input.cpp

/**
 * @file src/input.cpp
 * @brief Definitions for gamepad, keyboard, and mouse input handling.
 */
#include <cstdint>
extern "C" {
#include <moonlight-common-c/src/Input.h>
#include <moonlight-common-c/src/Limelight.h>
}

// standard includes
#include <bitset>
#include <chrono>
#include <cmath>
#include <list>
#include <thread>
#include <unordered_map>

// lib includes
#include <boost/endian/buffers.hpp>

// local includes
#include "config.h"
#include "globals.h"
#include "input.h"
#include "logging.h"
#include "platform/common.h"
#include "thread_pool.h"
#include "utility.h"

// Win32 WHEEL_DELTA constant
#ifndef WHEEL_DELTA
constexpr int WHEEL_DELTA = 120;  ///< Standard Windows wheel delta used to normalize scroll events.
#endif

using namespace std::literals;

namespace input {

  constexpr auto MAX_GAMEPADS = std::min((std::size_t) platf::MAX_GAMEPADS, sizeof(std::int16_t) * 8);  ///< Maximum gamepads representable by the active gamepad mask.
/**
 * @def DISABLE_LEFT_BUTTON_DELAY
 * @brief Macro for DISABLE LEFT BUTTON DELAY.
 */
#define DISABLE_LEFT_BUTTON_DELAY ((thread_pool_util::ThreadPool::task_id_t) 0x01)
/**
 * @def ENABLE_LEFT_BUTTON_DELAY
 * @brief Macro for ENABLE LEFT BUTTON DELAY.
 */
#define ENABLE_LEFT_BUTTON_DELAY nullptr

  constexpr auto VKEY_SHIFT = 0x10;  ///< Windows virtual-key code for shift.
  constexpr auto VKEY_LSHIFT = 0xA0;  ///< Windows virtual-key code for lshift.
  constexpr auto VKEY_RSHIFT = 0xA1;  ///< Windows virtual-key code for rshift.
  constexpr auto VKEY_CONTROL = 0x11;  ///< Windows virtual-key code for control.
  constexpr auto VKEY_LCONTROL = 0xA2;  ///< Windows virtual-key code for lcontrol.
  constexpr auto VKEY_RCONTROL = 0xA3;  ///< Windows virtual-key code for rcontrol.
  constexpr auto VKEY_MENU = 0x12;  ///< Windows virtual-key code for menu.
  constexpr auto VKEY_LMENU = 0xA4;  ///< Windows virtual-key code for lmenu.
  constexpr auto VKEY_RMENU = 0xA5;  ///< Windows virtual-key code for rmenu.

  /**
   * @brief Enumerates supported button state options.
   */
  enum class button_state_e {
    NONE,  ///< No button state
    DOWN,  ///< Button is down
    UP  ///< Button is up
  };

  /**
   * @brief Allocate an available input slot identifier.
   *
   * @param gamepad_mask Gamepad mask.
   * @return Allocated ID object, or null when unavailable.
   */
  template<std::size_t N>
  int alloc_id(std::bitset<N> &gamepad_mask) {
    for (int x = 0; x < gamepad_mask.size(); ++x) {
      if (!gamepad_mask[x]) {
        gamepad_mask[x] = true;
        return x;
      }
    }

    return -1;
  }

  /**
   * @brief Release ID resources.
   *
   * @param gamepad_mask Gamepad mask.
   * @param id Identifier for the controller, session, display, or resource.
   */
  template<std::size_t N>
  void free_id(std::bitset<N> &gamepad_mask, int id) {
    gamepad_mask[id] = false;
  }

  /**
   * @brief Packed identifier for a pressed key and its modifier flags.
   */
  typedef uint32_t key_press_id_t;

  /**
   * @brief Create a key-press identifier from the virtual-key code and flags.
   *
   * @param vk Virtual-key code from the client input packet.
   * @param flags Bit flags that modify the requested operation.
   * @return Constructed kpid object.
   */
  key_press_id_t make_kpid(uint16_t vk, uint8_t flags) {
    return (key_press_id_t) vk << 8 | flags;
  }

  /**
   * @brief Extract the virtual-key code from a packed key-press identifier.
   *
   * @param kpid Key-press identifier containing the virtual-key code and flags.
   * @return Virtual-key code stored in the high byte.
   */
  uint16_t vk_from_kpid(key_press_id_t kpid) {
    return kpid >> 8;
  }

  /**
   * @brief Extract the modifier flags from a packed key-press identifier.
   *
   * @param kpid Key-press identifier containing the virtual-key code and flags.
   * @return Modifier flags stored in the low byte.
   */
  uint8_t flags_from_kpid(key_press_id_t kpid) {
    return kpid & 0xFF;
  }

  /**
   * @brief Convert a little-endian netfloat to a native endianness float.
   * @param f Little-endian network float bytes.
   * @return Floating-point value decoded for the host CPU.
   */
  float from_netfloat(netfloat f) {
    return boost::endian::endian_load<float, sizeof(float), boost::endian::order::little>(f);
  }

  /**
   * @brief Convert a little-endian netfloat to a native float and clamp it to a range.
   * @param f Little-endian network float bytes.
   * @param min The minimium value for clamping.
   * @param max The maximum value for clamping.
   * @return Decoded floating-point value clamped between min and max.
   */
  float from_clamped_netfloat(netfloat f, float min, float max) {
    return std::clamp(from_netfloat(f), min, max);
  }

  static task_pool_util::TaskPool::task_id_t key_press_repeat_id {};
  static std::unordered_map<key_press_id_t, bool> key_press {};
  static std::array<std::uint8_t, 5> mouse_press {};

  static platf::input_t platf_input;
  static std::bitset<platf::MAX_GAMEPADS> gamepadMask {};

  /**
   * @brief Release all platform resources associated with a virtual gamepad.
   *
   * @param platf_input Platf input.
   * @param id Identifier for the controller, session, display, or resource.
   */
  void free_gamepad(platf::input_t &platf_input, int id) {
    platf::gamepad_update(platf_input, id, platf::gamepad_state_t {});
    platf::free_gamepad(platf_input, id);

    free_id(gamepadMask, id);
  }

  /**
   * @brief Per-client gamepad slot and feedback state.
   */
  struct gamepad_t {
    gamepad_t():
        gamepad_state {},
        back_timeout_id {},
        id {-1},
        back_button_state {button_state_e::NONE} {
    }

    ~gamepad_t() {
      if (id >= 0) {
        task_pool.push([id = this->id]() {
          free_gamepad(platf_input, id);
        });
      }
    }

    platf::gamepad_state_t gamepad_state;  ///< Gamepad state.

    thread_pool_util::ThreadPool::task_id_t back_timeout_id;  ///< Back timeout ID.

    int id;  ///< Global gamepad slot assigned to this client controller.

    // When emulating the HOME button, we may need to artificially release the back button.
    // Afterwards, the gamepad state on sunshine won't match the state on Moonlight.
    // To prevent Sunshine from sending erroneous input data to the active application,
    // Sunshine forces the button to be in a specific state until the gamepad state matches that of
    // Moonlight once more.
    button_state_e back_button_state;  ///< Back button state.
  };

  /**
   * @brief Input emulation settings loaded from configuration.
   */
  struct input_t {
    /**
     * @brief Enumerates supported shortkey options.
     */
    enum shortkey_e {
      CTRL = 0x1,  ///< Control key
      ALT = 0x2,  ///< Alt key
      SHIFT = 0x4,  ///< Shift key
      SHORTCUT = CTRL | ALT | SHIFT  ///< Shortcut combination
    };

    /**
     * @brief Construct input state from the mailbox and platform backend.
     *
     * @param touch_port_event Event carrying the active touch port.
     * @param feedback_queue Queue used for controller feedback.
     */
    input_t(
      safe::mail_raw_t::event_t<input::touch_port_t> touch_port_event,
      platf::feedback_queue_t feedback_queue
    ):
        shortcutFlags {},
        gamepads(MAX_GAMEPADS),
        client_context {platf::allocate_client_input_context(platf_input)},
        touch_port_event {std::move(touch_port_event)},
        feedback_queue {std::move(feedback_queue)},
        mouse_left_button_timeout {},
        touch_port {{0, 0, 0, 0}, 0, 0, 1.0f, 1.0f, 0, 0},
        accumulated_vscroll_delta {},
        accumulated_hscroll_delta {} {
    }

    // Keep track of alt+ctrl+shift key combo
    int shortcutFlags;  ///< Shortcut flags.

    bool left_alt_pressed = false;  ///< Tracks whether the left Alt key is currently pressed.
    bool right_alt_pressed = false;  ///< Tracks whether the right Alt key is currently pressed.

    std::vector<gamepad_t> gamepads;  ///< Virtual gamepad slots tracked for the stream.
    std::unique_ptr<platf::client_input_t> client_context;  ///< Client context.

    safe::mail_raw_t::event_t<input::touch_port_t> touch_port_event;  ///< Touch port event.
    platf::feedback_queue_t feedback_queue;  ///< Queue used to deliver controller feedback to the platform backend.

    std::list<std::vector<uint8_t>> input_queue;  ///< Pending raw input packets waiting for processing.
    std::mutex input_queue_lock;  ///< Input queue lock.

    thread_pool_util::ThreadPool::task_id_t mouse_left_button_timeout;  ///< Mouse left button timeout.

    input::touch_port_t touch_port;  ///< Touch coordinate bounds for the current stream.

    int32_t accumulated_vscroll_delta;  ///< Accumulated vscroll delta.
    int32_t accumulated_hscroll_delta;  ///< Accumulated hscroll delta.
  };

  /**
   * @brief Apply shortcut based on VKEY
   * @param keyCode The VKEY code
   * @return 0 if no shortcut applied, > 0 if shortcut applied.
   */
  inline int apply_shortcut(short keyCode) {
    constexpr auto VK_F1 = 0x70;
    constexpr auto VK_F13 = 0x7C;

    BOOST_LOG(debug) << "Apply Shortcut: 0x"sv << util::hex((std::uint8_t) keyCode).to_string_view();

    if (keyCode >= VK_F1 && keyCode <= VK_F13) {
      mail::man->event<int>(mail::switch_display)->raise(keyCode - VK_F1);
      return 1;
    }

    switch (keyCode) {
      case 0x4E /* VKEY_N */:
        display_cursor = !display_cursor;
        return 1;
    }

    return 0;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_REL_MOUSE_MOVE_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin relative mouse move packet--"sv << std::endl
      << "deltaX ["sv << util::endian::big(packet->deltaX) << ']' << std::endl
      << "deltaY ["sv << util::endian::big(packet->deltaY) << ']' << std::endl
      << "--end relative mouse move packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_ABS_MOUSE_MOVE_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin absolute mouse move packet--"sv << std::endl
      << "x      ["sv << util::endian::big(packet->x) << ']' << std::endl
      << "y      ["sv << util::endian::big(packet->y) << ']' << std::endl
      << "width  ["sv << util::endian::big(packet->width) << ']' << std::endl
      << "height ["sv << util::endian::big(packet->height) << ']' << std::endl
      << "--end absolute mouse move packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_MOUSE_BUTTON_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin mouse button packet--"sv << std::endl
      << "action ["sv << util::hex(packet->header.magic).to_string_view() << ']' << std::endl
      << "button ["sv << util::hex(packet->button).to_string_view() << ']' << std::endl
      << "--end mouse button packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_SCROLL_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin mouse scroll packet--"sv << std::endl
      << "scrollAmt1 ["sv << util::endian::big(packet->scrollAmt1) << ']' << std::endl
      << "--end mouse scroll packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PSS_HSCROLL_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin mouse hscroll packet--"sv << std::endl
      << "scrollAmount ["sv << util::endian::big(packet->scrollAmount) << ']' << std::endl
      << "--end mouse hscroll packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_KEYBOARD_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin keyboard packet--"sv << std::endl
      << "keyAction ["sv << util::hex(packet->header.magic).to_string_view() << ']' << std::endl
      << "keyCode ["sv << util::hex(packet->keyCode).to_string_view() << ']' << std::endl
      << "modifiers ["sv << util::hex(packet->modifiers).to_string_view() << ']' << std::endl
      << "flags ["sv << util::hex(packet->flags).to_string_view() << ']' << std::endl
      << "--end keyboard packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_UNICODE_PACKET packet) {
    std::string text(packet->text, util::endian::big(packet->header.size) - sizeof(packet->header.magic));
    BOOST_LOG(debug)
      << "--begin unicode packet--"sv << std::endl
      << "text ["sv << text << ']' << std::endl
      << "--end unicode packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   *
   * @param packet Protocol packet being processed.
   */
  void print(PNV_MULTI_CONTROLLER_PACKET packet) {
    // Moonlight spams controller packet even when not necessary
    BOOST_LOG(verbose)
      << "--begin controller packet--"sv << std::endl
      << "controllerNumber ["sv << packet->controllerNumber << ']' << std::endl
      << "activeGamepadMask ["sv << util::hex(packet->activeGamepadMask).to_string_view() << ']' << std::endl
      << "buttonFlags ["sv << util::hex((uint32_t) packet->buttonFlags | (packet->buttonFlags2 << 16)).to_string_view() << ']' << std::endl
      << "leftTrigger ["sv << util::hex(packet->leftTrigger).to_string_view() << ']' << std::endl
      << "rightTrigger ["sv << util::hex(packet->rightTrigger).to_string_view() << ']' << std::endl
      << "leftStickX ["sv << packet->leftStickX << ']' << std::endl
      << "leftStickY ["sv << packet->leftStickY << ']' << std::endl
      << "rightStickX ["sv << packet->rightStickX << ']' << std::endl
      << "rightStickY ["sv << packet->rightStickY << ']' << std::endl
      << "--end controller packet--"sv;
  }

  /**
   * @brief Prints a touch packet.
   * @param packet The touch packet.
   */
  void print(PSS_TOUCH_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin touch packet--"sv << std::endl
      << "eventType ["sv << util::hex(packet->eventType).to_string_view() << ']' << std::endl
      << "pointerId ["sv << util::hex(packet->pointerId).to_string_view() << ']' << std::endl
      << "x ["sv << from_netfloat(packet->x) << ']' << std::endl
      << "y ["sv << from_netfloat(packet->y) << ']' << std::endl
      << "pressureOrDistance ["sv << from_netfloat(packet->pressureOrDistance) << ']' << std::endl
      << "contactAreaMajor ["sv << from_netfloat(packet->contactAreaMajor) << ']' << std::endl
      << "contactAreaMinor ["sv << from_netfloat(packet->contactAreaMinor) << ']' << std::endl
      << "rotation ["sv << (uint32_t) packet->rotation << ']' << std::endl
      << "--end touch packet--"sv;
  }

  /**
   * @brief Prints a pen packet.
   * @param packet The pen packet.
   */
  void print(PSS_PEN_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin pen packet--"sv << std::endl
      << "eventType ["sv << util::hex(packet->eventType).to_string_view() << ']' << std::endl
      << "toolType ["sv << util::hex(packet->toolType).to_string_view() << ']' << std::endl
      << "penButtons ["sv << util::hex(packet->penButtons).to_string_view() << ']' << std::endl
      << "x ["sv << from_netfloat(packet->x) << ']' << std::endl
      << "y ["sv << from_netfloat(packet->y) << ']' << std::endl
      << "pressureOrDistance ["sv << from_netfloat(packet->pressureOrDistance) << ']' << std::endl
      << "contactAreaMajor ["sv << from_netfloat(packet->contactAreaMajor) << ']' << std::endl
      << "contactAreaMinor ["sv << from_netfloat(packet->contactAreaMinor) << ']' << std::endl
      << "rotation ["sv << (uint32_t) packet->rotation << ']' << std::endl
      << "tilt ["sv << (uint32_t) packet->tilt << ']' << std::endl
      << "--end pen packet--"sv;
  }

  /**
   * @brief Prints a controller arrival packet.
   * @param packet The controller arrival packet.
   */
  void print(PSS_CONTROLLER_ARRIVAL_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin controller arrival packet--"sv << std::endl
      << "controllerNumber ["sv << (uint32_t) packet->controllerNumber << ']' << std::endl
      << "type ["sv << util::hex(packet->type).to_string_view() << ']' << std::endl
      << "capabilities ["sv << util::hex(packet->capabilities).to_string_view() << ']' << std::endl
      << "supportedButtonFlags ["sv << util::hex(packet->supportedButtonFlags).to_string_view() << ']' << std::endl
      << "--end controller arrival packet--"sv;
  }

  /**
   * @brief Prints a controller touch packet.
   * @param packet The controller touch packet.
   */
  void print(PSS_CONTROLLER_TOUCH_PACKET packet) {
    BOOST_LOG(debug)
      << "--begin controller touch packet--"sv << std::endl
      << "controllerNumber ["sv << (uint32_t) packet->controllerNumber << ']' << std::endl
      << "eventType ["sv << util::hex(packet->eventType).to_string_view() << ']' << std::endl
      << "pointerId ["sv << util::hex(packet->pointerId).to_string_view() << ']' << std::endl
      << "x ["sv << from_netfloat(packet->x) << ']' << std::endl
      << "y ["sv << from_netfloat(packet->y) << ']' << std::endl
      << "pressure ["sv << from_netfloat(packet->pressure) << ']' << std::endl
      << "--end controller touch packet--"sv;
  }

  /**
   * @brief Prints a controller motion packet.
   * @param packet The controller motion packet.
   */
  void print(PSS_CONTROLLER_MOTION_PACKET packet) {
    BOOST_LOG(verbose)
      << "--begin controller motion packet--"sv << std::endl
      << "controllerNumber ["sv << util::hex(packet->controllerNumber).to_string_view() << ']' << std::endl
      << "motionType ["sv << util::hex(packet->motionType).to_string_view() << ']' << std::endl
      << "x ["sv << from_netfloat(packet->x) << ']' << std::endl
      << "y ["sv << from_netfloat(packet->y) << ']' << std::endl
      << "z ["sv << from_netfloat(packet->z) << ']' << std::endl
      << "--end controller motion packet--"sv;
  }

  /**
   * @brief Prints a controller battery packet.
   * @param packet The controller battery packet.
   */
  void print(PSS_CONTROLLER_BATTERY_PACKET packet) {
    BOOST_LOG(verbose)
      << "--begin controller battery packet--"sv << std::endl
      << "controllerNumber ["sv << util::hex(packet->controllerNumber).to_string_view() << ']' << std::endl
      << "batteryState ["sv << util::hex(packet->batteryState).to_string_view() << ']' << std::endl
      << "batteryPercentage ["sv << util::hex(packet->batteryPercentage).to_string_view() << ']' << std::endl
      << "--end controller battery packet--"sv;
  }

  /**
   * @brief Write a debug log representation of the input packet.
   */
  void print(void *payload) {
    auto header = (PNV_INPUT_HEADER) payload;

    switch (util::endian::little(header->magic)) {
      case MOUSE_MOVE_REL_MAGIC_GEN5:
        print((PNV_REL_MOUSE_MOVE_PACKET) payload);
        break;
      case MOUSE_MOVE_ABS_MAGIC:
        print((PNV_ABS_MOUSE_MOVE_PACKET) payload);
        break;
      case MOUSE_BUTTON_DOWN_EVENT_MAGIC_GEN5:
      case MOUSE_BUTTON_UP_EVENT_MAGIC_GEN5:
        print((PNV_MOUSE_BUTTON_PACKET) payload);
        break;
      case SCROLL_MAGIC_GEN5:
        print((PNV_SCROLL_PACKET) payload);
        break;
      case SS_HSCROLL_MAGIC:
        print((PSS_HSCROLL_PACKET) payload);
        break;
      case KEY_DOWN_EVENT_MAGIC:
      case KEY_UP_EVENT_MAGIC:
        print((PNV_KEYBOARD_PACKET) payload);
        break;
      case UTF8_TEXT_EVENT_MAGIC:
        print((PNV_UNICODE_PACKET) payload);
        break;
      case MULTI_CONTROLLER_MAGIC_GEN5:
        print((PNV_MULTI_CONTROLLER_PACKET) payload);
        break;
      case SS_TOUCH_MAGIC:
        print((PSS_TOUCH_PACKET) payload);
        break;
      case SS_PEN_MAGIC:
        print((PSS_PEN_PACKET) payload);
        break;
      case SS_CONTROLLER_ARRIVAL_MAGIC:
        print((PSS_CONTROLLER_ARRIVAL_PACKET) payload);
        break;
      case SS_CONTROLLER_TOUCH_MAGIC:
        print((PSS_CONTROLLER_TOUCH_PACKET) payload);
        break;
      case SS_CONTROLLER_MOTION_MAGIC:
        print((PSS_CONTROLLER_MOTION_PACKET) payload);
        break;
      case SS_CONTROLLER_BATTERY_MAGIC:
        print((PSS_CONTROLLER_BATTERY_PACKET) payload);
        break;
    }
  }

  /**
   * @brief Forward a client input packet directly to the platform backend.
   *
   * @param input Platform input backend that receives the event.
   * @param packet Protocol packet being processed.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_REL_MOUSE_MOVE_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    input->mouse_left_button_timeout = DISABLE_LEFT_BUTTON_DELAY;
    platf::move_mouse(platf_input, util::endian::big(packet->deltaX), util::endian::big(packet->deltaY));
  }

  /**
   * @brief Converts client coordinates on the specified surface into screen coordinates.
   * @param input The input context.
   * @param val The cartesian coordinate pair to convert.
   * @param size The size of the client's surface containing the value.
   * @return The host-relative coordinate pair if a touchport is available.
   */
  std::optional<std::pair<float, float>> client_to_touchport(std::shared_ptr<input_t> &input, const std::pair<float, float> &val, const std::pair<float, float> &size) {
    auto &touch_port_event = input->touch_port_event;
    auto &touch_port = input->touch_port;
    if (touch_port_event->peek()) {
      touch_port = *touch_port_event->pop();
    }
    if (!touch_port) {
      BOOST_LOG(verbose) << "Ignoring early absolute input without a touch port"sv;
      return std::nullopt;
    }

    auto scalarX = touch_port.width / size.first;
    auto scalarY = touch_port.height / size.second;

    float x = std::clamp(val.first, 0.0f, size.first) * scalarX;
    float y = std::clamp(val.second, 0.0f, size.second) * scalarY;

    auto offsetX = touch_port.client_offsetX;
    auto offsetY = touch_port.client_offsetY;

    x = std::clamp(x, offsetX, (size.first * scalarX) - offsetX);
    y = std::clamp(y, offsetY, (size.second * scalarY) - offsetY);

    /*
    x and y here below have the coordinates of the surface of the streaming resolution,
    and are dependent on how that comes configured from the client (scalar_inv is calculated
    from the proportion of that and the device's **physical** size).
    */
    x = (x - offsetX) * touch_port.scalar_inv;
    y = (y - offsetY) * touch_port.scalar_inv;

    /*
    This final operation is a bit weird and has been brought about with lots of trial and error. A better
    way to do this may exist.

    Basically, this is what makes the touchscreen map to the coordinates inputtino expects properly.
    Since inputtino's dimensions are now logical (because scaling breaks everything otherwise), using the previous
    x and y coordinates would be incorrect when screens are scaled, because the touch port is smaller (or larger)
    by a factor (that factor is touch_port.scalar_tpcoords), and that factor must be used to account for that difference
    when moving the cursor. Otherwise, it will move either slower or faster than your finger proportionally to
    scalar_tpcoords, and be offset *inversely* proportionally to scalar_tpcoords. So you must account for both differences
    by multiplying and dividing.
    */
    float final_x = (x + touch_port.offset_x * touch_port.scalar_tpcoords) / touch_port.scalar_tpcoords;
    float final_y = (y + touch_port.offset_y * touch_port.scalar_tpcoords) / touch_port.scalar_tpcoords;
    return std::pair {final_x, final_y};
  }

  /**
   * @brief Multiply a polar coordinate pair by a cartesian scaling factor.
   * @param r The radial coordinate.
   * @param angle The angular coordinate (radians).
   * @param scalar The scalar cartesian coordinate pair.
   * @return The scaled radial coordinate.
   */
  float multiply_polar_by_cartesian_scalar(float r, float angle, const std::pair<float, float> &scalar) {
    // Convert polar to cartesian coordinates
    float x = r * std::cos(angle);
    float y = r * std::sin(angle);

    // Scale the values
    x *= scalar.first;
    y *= scalar.second;

    // Convert the result back to a polar radial coordinate
    return std::sqrt(std::pow(x, 2) + std::pow(y, 2));
  }

  std::pair<float, float> scale_client_contact_area(const std::pair<float, float> &val, uint16_t rotation, const std::pair<float, float> &scalar) {
    // If the rotation is unknown, we'll just scale both axes equally by using
    // a 45-degree angle for our scaling calculations
    float angle = rotation == LI_ROT_UNKNOWN ? (M_PI / 4) : (rotation * (M_PI / 180));

    // If we have a major but not a minor axis, treat the touch as circular
    float major = val.first;
    float minor = val.second != 0.0f ? val.second : val.first;

    // The minor axis is perpendicular to major axis so the angle must be rotated by 90 degrees
    return {multiply_polar_by_cartesian_scalar(major, angle, scalar), multiply_polar_by_cartesian_scalar(minor, angle + (M_PI / 2), scalar)};
  }

  /**
   * @brief Forward a client input packet directly to the platform backend.
   *
   * @param input Platform input backend that receives the event.
   * @param packet Protocol packet being processed.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_ABS_MOUSE_MOVE_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    if (input->mouse_left_button_timeout == DISABLE_LEFT_BUTTON_DELAY) {
      input->mouse_left_button_timeout = ENABLE_LEFT_BUTTON_DELAY;
    }

    float x = util::endian::big(packet->x);
    float y = util::endian::big(packet->y);

    // Prevent divide by zero
    // Don't expect it to happen, but just in case
    if (!packet->width || !packet->height) {
      BOOST_LOG(warning) << "Moonlight passed invalid dimensions"sv;

      return;
    }

    auto width = (float) util::endian::big(packet->width);
    auto height = (float) util::endian::big(packet->height);

    auto tpcoords = client_to_touchport(input, {x, y}, {width, height});
    if (!tpcoords) {
      return;
    }

    auto &touch_port = input->touch_port;

    int touch_port_dim_x;
    int touch_port_dim_y;
    if (touch_port.env_logical_width != 0 && touch_port.env_logical_height != 0) {
      touch_port_dim_x = touch_port.env_logical_width;
      touch_port_dim_y = touch_port.env_logical_height;
    } else {
      touch_port_dim_x = touch_port.env_width;
      touch_port_dim_y = touch_port.env_height;
    }

    platf::touch_port_t abs_port {
      touch_port.offset_x,
      touch_port.offset_y,
      touch_port_dim_x,
      touch_port_dim_y
    };

    platf::abs_mouse(platf_input, abs_port, tpcoords->first, tpcoords->second);
  }

  /**
   * @brief Called to pass a mouse button message to the platform backend.
   *
   * @param input The input context pointer.
   * @param packet The mouse button packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_MOUSE_BUTTON_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    auto release = util::endian::little(packet->header.magic) == MOUSE_BUTTON_UP_EVENT_MAGIC_GEN5;
    auto button = util::endian::big(packet->button);
    if (button > 0 && button < mouse_press.size()) {
      if (mouse_press[button] != release) {
        // button state is already what we want
        return;
      }

      mouse_press[button] = !release;
    }
    /**
     * When Moonlight sends mouse input through absolute coordinates,
     * it's possible that BUTTON_RIGHT is pressed down immediately after releasing BUTTON_LEFT.
     * As a result, Sunshine will left-click on hyperlinks in the browser before right-clicking
     *
     * This can be solved by delaying BUTTON_LEFT, however, any delay on input is undesirable during gaming
     * As a compromise, Sunshine will only put delays on BUTTON_LEFT when
     * absolute mouse coordinates have been sent.
     *
     * Try to make sure BUTTON_RIGHT gets called before BUTTON_LEFT is released.
     *
     * input->mouse_left_button_timeout can only be nullptr
     * when the last mouse coordinates were absolute
     */
    if (button == BUTTON_LEFT && release && !input->mouse_left_button_timeout) {
      auto f = [=]() {
        auto left_released = mouse_press[BUTTON_LEFT];
        if (left_released) {
          // Already released left button
          return;
        }
        platf::button_mouse(platf_input, BUTTON_LEFT, release);

        mouse_press[BUTTON_LEFT] = false;
        input->mouse_left_button_timeout = nullptr;
      };

      input->mouse_left_button_timeout = task_pool.pushDelayed(std::move(f), 10ms).task_id;

      return;
    }
    if (
      button == BUTTON_RIGHT && !release &&
      input->mouse_left_button_timeout > DISABLE_LEFT_BUTTON_DELAY
    ) {
      platf::button_mouse(platf_input, BUTTON_RIGHT, false);
      platf::button_mouse(platf_input, BUTTON_RIGHT, true);

      mouse_press[BUTTON_RIGHT] = false;

      return;
    }

    platf::button_mouse(platf_input, button, release);
  }

  /**
   * @brief Apply configured keybinding remaps to a platform keycode.
   *
   * @param keycode Platform keycode being translated or emitted.
   * @return Remapped keycode when configured, otherwise the original keycode.
   */
  short map_keycode(short keycode) {
    auto it = config::input.keybindings.find(keycode);
    if (it != std::end(config::input.keybindings)) {
      return it->second;
    }

    return keycode;
  }

  /**
   * @brief Update flags for keyboard shortcut combo's
   *
   * @param flags Bit flags that modify the requested operation.
   * @param keyCode Moonlight keyboard packet key code.
   * @param release Whether the key or button event is a release.
   */
  inline void update_shortcutFlags(int *flags, short keyCode, bool release) {
    switch (keyCode) {
      case VKEY_SHIFT:
      case VKEY_LSHIFT:
      case VKEY_RSHIFT:
        if (release) {
          *flags &= ~input_t::SHIFT;
        } else {
          *flags |= input_t::SHIFT;
        }
        break;
      case VKEY_CONTROL:
      case VKEY_LCONTROL:
      case VKEY_RCONTROL:
        if (release) {
          *flags &= ~input_t::CTRL;
        } else {
          *flags |= input_t::CTRL;
        }
        break;
      case VKEY_MENU:
      case VKEY_LMENU:
      case VKEY_RMENU:
        if (release) {
          *flags &= ~input_t::ALT;
        } else {
          *flags |= input_t::ALT;
        }
        break;
    }
  }

  /**
   * @brief Check whether modifier.
   *
   * @param keyCode Moonlight keyboard packet key code.
   * @return True when the key code is a keyboard modifier.
   */
  bool is_modifier(uint16_t keyCode) {
    switch (keyCode) {
      case VKEY_SHIFT:
      case VKEY_LSHIFT:
      case VKEY_RSHIFT:
      case VKEY_CONTROL:
      case VKEY_LCONTROL:
      case VKEY_RCONTROL:
      case VKEY_MENU:
      case VKEY_LMENU:
      case VKEY_RMENU:
        return true;
      default:
        return false;
    }
  }

  /**
   * @brief Send key and modifiers.
   *
   * @param key_code Moonlight keyboard packet key code.
   * @param release Whether the key or button event is a release.
   * @param flags Bit flags that modify the requested operation.
   * @param synthetic_modifiers Synthetic modifiers.
   */
  void send_key_and_modifiers(uint16_t key_code, bool release, uint8_t flags, uint8_t synthetic_modifiers) {
    if (!release) {
      // Press any synthetic modifiers required for this key
      if (synthetic_modifiers & MODIFIER_SHIFT) {
        platf::keyboard_update(platf_input, VKEY_SHIFT, false, flags);
      }
      if (synthetic_modifiers & MODIFIER_CTRL) {
        platf::keyboard_update(platf_input, VKEY_CONTROL, false, flags);
      }
      if (synthetic_modifiers & MODIFIER_ALT) {
        platf::keyboard_update(platf_input, VKEY_MENU, false, flags);
      }
    }

    platf::keyboard_update(platf_input, map_keycode(key_code), release, flags);

    if (!release) {
      // Raise any synthetic modifier keys we pressed
      if (synthetic_modifiers & MODIFIER_SHIFT) {
        platf::keyboard_update(platf_input, VKEY_SHIFT, true, flags);
      }
      if (synthetic_modifiers & MODIFIER_CTRL) {
        platf::keyboard_update(platf_input, VKEY_CONTROL, true, flags);
      }
      if (synthetic_modifiers & MODIFIER_ALT) {
        platf::keyboard_update(platf_input, VKEY_MENU, true, flags);
      }
    }
  }

  /**
   * @brief Re-emit a held key until its repeat task is cancelled.
   *
   * @param key_code Moonlight keyboard packet key code.
   * @param flags Bit flags that modify the requested operation.
   * @param synthetic_modifiers Synthetic modifiers.
   */
  void repeat_key(uint16_t key_code, uint8_t flags, uint8_t synthetic_modifiers) {
    // If key no longer pressed, stop repeating
    if (!key_press[make_kpid(key_code, flags)]) {
      key_press_repeat_id = nullptr;
      return;
    }

    send_key_and_modifiers(key_code, false, flags, synthetic_modifiers);

    key_press_repeat_id = task_pool.pushDelayed(repeat_key, config::input.key_repeat_period, key_code, flags, synthetic_modifiers).task_id;
  }

  /**
   * @brief Forward a client input packet directly to the platform backend.
   *
   * @param input Platform input backend that receives the event.
   * @param packet Protocol packet being processed.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_KEYBOARD_PACKET packet) {
    if (!config::input.keyboard) {
      return;
    }

    auto release = util::endian::little(packet->header.magic) == KEY_UP_EVENT_MAGIC;
    auto keyCode = packet->keyCode & 0x00FF;

    if (keyCode == VKEY_LMENU) {
      input->left_alt_pressed = !release;
    } else if (keyCode == VKEY_RMENU) {
      input->right_alt_pressed = !release;
    }

    // Right-alt maps to meta, so it must not also register as ALT
    int modifiers = packet->modifiers;
    if (config::input.key_rightalt_to_key_win && input->right_alt_pressed && !input->left_alt_pressed) {
      modifiers &= ~MODIFIER_ALT;
    }

    // Set synthetic modifier flags if the keyboard packet is requesting modifier
    // keys that are not current pressed.
    uint8_t synthetic_modifiers = 0;
    if (!release && !is_modifier(keyCode)) {
      if (!(input->shortcutFlags & input_t::SHIFT) && (modifiers & MODIFIER_SHIFT)) {
        synthetic_modifiers |= MODIFIER_SHIFT;
      }
      if (!(input->shortcutFlags & input_t::CTRL) && (modifiers & MODIFIER_CTRL)) {
        synthetic_modifiers |= MODIFIER_CTRL;
      }
      if (!(input->shortcutFlags & input_t::ALT) && (modifiers & MODIFIER_ALT)) {
        synthetic_modifiers |= MODIFIER_ALT;
      }
    }

    auto &pressed = key_press[make_kpid(keyCode, packet->flags)];
    if (!pressed) {
      if (!release) {
        // A new key has been pressed down, we need to check for key combo's
        // If a key-combo has been pressed down, don't pass it through
        if (input->shortcutFlags == input_t::SHORTCUT && apply_shortcut(keyCode) > 0) {
          return;
        }

        if (key_press_repeat_id) {
          task_pool.cancel(key_press_repeat_id);
        }

        if (config::input.key_repeat_delay.count() > 0) {
          key_press_repeat_id = task_pool.pushDelayed(repeat_key, config::input.key_repeat_delay, keyCode, packet->flags, synthetic_modifiers).task_id;
        }
      } else {
        // Already released
        return;
      }
    } else if (!release) {
      // Already pressed down key
      return;
    }

    pressed = !release;

    send_key_and_modifiers(keyCode, release, packet->flags, synthetic_modifiers);

    update_shortcutFlags(&input->shortcutFlags, map_keycode(keyCode), release);
  }

  /**
   * @brief Called to pass a vertical scroll message the platform backend.
   * @param input The input context pointer.
   * @param packet The scroll packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_SCROLL_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    if (config::input.high_resolution_scrolling) {
      platf::scroll(platf_input, util::endian::big(packet->scrollAmt1));
    } else {
      input->accumulated_vscroll_delta += util::endian::big(packet->scrollAmt1);
      auto full_ticks = input->accumulated_vscroll_delta / WHEEL_DELTA;
      if (full_ticks) {
        // Send any full ticks that have accumulated and store the rest
        platf::scroll(platf_input, full_ticks * WHEEL_DELTA);
        input->accumulated_vscroll_delta -= full_ticks * WHEEL_DELTA;
      }
    }
  }

  /**
   * @brief Called to pass a horizontal scroll message the platform backend.
   * @param input The input context pointer.
   * @param packet The scroll packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_HSCROLL_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    if (config::input.high_resolution_scrolling) {
      platf::hscroll(platf_input, util::endian::big(packet->scrollAmount));
    } else {
      input->accumulated_hscroll_delta += util::endian::big(packet->scrollAmount);
      auto full_ticks = input->accumulated_hscroll_delta / WHEEL_DELTA;
      if (full_ticks) {
        // Send any full ticks that have accumulated and store the rest
        platf::hscroll(platf_input, full_ticks * WHEEL_DELTA);
        input->accumulated_hscroll_delta -= full_ticks * WHEEL_DELTA;
      }
    }
  }

  /**
   * @brief Forward a client input packet directly to the platform backend.
   *
   * @param packet Protocol packet being processed.
   */
  void passthrough(PNV_UNICODE_PACKET packet) {
    if (!config::input.keyboard) {
      return;
    }

    int size = util::endian::big(packet->header.size) - sizeof(packet->header.magic);
    platf::unicode(platf_input, packet->text, size);
  }

  /**
   * @brief Called to pass a controller arrival message to the platform backend.
   * @param input The input context pointer.
   * @param packet The controller arrival packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_CONTROLLER_ARRIVAL_PACKET packet) {
    if (!config::input.controller) {
      return;
    }

    if (packet->controllerNumber < 0 || packet->controllerNumber >= input->gamepads.size()) {
      BOOST_LOG(warning) << "ControllerNumber out of range ["sv << packet->controllerNumber << ']';
      return;
    }

    if (input->gamepads[packet->controllerNumber].id >= 0) {
      BOOST_LOG(warning) << "ControllerNumber already allocated ["sv << packet->controllerNumber << ']';
      return;
    }

    platf::gamepad_arrival_t arrival {
      packet->type,
      util::endian::little(packet->capabilities),
      util::endian::little(packet->supportedButtonFlags),
    };

    auto id = alloc_id(gamepadMask);
    if (id < 0) {
      return;
    }

    // Allocate a new gamepad
    if (platf::alloc_gamepad(platf_input, {id, packet->controllerNumber}, arrival, input->feedback_queue)) {
      free_id(gamepadMask, id);
      return;
    }

    input->gamepads[packet->controllerNumber].id = id;
  }

  std::optional<platf::touch_port_t> monitor_touch_port(
    const input::touch_port_t &touch_port,
    std::pair<float, float> &coords,
    bool use_effective_content
  ) {
    // client_to_touchport() has already subtracted the leading client padding from the coordinates. Remove padding
    // from both sides of the encoded extent here so effective-content coordinates still normalize to 0.0-1.0.
    const float frame_logical_w = (touch_port.width * touch_port.scalar_inv) / touch_port.scalar_tpcoords;
    const float frame_logical_h = (touch_port.height * touch_port.scalar_inv) / touch_port.scalar_tpcoords;
    const float content_width = touch_port.width - (2.0f * touch_port.client_offsetX);
    const float content_height = touch_port.height - (2.0f * touch_port.client_offsetY);
    const float monitor_logical_w = (content_width * touch_port.scalar_inv) / touch_port.scalar_tpcoords;
    const float monitor_logical_h = (content_height * touch_port.scalar_inv) / touch_port.scalar_tpcoords;
    const float normalization_width = use_effective_content ? monitor_logical_w : frame_logical_w;
    const float normalization_height = use_effective_content ? monitor_logical_h : frame_logical_h;
    if (!std::isfinite(normalization_width) ||
        !std::isfinite(normalization_height) ||
        normalization_width <= 0.0f ||
        normalization_height <= 0.0f) {
      BOOST_LOG(warning) << "Ignoring touch/pen input due to invalid logical touch dimensions"sv;
      return std::nullopt;
    }

    coords.first = (coords.first - touch_port.offset_x) / normalization_width;
    coords.second = (coords.second - touch_port.offset_y) / normalization_height;
    if (use_effective_content) {
      // client_to_touchport() maps encoded padding to the content edges. Keep those edge coordinates inside the
      // normalized target so native touch cannot escape onto an adjacent display.
      coords.first = std::clamp(coords.first, 0.0f, 1.0f);
      coords.second = std::clamp(coords.second, 0.0f, 1.0f);
    }

    return platf::touch_port_t {
      touch_port.offset_x,
      touch_port.offset_y,
      static_cast<int>(normalization_width),
      static_cast<int>(normalization_height)
    };
  }

  /**
   * @brief Called to pass a touch message to the platform backend.
   * @param input The input context pointer.
   * @param packet The touch packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_TOUCH_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    // Convert the client normalized coordinates to touchport coordinates
    auto coords = client_to_touchport(input, {from_clamped_netfloat(packet->x, 0.0f, 1.0f) * 65535.f, from_clamped_netfloat(packet->y, 0.0f, 1.0f) * 65535.f}, {65535.f, 65535.f});
    if (!coords) {
      return;
    }

    auto &touch_port = input->touch_port;

#ifdef _WIN32
    const bool use_effective_touch_content = config::input.touch_send_to_primary_display;
#else
    constexpr bool use_effective_touch_content = false;
#endif
    auto abs_port = monitor_touch_port(touch_port, *coords, use_effective_touch_content);
    if (!abs_port) {
      return;
    }

    // Normalize rotation value to 0-359 degree range
    auto rotation = util::endian::little(packet->rotation);
    if (rotation != LI_ROT_UNKNOWN) {
      rotation %= 360;
    }

    // Normalize the contact area based on the touchport
    auto contact_area = scale_client_contact_area(
      {from_clamped_netfloat(packet->contactAreaMajor, 0.0f, 1.0f) * 65535.f,
       from_clamped_netfloat(packet->contactAreaMinor, 0.0f, 1.0f) * 65535.f},
      rotation,
      {abs_port->width / 65535.f, abs_port->height / 65535.f}
    );

    platf::touch_input_t touch {
      packet->eventType,
      rotation,
      util::endian::little(packet->pointerId),
      coords->first,
      coords->second,
      from_clamped_netfloat(packet->pressureOrDistance, 0.0f, 1.0f),
      contact_area.first,
      contact_area.second,
    };

    platf::touch_update(input->client_context.get(), *abs_port, touch);
  }

  /**
   * @brief Called to pass a pen message to the platform backend.
   * @param input The input context pointer.
   * @param packet The pen packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_PEN_PACKET packet) {
    if (!config::input.mouse) {
      return;
    }

    // Convert the client normalized coordinates to touchport coordinates
    auto coords = client_to_touchport(input, {from_clamped_netfloat(packet->x, 0.0f, 1.0f) * 65535.f, from_clamped_netfloat(packet->y, 0.0f, 1.0f) * 65535.f}, {65535.f, 65535.f});
    if (!coords) {
      return;
    }

    auto &touch_port = input->touch_port;

    auto abs_port = monitor_touch_port(touch_port, *coords, false);
    if (!abs_port) {
      return;
    }

    // Normalize rotation value to 0-359 degree range
    auto rotation = util::endian::little(packet->rotation);
    if (rotation != LI_ROT_UNKNOWN) {
      rotation %= 360;
    }

    // Normalize the contact area based on the touchport
    auto contact_area = scale_client_contact_area(
      {from_clamped_netfloat(packet->contactAreaMajor, 0.0f, 1.0f) * 65535.f,
       from_clamped_netfloat(packet->contactAreaMinor, 0.0f, 1.0f) * 65535.f},
      rotation,
      {abs_port->width / 65535.f, abs_port->height / 65535.f}
    );

    platf::pen_input_t pen {
      packet->eventType,
      packet->toolType,
      packet->penButtons,
      packet->tilt,
      rotation,
      coords->first,
      coords->second,
      from_clamped_netfloat(packet->pressureOrDistance, 0.0f, 1.0f),
      contact_area.first,
      contact_area.second,
    };

    platf::pen_update(input->client_context.get(), *abs_port, pen);
  }

  /**
   * @brief Called to pass a controller touch message to the platform backend.
   * @param input The input context pointer.
   * @param packet The controller touch packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_CONTROLLER_TOUCH_PACKET packet) {
    if (!config::input.controller) {
      return;
    }

    if (packet->controllerNumber < 0 || packet->controllerNumber >= input->gamepads.size()) {
      BOOST_LOG(warning) << "ControllerNumber out of range ["sv << packet->controllerNumber << ']';
      return;
    }

    auto &gamepad = input->gamepads[packet->controllerNumber];
    if (gamepad.id < 0) {
      BOOST_LOG(warning) << "ControllerNumber ["sv << packet->controllerNumber << "] not allocated"sv;
      return;
    }

    platf::gamepad_touch_t touch {
      {gamepad.id, packet->controllerNumber},
      packet->eventType,
      util::endian::little(packet->pointerId),
      from_clamped_netfloat(packet->x, 0.0f, 1.0f),
      from_clamped_netfloat(packet->y, 0.0f, 1.0f),
      from_clamped_netfloat(packet->pressure, 0.0f, 1.0f),
    };

    platf::gamepad_touch(platf_input, touch);
  }

  /**
   * @brief Called to pass a controller motion message to the platform backend.
   * @param input The input context pointer.
   * @param packet The controller motion packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_CONTROLLER_MOTION_PACKET packet) {
    if (!config::input.controller) {
      return;
    }

    if (packet->controllerNumber < 0 || packet->controllerNumber >= input->gamepads.size()) {
      BOOST_LOG(warning) << "ControllerNumber out of range ["sv << packet->controllerNumber << ']';
      return;
    }

    auto &gamepad = input->gamepads[packet->controllerNumber];
    if (gamepad.id < 0) {
      BOOST_LOG(warning) << "ControllerNumber ["sv << packet->controllerNumber << "] not allocated"sv;
      return;
    }

    platf::gamepad_motion_t motion {
      {gamepad.id, packet->controllerNumber},
      packet->motionType,
      from_netfloat(packet->x),
      from_netfloat(packet->y),
      from_netfloat(packet->z),
    };

    platf::gamepad_motion(platf_input, motion);
  }

  /**
   * @brief Called to pass a controller battery message to the platform backend.
   * @param input The input context pointer.
   * @param packet The controller battery packet.
   */
  void passthrough(std::shared_ptr<input_t> &input, PSS_CONTROLLER_BATTERY_PACKET packet) {
    if (!config::input.controller) {
      return;
    }

    if (packet->controllerNumber < 0 || packet->controllerNumber >= input->gamepads.size()) {
      BOOST_LOG(warning) << "ControllerNumber out of range ["sv << packet->controllerNumber << ']';
      return;
    }

    auto &gamepad = input->gamepads[packet->controllerNumber];
    if (gamepad.id < 0) {
      BOOST_LOG(warning) << "ControllerNumber ["sv << packet->controllerNumber << "] not allocated"sv;
      return;
    }

    platf::gamepad_battery_t battery {
      {gamepad.id, packet->controllerNumber},
      packet->batteryState,
      packet->batteryPercentage
    };

    platf::gamepad_battery(platf_input, battery);
  }

  /**
   * @brief Forward a client input packet directly to the platform backend.
   *
   * @param input Platform input backend that receives the event.
   * @param packet Protocol packet being processed.
   */
  void passthrough(std::shared_ptr<input_t> &input, PNV_MULTI_CONTROLLER_PACKET packet) {
    if (!config::input.controller) {
      return;
    }

    if (packet->controllerNumber < 0 || packet->controllerNumber >= input->gamepads.size()) {
      BOOST_LOG(warning) << "ControllerNumber out of range ["sv << packet->controllerNumber << ']';

      return;
    }

    auto &gamepad = input->gamepads[packet->controllerNumber];

    // If this is an event for a new gamepad, create the gamepad now. Ideally, the client would
    // send a controller arrival instead of this but it's still supported for legacy clients.
    if ((packet->activeGamepadMask & (1 << packet->controllerNumber)) && gamepad.id < 0) {
      auto id = alloc_id(gamepadMask);
      if (id < 0) {
        return;
      }

      if (platf::alloc_gamepad(platf_input, {id, (uint8_t) packet->controllerNumber}, {}, input->feedback_queue)) {
        free_id(gamepadMask, id);
        return;
      }

      gamepad.id = id;
    } else if (!(packet->activeGamepadMask & (1 << packet->controllerNumber)) && gamepad.id >= 0) {
      // If this is the final event for a gamepad being removed, free the gamepad and return.
      free_gamepad(platf_input, gamepad.id);
      gamepad.id = -1;
      return;
    }

    // If this gamepad has not been initialized, ignore it.
    // This could happen when platf::alloc_gamepad fails
    if (gamepad.id < 0) {
      BOOST_LOG(warning) << "ControllerNumber ["sv << packet->controllerNumber << "] not allocated"sv;
      return;
    }

    std::uint16_t bf = packet->buttonFlags;
    std::uint32_t bf2 = packet->buttonFlags2;
    platf::gamepad_state_t gamepad_state {
      bf | (bf2 << 16),
      packet->leftTrigger,
      packet->rightTrigger,
      packet->leftStickX,
      packet->leftStickY,
      packet->rightStickX,
      packet->rightStickY
    };

    auto bf_new = gamepad_state.buttonFlags;
    switch (gamepad.back_button_state) {
      case button_state_e::UP:
        if (!(platf::BACK & bf_new)) {
          gamepad.back_button_state = button_state_e::NONE;
        }
        gamepad_state.buttonFlags &= ~platf::BACK;
        break;
      case button_state_e::DOWN:
        if (platf::BACK & bf_new) {
          gamepad.back_button_state = button_state_e::NONE;
        }
        gamepad_state.buttonFlags |= platf::BACK;
        break;
      case button_state_e::NONE:
        break;
    }

    bf = gamepad_state.buttonFlags ^ gamepad.gamepad_state.buttonFlags;
    bf_new = gamepad_state.buttonFlags;

    if (platf::BACK & bf) {
      if (platf::BACK & bf_new) {
        // Don't emulate home button if timeout < 0
        if (config::input.back_button_timeout >= 0ms) {
          auto f = [input, controller = packet->controllerNumber]() {
            auto &gamepad = input->gamepads[controller];

            auto &state = gamepad.gamepad_state;

            // Force the back button up
            gamepad.back_button_state = button_state_e::UP;
            state.buttonFlags &= ~platf::BACK;
            platf::gamepad_update(platf_input, gamepad.id, state);

            // Press Home button
            state.buttonFlags |= platf::HOME;
            platf::gamepad_update(platf_input, gamepad.id, state);

            // Sleep for a short time to allow the input to be detected
            std::this_thread::sleep_for(std::chrono::milliseconds(100));

            // Release Home button
            state.buttonFlags &= ~platf::HOME;
            platf::gamepad_update(platf_input, gamepad.id, state);

            gamepad.back_timeout_id = nullptr;
          };

          gamepad.back_timeout_id = task_pool.pushDelayed(std::move(f), config::input.back_button_timeout).task_id;
        }
      } else if (gamepad.back_timeout_id) {
        task_pool.cancel(gamepad.back_timeout_id);
        gamepad.back_timeout_id = nullptr;
      }
    }

    platf::gamepad_update(platf_input, gamepad.id, gamepad_state);

    gamepad.gamepad_state = gamepad_state;
  }

  /**
   * @brief Enumerates supported batch result options.
   */
  enum class batch_result_e {
    batched,  ///< This entry was batched with the source entry
    not_batchable,  ///< Not eligible to batch but continue attempts to batch
    terminate_batch,  ///< Stop trying to batch with this entry
  };

  /**
   * @brief Batch two relative mouse messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PNV_REL_MOUSE_MOVE_PACKET dest, PNV_REL_MOUSE_MOVE_PACKET src) {
    short deltaX;
    short deltaY;

    // Batching is safe as long as the result doesn't overflow a 16-bit integer
    if (!__builtin_add_overflow(util::endian::big(dest->deltaX), util::endian::big(src->deltaX), &deltaX)) {
      return batch_result_e::terminate_batch;
    }
    if (!__builtin_add_overflow(util::endian::big(dest->deltaY), util::endian::big(src->deltaY), &deltaY)) {
      return batch_result_e::terminate_batch;
    }

    // Take the sum of deltas
    dest->deltaX = util::endian::big(deltaX);
    dest->deltaY = util::endian::big(deltaY);
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two absolute mouse messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PNV_ABS_MOUSE_MOVE_PACKET dest, PNV_ABS_MOUSE_MOVE_PACKET src) {
    // Batching must only happen if the reference width and height don't change
    if (dest->width != src->width || dest->height != src->height) {
      return batch_result_e::terminate_batch;
    }

    // Take the latest absolute position
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two vertical scroll messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PNV_SCROLL_PACKET dest, PNV_SCROLL_PACKET src) {
    short scrollAmt;

    // Batching is safe as long as the result doesn't overflow a 16-bit integer
    if (!__builtin_add_overflow(util::endian::big(dest->scrollAmt1), util::endian::big(src->scrollAmt1), &scrollAmt)) {
      return batch_result_e::terminate_batch;
    }

    // Take the sum of delta
    dest->scrollAmt1 = util::endian::big(scrollAmt);
    dest->scrollAmt2 = util::endian::big(scrollAmt);
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two horizontal scroll messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PSS_HSCROLL_PACKET dest, PSS_HSCROLL_PACKET src) {
    short scrollAmt;

    // Batching is safe as long as the result doesn't overflow a 16-bit integer
    if (!__builtin_add_overflow(util::endian::big(dest->scrollAmount), util::endian::big(src->scrollAmount), &scrollAmt)) {
      return batch_result_e::terminate_batch;
    }

    // Take the sum of delta
    dest->scrollAmount = util::endian::big(scrollAmt);
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two controller state messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PNV_MULTI_CONTROLLER_PACKET dest, PNV_MULTI_CONTROLLER_PACKET src) {
    // Do not allow batching if the active controllers change
    if (dest->activeGamepadMask != src->activeGamepadMask) {
      return batch_result_e::terminate_batch;
    }

    // We can only batch entries for the same controller, but allow batching attempts to continue
    // in case we have more packets for this controller later in the queue.
    if (dest->controllerNumber != src->controllerNumber) {
      return batch_result_e::not_batchable;
    }

    // Do not allow batching if the button state changes on this controller
    if (dest->buttonFlags != src->buttonFlags || dest->buttonFlags2 != src->buttonFlags2) {
      return batch_result_e::terminate_batch;
    }

    // Take the latest state
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two touch messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PSS_TOUCH_PACKET dest, PSS_TOUCH_PACKET src) {
    // Only batch hover or move events
    if (dest->eventType != LI_TOUCH_EVENT_MOVE && dest->eventType != LI_TOUCH_EVENT_HOVER) {
      return batch_result_e::terminate_batch;
    }

    // Don't batch beyond state changing events
    if (src->eventType != LI_TOUCH_EVENT_MOVE && src->eventType != LI_TOUCH_EVENT_HOVER) {
      return batch_result_e::terminate_batch;
    }

    // Batched events must be the same pointer ID
    if (dest->pointerId != src->pointerId) {
      return batch_result_e::not_batchable;
    }

    // The pointer must be in the same state
    if (dest->eventType != src->eventType) {
      return batch_result_e::terminate_batch;
    }

    // Take the latest state
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two pen messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PSS_PEN_PACKET dest, PSS_PEN_PACKET src) {
    // Only batch hover or move events
    if (dest->eventType != LI_TOUCH_EVENT_MOVE && dest->eventType != LI_TOUCH_EVENT_HOVER) {
      return batch_result_e::terminate_batch;
    }

    // Batched events must be the same type
    if (dest->eventType != src->eventType) {
      return batch_result_e::terminate_batch;
    }

    // Do not allow batching if the button state changes
    if (dest->penButtons != src->penButtons) {
      return batch_result_e::terminate_batch;
    }

    // Do not batch beyond tool changes
    if (dest->toolType != src->toolType) {
      return batch_result_e::terminate_batch;
    }

    // Take the latest state
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two controller touch messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PSS_CONTROLLER_TOUCH_PACKET dest, PSS_CONTROLLER_TOUCH_PACKET src) {
    // Only batch hover or move events
    if (dest->eventType != LI_TOUCH_EVENT_MOVE && dest->eventType != LI_TOUCH_EVENT_HOVER) {
      return batch_result_e::terminate_batch;
    }

    // We can only batch entries for the same controller, but allow batching attempts to continue
    // in case we have more packets for this controller later in the queue.
    if (dest->controllerNumber != src->controllerNumber) {
      return batch_result_e::not_batchable;
    }

    // Don't batch beyond state changing events
    if (src->eventType != LI_TOUCH_EVENT_MOVE && src->eventType != LI_TOUCH_EVENT_HOVER) {
      return batch_result_e::terminate_batch;
    }

    // Batched events must be the same pointer ID
    if (dest->pointerId != src->pointerId) {
      return batch_result_e::not_batchable;
    }

    // The pointer must be in the same state
    if (dest->eventType != src->eventType) {
      return batch_result_e::terminate_batch;
    }

    // Take the latest state
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two controller motion messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PSS_CONTROLLER_MOTION_PACKET dest, PSS_CONTROLLER_MOTION_PACKET src) {
    // We can only batch entries for the same controller, but allow batching attempts to continue
    // in case we have more packets for this controller later in the queue.
    if (dest->controllerNumber != src->controllerNumber) {
      return batch_result_e::not_batchable;
    }

    // Batched events must be the same sensor
    if (dest->motionType != src->motionType) {
      return batch_result_e::not_batchable;
    }

    // Take the latest state
    *dest = *src;
    return batch_result_e::batched;
  }

  /**
   * @brief Batch two input messages.
   * @param dest The original packet to batch into.
   * @param src A later packet to attempt to batch.
   * @return The status of the batching operation.
   */
  batch_result_e batch(PNV_INPUT_HEADER dest, PNV_INPUT_HEADER src) {
    // We can only batch if the packet types are the same
    if (dest->magic != src->magic) {
      return batch_result_e::terminate_batch;
    }

    // We can only batch certain message types
    switch (util::endian::little(dest->magic)) {
      case MOUSE_MOVE_REL_MAGIC_GEN5:
        return batch((PNV_REL_MOUSE_MOVE_PACKET) dest, (PNV_REL_MOUSE_MOVE_PACKET) src);
      case MOUSE_MOVE_ABS_MAGIC:
        return batch((PNV_ABS_MOUSE_MOVE_PACKET) dest, (PNV_ABS_MOUSE_MOVE_PACKET) src);
      case SCROLL_MAGIC_GEN5:
        return batch((PNV_SCROLL_PACKET) dest, (PNV_SCROLL_PACKET) src);
      case SS_HSCROLL_MAGIC:
        return batch((PSS_HSCROLL_PACKET) dest, (PSS_HSCROLL_PACKET) src);
      case MULTI_CONTROLLER_MAGIC_GEN5:
        return batch((PNV_MULTI_CONTROLLER_PACKET) dest, (PNV_MULTI_CONTROLLER_PACKET) src);
      case SS_TOUCH_MAGIC:
        return batch((PSS_TOUCH_PACKET) dest, (PSS_TOUCH_PACKET) src);
      case SS_PEN_MAGIC:
        return batch((PSS_PEN_PACKET) dest, (PSS_PEN_PACKET) src);
      case SS_CONTROLLER_TOUCH_MAGIC:
        return batch((PSS_CONTROLLER_TOUCH_PACKET) dest, (PSS_CONTROLLER_TOUCH_PACKET) src);
      case SS_CONTROLLER_MOTION_MAGIC:
        return batch((PSS_CONTROLLER_MOTION_PACKET) dest, (PSS_CONTROLLER_MOTION_PACKET) src);
      default:
        // Not a batchable message type
        return batch_result_e::terminate_batch;
    }
  }

  /**
   * @brief Called on a thread pool thread to process an input message.
   * @param input The input context pointer.
   */
  void passthrough_next_message(std::shared_ptr<input_t> input) {
    // 'entry' backs the 'payload' pointer, so they must remain in scope together
    std::vector<uint8_t> entry;
    PNV_INPUT_HEADER payload;

    // Lock the input queue while batching, but release it before sending
    // the input to the OS. This avoids potentially lengthy lock contention
    // in the control stream thread while input is being processed by the OS.
    {
      std::lock_guard<std::mutex> lg(input->input_queue_lock);

      // If all entries have already been processed, nothing to do
      if (input->input_queue.empty()) {
        return;
      }

      // Pop off the first entry, which we will send
      entry = input->input_queue.front();
      payload = (PNV_INPUT_HEADER) entry.data();
      input->input_queue.pop_front();

      // Try to batch with remaining items on the queue
      auto i = input->input_queue.begin();
      while (i != input->input_queue.end()) {
        auto batchable_entry = *i;
        auto batchable_payload = (PNV_INPUT_HEADER) batchable_entry.data();

        auto batch_result = batch(payload, batchable_payload);
        if (batch_result == batch_result_e::terminate_batch) {
          // Stop batching
          break;
        } else if (batch_result == batch_result_e::batched) {
          // Erase this entry since it was batched
          i = input->input_queue.erase(i);
        } else {
          // We couldn't batch this entry, but try to batch later entries.
          i++;
        }
      }
    }

    // Print the final input packet
    input::print((void *) payload);

    // Send the batched input to the OS
    switch (util::endian::little(payload->magic)) {
      case MOUSE_MOVE_REL_MAGIC_GEN5:
        passthrough(input, (PNV_REL_MOUSE_MOVE_PACKET) payload);
        break;
      case MOUSE_MOVE_ABS_MAGIC:
        passthrough(input, (PNV_ABS_MOUSE_MOVE_PACKET) payload);
        break;
      case MOUSE_BUTTON_DOWN_EVENT_MAGIC_GEN5:
      case MOUSE_BUTTON_UP_EVENT_MAGIC_GEN5:
        passthrough(input, (PNV_MOUSE_BUTTON_PACKET) payload);
        break;
      case SCROLL_MAGIC_GEN5:
        passthrough(input, (PNV_SCROLL_PACKET) payload);
        break;
      case SS_HSCROLL_MAGIC:
        passthrough(input, (PSS_HSCROLL_PACKET) payload);
        break;
      case KEY_DOWN_EVENT_MAGIC:
      case KEY_UP_EVENT_MAGIC:
        passthrough(input, (PNV_KEYBOARD_PACKET) payload);
        break;
      case UTF8_TEXT_EVENT_MAGIC:
        passthrough((PNV_UNICODE_PACKET) payload);
        break;
      case MULTI_CONTROLLER_MAGIC_GEN5:
        passthrough(input, (PNV_MULTI_CONTROLLER_PACKET) payload);
        break;
      case SS_TOUCH_MAGIC:
        passthrough(input, (PSS_TOUCH_PACKET) payload);
        break;
      case SS_PEN_MAGIC:
        passthrough(input, (PSS_PEN_PACKET) payload);
        break;
      case SS_CONTROLLER_ARRIVAL_MAGIC:
        passthrough(input, (PSS_CONTROLLER_ARRIVAL_PACKET) payload);
        break;
      case SS_CONTROLLER_TOUCH_MAGIC:
        passthrough(input, (PSS_CONTROLLER_TOUCH_PACKET) payload);
        break;
      case SS_CONTROLLER_MOTION_MAGIC:
        passthrough(input, (PSS_CONTROLLER_MOTION_PACKET) payload);
        break;
      case SS_CONTROLLER_BATTERY_MAGIC:
        passthrough(input, (PSS_CONTROLLER_BATTERY_PACKET) payload);
        break;
    }
  }

  /**
   * @brief Called on the control stream thread to queue an input message.
   * @param input The input context pointer.
   * @param input_data The input message.
   */
  void passthrough(std::shared_ptr<input_t> &input, std::vector<std::uint8_t> &&input_data) {
    {
      std::lock_guard<std::mutex> lg(input->input_queue_lock);
      input->input_queue.push_back(std::move(input_data));
    }
    task_pool.push(passthrough_next_message, input);
  }

  /**
   * @brief Reset the object to its initial empty state.
   */
  void reset(std::shared_ptr<input_t> &input) {
    task_pool.cancel(key_press_repeat_id);
    task_pool.cancel(input->mouse_left_button_timeout);

    // Ensure input is synchronous, by using the task_pool
    task_pool.push([]() {
      for (int x = 0; x < mouse_press.size(); ++x) {
        if (mouse_press[x]) {
          platf::button_mouse(platf_input, x, true);
          mouse_press[x] = false;
        }
      }

      for (auto &kp : key_press) {
        if (!kp.second) {
          // already released
          continue;
        }
        platf::keyboard_update(platf_input, vk_from_kpid(kp.first) & 0x00FF, true, flags_from_kpid(kp.first));
        key_press[kp.first] = false;
      }
    });
  }

  /**
   * @brief RAII helper that runs shutdown cleanup when destroyed.
   */
  class deinit_t: public platf::deinit_t {
  public:
    /**
     * @brief Destroy the input subsystem deinitializer.
     */
    ~deinit_t() override {
      platf_input.reset();
    }
  };

  /**
   * @brief Initialize the platform input backend.
   */
  [[nodiscard]] std::unique_ptr<platf::deinit_t> init() {
    platf_input = platf::input();

    return std::make_unique<deinit_t>();
  }

  /**
   * @brief Probe connected gamepads and update input capability state.
   */
  bool probe_gamepads() {
    auto input = static_cast<platf::input_t *>(platf_input.get());
    const auto gamepads = platf::supported_gamepads(input);
    for (auto &gamepad : gamepads) {
      if (gamepad.is_enabled && gamepad.name != "auto") {
        return false;
      }
    }
    return true;
  }

  /**
   * @brief Allocate and initialize platform input state for a stream.
   */
  std::shared_ptr<input_t> alloc(safe::mail_t mail) {
    auto input = std::make_shared<input_t>(
      mail->event<input::touch_port_t>(mail::touch_port),
      mail->queue<platf::gamepad_feedback_msg_t>(mail::gamepad_feedback)
    );

    // Workaround to ensure new frames will be captured when a client connects
    task_pool.pushDelayed([]() {
      platf::move_mouse(platf_input, 1, 1);
      platf::move_mouse(platf_input, -1, -1);
    },
                          100ms);

    return input;
  }
}  // namespace input