controller::LS_Y);
            partitionTouchpad(controller::RS, controller::RX, controller::RY, controller::RS_CENTER, controller::RS_X, controller::RS_Y);
         }
    }
}

void ViveControllerManager::InputDevice::partitionTouchpad(int sButton, int xAxis, int yAxis, int centerPseudoButton, int xPseudoButton, int yPseudoButton) {
    // Populate the L/RS_CENTER/OUTER pseudo buttons, corresponding to a partition of the L/RS space based on the X/Y values.
    const float CENTER_DEADBAND = 0.6f;
    const float DIAGONAL_DIVIDE_IN_RADIANS = PI / 4.0f;
    if (_buttonPressedMap.find(sButton) != _buttonPressedMap.end()) {
        float absX = abs(_axisStateMap[xAxis]);
        float absY = abs(_axisStateMap[yAxis]);
        glm::vec2 cartesianQuadrantI(absX, absY);
        float angle = glm::atan(cartesianQuadrantI.y / cartesianQuadrantI.x);
        float radius = glm::length(cartesianQuadrantI);
        bool isCenter = radius < CENTER_DEADBAND;
        _buttonPressedMap.insert(isCenter ? centerPseudoButton : ((angle < DIAGONAL_DIVIDE_IN_RADIANS) ? xPseudoButton :yPseudoButton));
    }
}

void ViveControllerManager::InputDevice::focusOutEvent() {
    _axisStateMap.clear();
    _buttonPressedMap.clear();
};

// These functions do translation from the Steam IDs to the standard controller IDs
void ViveControllerManager::InputDevice::handleAxisEvent(float deltaTime, uint32_t axis, float x, float y, bool isLeftHand) {
    //FIX ME? It enters here every frame: probably we want to enter only if an event occurs
    axis += vr::k_EButton_Axis0;
    using namespace controller;

    if (axis == vr::k_EButton_SteamVR_Touchpad) {
        glm::vec2 stick(x, y);
        if (isLeftHand) {
            stick = _filteredLeftStick.process(deltaTime, stick);
        } else {
            stick = _filteredRightStick.process(deltaTime, stick);
        }
        _axisStateMap[isLeftHand ? LX : RX] = stick.x;
        _axisStateMap[isLeftHand ? LY : RY] = stick.y;
    } else if (axis == vr::k_EButton_SteamVR_Trigger) {
        _axisStateMap[isLeftHand ? LT : RT] = x;
        // The click feeling on the Vive controller trigger represents a value of *precisely* 1.0,
        // so we can expose that as an additional button
        if (x >= 1.0f) {
            _buttonPressedMap.insert(isLeftHand ? LT_CLICK : RT_CLICK);
        }
    }
}

// An enum for buttons which do not exist in the StandardControls enum
enum ViveButtonChannel {
    LEFT_APP_MENU = controller::StandardButtonChannel::NUM_STANDARD_BUTTONS,
    RIGHT_APP_MENU
};

bool ViveControllerManager::InputDevice::checkForCalibrationEvent() {
    auto& endOfMap = _buttonPressedMap.end();
    auto& leftTrigger = _buttonPressedMap.find(controller::LT);
    auto& rightTrigger = _buttonPressedMap.find(controller::RT);
    auto& leftAppButton = _buttonPressedMap.find(LEFT_APP_MENU);
    auto& rightAppButton = _buttonPressedMap.find(RIGHT_APP_MENU);
    return ((leftTrigger != endOfMap && leftAppButton != endOfMap) && (rightTrigger != endOfMap && rightAppButton != endOfMap));
}

// These functions do translation from the Steam IDs to the standard controller IDs
void ViveControllerManager::InputDevice::handleButtonEvent(float deltaTime, uint32_t button, bool pressed, bool touched, bool isLeftHand) {

    using namespace controller;

    if (pressed) {
        if (button == vr::k_EButton_ApplicationMenu) {
            _buttonPressedMap.insert(isLeftHand ? LEFT_APP_MENU : RIGHT_APP_MENU);
        } else if (button == vr::k_EButton_Grip) {
            _axisStateMap[isLeftHand ? LEFT_GRIP : RIGHT_GRIP] = 1.0f;
        } else if (button == vr::k_EButton_SteamVR_Trigger) {
            _buttonPressedMap.insert(isLeftHand ? LT : RT);
        } else if (button == vr::k_EButton_SteamVR_Touchpad) {
            _buttonPressedMap.insert(isLeftHand ? LS : RS);
        }
    } else {
        if (button == vr::k_EButton_Grip) {
            _axisStateMap[isLeftHand ? LEFT_GRIP : RIGHT_GRIP] = 0.0f;
        }
    }

    if (touched) {
         if (button == vr::k_EButton_SteamVR_Touchpad) {
             _buttonPressedMap.insert(isLeftHand ? LS_TOUCH : RS_TOUCH);
        }
    }
}

void ViveControllerManager::InputDevice::handleHeadPoseEvent(const controller::InputCalibrationData& inputCalibrationData, const mat4& mat,
                                                             const vec3& linearVelocity, const vec3& angularVelocity) {

    //perform a 180 flip to make the HMD face the +z instead of -z, beacuse the head faces +z
    glm::mat4 matYFlip = mat * Matrices::Y_180;
    controller::Pose pose(extractTranslation(matYFlip), glmExtractRotation(matYFlip), linearVelocity, angularVelocity);

    glm::mat4 sensorToAvatar = glm::inverse(inputCalibrationData.avatarMat) * inputCalibrationData.sensorToWorldMat;
    glm::mat4 defaultHeadOffset = glm::inverse(inputCalibrationData.defaultCenterEyeMat) * inputCalibrationData.defaultHeadMat;
    controller::Pose hmdHeadPose = pose.transform(sensorToAvatar);
    _poseStateMap[controller::HEAD] = hmdHeadPose.postTransform(defaultHeadOffset);
}

void ViveControllerManager::InputDevice::handlePoseEvent(float deltaTime, const controller::InputCalibrationData& inputCalibrationData,
                                                         const mat4& mat, const vec3& linearVelocity,
                                                         const vec3& angularVelocity, bool isLeftHand) {
    auto pose = openVrControllerPoseToHandPose(isLeftHand, mat, linearVelocity, angularVelocity);

    // transform into avatar frame
    glm::mat4 controllerToAvatar = glm::inverse(inputCalibrationData.avatarMat) * inputCalibrationData.sensorToWorldMat;
    _poseStateMap[isLeftHand ? controller::LEFT_HAND : controller::RIGHT_HAND] = pose.transform(controllerToAvatar);
}

bool ViveControllerManager::InputDevice::triggerHapticPulse(float strength, float duration, controller::Hand hand) {
    Locker locker(_lock);
    if (hand == controller::BOTH || hand == controller::LEFT) {
        if (strength == 0.0f) {
            _leftHapticStrength = 0.0f;
            _leftHapticDuration = 0.0f;
        } else {
            _leftHapticStrength = (duration > _leftHapticDuration) ? strength : _leftHapticStrength;
            _leftHapticDuration = std::max(duration, _leftHapticDuration);
        }
    }
    if (hand == controller::BOTH || hand == controller::RIGHT) {
        if (strength == 0.0f) {
            _rightHapticStrength = 0.0f;
            _rightHapticDuration = 0.0f;
        } else {
            _rightHapticStrength = (duration > _rightHapticDuration) ? strength : _rightHapticStrength;
            _rightHapticDuration = std::max(duration, _rightHapticDuration);
        }
    }
    return true;
}

void ViveControllerManager::InputDevice::hapticsHelper(float deltaTime, bool leftHand) {
    auto handRole = leftHand ? vr::TrackedControllerRole_LeftHand : vr::TrackedControllerRole_RightHand;
    auto deviceIndex = _system->GetTrackedDeviceIndexForControllerRole(handRole);

    if (_system->IsTrackedDeviceConnected(deviceIndex) &&
        _system->GetTrackedDeviceClass(deviceIndex) == vr::TrackedDeviceClass_Controller &&
        _nextSimPoseData.vrPoses[deviceIndex].bPoseIsValid) {
        float strength = leftHand ? _leftHapticStrength : _rightHapticStrength;
        float duration = leftHand ? _leftHapticDuration : _rightHapticDuration;

        // Vive Controllers only support duration up to 4 ms, which is short enough that any variation feels more like strength
        const float MAX_HAPTIC_TIME = 3999.0f; // in microseconds
        float hapticTime = strength * MAX_HAPTIC_TIME;
        if (hapticTime < duration * 1000.0f) {
            _system->TriggerHapticPulse(deviceIndex, 0, hapticTime);
       }

        float remainingHapticTime = duration - (hapticTime / 1000.0f + deltaTime * 1000.0f); // in milliseconds
        if (leftHand) {
            _leftHapticDuration = remainingHapticTime;
        } else {
            _rightHapticDuration = remainingHapticTime;
        }
    }
}

controller::Input::NamedVector ViveControllerManager::InputDevice::getAvailableInputs() const {
    using namespace controller;
    QVector<Input::NamedPair> availableInputs{
        // Trackpad analogs
        makePair(LX, "LX"),
        makePair(LY, "LY"),
        makePair(RX, "RX"),
        makePair(RY, "RY"),

        // capacitive touch on the touch pad
        makePair(LS_TOUCH, "LSTouch"),
        makePair(RS_TOUCH, "RSTouch"),

        // touch pad press
        makePair(LS, "LS"),
        makePair(RS, "RS"),
        // Differentiate where we are in the touch pad click
        makePair(LS_CENTER, "LSCenter"),
        makePair(LS_X, "LSX"),
        makePair(LS_Y, "LSY"),
        makePair(RS_CENTER, "RSCenter"),
        makePair(RS_X, "RSX"),
        makePair(RS_Y, "RSY"),


        // triggers
        makePair(LT, "LT"),
        makePair(RT, "RT"),

        // Trigger clicks
        makePair(LT_CLICK, "LTClick"),
        makePair(RT_CLICK, "RTClick"),

        // low profile side grip button.
        makePair(LEFT_GRIP, "LeftGrip"),
        makePair(RIGHT_GRIP, "RightGrip"),

        // 3d location of controller
        makePair(LEFT_HAND, "LeftHand"),
        makePair(RIGHT_HAND, "RightHand"),
        makePair(LEFT_FOOT, "LeftFoot"),
        makePair(RIGHT_FOOT, "RightFoot"),
        makePair(HIPS, "Hips"),
        makePair(SPINE2, "Spine2"),
        makePair(HEAD, "Head"),

        // 16 tracked poses
        makePair(TRACKED_OBJECT_00, "TrackedObject00"),
        makePair(TRACKED_OBJECT_01, "TrackedObject01"),
        makePair(TRACKED_OBJECT_02, "TrackedObject02"),
        makePair(TRACKED_OBJECT_03, "TrackedObject03"),
        makePair(TRACKED_OBJECT_04, "TrackedObject04"),
        makePair(TRACKED_OBJECT_05, "TrackedObject05"),
        makePair(TRACKED_OBJECT_06, "TrackedObject06"),
        makePair(TRACKED_OBJECT_07, "TrackedObject07"),
        makePair(TRACKED_OBJECT_08, "TrackedObject08"),
        makePair(TRACKED_OBJECT_09, "TrackedObject09"),
        makePair(TRACKED_OBJECT_10, "TrackedObject10"),
        makePair(TRACKED_OBJECT_11, "TrackedObject11"),
        makePair(TRACKED_OBJECT_12, "TrackedObject12"),
        makePair(TRACKED_OBJECT_13, "TrackedObject13"),
        makePair(TRACKED_OBJECT_14, "TrackedObject14"),
        makePair(TRACKED_OBJECT_15, "TrackedObject15"),

        // app button above trackpad.
        Input::NamedPair(Input(_deviceID, LEFT_APP_MENU, ChannelType::BUTTON), "LeftApplicationMenu"),
        Input::NamedPair(Input(_deviceID, RIGHT_APP_MENU, ChannelType::BUTTON), "RightApplicationMenu"),
    };

    return availableInputs;
}

QString ViveControllerManager::InputDevice::getDefaultMappingConfig() const {
    static const QString MAPPING_JSON = PathUtils::resourcesPath() + "/controllers/vive.json";
    return MAPPING_JSON;
}