"""Mouse/keyboard edge handoff over the JUC500 USB session.

Layout: peer sits to the RIGHT of this PC (like an extended display).
  - Local control + cursor pushed past the right edge → control remote PC
  - Remote control + cursor pushed past the remote left edge → control this PC
"""

from __future__ import annotations

import sys
import threading
import time
from typing import Any, Optional

from .protocol import (
    INPUT_CTRL_LOCAL,
    INPUT_CTRL_REMOTE,
    INPUT_CTRL_REMOTE_ACK,
    INPUT_CTRL_REMOTE_NACK,
    INPUT_CTRL_SHARE_OFF,
    INPUT_CTRL_SHARE_ON,
    INPUT_CTRL_PEER_CLICK,
    Session,
)

_IS_WIN = sys.platform == "win32"
_IS_MAC = sys.platform == "darwin"

# Bump when input-share behaviour changes (sync / peer version check).
INPUTSHARE_BUILD = "2026-07-21-caps-hangul-attach-pulse"

# Physical edge strip on this PC (screen coordinates)
EDGE_PX = 28
# Wider strip on remote virtual desktop to return control (move mouse left)
RETURN_EDGE_PX = 56
# How long cursor must stay in the return strip before handoff back
RETURN_EDGE_DWELL_S = 0.12
# How long the cursor must stay in the strip before handoff
EDGE_DWELL_S = 0.05
# After a handoff, ignore edges briefly to avoid bounce
EDGE_COOLDOWN_S = 0.75
# Place cursor this far inside after returning to local (must clear EDGE_PX)
LOCAL_RETURN_INSET = 96
# Start remote virtual cursor this far from the left edge
REMOTE_ENTER_INSET = 80
# Slight boost — keep near 1.0; large gain amplifies jitter
MOVE_GAIN = 1.35
# Capture-side coalesce window (~90–120 Hz source → fewer USB frames)
MOVE_SEND_INTERVAL_S = 0.008
# Keep local cursor inside this inset of the grab display (poll fallback)
GRAB_EDGE_MARGIN_PX = 48
# Ignore absurd per-poll jumps (display switch / warp glitch)
MAX_DELTA_PER_POLL = 80
# After requesting remote control, wait this long for peer ACK before aborting
REMOTE_ACK_TIMEOUT_S = 4.0

def _list_displays() -> list[tuple[float, float, float, float]]:
    """Return display rects as (x, y, w, h) in pynput/Quartz top-left coords."""
    rects: list[tuple[float, float, float, float]] = []
    if _IS_MAC:
        try:
            import Quartz

            err, ids, count = Quartz.CGGetActiveDisplayList(32, None, None)
            if err == 0 and ids:
                for did in ids[: int(count)]:
                    b = Quartz.CGDisplayBounds(did)
                    rects.append(
                        (
                            float(b.origin.x),
                            float(b.origin.y),
                            float(b.size.width),
                            float(b.size.height),
                        )
                    )
        except Exception:
            pass
    elif _IS_WIN:
        try:
            import ctypes
            from ctypes import wintypes

            user32 = ctypes.windll.user32
            MONITORINFOF_PRIMARY = 1
            monitors: list[tuple[float, float, float, float]] = []

            class RECT(ctypes.Structure):
                _fields_ = [
                    ("left", wintypes.LONG),
                    ("top", wintypes.LONG),
                    ("right", wintypes.LONG),
                    ("bottom", wintypes.LONG),
                ]

            class MONITORINFO(ctypes.Structure):
                _fields_ = [
                    ("cbSize", wintypes.DWORD),
                    ("rcMonitor", RECT),
                    ("rcWork", RECT),
                    ("dwFlags", wintypes.DWORD),
                ]

            MonitorEnumProc = ctypes.WINFUNCTYPE(
                wintypes.BOOL,
                wintypes.HMONITOR,
                wintypes.HDC,
                ctypes.POINTER(RECT),
                wintypes.LPARAM,
            )

            def _cb(hmon, _hdc, _lprc, _data):
                info = MONITORINFO()
                info.cbSize = ctypes.sizeof(MONITORINFO)
                if user32.GetMonitorInfoW(hmon, ctypes.byref(info)):
                    r = info.rcMonitor
                    monitors.append(
                        (
                            float(r.left),
                            float(r.top),
                            float(r.right - r.left),
                            float(r.bottom - r.top),
                        )
                    )
                return True

            user32.EnumDisplayMonitors(0, 0, MonitorEnumProc(_cb), 0)
            rects = monitors
        except Exception:
            pass
    if rects:
        return rects
    try:
        import tkinter as tk

        root = tk.Tk()
        root.withdraw()
        w = float(root.winfo_screenwidth())
        h = float(root.winfo_screenheight())
        root.destroy()
        if w > 0 and h > 0:
            return [(0.0, 0.0, w, h)]
    except Exception:
        pass
    return [(0.0, 0.0, 1920.0, 1080.0)]


def _screen_size() -> tuple[int, int]:
    """Primary (origin nearest 0,0) display size — used for grab center / peer size."""
    rects = _list_displays()
    best = min(rects, key=lambda r: (abs(r[0]) + abs(r[1]), -r[2] * r[3]))
    return max(1, int(best[2])), max(1, int(best[3]))


def _virtual_desktop() -> tuple[float, float, int, int]:
    """Union of all displays: (origin_x, origin_y, width, height)."""
    rects = _list_displays()
    if not rects:
        w, h = _screen_size()
        return 0.0, 0.0, w, h
    min_x = min(r[0] for r in rects)
    min_y = min(r[1] for r in rects)
    max_x = max(r[0] + r[2] for r in rects)
    max_y = max(r[1] + r[3] for r in rects)
    return (
        float(min_x),
        float(min_y),
        max(1, int(max_x - min_x)),
        max(1, int(max_y - min_y)),
    )


def _display_at(x: float, y: float) -> tuple[float, float, float, float] | None:
    for r in _list_displays():
        rx, ry, rw, rh = r
        if rx <= x < rx + rw and ry <= y < ry + rh:
            return r
    # Near-edge: allow a few px of slack outside
    for r in _list_displays():
        rx, ry, rw, rh = r
        if rx - EDGE_PX <= x < rx + rw + EDGE_PX and ry - EDGE_PX <= y < ry + rh + EDGE_PX:
            return r
    return None


def _has_neighbor_right(
    disp: tuple[float, float, float, float], y: float, gap: float = 24.0
) -> bool:
    """True if another display continues past this display's right edge at row y."""
    rx, ry, rw, rh = disp
    right = rx + rw
    for ox, oy, ow, oh in _list_displays():
        if abs(ox - right) > gap:
            continue
        if oy <= y < oy + oh or ry <= oy < ry + rh:
            return True
    return False


def _has_neighbor_left(
    disp: tuple[float, float, float, float], y: float, gap: float = 24.0
) -> bool:
    """True if another display continues past this display's left edge at row y."""
    rx, ry, rw, rh = disp
    left = rx
    for ox, oy, ow, oh in _list_displays():
        if abs(ox + ow - left) > gap:
            continue
        if oy <= y < oy + oh or ry <= oy < ry + rh:
            return True
    return False


def _left_reclaim_x(x: float, y: float) -> float | None:
    """Left edge x for reclaiming local control when peer is driving this PC."""
    disp = _display_at(x, y)
    if disp is None:
        return None
    rx, ry, rw, rh = disp
    if _has_neighbor_left(disp, y):
        return None
    return rx


def _right_handoff_x(x: float, y: float) -> float | None:
    """Right-edge X that should trigger peer handoff for cursor (x,y), or None."""
    disp = _display_at(x, y)
    if disp is None:
        return None
    if _has_neighbor_right(disp, y):
        return None
    return disp[0] + disp[2]


def _mac_mouse_delta() -> tuple[int, int]:
    """Read relative mouse delta without warping the cursor (macOS)."""
    try:
        from ctypes import CDLL, POINTER, byref, c_int

        cg = CDLL(
            "/System/Library/Frameworks/CoreGraphics.framework/CoreGraphics"
        )
        cg.CGGetLastMouseDelta.argtypes = [POINTER(c_int), POINTER(c_int)]
        cg.CGGetLastMouseDelta.restype = None
        dx = c_int(0)
        dy = c_int(0)
        cg.CGGetLastMouseDelta(byref(dx), byref(dy))
        return int(dx.value), int(dy.value)
    except Exception:
        pass
    try:
        import Quartz

        # Some PyObjC builds expose the helper directly
        t = Quartz.CGGetLastMouseDelta(None, None)
        if isinstance(t, tuple) and len(t) >= 2:
            return int(t[0]), int(t[1])
    except Exception:
        pass
    return 0, 0


def _mac_set_mouse_associated(associated: bool) -> None:
    try:
        from ctypes import CDLL, c_int

        cg = CDLL(
            "/System/Library/Frameworks/CoreGraphics.framework/CoreGraphics"
        )
        cg.CGAssociateMouseAndMouseCursorPosition.argtypes = [c_int]
        cg.CGAssociateMouseAndMouseCursorPosition.restype = None
        cg.CGAssociateMouseAndMouseCursorPosition(1 if associated else 0)
    except Exception:
        try:
            import Quartz

            Quartz.CGAssociateMouseAndMouseCursorPosition(bool(associated))
        except Exception:
            pass


def _mac_zero_event_suppression() -> None:
    """Set the local-events suppression interval to 0 so that warping the cursor
    back to a pin point does not swallow / inflate the next real mouse delta.

    This is what makes the reference (usbLAN) warp-back approach smooth: after a
    CGWarpMouseCursorPosition, macOS normally suppresses local events for ~0.25s
    which corrupts the per-event HID deltas we forward to the peer.
    """
    try:
        from ctypes import CDLL, c_double, c_uint32, c_void_p

        cg = CDLL(
            "/System/Library/Frameworks/CoreGraphics.framework/CoreGraphics"
        )
        cg.CGEventSourceCreate.argtypes = [c_uint32]
        cg.CGEventSourceCreate.restype = c_void_p
        src = cg.CGEventSourceCreate(1) or cg.CGEventSourceCreate(0)
        if src:
            cg.CGEventSourceSetLocalEventsSuppressionInterval.argtypes = [
                c_void_p,
                c_double,
            ]
            cg.CGEventSourceSetLocalEventsSuppressionInterval(src, 0.0)
    except Exception:
        pass


def _mac_post_event(ev: Any) -> None:
    """Post a synthetic event to all taps (HID + Session + Annotated)."""
    try:
        import Quartz

        taps = [Quartz.kCGHIDEventTap, Quartz.kCGSessionEventTap]
        ann = getattr(Quartz, "kCGAnnotatedSessionEventTap", None)
        if ann is not None:
            taps.append(ann)
        for tap in taps:
            try:
                Quartz.CGEventPost(tap, ev)
            except Exception:
                pass
    except Exception:
        pass


def _mac_accessibility_ok() -> bool:
    try:
        import ApplicationServices  # type: ignore

        return bool(ApplicationServices.AXIsProcessTrusted())
    except Exception:
        pass
    try:
        import ctypes

        lib = ctypes.CDLL(
            "/System/Library/Frameworks/ApplicationServices.framework/ApplicationServices"
        )
        lib.AXIsProcessTrusted.restype = ctypes.c_bool
        return bool(lib.AXIsProcessTrusted())
    except Exception:
        return False


def _mac_request_accessibility() -> bool:
    """Prompt macOS Accessibility dialog if not yet trusted."""
    if _mac_accessibility_ok():
        return True
    try:
        import ApplicationServices  # type: ignore

        opts = {
            ApplicationServices.kAXTrustedCheckOptionPrompt.takeRetainedValue(): True
        }
        return bool(ApplicationServices.AXIsProcessTrustedWithOptions(opts))
    except Exception:
        return False


# macOS keyboard event taps need "Input Monitoring" (kIOHIDRequestTypeListenEvent),
# which is a SEPARATE permission from Accessibility. Mouse taps work with
# Accessibility alone, so a missing Input Monitoring grant shows up as
# "mouse works but keyboard does nothing on the peer".
_IOHID_REQUEST_TYPE_LISTEN_EVENT = 1


def _iokit_lib():
    import ctypes

    return ctypes.CDLL("/System/Library/Frameworks/IOKit.framework/IOKit")


def _mac_input_monitoring_ok() -> bool:
    """True when Input Monitoring is granted (keyboard tap can read events)."""
    if not _IS_MAC:
        return True
    try:
        import ctypes

        lib = _iokit_lib()
        lib.IOHIDCheckAccess.restype = ctypes.c_int
        lib.IOHIDCheckAccess.argtypes = [ctypes.c_uint]
        # 0 = granted, 1 = denied, 2 = unknown/not-determined
        return int(lib.IOHIDCheckAccess(_IOHID_REQUEST_TYPE_LISTEN_EVENT)) == 0
    except Exception:
        # API unavailable (older macOS) — assume ok so we don't block handoff.
        return True


def _mac_request_input_monitoring() -> bool:
    """Prompt the Input Monitoring dialog if keyboard capture is not yet allowed."""
    if not _IS_MAC:
        return True
    if _mac_input_monitoring_ok():
        return True
    try:
        import ctypes

        lib = _iokit_lib()
        lib.IOHIDRequestAccess.restype = ctypes.c_bool
        lib.IOHIDRequestAccess.argtypes = [ctypes.c_uint]
        return bool(lib.IOHIDRequestAccess(_IOHID_REQUEST_TYPE_LISTEN_EVENT))
    except Exception:
        return False


def _mac_osascript_click(ax: int, ay: int) -> bool:
    """Fallback click via System Events (needs Accessibility like pynput)."""
    try:
        import subprocess

        script = (
            f'tell application "System Events" to click at '
            f"{{{int(ax)}, {int(ay)}}}"
        )
        r = subprocess.run(
            ["osascript", "-e", script],
            capture_output=True,
            timeout=3,
            check=False,
        )
        return r.returncode == 0
    except Exception:
        return False


def _mac_click_at(ax: int, ay: int, button: int) -> bool:
    """Full click at Quartz global coords — warp then down+up."""
    _mac_inject_mouse_pos(ax, ay)
    if _mac_osascript_click(ax, ay):
        return True
    if _mac_inject_mouse_button(ax, ay, button, True):
        time.sleep(0.025)
        _mac_inject_mouse_button(ax, ay, button, False)
        return True
    return False


_MAC_MODIFIER_NAMES = frozenset(
    {
        "cmd",
        "cmd_l",
        "cmd_r",
        "command",
        "super",
        "windows",
        "win",
        "ctrl",
        "ctrl_l",
        "ctrl_r",
        "control",
        "shift",
        "shift_l",
        "shift_r",
        "alt",
        "alt_l",
        "alt_r",
        "option",
        "alt_gr",
    }
)

_MAC_VK_ALIASES: dict[str, int] = {
    "cmd": 0x37,
    "cmd_l": 0x37,
    "command": 0x37,
    "super": 0x37,
    "windows": 0x37,
    "win": 0x37,
    "cmd_r": 0x36,
    "ctrl": 0x3B,
    "ctrl_l": 0x3B,
    "control": 0x3B,
    "ctrl_r": 0x3E,
    "shift": 0x38,
    "shift_l": 0x38,
    "shift_r": 0x3C,
    "alt": 0x3A,
    "alt_l": 0x3A,
    "option": 0x3A,
    "alt_r": 0x3D,
    "alt_gr": 0x3D,
    "space": 0x31,
    "tab": 0x30,
    "enter": 0x24,
    "return": 0x24,
    "esc": 0x35,
    "escape": 0x35,
    "backspace": 0x33,
    "delete": 0x75,
    "up": 0x7E,
    "down": 0x7D,
    "left": 0x7B,
    "right": 0x7C,
    "home": 0x73,
    "end": 0x77,
    "page_up": 0x74,
    "page_down": 0x79,
    "caps_lock": 0x39,
}


def _mac_vk_from_name(name: str) -> int | None:
    if not name:
        return None
    low = name.lower()
    if low in _MAC_VK_ALIASES:
        return _MAC_VK_ALIASES[low]
    if name.startswith("vk:"):
        try:
            return int(name.split(":", 1)[1]) & 0xFF
        except Exception:
            return None
    if len(name) == 1:
        try:
            from pynput._util.darwin import get_unicode_to_keycode_map

            return get_unicode_to_keycode_map().get(name)
        except Exception:
            return None
    if low.startswith("f") and low[1:].isdigit():
        try:
            from pynput.keyboard._darwin import Key

            key = Key[low]
            return int(key.value.vk) if key.value.vk is not None else None
        except Exception:
            return None
    try:
        from pynput.keyboard._darwin import Key

        key = Key[low]
        return int(key.value.vk) if key.value.vk is not None else None
    except Exception:
        return None


def _mac_modifier_flags(active: set[str]) -> int:
    try:
        import Quartz

        flags = 0
        if active & {"cmd", "cmd_l", "cmd_r", "command", "super", "windows", "win"}:
            flags |= Quartz.kCGEventFlagMaskCommand
        if active & {"ctrl", "ctrl_l", "ctrl_r", "control"}:
            flags |= Quartz.kCGEventFlagMaskControl
        if active & {"shift", "shift_l", "shift_r"}:
            flags |= Quartz.kCGEventFlagMaskShift
        if active & {"alt", "alt_l", "alt_r", "option", "alt_gr"}:
            flags |= Quartz.kCGEventFlagMaskAlternate
        return int(flags)
    except Exception:
        return 0


def _mac_inject_key(name: str, pressed: bool, active_mods: set[str]) -> bool:
    """Inject keyboard event on macOS with modifier flags."""
    try:
        import Quartz

        vk = _mac_vk_from_name(name)
        if vk is None:
            return False
        ev = Quartz.CGEventCreateKeyboardEvent(None, int(vk), bool(pressed))
        if ev is None:
            return False
        flags = _mac_modifier_flags(active_mods)
        if flags:
            Quartz.CGEventSetFlags(ev, flags)
        if len(name) == 1 and name.isprintable():
            try:
                Quartz.CGEventKeyboardSetUnicodeString(ev, 1, name)
            except Exception:
                pass
        _mac_post_event(ev)
        return True
    except Exception:
        return False


def _main_display_height() -> float:
    rects = _list_displays()
    if not rects:
        return 1080.0
    main = min(rects, key=lambda r: (abs(r[0]) + abs(r[1]), -r[2] * r[3]))
    return float(main[3])


def _mac_mouse_xy() -> tuple[float, float] | None:
    """Cursor position in Quartz global coords (avoid CGEventGetLocation on arm64)."""
    if not _IS_MAC:
        return None
    try:
        from AppKit import NSEvent

        p = NSEvent.mouseLocation()
        return float(p.x), float(_main_display_height() - p.y)
    except Exception:
        return None


def _mac_show_cursor() -> None:
    """Force the OS pointer visible (controlled peer / after remote session)."""
    try:
        import Quartz

        mid = Quartz.CGMainDisplayID()
        for _ in range(32):
            Quartz.CGDisplayShowCursor(mid)
            Quartz.CGDisplayShowCursor(Quartz.kCGNullDirectDisplay)
        try:
            from AppKit import NSCursor  # type: ignore

            for _ in range(8):
                NSCursor.unhide()
        except Exception:
            pass
    except Exception:
        pass


def _mac_virtual_to_cg(
    vx: float, vy: float, ox: float, oy: float, _desk_h: int
) -> tuple[float, float]:
    """Virtual desktop (top-left origin, y down) → global screen coords."""
    return float(ox + vx), float(oy + vy)


def _mac_event_source() -> Any:
    """HID/session event source — None often drops clicks in background apps."""
    try:
        import Quartz

        for state in (
            Quartz.kCGEventSourceStateHIDSystemState,
            Quartz.kCGEventSourceStateCombinedSessionState,
            Quartz.kCGEventSourceStatePrivate,
        ):
            try:
                src = Quartz.CGEventSourceCreate(state)
                if src is not None:
                    return src
            except Exception:
                pass
    except Exception:
        pass
    return None


def _mac_inject_mouse_pos(ax: int, ay: int, held_button: int = 0) -> bool:
    """Inject absolute cursor position on macOS (controlled peer).

    pynput alone often fails when this process is not the foreground app.
    usbLAN-style: warp + post MouseMoved on HID/Session taps.

    When a button is held (``held_button`` in 1/2/3) the move must be posted as
    the matching *Dragged* event, not MouseMoved — otherwise macOS apps see the
    button down but treat the motion as a plain hover, so text selection /
    title-bar / file drags never register.
    """
    try:
        import Quartz

        _mac_set_mouse_associated(True)
        pt = (float(ax), float(ay))
        src = _mac_event_source()
        Quartz.CGWarpMouseCursorPosition(pt)
        _mac_show_cursor()
        if held_button == 2:
            etype = Quartz.kCGEventRightMouseDragged
            btn_num = Quartz.kCGMouseButtonRight
        elif held_button == 3:
            etype = Quartz.kCGEventOtherMouseDragged
            btn_num = getattr(Quartz, "kCGMouseButtonCenter", 2)
        elif held_button == 1:
            etype = Quartz.kCGEventLeftMouseDragged
            btn_num = Quartz.kCGMouseButtonLeft
        else:
            etype = Quartz.kCGEventMouseMoved
            btn_num = Quartz.kCGMouseButtonLeft
        ev = Quartz.CGEventCreateMouseEvent(src, etype, pt, btn_num)
        if ev is not None:
            _mac_post_event(ev)
        return True
    except Exception:
        return False


def _mac_inject_mouse_button(
    ax: int, ay: int, button: int, pressed: bool, click_state: int = 1
) -> bool:
    """Inject mouse button — same direct path as cursor warp (moves already work)."""
    try:
        import Quartz
        from pynput.mouse import Button

        _mac_set_mouse_associated(True)
        pt = (float(ax), float(ay))
        Quartz.CGWarpMouseCursorPosition(pt)
        _mac_show_cursor()

        btn_num = max(0, int(button) - 1)
        if button == 2:
            etype = (
                Quartz.kCGEventRightMouseDown
                if pressed
                else Quartz.kCGEventRightMouseUp
            )
            pbtn = Button.right
        elif button == 3:
            etype = (
                Quartz.kCGEventOtherMouseDown
                if pressed
                else Quartz.kCGEventOtherMouseUp
            )
            pbtn = Button.middle
        else:
            etype = (
                Quartz.kCGEventLeftMouseDown
                if pressed
                else Quartz.kCGEventLeftMouseUp
            )
            pbtn = Button.left

        ev = Quartz.CGEventCreateMouseEvent(None, etype, pt, btn_num)
        if ev is not None:
            click_field = getattr(Quartz, "kCGMouseEventClickState", 2)
            try:
                Quartz.CGEventSetIntegerValueField(
                    ev, click_field, max(1, int(click_state))
                )
            except Exception:
                pass
            _mac_post_event(ev)

        # pynput uses the same HID post — belt-and-suspenders with warp above.
        try:
            from pynput.mouse import Controller

            ctl = Controller()
            ctl.position = (int(ax), int(ay))
            if pressed:
                ctl.press(pbtn)
            else:
                ctl.release(pbtn)
        except Exception:
            pass
        return True
    except Exception:
        return False


def _win_clip_cursor(rect: tuple[float, float, float, float] | None) -> None:
    """Confine the Windows cursor to a display rect, or release with None."""
    try:
        import ctypes
        from ctypes import wintypes

        user32 = ctypes.windll.user32
        if rect is None:
            user32.ClipCursor(None)
            return
        rx, ry, rw, rh = rect
        r = wintypes.RECT(
            int(rx),
            int(ry),
            int(rx + rw),
            int(ry + rh),
        )
        user32.ClipCursor(ctypes.byref(r))
    except Exception:
        pass


def _force_release_os_input() -> None:
    """Best-effort: unstick modifiers/buttons and restore cursor after KM inject.

    When the controller disconnects while keys are held, Windows/macOS can keep
    Ctrl/Alt/Shift or mouse buttons 'down', making local KM feel broken even
    after input-share is turned off.
    """
    if _IS_WIN:
        try:
            import ctypes

            user32 = ctypes.windll.user32
            KEYEVENTF_KEYUP = 0x0002
            # L/R Shift, Ctrl, Alt, LWin, RWin
            for vk in (0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x5B, 0x5C, 0x10, 0x11, 0x12):
                try:
                    user32.keybd_event(vk, 0, KEYEVENTF_KEYUP, 0)
                except Exception:
                    pass
            for flag in (0x0004, 0x0010, 0x0040):  # LEFTUP RIGHTUP MIDDLEUP
                try:
                    user32.mouse_event(flag, 0, 0, 0, 0)
                except Exception:
                    pass
            try:
                user32.ClipCursor(None)
            except Exception:
                pass
            try:
                for _ in range(64):
                    if user32.ShowCursor(True) >= 0:
                        break
            except Exception:
                pass
        except Exception:
            pass
        return
    if _IS_MAC:
        try:
            import Quartz

            Quartz.CGAssociateMouseAndMouseCursorPosition(True)
            # Release common modifiers via synthetic key-up events
            for keycode in (0x37, 0x36, 0x3A, 0x3D, 0x3B, 0x3E, 0x38, 0x3C):  # cmd/opt/ctrl/shift
                try:
                    ev = Quartz.CGEventCreateKeyboardEvent(None, keycode, False)
                    if ev is not None:
                        Quartz.CGEventPost(Quartz.kCGHIDEventTap, ev)
                except Exception:
                    pass
            for _ in range(64):
                try:
                    Quartz.CGDisplayShowCursor(Quartz.kCGNullDirectDisplay)
                except Exception:
                    break
            try:
                from AppKit import NSCursor  # type: ignore

                for _ in range(16):
                    NSCursor.unhide()
            except Exception:
                pass
        except Exception:
            pass


def _point_in_rect(
    x: float, y: float, rect: tuple[float, float, float, float], margin: float = 0.0
) -> bool:
    rx, ry, rw, rh = rect
    return (
        rx + margin <= x < rx + rw - margin
        and ry + margin <= y < ry + rh - margin
    )


def _key_name(key: Any) -> str:
    from pynput.keyboard import Key, KeyCode

    if isinstance(key, KeyCode):
        if key.char:
            return key.char
        if key.vk is not None:
            return f"vk:{key.vk}"
        return str(key)
    if isinstance(key, Key):
        return key.name or str(key).replace("Key.", "")
    return str(key)


def _key_from_name(name: str) -> Any:
    from pynput.keyboard import Key, KeyCode

    if not name:
        return None
    if name.startswith("vk:"):
        try:
            return KeyCode.from_vk(int(name.split(":", 1)[1]))
        except Exception:
            return None
    if len(name) == 1:
        return KeyCode.from_char(name)
    try:
        return Key[name]
    except KeyError:
        # aliases
        aliases = {
            "cmd": "cmd",
            "command": "cmd",
            "windows": "cmd",
            "return": "enter",
            "esc": "esc",
            "escape": "esc",
        }
        alt = aliases.get(name)
        if alt:
            try:
                return Key[alt]
            except KeyError:
                pass
    return None


_MAC_MOD_KEYCODES: dict[int, str] = {
    54: "cmd_r",
    55: "cmd_l",
    56: "shift",
    60: "shift",
    58: "alt_l",
    61: "alt_r",
    59: "ctrl",
    62: "ctrl",
    57: "caps_lock",
}


# Mac ANSI virtual keycodes → canonical, platform-neutral names.
# Sending "vk:<mac_keycode>" broke Windows peers, which read the number as a
# Windows VK (e.g. mac keycode 1 = 's' but VK 1 = left mouse button). Names here
# are understood by both _win_vk_from_name and _mac_vk_from_name.
_MAC_KEYCODE_TO_NAME: dict[int, str] = {
    0: "a", 1: "s", 2: "d", 3: "f", 4: "h", 5: "g", 6: "z", 7: "x", 8: "c",
    9: "v", 11: "b", 12: "q", 13: "w", 14: "e", 15: "r", 16: "y", 17: "t",
    18: "1", 19: "2", 20: "3", 21: "4", 22: "6", 23: "5", 24: "=", 25: "9",
    26: "7", 27: "-", 28: "8", 29: "0", 30: "]", 31: "o", 32: "u", 33: "[",
    34: "i", 35: "p", 37: "l", 38: "j", 39: "'", 40: "k", 41: ";", 42: "\\",
    43: ",", 44: "/", 45: "n", 46: "m", 47: ".", 50: "`",
    36: "enter", 48: "tab", 49: "space", 51: "backspace", 53: "esc",
    117: "delete", 115: "home", 116: "page_up", 119: "end", 121: "page_down",
    123: "left", 124: "right", 125: "down", 126: "up",
    122: "f1", 120: "f2", 99: "f3", 118: "f4", 96: "f5", 97: "f6", 98: "f7",
    100: "f8", 101: "f9", 109: "f10", 103: "f11", 111: "f12",
    76: "enter", 71: "esc",
    # Korean/Japanese input-source keys on Apple keyboards. The 한/A key maps to
    # Windows VK_HANGUL and 한자 to VK_HANJA so IME toggle reaches a Win peer.
    104: "hangul", 102: "hangul", 110: "hanja",
}

# Keys that must always be forwarded by name (never as a typed character).
_MAC_NAMED_KEYS = frozenset(
    {
        "enter", "tab", "space", "backspace", "esc", "delete", "home", "end",
        "page_up", "page_down", "left", "right", "up", "down",
        "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "f9", "f10", "f11", "f12",
        "hangul", "hanja",
    }
)


def _mac_key_from_cgevent(event: Any, etype: int) -> tuple[str, bool] | None:
    """Map a CGEvent key event to (name, pressed) for USB forwarding."""
    try:
        import Quartz
    except Exception:
        return None
    if etype == Quartz.kCGEventFlagsChanged:
        kc = int(
            Quartz.CGEventGetIntegerValueField(event, Quartz.kCGKeyboardEventKeycode)
        )
        name = _MAC_MOD_KEYCODES.get(kc)
        if not name:
            return None
        flags = int(Quartz.CGEventGetFlags(event))
        flag_masks = {
            54: Quartz.kCGEventFlagMaskCommand,
            55: Quartz.kCGEventFlagMaskCommand,
            56: Quartz.kCGEventFlagMaskShift,
            60: Quartz.kCGEventFlagMaskShift,
            58: Quartz.kCGEventFlagMaskAlternate,
            61: Quartz.kCGEventFlagMaskAlternate,
            59: Quartz.kCGEventFlagMaskControl,
            62: Quartz.kCGEventFlagMaskControl,
            57: Quartz.kCGEventFlagMaskAlphaShift,
        }
        mask = flag_masks.get(kc, 0)
        return name, bool(flags & mask)
    if etype not in (Quartz.kCGEventKeyDown, Quartz.kCGEventKeyUp):
        return None
    pressed = etype == Quartz.kCGEventKeyDown
    kc = int(
        Quartz.CGEventGetIntegerValueField(event, Quartz.kCGKeyboardEventKeycode)
    )
    named = _MAC_KEYCODE_TO_NAME.get(kc)
    # Navigation / editing / function keys: always forward by canonical name.
    if named in _MAC_NAMED_KEYS:
        return named, pressed
    # Text keys: prefer the produced character so Shift/AltGr/IME layouts work.
    try:
        import ctypes

        buf = (ctypes.c_uint16 * 8)()
        n = ctypes.c_uint32(0)
        Quartz.CGEventKeyboardGetUnicodeString(
            event, 8, buf, ctypes.byref(n)
        )
        if int(n.value) > 0:
            text = "".join(chr(int(buf[i])) for i in range(int(n.value)))
            if len(text) == 1 and text.isprintable():
                return text, pressed
    except Exception:
        pass
    # No printable char (e.g. Ctrl/Cmd held) — fall back to the canonical name
    # so the peer receives "s" rather than an unusable "vk:1".
    if named:
        return named, pressed
    return f"vk:{kc}", pressed


_WIN_VK_NAMES: dict[int, str] = {
    0x08: "backspace",
    0x09: "tab",
    0x0D: "enter",
    0x1B: "esc",
    0x20: "space",
    0x21: "page_up",
    0x22: "page_down",
    0x23: "end",
    0x24: "home",
    0x25: "left",
    0x26: "up",
    0x27: "right",
    0x28: "down",
    0x2D: "insert",
    0x2E: "delete",
    0x14: "caps_lock",  # VK_CAPITAL — Caps Lock (대소문자) toggle
    0x15: "hangul",  # VK_HANGUL / VK_KANA — Korean/English IME toggle
    0x19: "hanja",   # VK_HANJA / VK_KANJI
    0x5B: "cmd",
    0x5C: "cmd",
    0xA0: "shift",
    0xA1: "shift",
    0xA2: "ctrl",
    0xA3: "ctrl",
    0xA4: "alt",
    0xA5: "alt",
}


def _win_vk_to_name(vk: int) -> str:
    vk = int(vk) & 0xFF
    if 0x30 <= vk <= 0x39:
        return chr(vk)
    if 0x41 <= vk <= 0x5A:
        return chr(vk).lower()
    if 0x60 <= vk <= 0x69:
        return f"f{vk - 0x60}"
    if 0x70 <= vk <= 0x87:
        return f"f{vk - 0x6F}"
    return _WIN_VK_NAMES.get(vk, f"vk:{vk}")


def _win_vk_from_name(name: str) -> int | None:
    if not name:
        return None
    low = name.lower()
    for vk, n in _WIN_VK_NAMES.items():
        if n == low:
            return vk
    if name.startswith("vk:"):
        try:
            return int(name.split(":", 1)[1]) & 0xFFFF
        except Exception:
            return None
    if len(name) == 1:
        ch = name.upper()
        if "A" <= ch <= "Z":
            return ord(ch)
        if "0" <= ch <= "9":
            return ord(ch)
    if low.startswith("f") and low[1:].isdigit():
        n = int(low[1:])
        if 1 <= n <= 12:
            return 0x6F + n
        if 13 <= n <= 24:
            return 0x60 + (n - 12)
    return None


def _win_attach_foreground(user32: Any) -> tuple[int, int] | None:
    """Attach our thread to the foreground window's input queue (better key inject)."""
    import ctypes

    hwnd = int(user32.GetForegroundWindow() or 0)
    if not hwnd:
        return None
    pid = ctypes.c_ulong(0)
    tid = int(user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid)) or 0)
    our = int(ctypes.windll.kernel32.GetCurrentThreadId())
    if not tid or tid == our:
        return (hwnd, 0)
    if not user32.AttachThreadInput(our, tid, True):
        return (hwnd, 0)
    return (hwnd, tid)


def _win_detach_foreground(user32: Any, tid: int) -> None:
    import ctypes

    if tid:
        our = int(ctypes.windll.kernel32.GetCurrentThreadId())
        user32.AttachThreadInput(our, tid, False)


def _win_ime_open_status(user32: Any, hwnd: int) -> int | None:
    """Return IME open status (1=Hangul-ish open, 0=closed) or None if unknown."""
    import ctypes

    if not hwnd:
        return None
    imm32 = ctypes.windll.imm32
    WM_IME_CONTROL = 0x0283
    IMC_GETOPENSTATUS = 0x0005
    hime = imm32.ImmGetDefaultIMEWnd(hwnd)
    if not hime:
        return None
    return int(user32.SendMessageW(hime, WM_IME_CONTROL, IMC_GETOPENSTATUS, 0))


def _win_toggle_caps_lock(user32: Any) -> bool:
    """Flip Caps Lock so GetKeyState(VK_CAPITAL) actually changes.

    Plain SendInput(VK_CAPITAL) often only blinks the indicator. The classic
    keybd_event pattern (scan 0x45 + KEYEVENTF_EXTENDEDKEY) is what apps respect.
    """
    import ctypes
    from ctypes import wintypes

    KEYEVENTF_EXTENDEDKEY = 0x0001
    KEYEVENTF_KEYUP = 0x0002
    KEYEVENTF_SCANCODE = 0x0008
    VK_CAPITAL = 0x14

    attached = _win_attach_foreground(user32)
    tid = attached[1] if attached else 0
    try:
        before = int(user32.GetKeyState(VK_CAPITAL)) & 1
        user32.keybd_event(VK_CAPITAL, 0x45, KEYEVENTF_EXTENDEDKEY, 0)
        time.sleep(0.04)
        user32.keybd_event(
            VK_CAPITAL, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0
        )
        time.sleep(0.03)
        after = int(user32.GetKeyState(VK_CAPITAL)) & 1
        if before != after:
            return True

        ULONG_PTR = (
            ctypes.c_ulonglong
            if ctypes.sizeof(ctypes.c_void_p) == 8
            else ctypes.c_ulong
        )

        class KEYBDINPUT(ctypes.Structure):
            _fields_ = [
                ("wVk", wintypes.WORD),
                ("wScan", wintypes.WORD),
                ("dwFlags", wintypes.DWORD),
                ("time", wintypes.DWORD),
                ("dwExtraInfo", ULONG_PTR),
            ]

        class MOUSEINPUT(ctypes.Structure):
            _fields_ = [
                ("dx", wintypes.LONG),
                ("dy", wintypes.LONG),
                ("mouseData", wintypes.DWORD),
                ("dwFlags", wintypes.DWORD),
                ("time", wintypes.DWORD),
                ("dwExtraInfo", ULONG_PTR),
            ]

        class INPUT(ctypes.Structure):
            class _I(ctypes.Union):
                _fields_ = [("mi", MOUSEINPUT), ("ki", KEYBDINPUT)]

            _anonymous_ = ("i",)
            _fields_ = [("type", wintypes.DWORD), ("i", _I)]

        for up in (False, True):
            flags = KEYEVENTF_SCANCODE | (KEYEVENTF_KEYUP if up else 0)
            inp = INPUT()
            inp.type = 1
            inp.ki = KEYBDINPUT(0, 0x3A, flags, 0, 0)
            user32.SendInput(1, ctypes.byref(inp), ctypes.sizeof(INPUT))
            if not up:
                time.sleep(0.04)
        return True
    finally:
        _win_detach_foreground(user32, tid)


def _win_pulse_vk(
    user32: Any, vk: int, scan: int = 0, *, extended: bool = False
) -> None:
    KEYEVENTF_EXTENDEDKEY = 0x0001
    KEYEVENTF_KEYUP = 0x0002
    flags = KEYEVENTF_EXTENDEDKEY if extended else 0
    user32.keybd_event(vk, scan, flags, 0)
    time.sleep(0.04)
    user32.keybd_event(vk, scan, flags | KEYEVENTF_KEYUP, 0)


def _win_toggle_hangul(user32: Any) -> bool:
    """Toggle Korean Hangul/English — exactly ONE key pulse.

    Win11 Microsoft IME (TSF) often ignores Imm* and bare SendInput(VK_HANGUL).
    Attach to the foreground input queue and fire one Hangul key (scan 0xF2);
    if IME open status is readable and still unchanged, try Right Alt once.
    """
    attached = _win_attach_foreground(user32)
    hwnd = attached[0] if attached else int(user32.GetForegroundWindow() or 0)
    tid = attached[1] if attached else 0
    try:
        before = _win_ime_open_status(user32, hwnd)
        # VK_HANGUL + Korean-keyboard scan 0xF2
        _win_pulse_vk(user32, 0x15, 0xF2)
        after = _win_ime_open_status(user32, hwnd)
        if before is None or after is None:
            # Status unknown — do not stack a second key (risk of net-zero).
            return True
        if before != after:
            return True
        # Status readable and unchanged — Right Alt (common KR Hangul key)
        _win_pulse_vk(user32, 0xA5, 0x38, extended=True)
        return True
    finally:
        _win_detach_foreground(user32, tid)


def _win_inject_key(name: str, pressed: bool, active_mods: set[str]) -> bool:
    """Inject keyboard on Windows — Unicode for IME/Hangul, VK for specials."""
    try:
        import ctypes
        from ctypes import wintypes

        user32 = ctypes.windll.user32
        KEYEVENTF_KEYUP = 0x0002
        KEYEVENTF_UNICODE = 0x0004

        ULONG_PTR = (
            ctypes.c_ulonglong
            if ctypes.sizeof(ctypes.c_void_p) == 8
            else ctypes.c_ulong
        )

        class MOUSEINPUT(ctypes.Structure):
            _fields_ = [
                ("dx", wintypes.LONG),
                ("dy", wintypes.LONG),
                ("mouseData", wintypes.DWORD),
                ("dwFlags", wintypes.DWORD),
                ("time", wintypes.DWORD),
                ("dwExtraInfo", ULONG_PTR),
            ]

        class KEYBDINPUT(ctypes.Structure):
            _fields_ = [
                ("wVk", wintypes.WORD),
                ("wScan", wintypes.WORD),
                ("dwFlags", wintypes.DWORD),
                ("time", wintypes.DWORD),
                ("dwExtraInfo", ULONG_PTR),
            ]

        class INPUT(ctypes.Structure):
            # The union MUST carry MOUSEINPUT so sizeof(INPUT) matches the real
            # Win32 INPUT (40 bytes on x64). With only KEYBDINPUT the struct is
            # 32 bytes, so SendInput sees cbSize != sizeof(INPUT) and fails
            # silently (returns 0, no exception) — keystrokes never land.
            class _I(ctypes.Union):
                _fields_ = [("mi", MOUSEINPUT), ("ki", KEYBDINPUT)]

            _anonymous_ = ("i",)
            _fields_ = [("type", wintypes.DWORD), ("i", _I)]

        user32.SendInput.argtypes = [
            wintypes.UINT,
            ctypes.POINTER(INPUT),
            ctypes.c_int,
        ]
        user32.SendInput.restype = wintypes.UINT

        def _send(inp: INPUT) -> None:
            sent = user32.SendInput(1, ctypes.byref(inp), ctypes.sizeof(INPUT))
            if sent != 1:
                raise OSError(f"SendInput rejected input (sent={sent})")

        def _send_vk(vk: int, scan: int, extended: bool, up: bool) -> None:
            KEYEVENTF_EXTENDEDKEY = 0x0001
            flags = 0
            if extended:
                flags |= KEYEVENTF_EXTENDEDKEY
            if up:
                flags |= KEYEVENTF_KEYUP
            inp = INPUT()
            inp.type = 1
            inp.ki = KEYBDINPUT(vk, scan, flags, 0, 0)
            _send(inp)

        # Caps Lock / 한·영 / 한자: do NOT rely on SendInput alone.
        # - Caps Lock: classic keybd_event(VK_CAPITAL, 0x45, EXTENDEDKEY) is the
        #   MSDN pattern that actually flips GetKeyState (plain SendInput often
        #   only blinks the indicator).
        # - Hangul: Microsoft IME ignores injected VK_HANGUL unless the IME
        #   conversion/open status is toggled via imm32.
        # Key-up frames are no-ops so one Mac pulse = one Windows toggle.
        low = name.lower()
        if low in ("caps_lock", "hangul", "hanja"):
            if not pressed:
                return True
            if low == "caps_lock":
                return _win_toggle_caps_lock(user32)
            if low == "hangul":
                return _win_toggle_hangul(user32)
            # hanja — best-effort VK pulse
            _send_vk(0x19, 0x71, False, up=False)
            time.sleep(0.03)
            _send_vk(0x19, 0x71, False, up=True)
            return True

        # Shortcut combos (Ctrl/Alt/Win + key) must go through VK codes so the
        # modifier actually combines. Unicode injection ignores modifier state,
        # so Ctrl+C etc. would type a character instead of firing the shortcut.
        combo_active = bool(
            active_mods
            & {
                "ctrl", "ctrl_l", "ctrl_r", "control",
                "alt", "alt_l", "alt_r", "option", "alt_gr",
                "cmd", "cmd_l", "cmd_r", "command", "super", "windows", "win",
            }
        )
        if len(name) == 1 and name.isprintable() and not combo_active:
            if not pressed:
                return True
            code = ord(name)
            for up in (False, True):
                inp = INPUT()
                inp.type = 1
                inp.ki = KEYBDINPUT(
                    0,
                    code,
                    KEYEVENTF_UNICODE | (KEYEVENTF_KEYUP if up else 0),
                    0,
                    0,
                )
                _send(inp)
            return True

        vk = _win_vk_from_name(name)
        if vk is None and len(name) == 1 and name.isprintable():
            # Printable char under a modifier but no VK mapping — fall back to
            # Unicode so at least the character is delivered.
            if not pressed:
                return True
            code = ord(name)
            for up in (False, True):
                inp = INPUT()
                inp.type = 1
                inp.ki = KEYBDINPUT(
                    0,
                    code,
                    KEYEVENTF_UNICODE | (KEYEVENTF_KEYUP if up else 0),
                    0,
                    0,
                )
                _send(inp)
            return True
        if vk is None:
            return False
        flags = KEYEVENTF_KEYUP if not pressed else 0
        inp = INPUT()
        inp.type = 1
        inp.ki = KEYBDINPUT(vk, 0, flags, 0, 0)
        _send(inp)
        return True
    except Exception:
        return False


class InputShare:
    """Edge-triggered KM handoff bound to a live Session."""

    def __init__(self, on_log: Optional[Any] = None) -> None:
        self._log = on_log or (lambda m: None)
        self._lock = threading.RLock()
        self.session: Session | None = None
        self.enabled = False
        self.trusted = False
        self.controlling_remote = False
        self.being_controlled = False
        self._local_w, self._local_h = _screen_size()
        self._remote_w, self._remote_h = 1920, 1080
        self._vx = 0.0
        self._vy = 0.0
        self._desk_ox = 0.0
        self._desk_oy = 0.0
        self._edge_since: float | None = None
        self._handoff_until = 0.0
        self._inject_release_until = 0.0
        self._watch_stop = threading.Event()
        self._watch_thread: threading.Thread | None = None
        self._toggle_listener = None
        self._toggle_ctrl_down = False
        self._toggle_last_at = 0.0
        self._mouse_listener = None
        self._key_listener = None
        self._mac_tap = None
        self._mac_tap_source = None
        self._mac_tap_thread: threading.Thread | None = None
        self._mac_tap_callback = None
        self._mac_click_state = 0
        self._click_sent = 0
        self._click_anchor: tuple[int, int] | None = None
        self._peer_click_recv = 0
        self._left_return_since: float | None = None
        self._peer_left_return_since: float | None = None
        self._local_reclaim_since: float | None = None
        self._win_mouse_hook = None
        self._win_mouse_proc = None
        self._win_kbd_proc = None
        self._win_hook_thread: threading.Thread | None = None
        self._kb_from_hook = False
        self._mouse_ctl = None
        self._key_ctl = None
        self._suppressing = False
        self._injecting = False
        self._warping = False
        self._grab_center: tuple[int, int] = (0, 0)
        self._grab_rect: tuple[float, float, float, float] | None = None
        self._move_from_tap = False
        self._delta_capture = False
        self._soft_grab = False
        self._status = "꺼짐"
        self.howto = ""
        self.platform = "windows" if _IS_WIN else ("macos" if _IS_MAC else "other")
        self._cursor_hidden = False
        self._debug_edge_log_at = 0.0
        self._cap_stop = threading.Event()
        self._cap_thread: threading.Thread | None = None
        self._remote_acked = False
        self._capture_armed = False
        self._move_sent = 0
        self._ack_gen = 0
        self._delta_capture = False
        # A single Mac Caps Lock tap can emit two flags-changed events (ON then
        # OFF); coalesce them so Windows receives one toggle, not two (net zero).
        self._last_caps_at = 0.0
        # Modifier tracking for paste intercept
        self._mod_cmd = False
        self._mod_ctrl = False
        self._mod_shift = False
        self._mod_alt = False
        # Diagnostics: count keys forwarded to / injected from the peer
        self._key_sent_count = 0
        self._key_recv_count = 0
        # Keys/buttons held via peer inject — must release on handoff/disable
        self._injected_keys_down: set[str] = set()
        self._injected_buttons_down: set[int] = set()
        self._peer_modifiers: set[str] = set()
        # Callback: () -> dict-like result from start_clipboard_send
        self.on_clipboard_paste: Optional[Any] = None
        # Callback: () -> None — Esc while KM capture: disable share + quit app
        self.on_escape_quit: Optional[Any] = None

    def bind_session(self, session: Session | None) -> None:
        share_on = False
        lw = lh = 0
        with self._lock:
            if self.session is session:
                return
            self._unbind_session()
            self.session = session
            if session is not None:
                session.on_input_ctrl = self._on_peer_ctrl
                session.on_input_move = self._on_peer_move
                session.on_input_button = self._on_peer_button
                session.on_input_wheel = self._on_peer_wheel
                session.on_input_key = self._on_peer_key
                session.on_input_clipboard = self._on_peer_clipboard
                share_on = self.enabled
                if share_on:
                    self._local_size()
                    lw, lh = self._local_w, self._local_h
        if session is not None and share_on:
            try:
                session.send_input_ctrl(INPUT_CTRL_SHARE_ON, lw, lh)
            except Exception as exc:
                self._log(f"입력공유 동기화 전송 실패: {exc}")

    def _unbind_session(self) -> None:
        if self.session is not None:
            self.session.on_input_ctrl = None
            self.session.on_input_move = None
            self.session.on_input_button = None
            self.session.on_input_wheel = None
            self.session.on_input_key = None
            self.session.on_input_clipboard = None
        self.session = None

    def status_dict(self) -> dict[str, Any]:
        with self._lock:
            peer_ready = self.session is not None and self.session._connected.is_set()
            return {
                "supported": True,
                "enabled": self.enabled,
                "trusted": self.trusted,
                "peer": peer_ready,
                "controlling_remote": self.controlling_remote,
                "being_controlled": self.being_controlled,
                "primary_ready": peer_ready,
                "remote_acked": self._remote_acked,
                "capture_armed": self._capture_armed,
                "move_sent": self._move_sent,
                "status": self._status,
                "howto": self.howto,
                "platform": self.platform,
                "move_from_tap": bool(getattr(self, "_move_from_tap", False)),
                "soft_grab": bool(getattr(self, "_soft_grab", False)),
                "mac_tap_kind": getattr(self, "_mac_tap_kind", None),
                "build": INPUTSHARE_BUILD,
                "click_sent": self._click_sent,
                "click_recv": self._peer_click_recv,
                "accessibility": _mac_accessibility_ok() if _IS_MAC else None,
                "input_monitoring": (
                    _mac_input_monitoring_ok() if _IS_MAC else None
                ),
                "ok": True,
            }

    def prompt_trust(self) -> dict[str, Any]:
        self._ensure_controllers()
        info = self.status_dict()
        if _IS_MAC:
            info["howto"] = (
                "시스템 설정 → 개인정보 보호 및 보안 에서 "
                "① 손쉬운 사용(마우스·클릭) ② 입력 모니터링(키보드) 두 곳 모두 "
                "Terminal/Python/JUC500 앱을 허용한 뒤 앱을 재시작하세요."
            )
            info["message"] = info["howto"]
            if not _mac_input_monitoring_ok():
                _mac_request_input_monitoring()
        elif _IS_WIN:
            info["howto"] = (
                "Windows에서 입력공유는 관리자 권한 없이 동작합니다. "
                "일부 보안 소프트웨어가 훅을 막으면 예외를 추가하세요."
            )
            info["message"] = info["howto"]
        else:
            info["howto"] = "이 OS에서는 입력공유가 제한될 수 있습니다."
            info["message"] = info["howto"]
        self.howto = info["howto"]
        return info

    def set_enabled(self, enabled: bool, *, from_peer: bool = False) -> dict[str, Any]:
        sync_peer = False
        sync_on = False
        lw = lh = 0
        with self._lock:
            session_ok = (
                self.session is not None and self.session._connected.is_set()
            )
            if enabled and self.enabled and from_peer:
                return self.status_dict()
            if not enabled and not self.enabled and from_peer:
                return self.status_dict()
            if enabled:
                if not session_ok:
                    return {
                        **self.status_dict(),
                        "ok": False,
                        "error": "먼저 USB 「연결」을 완료하세요.",
                    }
                if from_peer and _IS_MAC:
                    _mac_request_accessibility()
                ok, err = self._ensure_controllers()
                if not ok:
                    self.enabled = False
                    self.trusted = False
                    self._status = "권한 필요"
                    if from_peer:
                        self._log(
                            f"상대는 입력공유 ON — 이 PC 권한 부족: {err}"
                        )
                    return {**self.status_dict(), "ok": False, "error": err}
                self.enabled = True
                self.trusted = True
                self._status = "이 PC 제어"
                self._edge_since = None
                self._handoff_until = time.monotonic() + EDGE_COOLDOWN_S
                self._local_size()
                lw, lh = self._local_w, self._local_h
                rects = _list_displays()
                self._start_watch()
                self._start_toggle_hotkey_locked()
                if from_peer:
                    self._log("상대와 입력공유 동기화 — 켜짐")
                else:
                    self._log(
                        "입력공유 켜짐 — 모니터 오른쪽 끝(옆 모니터 없을 때) → 상대 PC / "
                        "상대 왼쪽 끝 → 이 PC / Ctrl+R → 제어권 토글 / Esc → 끄고 종료"
                    )
                    if _IS_MAC:
                        _mac_request_accessibility()
                self._log(
                    f"화면 {self._local_w}x{self._local_h}, 디스플레이 {len(rects)}개"
                )
                sync_peer = not from_peer and session_ok
                sync_on = True
            else:
                self._disable_locked()
                if from_peer:
                    self._log("상대와 입력공유 동기화 — 꺼짐")
                else:
                    self._log("입력공유 꺼짐")
                sync_peer = not from_peer and session_ok
                sync_on = False
            result = self.status_dict()

        if sync_peer and self.session is not None:
            try:
                if sync_on:
                    self.session.send_input_ctrl(INPUT_CTRL_SHARE_ON, lw, lh)
                else:
                    self.session.send_input_ctrl(INPUT_CTRL_SHARE_OFF, 0, 0)
            except Exception as exc:
                self._log(f"상대 입력공유 동기화 전송 실패: {exc}")
        return result

    def set_control(self, target: str) -> dict[str, Any]:
        with self._lock:
            if not self.enabled:
                return {
                    **self.status_dict(),
                    "ok": False,
                    "error": "먼저 「입력공유」를 켜세요.",
                }
            if self.session is None or not self.session._connected.is_set():
                return {
                    **self.status_dict(),
                    "ok": False,
                    "error": "먼저 USB 「연결」을 완료하세요.",
                }
            if target == "remote":
                if self.being_controlled:
                    # Take over: stop being controlled, start controlling peer
                    self._stop_being_controlled_locked()
                self._take_remote_locked()
            else:
                if self.controlling_remote:
                    self._release_local_locked()
                elif self.being_controlled:
                    self._stop_being_controlled_locked()
                    if self.session:
                        self.session.send_input_ctrl(INPUT_CTRL_LOCAL, *self._local_size())
            return {**self.status_dict(), "ok": True}

    def ensure_local_input_restored(self, *, notify_peer: bool = True) -> None:
        """Idempotent: drop KM roles and always restore OS mouse/keyboard.

        Must run on normal exit, signal exit, disconnect, and GUI start so a
        force-killed previous process' sticky modifiers can also be cleared.
        """
        with self._lock:
            was_controlling = self.controlling_remote
            if notify_peer and was_controlling and self.session is not None:
                try:
                    self._send_modifier_keyup_to_peer()
                except Exception:
                    pass
                try:
                    self.session.send_input_ctrl(INPUT_CTRL_LOCAL, *self._local_size())
                except Exception:
                    pass
            self.enabled = False
            self._ack_gen += 1
            self._stop_watch()
            self._stop_toggle_hotkey_locked()
            self._stop_capture_locked()
            self._stop_being_controlled_locked()
            self.controlling_remote = False
            self.being_controlled = False
            self._remote_acked = False
            self._capture_armed = False
            self._clear_injected_input_locked()
            _force_release_os_input()
            self._show_local_cursor()
            self._status = "꺼짐"

    def recover_local_input(self) -> dict[str, Any]:
        """Emergency unstick: stop KM roles and force-release OS modifiers/cursor."""
        self.ensure_local_input_restored(notify_peer=True)
        self._log("로컬 마우스·키보드 강제 복구 실행")
        return {**self.status_dict(), "ok": True, "recovered": True}

    def on_disconnect(self) -> None:
        self.ensure_local_input_restored(notify_peer=False)
        with self._lock:
            self._unbind_session()

    def _disable_locked(self) -> None:
        was_controlling = self.controlling_remote
        # Tell peer to drop "being controlled" + release any stuck remote keys.
        if was_controlling and self.session is not None:
            try:
                self._send_modifier_keyup_to_peer()
            except Exception:
                pass
            try:
                self.session.send_input_ctrl(INPUT_CTRL_LOCAL, *self._local_size())
            except Exception:
                pass
        self.enabled = False
        self._ack_gen += 1
        self._stop_watch()
        self._stop_toggle_hotkey_locked()
        self._stop_capture_locked()
        self._stop_being_controlled_locked()
        self.controlling_remote = False
        self.being_controlled = False
        self._remote_acked = False
        self._capture_armed = False
        self._clear_injected_input_locked()
        self._show_local_cursor()
        _force_release_os_input()
        self._status = "꺼짐"
        self._log("입력 상태 복구 — 커서/수정키 강제 해제")

    def _send_modifier_keyup_to_peer(self) -> None:
        if self.session is None:
            return
        for name in (
            "ctrl",
            "ctrl_l",
            "ctrl_r",
            "alt",
            "alt_l",
            "alt_r",
            "shift",
            "shift_l",
            "shift_r",
            "cmd",
            "cmd_l",
            "cmd_r",
            "super",
            "windows",
        ):
            try:
                self.session.send_input_key(name, False)
            except Exception:
                pass
        for button in (1, 2, 3):
            try:
                self.session.send_input_button(button, False)
            except Exception:
                pass

    def _clear_injected_input_locked(self) -> None:
        """Release keys/buttons we synthetically pressed on this PC."""
        keys = list(self._injected_keys_down)
        buttons = list(self._injected_buttons_down)
        self._injected_keys_down.clear()
        self._injected_buttons_down.clear()
        self._peer_modifiers.clear()
        self._mod_cmd = self._mod_ctrl = self._mod_shift = self._mod_alt = False
        if self._key_ctl is not None:
            for name in keys:
                mapped = name
                if _IS_WIN and name.lower() in (
                    "cmd",
                    "cmd_l",
                    "cmd_r",
                    "command",
                    "super",
                    "windows",
                    "win",
                ):
                    mapped = "ctrl"
                key = _key_from_name(mapped)
                if key is None:
                    continue
                try:
                    self._key_ctl.release(key)
                except Exception:
                    pass
            # Always poke common modifiers even if tracking missed them
            for name in ("ctrl", "alt", "shift", "cmd"):
                key = _key_from_name(name)
                if key is None:
                    continue
                try:
                    self._key_ctl.release(key)
                except Exception:
                    pass
        for button in (1, 2, 3):
            try:
                self._inject_mouse_button(button, False)
            except Exception:
                pass
        try:
            # Restore cursor visibility before clearing the flag
            if self._cursor_hidden:
                self._show_local_cursor()
        except Exception:
            self._cursor_hidden = False
        _force_release_os_input()


    def _local_size(self) -> tuple[int, int]:
        ox, oy, w, h = _virtual_desktop()
        self._desk_ox, self._desk_oy = ox, oy
        self._local_w, self._local_h = w, h
        return self._local_w, self._local_h

    def _ensure_controllers(self) -> tuple[bool, str]:
        try:
            from pynput.keyboard import Controller as KeyController
            from pynput.mouse import Controller as MouseController

            if self._mouse_ctl is None:
                self._mouse_ctl = MouseController()
            if self._key_ctl is None:
                self._key_ctl = KeyController()
            # smoke: read position
            _ = self._mouse_ctl.position
            self.trusted = True
            return True, ""
        except Exception as exc:
            self.trusted = False
            if _IS_MAC:
                msg = (
                    "macOS 손쉬운 사용(Accessibility) 권한이 필요합니다. "
                    f"({exc})"
                )
            else:
                msg = f"입력 장치를 열 수 없습니다: {exc}"
            self.howto = msg
            return False, msg

    def _start_watch(self) -> None:
        self._stop_watch()
        self._watch_stop.clear()
        self._watch_thread = threading.Thread(
            target=self._watch_loop, name="juc500-input-edge", daemon=True
        )
        self._watch_thread.start()

    def _stop_watch(self) -> None:
        self._watch_stop.set()
        t = self._watch_thread
        self._watch_thread = None
        if t and t.is_alive():
            t.join(timeout=1.0)

    def _start_toggle_hotkey_locked(self) -> None:
        """Watch Ctrl+R while local; remote capture handles the chord itself."""
        if self._toggle_listener is not None:
            return
        try:
            from pynput.keyboard import Listener

            self._toggle_ctrl_down = False
            listener = Listener(
                on_press=lambda key: self._on_toggle_hotkey_key(key, True),
                on_release=lambda key: self._on_toggle_hotkey_key(key, False),
                suppress=False,
            )
            self._toggle_listener = listener
            listener.start()
        except Exception as exc:
            self._toggle_listener = None
            self._log(f"Ctrl+R 제어권 단축키 등록 실패: {exc}")

    def _stop_toggle_hotkey_locked(self) -> None:
        listener = self._toggle_listener
        self._toggle_listener = None
        self._toggle_ctrl_down = False
        if listener is not None:
            try:
                listener.stop()
            except Exception:
                pass

    def _on_toggle_hotkey_key(self, key: Any, pressed: bool) -> None:
        """Handle physical Ctrl+R while this PC currently owns local input."""
        name = _key_name(key).lower()
        with self._lock:
            if name in ("ctrl", "ctrl_l", "ctrl_r", "control"):
                self._toggle_ctrl_down = bool(pressed)
                return
            # During remote capture the native tap/hook handles the chord.
            if (
                not pressed
                or name not in ("r", "vk:82", "vk:15")
                or not self._toggle_ctrl_down
                or self.controlling_remote
                or self.being_controlled
            ):
                return
        self._trigger_control_toggle()

    def _trigger_control_toggle(self) -> None:
        """Debounced Ctrl+R toggle; safe from keyboard tap/hook threads."""
        with self._lock:
            now = time.monotonic()
            if now - self._toggle_last_at < 0.6:
                return
            if (
                not self.enabled
                or self.session is None
                or not self.session._connected.is_set()
            ):
                return
            self._toggle_last_at = now
            target = "local" if self.controlling_remote else "remote"

        def _switch() -> None:
            result = self.set_control(target)
            if result.get("ok"):
                self._log(
                    f"Ctrl+R — 제어권 토글 → "
                    f"{'이 PC' if target == 'local' else '상대 PC'}"
                )
            else:
                self._log(
                    f"Ctrl+R 제어권 전환 실패: {result.get('error', '알 수 없음')}"
                )

        threading.Thread(
            target=_switch, name="juc500-ctrl-r-toggle", daemon=True
        ).start()

    def _watch_loop(self) -> None:
        while not self._watch_stop.is_set():
            try:
                with self._lock:
                    now = time.monotonic()
                    cooling = now < self._handoff_until
                    enabled = self.enabled
                    cr = self.controlling_remote
                    bc = self.being_controlled
                    ctl = self._mouse_ctl
                if enabled and not cooling and ctl is not None and not cr and not bc:
                    x, y = ctl.position
                    fx, fy = float(x), float(y)
                    edge_x = _right_handoff_x(fx, fy)
                    near = edge_x is not None and fx >= edge_x - EDGE_PX
                    if near:
                        if self._edge_since is None:
                            self._edge_since = time.monotonic()
                            if time.monotonic() >= self._debug_edge_log_at:
                                self._debug_edge_log_at = time.monotonic() + 2.0
                                self._log(
                                    f"가장자리 감지 x={fx:.0f}/{edge_x:.0f} — 상대 PC로 전환 중…"
                                )
                        elif time.monotonic() - self._edge_since >= EDGE_DWELL_S:
                            with self._lock:
                                if (
                                    self.enabled
                                    and not self.controlling_remote
                                    and not self.being_controlled
                                    and time.monotonic() >= self._handoff_until
                                ):
                                    self._take_remote_locked()
                            self._edge_since = None
                    else:
                        self._edge_since = None
                elif enabled and bc and not cooling and ctl is not None:
                    x, y = ctl.position
                    fx, fy = float(x), float(y)
                    left_x = _left_reclaim_x(fx, fy)
                    near = left_x is not None and fx <= left_x + RETURN_EDGE_PX
                    if near:
                        if self._local_reclaim_since is None:
                            self._local_reclaim_since = time.monotonic()
                        elif time.monotonic() - self._local_reclaim_since >= RETURN_EDGE_DWELL_S:
                            with self._lock:
                                if self.being_controlled:
                                    w, h = self._local_w, self._local_h
                                    self._stop_being_controlled_locked()
                                    self._status = "이 PC 제어" if self.enabled else "꺼짐"
                                    session = self.session
                                    if session:
                                        try:
                                            session.send_input_ctrl(INPUT_CTRL_LOCAL, w, h)
                                        except Exception:
                                            pass
                                    self._log(
                                        f"로컬 왼쪽 가장자리 — 제어권 회수 "
                                        f"(x≤{RETURN_EDGE_PX}px)"
                                    )
                                    _force_release_os_input()
                            self._local_reclaim_since = None
                    else:
                        self._local_reclaim_since = None
                else:
                    self._edge_since = None
                    self._local_reclaim_since = None
            except Exception:
                pass
            self._watch_stop.wait(0.02)

    def _arm_cooldown(self) -> None:
        self._handoff_until = time.monotonic() + EDGE_COOLDOWN_S
        self._edge_since = None
        self._left_return_since = None
        self._peer_left_return_since = None
        self._local_reclaim_since = None

    def _should_return_from_remote_left(self, vx: float, now: float) -> bool:
        """Virtual cursor in left return strip long enough → release to local."""
        edge = float(RETURN_EDGE_PX)
        if vx > edge or now < self._handoff_until:
            self._left_return_since = None
            return False
        if self._left_return_since is None:
            self._left_return_since = now
            return False
        if now - self._left_return_since >= RETURN_EDGE_DWELL_S:
            self._left_return_since = None
            return True
        return False

    def _should_peer_return_left(self, ax: float, now: float) -> bool:
        """Peer being_controlled: left-edge dwell → request LOCAL."""
        edge = float(RETURN_EDGE_PX)
        if ax > edge or now < self._handoff_until:
            self._peer_left_return_since = None
            return False
        if self._peer_left_return_since is None:
            self._peer_left_return_since = now
            return False
        if now - self._peer_left_return_since >= RETURN_EDGE_DWELL_S:
            self._peer_left_return_since = None
            return True
        return False

    def _take_remote_locked(self) -> None:
        if self.session is None:
            return
        self._local_size()
        self._remote_acked = False
        self._capture_armed = False
        self._move_sent = 0
        self.controlling_remote = True
        self.being_controlled = False
        self._mod_cmd = False
        self._mod_ctrl = False
        self._mod_shift = False
        self._mod_alt = False
        # Enter remote from the left side (as if coming from this PC on the left)
        self._vx = float(REMOTE_ENTER_INSET)
        self._vy = float(self._remote_h) / 2.0
        self._status = "상대 응답 대기"
        self._arm_cooldown()
        self._ack_gen += 1
        gen = self._ack_gen
        self._log("제어권 요청 → 상대 PC (상대 수락 후 커서 전달 시작)")
        # Tell peer; do NOT hide/suppress until ACK — otherwise dead cursor + stuck UI.
        try:
            self.session.send_input_ctrl(INPUT_CTRL_REMOTE, self._local_w, self._local_h)
        except Exception as exc:
            self._log(f"제어권 전송 실패: {exc}")
            self.controlling_remote = False
            self._status = "이 PC 제어" if self.enabled else "꺼짐"
            return
        threading.Thread(
            target=self._await_remote_ack, args=(gen,), name="juc500-km-ack", daemon=True
        ).start()

    def _await_remote_ack(self, gen: int) -> None:
        deadline = time.monotonic() + REMOTE_ACK_TIMEOUT_S
        while time.monotonic() < deadline:
            time.sleep(0.04)
            with self._lock:
                if gen != self._ack_gen:
                    return
                if not self.controlling_remote:
                    return
                if self._remote_acked:
                    if not self._capture_armed:
                        self._arm_capture_after_ack_locked()
                    return
        with self._lock:
            if gen != self._ack_gen:
                return
            if self.controlling_remote and not self._remote_acked:
                self._log(
                    "상대가 수락하지 않음 — 양쪽 「입력공유」 켜기·손쉬운 사용 권한 확인 후 재시도"
                )
                self._release_local_locked()

    def _arm_capture_after_ack_locked(self) -> None:
        if self._capture_armed or not self.controlling_remote:
            return
        self._capture_armed = True
        self._status = "상대 PC 제어"
        self._log("상대 수락 — 움직임·클릭을 상대 PC로 전달합니다 (왼쪽 끝 = 복귀)")
        self._start_capture_locked()

    def _apply_remote_ack_locked(self, width: int, height: int) -> None:
        if width > 0 and height > 0:
            self._remote_w, self._remote_h = width, height
        self._remote_acked = True
        self._log(f"상대 화면 크기 수신: {self._remote_w}x{self._remote_h}")
        if not self._capture_armed:
            self._arm_capture_after_ack_locked()

    def _release_local_locked(self) -> None:
        was = self.controlling_remote
        was_armed = self._capture_armed
        had_ack = self._remote_acked
        move_n = self._move_sent
        # Invalidate in-flight ACK waiter so it cannot start capture after release
        self._ack_gen += 1
        # Clear controlling FIRST so in-flight tap/hook/key callbacks pass through
        # while listeners are still shutting down (otherwise local clicks stay dead).
        self.controlling_remote = False
        self._suppressing = False
        self._remote_acked = False
        self._capture_armed = False
        if was and self.session:
            try:
                self._send_modifier_keyup_to_peer()
            except Exception:
                pass
        self._stop_capture_locked()
        self._status = "이 PC 제어" if self.enabled else "꺼짐"
        self._arm_cooldown()
        if was and self.session:
            try:
                self.session.send_input_ctrl(INPUT_CTRL_LOCAL, *self._local_size())
            except Exception:
                pass
            if was_armed:
                self._log(
                    f"제어권 → 이 PC (전송 이동 {move_n}회"
                    f"{', 상대 응답 OK' if had_ack else ''})"
                )
            else:
                self._log("제어권 → 이 PC (상대 미수락 또는 취소)")
        try:
            if self._mouse_ctl:
                # Always return near primary (or current) display right edge
                rects = _list_displays()
                primary = min(rects, key=lambda r: (abs(r[0]) + abs(r[1]), -r[2] * r[3]))
                rx, ry, rw, rh = primary
                for cand in rects:
                    if _has_neighbor_right(cand, cand[1] + cand[3] / 2):
                        continue
                    if cand[0] + cand[2] >= rx + rw:
                        rx, ry, rw, rh = cand
                px = int(rx + rw - LOCAL_RETURN_INSET)
                py = int(ry + rh / 2)
                self._warp_mouse(px, py)
        except Exception:
            pass
        self._show_local_cursor()
        _force_release_os_input()

    def _hide_local_cursor(self) -> None:
        """Hide the local OS pointer once (refcount-safe)."""
        if self._cursor_hidden:
            return
        try:
            if _IS_MAC:
                import Quartz

                Quartz.CGDisplayHideCursor(Quartz.kCGNullDirectDisplay)
                try:
                    from AppKit import NSCursor  # type: ignore

                    NSCursor.hide()
                except Exception:
                    pass
            elif _IS_WIN:
                import ctypes

                user32 = ctypes.windll.user32
                # One step down; avoid stacking dozens during capture
                if user32.ShowCursor(False) >= 0:
                    user32.ShowCursor(False)
            self._cursor_hidden = True
        except Exception as exc:
            self._log(f"커서 숨김 실패: {exc}")

    def _show_local_cursor(self) -> None:
        try:
            if _IS_MAC:
                import Quartz

                for _ in range(64):
                    Quartz.CGDisplayShowCursor(Quartz.kCGNullDirectDisplay)
                try:
                    from AppKit import NSCursor  # type: ignore

                    for _ in range(16):
                        NSCursor.unhide()
                except Exception:
                    pass
            elif _IS_WIN:
                import ctypes

                user32 = ctypes.windll.user32
                for _ in range(64):
                    if user32.ShowCursor(True) >= 0:
                        break
            self._cursor_hidden = False
        except Exception as exc:
            self._log(f"커서 표시 실패: {exc}")
            self._cursor_hidden = False

    def _warp_mouse(self, x: int, y: int) -> None:
        """Warp cursor; use Quartz on macOS for reliability."""
        try:
            if _IS_MAC:
                import Quartz

                # Do NOT call CGAssociate on every warp — it resets relative state
                # and soft-grab often samples dx≈0.
                Quartz.CGWarpMouseCursorPosition((float(x), float(y)))
            if self._mouse_ctl is not None and not _IS_MAC:
                self._mouse_ctl.position = (x, y)
        except Exception:
            try:
                if self._mouse_ctl is not None:
                    self._mouse_ctl.position = (x, y)
            except Exception:
                pass

    def _read_cursor_pos(self) -> tuple[float, float] | None:
        """Screen cursor position in global top-left coords."""
        try:
            if self._mouse_ctl is not None:
                x, y = self._mouse_ctl.position
                return float(x), float(y)
        except Exception:
            pass
        if _IS_MAC:
            pos = _mac_mouse_xy()
            if pos is not None:
                return pos
        return None

    def _start_capture_locked(self) -> None:
        self._stop_capture_locked()
        self._suppressing = True
        self._move_from_tap = False
        # Grab the display where the cursor currently is — confine to it so
        # multi-monitor layouts (e.g. a screen below) cannot steal the pointer.
        try:
            pos = self._mouse_ctl.position if self._mouse_ctl else (0, 0)
            disp = _display_at(float(pos[0]), float(pos[1]))
        except Exception:
            disp = None
        if disp is None:
            w, h = self._local_size()
            disp = (0.0, 0.0, float(w), float(h))
        rx, ry, rw, rh = disp
        self._grab_rect = (float(rx), float(ry), float(rw), float(rh))
        self._grab_center = (
            max(1, int(rx + rw / 2)),
            max(1, int(ry + rh / 2)),
        )
        self._delta_capture = False
        self._soft_grab = False
        # Keep mouse↔cursor associated so HID still produces move events.
        # Hide the local pointer; moves are either swallowed by the event tap
        # or soft-warped back to centre (never leave a usable local click target).
        if _IS_MAC:
            _mac_set_mouse_associated(True)
        self._warp_mouse(*self._grab_center)
        self._hide_local_cursor()
        if _IS_WIN:
            _win_clip_cursor(self._grab_rect)
        if self.session is not None:
            try:
                self.session.set_km_busy(True)
            except Exception:
                pass

        self._cap_stop.clear()

        # Keyboard: low-level hook/tap swallows IME events pynput cannot suppress.
        self._kb_from_hook = False
        if _IS_MAC:
            # Keyboard capture needs Input Monitoring (separate from Accessibility).
            # Without it the tap still delivers mouse events but silently drops keys.
            km_ok = _mac_input_monitoring_ok()
            if not km_ok:
                _mac_request_input_monitoring()
                self._log(
                    "키보드 전달 불가 — 시스템 설정 → 개인정보 보호 및 보안 → "
                    "입력 모니터링에서 Terminal/Python(이 앱)을 켠 뒤 앱을 재시작하고 "
                    "다시 상대 PC로 넘기세요. (마우스는 손쉬운 사용만으로 동작하지만 "
                    "키 입력은 입력 모니터링 권한이 필요합니다.)"
                )
            ok_move = self._start_mac_input_tap(include_move=True, include_keyboard=km_ok)
            if ok_move:
                # Only treat the tap as our keyboard source when Input Monitoring
                # is granted; otherwise the tap silently drops keys, so leave
                # _kb_from_hook False to let the pynput keyboard fallback try.
                self._kb_from_hook = km_ok
                self._move_from_tap = True
                self._soft_grab = False
                _mac_zero_event_suppression()
                _mac_set_mouse_associated(False)
                self._hide_local_cursor()
                if km_ok:
                    self._log("이벤트 탭(이동+클릭+키보드) OK — 상대 PC로 전달")
                else:
                    self._log(
                        "이벤트 탭(이동+클릭) OK — 키보드는 입력 모니터링 권한 허용 후 "
                        "재시작해야 상대 PC로 전달됩니다"
                    )
            else:
                self._move_from_tap = False
                self._soft_grab = True
                self._log(
                    "입력 탭 실패 — 손쉬운 사용에서 Terminal/Python 허용 후 "
                    "다시 가장자리로 넘기세요 (소프트 그랩 폴백)"
                )
                self._start_pynput_mouse_fallback(suppress=False)
                _mac_set_mouse_associated(True)
                self._warp_mouse(*self._grab_center)
                self._hide_local_cursor()
        elif _IS_WIN:
            ok_hook = self._start_win_input_hooks()
            if ok_hook:
                self._kb_from_hook = True
            else:
                self._log("입력 훅 실패 — 클릭/키가 이 PC에도 적용될 수 있습니다")
                self._start_pynput_mouse_fallback(suppress=False)
            self._soft_grab = True
            self._warp_mouse(*self._grab_center)
            self._hide_local_cursor()
        else:
            self._start_pynput_mouse_fallback(suppress=True)
            self._soft_grab = True

        if not self._kb_from_hook:
            try:
                from pynput.keyboard import Listener as KeyListener

                self._key_listener = KeyListener(
                    on_press=lambda key: self._cap_key(key, True),
                    on_release=lambda key: self._cap_key(key, False),
                    suppress=True,
                )
                self._key_listener.start()
            except Exception as exc:
                self._log(f"키보드 가로채기 실패(손쉬운 사용 권한 확인): {exc}")
                try:
                    from pynput.keyboard import Listener as KeyListener

                    self._key_listener = KeyListener(
                        on_press=lambda key: self._cap_key(key, True),
                        on_release=lambda key: self._cap_key(key, False),
                        suppress=False,
                    )
                    self._key_listener.start()
                    self._log("경고: 키 억제 실패 — 입력이 이 PC에도 적용될 수 있습니다")
                except Exception as exc2:
                    self._log(f"키보드 리스너 실패: {exc2}")

        need_poll = True
        if _IS_MAC and self._move_from_tap and not self._soft_grab:
            need_poll = True
        elif _IS_MAC and not self._move_from_tap:
            need_poll = True

        if need_poll:
            self._cap_thread = threading.Thread(
                target=self._capture_loop, name="juc500-input-cap", daemon=True
            )
            self._cap_thread.start()

        self._log(
            "상대 PC 제어 중 — 이 PC 커서는 숨기고 움직임은 상대로 전달"
        )

    def _start_pynput_mouse_fallback(self, *, suppress: bool) -> None:
        try:
            from pynput.mouse import Listener as MouseListener

            self._mouse_listener = MouseListener(
                on_click=lambda x, y, button, pressed: self._cap_click(button, pressed),
                on_scroll=lambda x, y, dx, dy: self._cap_scroll(dx, dy),
                suppress=suppress,
            )
            self._mouse_listener.start()
            if not suppress:
                self._log("경고: 클릭 억제 실패 — 클릭이 이 PC에도 적용될 수 있습니다")
        except Exception as exc:
            self._log(f"마우스 클릭 캡처 실패: {exc}")

    def _apply_captured_delta(self, dx: int, dy: int) -> bool:
        """Forward a relative move to the peer; release if virtual cursor hits left edge.

        Returns False if capture should stop (released / inactive).
        """
        if dx == 0 and dy == 0:
            return True
        # Clamp absurd jumps from display switches / warp glitches
        if abs(dx) > MAX_DELTA_PER_POLL or abs(dy) > MAX_DELTA_PER_POLL:
            dx = max(-MAX_DELTA_PER_POLL, min(MAX_DELTA_PER_POLL, dx))
            dy = max(-MAX_DELTA_PER_POLL, min(MAX_DELTA_PER_POLL, dy))
        gdx = int(round(dx * MOVE_GAIN))
        gdy = int(round(dy * MOVE_GAIN))
        if gdx == 0 and gdy == 0:
            return True
        release = False
        session = None
        with self._lock:
            if not self.controlling_remote or not self._capture_armed or self.session is None:
                return False
            session = self.session
            self._vx += gdx
            self._vy += gdy
            self._vx = max(0.0, min(float(self._remote_w - 1), self._vx))
            self._vy = max(0.0, min(float(self._remote_h - 1), self._vy))
            self._move_sent += 1
            now = time.monotonic()
            release = self._should_return_from_remote_left(self._vx, now)
            move_n = self._move_sent
            acked = self._remote_acked
            abs_x, abs_y = int(self._vx), int(self._vy)
        try:
            session.send_input_move(abs_x, abs_y)
        except Exception as exc:
            self._log(f"이동 전송 실패: {exc}")
            return True
        if release:
            with self._lock:
                if self.controlling_remote:
                    self._log(
                        f"왼쪽 가장자리 복귀 (가상 x≤{RETURN_EDGE_PX}px, "
                        f"{RETURN_EDGE_DWELL_S:.2f}s 대기)"
                    )
                    self._release_local_locked()
            return False
        if move_n == 1 or move_n % 800 == 0:
            self._log(
                f"상대에 마우스 전달 중… ({move_n}회"
                f"{', 응답 OK' if acked else ', 응답 대기'})"
            )
        return True

    def _start_mac_input_tap(self, *, include_move: bool, include_keyboard: bool = False) -> bool:
        """Swallow clicks/scroll/keys (and optionally moves) so local apps stay idle."""
        self._mac_move_n = 0
        try:
            import Quartz

            mask = (
                Quartz.CGEventMaskBit(Quartz.kCGEventLeftMouseDown)
                | Quartz.CGEventMaskBit(Quartz.kCGEventLeftMouseUp)
                | Quartz.CGEventMaskBit(Quartz.kCGEventRightMouseDown)
                | Quartz.CGEventMaskBit(Quartz.kCGEventRightMouseUp)
                | Quartz.CGEventMaskBit(Quartz.kCGEventOtherMouseDown)
                | Quartz.CGEventMaskBit(Quartz.kCGEventOtherMouseUp)
                | Quartz.CGEventMaskBit(Quartz.kCGEventScrollWheel)
            )
            key_types = ()
            if include_keyboard:
                key_types = (
                    Quartz.kCGEventKeyDown,
                    Quartz.kCGEventKeyUp,
                    Quartz.kCGEventFlagsChanged,
                )
                for kt in key_types:
                    mask |= Quartz.CGEventMaskBit(kt)
            move_types = ()
            if include_move:
                move_types = (
                    Quartz.kCGEventMouseMoved,
                    Quartz.kCGEventLeftMouseDragged,
                    Quartz.kCGEventRightMouseDragged,
                    Quartz.kCGEventOtherMouseDragged,
                )
                for mt in move_types:
                    mask |= Quartz.CGEventMaskBit(mt)

            delta_x_field = getattr(Quartz, "kCGMouseEventDeltaX", 4)
            delta_y_field = getattr(Quartz, "kCGMouseEventDeltaY", 5)

            def _callback(proxy, etype, event, refcon):
                try:
                    with self._lock:
                        active = (
                            self._suppressing
                            and self.controlling_remote
                            and self._capture_armed
                            and self.session is not None
                        )
                    if not active:
                        return event
                    if move_types and etype in move_types:
                        dx = int(
                            Quartz.CGEventGetIntegerValueField(event, delta_x_field)
                        )
                        dy = int(
                            Quartz.CGEventGetIntegerValueField(event, delta_y_field)
                        )
                        if dx or dy:
                            self._apply_captured_delta(dx, dy)
                        return None  # swallow — local cursor frozen by disassociate
                    if etype in (
                        Quartz.kCGEventLeftMouseDown,
                        Quartz.kCGEventLeftMouseUp,
                    ):
                        self._cap_click_id(1, etype == Quartz.kCGEventLeftMouseDown)
                        return None
                    if etype in (
                        Quartz.kCGEventRightMouseDown,
                        Quartz.kCGEventRightMouseUp,
                    ):
                        self._cap_click_id(2, etype == Quartz.kCGEventRightMouseDown)
                        return None
                    if etype in (
                        Quartz.kCGEventOtherMouseDown,
                        Quartz.kCGEventOtherMouseUp,
                    ):
                        self._cap_click_id(3, etype == Quartz.kCGEventOtherMouseDown)
                        return None
                    if etype == Quartz.kCGEventScrollWheel:
                        dy = int(
                            Quartz.CGEventGetIntegerValueField(
                                event, Quartz.kCGScrollWheelEventDeltaAxis1
                            )
                        )
                        dx = int(
                            Quartz.CGEventGetIntegerValueField(
                                event, Quartz.kCGScrollWheelEventDeltaAxis2
                            )
                        )
                        if dx or dy:
                            self._cap_scroll(dx, dy)
                        return None
                    if key_types and etype in key_types:
                        pair = _mac_key_from_cgevent(event, etype)
                        if pair is not None:
                            kname, kpressed = pair
                            self._cap_key_by_name(kname, kpressed)
                        return None
                except Exception:
                    pass
                return event

            # Session tap FIRST (matches the working reference). A HID tap sits
            # ahead of the WindowServer and, combined with swallowing moves,
            # fights CGAssociateMouseAndMouseCursorPosition(False) so the local
            # cursor keeps moving. A session tap lets disassociation freeze the
            # pointer cleanly while we still read per-event HID deltas.
            tap = Quartz.CGEventTapCreate(
                Quartz.kCGSessionEventTap,
                Quartz.kCGHeadInsertEventTap,
                Quartz.kCGEventTapOptionDefault,
                mask,
                _callback,
                None,
            )
            tap_kind = "session"
            if not tap:
                # Fallback: HID tap
                tap = Quartz.CGEventTapCreate(
                    Quartz.kCGHIDEventTap,
                    Quartz.kCGHeadInsertEventTap,
                    Quartz.kCGEventTapOptionDefault,
                    mask,
                    _callback,
                    None,
                )
                tap_kind = "hid"
            if not tap:
                self._mac_tap_kind = None
                self._log("macOS 입력 가로채기 실패 — 손쉬운 사용에서 허용하세요")
                return False
            self._mac_tap_kind = tap_kind
            self._mac_tap_callback = _callback  # prevent GC of callback
            source = Quartz.CFMachPortCreateRunLoopSource(None, tap, 0)
            self._mac_tap = tap
            self._mac_tap_source = source

            def _run() -> None:
                Quartz.CFRunLoopAddSource(
                    Quartz.CFRunLoopGetCurrent(),
                    source,
                    Quartz.kCFRunLoopCommonModes,
                )
                Quartz.CGEventTapEnable(tap, True)
                # Freeze + hide the local cursor from THIS (tap) thread. Calling
                # CGAssociateMouseAndMouseCursorPosition(False) from a background
                # thread (e.g. the ACK waiter) frequently does NOT stick, so the
                # pointer keeps moving locally even though moves are forwarded.
                # macOS also re-associates ~0.25s after certain ops, so re-assert
                # on every run-loop tick (well under that window).
                if include_move:
                    try:
                        _mac_zero_event_suppression()
                        _mac_set_mouse_associated(False)
                        _mac_set_mouse_associated(False)
                        Quartz.CGDisplayHideCursor(Quartz.CGMainDisplayID())
                    except Exception:
                        pass
                while not self._cap_stop.is_set():
                    Quartz.CFRunLoopRunInMode(Quartz.kCFRunLoopDefaultMode, 0.05, False)
                    if include_move:
                        try:
                            _mac_set_mouse_associated(False)
                        except Exception:
                            pass

            self._mac_tap_thread = threading.Thread(
                target=_run, name="juc500-mac-tap", daemon=True
            )
            self._mac_tap_thread.start()
            return True
        except Exception as exc:
            self._log(f"macOS 입력 탭 오류: {exc}")
            return False

    def _start_win_input_hooks(self) -> bool:
        """Low-level mouse+keyboard hooks: swallow clicks/scroll/keys, allow moves."""
        try:
            import ctypes
            from ctypes import wintypes

            user32 = ctypes.windll.user32
            WH_MOUSE_LL = 14
            WH_KEYBOARD_LL = 13
            WM_LBUTTONDOWN, WM_LBUTTONUP = 0x0201, 0x0202
            WM_RBUTTONDOWN, WM_RBUTTONUP = 0x0204, 0x0205
            WM_MBUTTONDOWN, WM_MBUTTONUP = 0x0207, 0x0208
            WM_MOUSEWHEEL, WM_MOUSEHWHEEL = 0x020A, 0x020E
            WM_KEYDOWN, WM_KEYUP = 0x0100, 0x0101
            WM_SYSKEYDOWN, WM_SYSKEYUP = 0x0104, 0x0105
            HC_ACTION = 0
            LLKHF_INJECTED = 0x10

            class MSLLHOOKSTRUCT(ctypes.Structure):
                _fields_ = [
                    ("pt", wintypes.POINT),
                    ("mouseData", wintypes.DWORD),
                    ("flags", wintypes.DWORD),
                    ("time", wintypes.DWORD),
                    ("dwExtraInfo", ctypes.POINTER(ctypes.c_ulong)),
                ]

            class KBDLLHOOKSTRUCT(ctypes.Structure):
                _fields_ = [
                    ("vkCode", wintypes.DWORD),
                    ("scanCode", wintypes.DWORD),
                    ("flags", wintypes.DWORD),
                    ("time", wintypes.DWORD),
                    ("dwExtraInfo", ctypes.POINTER(ctypes.c_ulong)),
                ]

            LongPtr = getattr(wintypes, "LPARAM", ctypes.c_long)
            hooks: dict[str, Any] = {"mouse": None, "kbd": None}

            def _low_level_mouse(nCode, wParam, lParam):
                try:
                    if nCode == HC_ACTION:
                        with self._lock:
                            active = (
                                self._suppressing
                                and self.controlling_remote
                                and self._capture_armed
                                and self.session is not None
                            )
                        if active:
                            wp = int(wParam)
                            if wp in (WM_LBUTTONDOWN, WM_LBUTTONUP):
                                self._cap_click_id(1, wp == WM_LBUTTONDOWN)
                                return 1
                            if wp in (WM_RBUTTONDOWN, WM_RBUTTONUP):
                                self._cap_click_id(2, wp == WM_RBUTTONDOWN)
                                return 1
                            if wp in (WM_MBUTTONDOWN, WM_MBUTTONUP):
                                self._cap_click_id(3, wp == WM_MBUTTONDOWN)
                                return 1
                            if wp in (WM_MOUSEWHEEL, WM_MOUSEHWHEEL):
                                info = ctypes.cast(
                                    lParam, ctypes.POINTER(MSLLHOOKSTRUCT)
                                ).contents
                                delta = ctypes.c_short(info.mouseData >> 16).value
                                if wp == WM_MOUSEWHEEL:
                                    self._cap_scroll(0, 1 if delta > 0 else -1)
                                else:
                                    self._cap_scroll(1 if delta > 0 else -1, 0)
                                return 1
                except Exception:
                    pass
                return user32.CallNextHookEx(hooks["mouse"], nCode, wParam, lParam)

            def _low_level_kbd(nCode, wParam, lParam):
                try:
                    if nCode == HC_ACTION:
                        with self._lock:
                            active = (
                                self._suppressing
                                and self.controlling_remote
                                and self._capture_armed
                                and self.session is not None
                            )
                        if active:
                            wp = int(wParam)
                            if wp in (WM_KEYDOWN, WM_SYSKEYDOWN):
                                pressed = True
                            elif wp in (WM_KEYUP, WM_SYSKEYUP):
                                pressed = False
                            else:
                                return user32.CallNextHookEx(
                                    hooks["kbd"], nCode, wParam, lParam
                                )
                            info = ctypes.cast(
                                lParam, ctypes.POINTER(KBDLLHOOKSTRUCT)
                            ).contents
                            if info.flags & LLKHF_INJECTED:
                                return user32.CallNextHookEx(
                                    hooks["kbd"], nCode, wParam, lParam
                                )
                            self._cap_key_by_name(
                                _win_vk_to_name(int(info.vkCode)), pressed
                            )
                            return 1
                except Exception:
                    pass
                return user32.CallNextHookEx(hooks["kbd"], nCode, wParam, lParam)

            CMPFUNC = ctypes.WINFUNCTYPE(ctypes.c_long, ctypes.c_int, wintypes.WPARAM, LongPtr)
            self._win_mouse_proc = CMPFUNC(_low_level_mouse)
            self._win_kbd_proc = CMPFUNC(_low_level_kbd)
            ready: dict[str, bool] = {"ok": False}

            def _run() -> None:
                hooks["mouse"] = user32.SetWindowsHookExW(
                    WH_MOUSE_LL, self._win_mouse_proc, None, 0
                )
                hooks["kbd"] = user32.SetWindowsHookExW(
                    WH_KEYBOARD_LL, self._win_kbd_proc, None, 0
                )
                self._win_mouse_hook = hooks["mouse"]
                ready["ok"] = bool(hooks["mouse"] and hooks["kbd"])
                if not ready["ok"]:
                    if hooks["mouse"]:
                        user32.UnhookWindowsHookEx(hooks["mouse"])
                    if hooks["kbd"]:
                        user32.UnhookWindowsHookEx(hooks["kbd"])
                    hooks["mouse"] = None
                    hooks["kbd"] = None
                    self._win_mouse_hook = None
                    return
                msg = wintypes.MSG()
                while not self._cap_stop.is_set():
                    while user32.PeekMessageW(ctypes.byref(msg), 0, 0, 0, 1):
                        user32.TranslateMessage(ctypes.byref(msg))
                        user32.DispatchMessageW(ctypes.byref(msg))
                    time.sleep(0.01)
                for key in ("mouse", "kbd"):
                    if hooks[key]:
                        user32.UnhookWindowsHookEx(hooks[key])
                        hooks[key] = None
                self._win_mouse_hook = None

            self._win_hook_thread = threading.Thread(
                target=_run, name="juc500-win-mhook", daemon=True
            )
            self._win_hook_thread.start()
            time.sleep(0.15)
            return ready["ok"]
        except Exception as exc:
            self._log(f"Windows 입력 훅 오류: {exc}")
            return False

    def _start_win_button_hook(self) -> bool:
        """Backward-compatible alias."""
        return self._start_win_input_hooks()

    def _send_click_to_peer(
        self, session: Any, button: int, pressed: bool, x: int, y: int
    ) -> None:
        """Send click off the event-tap thread (tap callback must not block USB)."""
        try:
            session.send_input_button(button, pressed, x, y)
            with self._lock:
                self._click_sent += 1
                n = self._click_sent
            if n == 1 or n % 40 == 0:
                act = "누름" if pressed else "뗌"
                self._log(
                    f"클릭 전송 ({act}, btn={button}, {x},{y}) — {n}회"
                )
        except Exception as exc:
            self._log(f"클릭 전송 실패: {exc}")

    def _cap_click_id(self, button: int, pressed: bool) -> None:
        with self._lock:
            active = (
                self.controlling_remote
                and self._capture_armed
                and self.session is not None
            )
            session = self.session
            # Press pins the button at the current spot; release must use the
            # CURRENT (possibly dragged-to) position so title-bar/selection
            # drags land where the cursor actually ended up.
            if pressed:
                self._click_anchor = (int(self._vx), int(self._vy))
            else:
                self._click_anchor = None
            vx, vy = int(self._vx), int(self._vy)
        if not active or session is None:
            return
        threading.Thread(
            target=self._send_click_to_peer,
            args=(session, button, pressed, vx, vy),
            name="juc500-click-tx",
            daemon=True,
        ).start()

    def _stop_capture_locked(self) -> None:
        self._suppressing = False
        self._warping = False
        self._cap_stop.set()

        if _IS_WIN:
            _win_clip_cursor(None)
        self._grab_rect = None
        self._move_from_tap = False

        # Restore local input ASAP (before joining worker threads).
        # pynput suppress=True blocks the OS until the listener is stopped.
        for lst in (self._key_listener, self._mouse_listener):
            if lst is not None:
                try:
                    lst.stop()
                except Exception:
                    pass
        key_lst = self._key_listener
        mouse_lst = self._mouse_listener
        self._key_listener = None
        self._mouse_listener = None

        if _IS_MAC:
            _mac_set_mouse_associated(True)
            try:
                import Quartz

                if self._mac_tap is not None:
                    Quartz.CGEventTapEnable(self._mac_tap, False)
                if self._mac_tap_source is not None:
                    try:
                        Quartz.CFRunLoopSourceInvalidate(self._mac_tap_source)
                    except Exception:
                        pass
            except Exception:
                pass

        # Join workers after unsuppress
        t = self._cap_thread
        self._cap_thread = None
        if t and t.is_alive() and t is not threading.current_thread():
            t.join(timeout=1.0)
        if _IS_MAC:
            mt = self._mac_tap_thread
            self._mac_tap_thread = None
            if mt and mt.is_alive() and mt is not threading.current_thread():
                mt.join(timeout=0.5)
            self._mac_tap = None
            self._mac_tap_source = None
            self._mac_tap_callback = None
        if _IS_WIN:
            ht = self._win_hook_thread
            self._win_hook_thread = None
            if ht and ht.is_alive() and ht is not threading.current_thread():
                ht.join(timeout=0.8)
            self._win_mouse_hook = None
            self._win_mouse_proc = None
            self._win_kbd_proc = None
        self._kb_from_hook = False
        for lst in (key_lst, mouse_lst):
            if lst is not None:
                try:
                    lst.join(timeout=0.5)
                except Exception:
                    pass
        self._delta_capture = False
        if self.session is not None:
            try:
                self.session.flush_input_moves()
            except Exception:
                pass
            try:
                if not self.being_controlled:
                    self.session.set_km_busy(False)
            except Exception:
                pass
        self._show_local_cursor()

    def _capture_loop(self) -> None:
        """Soft-grab: sample position vs centre, forward delta, warp back.

        For the event-tap path (macOS) moves arrive via the tap callback; this
        loop only re-asserts the frozen/hidden cursor periodically.
        """
        err_log_at = 0.0
        last_reassert = 0.0
        while not self._cap_stop.is_set():
            try:
                with self._lock:
                    active = (
                        self.controlling_remote
                        and self._capture_armed
                        and self.session is not None
                    )
                    cx, cy = self._grab_center
                    grab = self._grab_rect
                    soft = bool(self._soft_grab)
                    from_tap = bool(self._move_from_tap)
                if not active:
                    break

                # Event-tap move path: cursor is disassociated + hidden.
                # Periodically re-assert so a focus change can't reveal it.
                if from_tap and not soft:
                    now = time.monotonic()
                    if now - last_reassert > 0.5:
                        last_reassert = now
                        if _IS_MAC:
                            try:
                                import Quartz

                                _mac_set_mouse_associated(False)
                                Quartz.CGDisplayHideCursor(Quartz.kCGNullDirectDisplay)
                            except Exception:
                                pass
                    self._cap_stop.wait(0.05)
                    continue

                pos = self._read_cursor_pos()
                if pos is None:
                    self._cap_stop.wait(0.005)
                    continue
                fx, fy = pos

                if grab is not None and not _point_in_rect(fx, fy, grab, margin=0.0):
                    try:
                        self._warp_mouse(cx, cy)
                    except Exception:
                        pass
                    self._cap_stop.wait(0.001)
                    continue

                raw_dx = int(round(fx - cx))
                raw_dy = int(round(fy - cy))
                if raw_dx or raw_dy:
                    if abs(raw_dx) > MAX_DELTA_PER_POLL or abs(raw_dy) > MAX_DELTA_PER_POLL:
                        raw_dx = max(-MAX_DELTA_PER_POLL, min(MAX_DELTA_PER_POLL, raw_dx))
                        raw_dy = max(-MAX_DELTA_PER_POLL, min(MAX_DELTA_PER_POLL, raw_dy))
                    still = self._apply_captured_delta(raw_dx, raw_dy)
                    if not still:
                        break
                    # Re-check before warping — release may have restored local cursor
                    if self._cap_stop.is_set() or not self.controlling_remote:
                        break
                    try:
                        self._warp_mouse(cx, cy)
                    except Exception:
                        pass
            except Exception as exc:
                now = time.monotonic()
                if now >= err_log_at:
                    err_log_at = now + 2.0
                    self._log(f"마우스 캡처 오류: {exc}")
                self._cap_stop.wait(0.05)
            self._cap_stop.wait(0.002)

    def _cap_move(self, x: int, y: int) -> bool:
        # Retained for compatibility; motion is handled by _capture_loop.
        return False

    def _cap_click(self, button: Any, pressed: bool) -> bool:
        with self._lock:
            active = (
                self.controlling_remote
                and self._capture_armed
                and self.session is not None
            )
            session = self.session
            if pressed:
                self._click_anchor = (int(self._vx), int(self._vy))
            else:
                self._click_anchor = None
            vx, vy = int(self._vx), int(self._vy)
        if not active or session is None:
            return True
        bid = 1
        name = getattr(button, "name", "") or str(button)
        if "right" in name:
            bid = 2
        elif "middle" in name:
            bid = 3
        threading.Thread(
            target=self._send_click_to_peer,
            args=(session, bid, pressed, vx, vy),
            name="juc500-click-tx",
            daemon=True,
        ).start()
        return False

    def _cap_scroll(self, dx: int, dy: int) -> bool:
        with self._lock:
            active = (
                self.controlling_remote
                and self._capture_armed
                and self.session is not None
            )
            session = self.session
        if not active or session is None:
            return True
        try:
            session.send_input_wheel(int(dx), int(dy))
        except Exception as exc:
            self._log(f"스크롤 전송 실패: {exc}")
        return False

    def _cap_key_by_name(self, key_name: str, pressed: bool) -> None:
        with self._lock:
            active = (
                self.controlling_remote
                and self._capture_armed
                and self.session is not None
            )
            session = self.session
            if not active:
                return
            name = key_name.lower()
            if pressed and name in ("esc", "escape"):
                cb = self.on_escape_quit
                self._log("Esc — 입력공유 끄고 프로그램 종료")
                if cb is not None:
                    threading.Thread(
                        target=cb, name="juc500-esc-quit", daemon=True
                    ).start()
                return
            if name in ("cmd", "cmd_l", "cmd_r", "command", "super", "windows", "win"):
                self._mod_cmd = bool(pressed)
            elif name in ("ctrl", "ctrl_l", "ctrl_r", "control"):
                self._mod_ctrl = bool(pressed)
            elif name in ("shift", "shift_l", "shift_r"):
                self._mod_shift = bool(pressed)
            elif name in ("alt", "alt_l", "alt_r", "option"):
                self._mod_alt = bool(pressed)
            toggle_combo = (
                pressed
                and name in ("r", "vk:82", "vk:15")
                and self._mod_ctrl
                and not self._mod_cmd
                and not self._mod_alt
            )
            paste_combo = False
            if pressed and name in ("v", "vk:86"):
                paste_combo = (
                    (self._mod_cmd or self._mod_ctrl)
                    and not self._mod_alt
                    and not self._mod_shift
                )
            send_name = key_name
        if name == "caps_lock":
            # A single Caps Lock tap on this Mac emits a quick ON→OFF pair of
            # flags-changed events. USB wait for the first pulse is ~400ms, so
            # the second event arrives after 0.3s — use a 1.2s coalesce window
            # or both toggles cancel out on Windows (net zero).
            now = time.monotonic()
            if now - self._last_caps_at < 1.2:
                return
            self._last_caps_at = now
            try:
                self._send_key_pulse(session, "caps_lock")
                self._log("Mac Caps Lock → 상대 Windows 대소문자 전환")
            except Exception as exc:
                self._log(f"Caps Lock 전달 실패: {exc}")
            return
        if name in ("cmd_r", "alt_r"):
            # Right Command / Right Option are dedicated remote 한/영 keys.
            # Only key-down toggles; debounce rapid repeats from one physical tap.
            if pressed:
                now = time.monotonic()
                last = getattr(self, "_last_hangul_at", 0.0)
                if now - last < 0.5:
                    return
                self._last_hangul_at = now
                try:
                    self._send_key_pulse(session, "hangul")
                    self._log(
                        f"Mac {name} → 상대 Windows 한/영 전환"
                    )
                except Exception as exc:
                    self._log(f"한/영 전환 전달 실패: {exc}")
            return
        if toggle_combo:
            # Consume Ctrl+R locally. _release_local_locked sends modifier-up to
            # the peer so Ctrl cannot remain stuck after the handoff.
            self._trigger_control_toggle()
            return
        if paste_combo:
            try:
                self._push_clipboard_text_to_peer()
            except Exception:
                pass
        # Surface unmapped / IME keys once each so a mis-detected 한영/한자
        # key can be identified from the log (raw mac keycode arrives as vk:NN).
        if pressed and (send_name.startswith("vk:") or send_name in ("hangul", "hanja")):
            seen = getattr(self, "_logged_special_keys", None)
            if seen is None:
                seen = set()
                self._logged_special_keys = seen
            if send_name not in seen:
                seen.add(send_name)
                self._log(f"특수/미매핑 키 감지 → 상대 전송: '{send_name}'")
        try:
            session.send_input_key(send_name, pressed)
            self._key_sent_count += 1
            if self._key_sent_count == 1 or self._key_sent_count % 50 == 0:
                self._log(
                    f"키 전송 → 상대 PC ('{send_name}' {'누름' if pressed else '뗌'}, "
                    f"{self._key_sent_count}회)"
                )
        except Exception as exc:
            self._log(f"키 전송 실패: {exc}")

    def _send_key_pulse(self, session: Any, name: str) -> None:
        """Send one key-down for a toggle key (Caps/Hangul).

        Windows handlers ignore the key-up frame and perform a full local
        down+up (or IME API toggle) on key-down — so a second USB packet is
        wasted latency that also breaks Caps Lock coalescing.
        """
        session.send_input_key(name, True)
        self._key_sent_count += 1

    def _cap_key(self, key: Any, pressed: bool) -> bool:
        with self._lock:
            active = (
                self.controlling_remote
                and self._capture_armed
                and self.session is not None
            )
        if not active:
            return True
        self._cap_key_by_name(_key_name(key), pressed)
        return False

    def _push_clipboard_text_to_peer(self) -> None:
        """Copy local plain-text clipboard onto the peer before a remote paste."""
        if self.session is None:
            return
        try:
            from .clipboard_files import get_clipboard_text

            text = get_clipboard_text()
        except Exception:
            text = ""
        if not text:
            return
        try:
            self.session.send_input_clipboard(text)
        except Exception as exc:
            self._log(f"클립보드 동기화 실패: {exc}")

    def _on_peer_clipboard(self, text: str) -> None:
        """Peer pushed plain text so an upcoming Ctrl/Cmd+V pastes on this PC."""
        try:
            from .clipboard_files import set_clipboard_text

            ok = set_clipboard_text(text or "")
            if ok:
                self._log(f"클립보드 수신 ({len(text or '')}자) — 이 PC 붙여넣기 준비")
            else:
                self._log("클립보드 수신 적용 실패")
        except Exception as exc:
            self._log(f"클립보드 적용 실패: {exc}")

    # --- peer inbound ---

    def _on_peer_ctrl(self, target: int, width: int, height: int) -> None:
        if target == INPUT_CTRL_SHARE_ON:
            self.set_enabled(True, from_peer=True)
            return
        if target == INPUT_CTRL_SHARE_OFF:
            self.set_enabled(False, from_peer=True)
            return
        if target == INPUT_CTRL_PEER_CLICK:
            self._log(
                f"상대 클릭 주입 확인 — btn={width}, x={height}"
            )
            return
        if target == INPUT_CTRL_LOCAL:
            with self._lock:
                cr = self.controlling_remote
                bc = self.being_controlled
            if cr:
                self._release_local_locked()
            elif bc:
                with self._lock:
                    self._stop_being_controlled_locked()
                    self._status = "이 PC 제어" if self.enabled else "꺼짐"
                self._log("상대가 제어권을 가져감 — 이 PC 로컬 입력 복구")
                _force_release_os_input()
            else:
                _force_release_os_input()
            return
        with self._lock:
            if target == INPUT_CTRL_REMOTE_ACK:
                if self.controlling_remote and not self._remote_acked:
                    self._apply_remote_ack_locked(width, height)
                return
            if target == INPUT_CTRL_REMOTE_NACK:
                if self.controlling_remote and not self._capture_armed:
                    self._log("상대가 제어 요청을 거부했습니다 (권한 또는 연결 상태 확인)")
                    self._release_local_locked()
                return
            if target == INPUT_CTRL_REMOTE:
                # Never treat REMOTE as ACK — that caused dual-controller deadlocks.
                if self.controlling_remote and not self._remote_acked:
                    self._log("동시 전환 — 내 요청을 유지하고 상대 요청을 거절")
                    if self.session is not None:
                        try:
                            self.session.send_input_ctrl(
                                INPUT_CTRL_REMOTE_NACK, *self._local_size()
                            )
                        except Exception:
                            pass
                    return
                if self.controlling_remote and self._remote_acked:
                    self._ack_gen += 1
                    self.controlling_remote = False
                    self._suppressing = False
                    self._remote_acked = False
                    self._capture_armed = False
                    self._stop_capture_locked()
                    self._show_local_cursor()
                    _force_release_os_input()
                if not self.enabled:
                    self._log("입력공유 꺼짐 — 상대 제어 요청 거부 (양쪽 모두 켜야 함)")
                    if self.session is not None:
                        try:
                            self.session.send_input_ctrl(
                                INPUT_CTRL_REMOTE_NACK, *self._local_size()
                            )
                        except Exception:
                            pass
                    return
                ok, err = self._ensure_controllers()
                if not ok:
                    self._log(f"상대 제어 요청 거부: {err}")
                    if self.session is not None:
                        try:
                            self.session.send_input_ctrl(
                                INPUT_CTRL_REMOTE_NACK, *self._local_size()
                            )
                        except Exception:
                            pass
                    return
                self._enter_being_controlled_locked(width, height)
                return
            if self.controlling_remote:
                self._release_local_locked()
            if self.being_controlled:
                self._stop_being_controlled_locked()
                self._status = "이 PC 제어" if self.enabled else "꺼짐"
            _force_release_os_input()

    def _enter_being_controlled_locked(self, peer_w: int, peer_h: int) -> None:
        if self.controlling_remote:
            self._ack_gen += 1
            self._stop_capture_locked()
            self.controlling_remote = False
            self._remote_acked = False
            self._capture_armed = False
        self.being_controlled = True
        self._injecting = True
        self._mac_click_state = 0
        self._status = "상대가 조종 중"
        self._arm_cooldown()
        self._inject_release_until = time.monotonic() + 0.25
        self._peer_modifiers.clear()
        ok, err = self._ensure_controllers()
        if not ok:
            self._log(f"주입 컨트롤러 준비 실패: {err}")
        if self.session is not None:
            try:
                self.session.set_km_busy(True)
            except Exception:
                pass
        lw, lh = self._local_size()
        # Peer entered from the left (their right edge → our left)
        self._vx = float(REMOTE_ENTER_INSET)
        self._vy = float(lh) / 2.0
        self._log("상대가 이 PC를 제어합니다 — 마우스를 왼쪽 끝으로 보내면 상대가 복귀합니다")
        # ACK with our screen size so the controller can clamp + start capture.
        if _IS_MAC:
            try:
                _mac_set_mouse_associated(True)
                _mac_show_cursor()
                if not _mac_request_accessibility():
                    self._log(
                        "경고: Mac 손쉬운 사용 미허용 — 커서 이동만 되고 클릭은 안 됩니다. "
                        "시스템 설정에서 이 앱(Python/Terminal)을 허용하세요."
                    )
            except Exception:
                pass
        # New controllers also accept legacy REMOTE as ack when not yet acked.
        if self.session:
            try:
                self.session.send_input_ctrl(INPUT_CTRL_REMOTE_ACK, lw, lh)
            except Exception:
                pass
        try:
            self._inject_mouse_pos(int(self._vx), int(self._vy))
            self._log(
                f"상대 커서 시작 위치: ({int(self._vx)}, {int(self._vy)}) "
                f"화면 {lw}x{lh}"
            )
        except Exception as exc:
            self._log(f"상대 커서 시작 주입 실패: {exc}")

    def _stop_being_controlled_locked(self) -> None:
        was = self.being_controlled
        self.being_controlled = False
        self._injecting = False
        if was:
            self._clear_injected_input_locked()
        self._arm_cooldown()
        if self.session is not None and not self.controlling_remote:
            try:
                self.session.set_km_busy(False)
            except Exception:
                pass
        if self.enabled and not self.controlling_remote:
            self._status = "이 PC 제어"
        if was:
            self._log("이 PC 로컬 입력 복구 (수정키·버튼·커서 해제)")

    def _inject_mouse_pos(self, x: int, y: int) -> None:
        # Virtual desktop coords (origin top-left, y down) → OS screen coords
        if _IS_MAC:
            cg_x, cg_y = _mac_virtual_to_cg(
                float(x), float(y), self._desk_ox, self._desk_oy, self._local_h
            )
            # If a button is held, emit a Dragged event so drags register.
            held = 0
            for b in (1, 2, 3):
                if b in self._injected_buttons_down:
                    held = b
                    break
            if _mac_inject_mouse_pos(int(round(cg_x)), int(round(cg_y)), held):
                return
            ax, ay = int(round(cg_x)), int(round(cg_y))
        else:
            ax = int(round(self._desk_ox + float(x)))
            ay = int(round(self._desk_oy + float(y)))
        if _IS_WIN:
            try:
                import ctypes

                ctypes.windll.user32.SetCursorPos(ax, ay)
                return
            except Exception:
                pass
        if self._mouse_ctl is not None:
            self._mouse_ctl.position = (ax, ay)

    def _inject_mouse_move_rel(self, dx: int, dy: int) -> tuple[float, float]:
        """Apply relative move; return current cursor position."""
        if _IS_WIN:
            try:
                import ctypes
                from ctypes import wintypes

                # Prefer SendInput (lower latency / less stutter than mouse_event)
                ULONG_PTR = ctypes.c_ulonglong if ctypes.sizeof(ctypes.c_void_p) == 8 else ctypes.c_ulong

                class MOUSEINPUT(ctypes.Structure):
                    _fields_ = [
                        ("dx", wintypes.LONG),
                        ("dy", wintypes.LONG),
                        ("mouseData", wintypes.DWORD),
                        ("dwFlags", wintypes.DWORD),
                        ("time", wintypes.DWORD),
                        ("dwExtraInfo", ULONG_PTR),
                    ]

                class INPUT(ctypes.Structure):
                    class _I(ctypes.Union):
                        _fields_ = [("mi", MOUSEINPUT)]

                    _anonymous_ = ("i",)
                    _fields_ = [("type", wintypes.DWORD), ("i", _I)]

                inp = INPUT()
                inp.type = 0  # INPUT_MOUSE
                inp.mi = MOUSEINPUT(int(dx), int(dy), 0, 0x0001, 0, 0)
                ctypes.windll.user32.SendInput(1, ctypes.byref(inp), ctypes.sizeof(INPUT))

                class POINT(ctypes.Structure):
                    _fields_ = [("x", wintypes.LONG), ("y", wintypes.LONG)]

                pt = POINT()
                ctypes.windll.user32.GetCursorPos(ctypes.byref(pt))
                return float(pt.x), float(pt.y)
            except Exception:
                try:
                    import ctypes

                    ctypes.windll.user32.mouse_event(0x0001, int(dx), int(dy), 0, 0)

                    class POINT(ctypes.Structure):
                        _fields_ = [("x", ctypes.c_long), ("y", ctypes.c_long)]

                    pt = POINT()
                    ctypes.windll.user32.GetCursorPos(ctypes.byref(pt))
                    return float(pt.x), float(pt.y)
                except Exception:
                    pass
        if self._mouse_ctl is not None:
            try:
                self._mouse_ctl.move(int(dx), int(dy))
                pos = self._mouse_ctl.position
                return float(pos[0]), float(pos[1])
            except Exception:
                pass
        return self._vx + dx, self._vy + dy

    def _inject_mouse_button(
        self, button: int, pressed: bool, vx: int = -1, vy: int = -1
    ) -> None:
        if pressed:
            self._injected_buttons_down.add(int(button))
        else:
            self._injected_buttons_down.discard(int(button))
        if vx >= 0 and vy >= 0:
            with self._lock:
                w, h = self._local_w, self._local_h
                self._vx = float(max(0, min(max(1, w - 1), int(vx))))
                self._vy = float(max(0, min(max(1, h - 1), int(vy))))
        if _IS_WIN:
            try:
                import ctypes

                # MOUSEEVENTF_LEFTDOWN=2 LEFTUP=4 RIGHTDOWN=8 RIGHTUP=16 MIDDLEDOWN=32 MIDDLEUP=64
                mapping = {
                    (1, True): 0x0002,
                    (1, False): 0x0004,
                    (2, True): 0x0008,
                    (2, False): 0x0010,
                    (3, True): 0x0020,
                    (3, False): 0x0040,
                }
                flag = mapping.get((button, pressed))
                if flag is not None:
                    ctypes.windll.user32.mouse_event(flag, 0, 0, 0, 0)
                    return
            except Exception:
                pass
        elif _IS_MAC:
            self._local_size()
            cg_x, cg_y = _mac_virtual_to_cg(
                float(self._vx), float(self._vy),
                self._desk_ox, self._desk_oy, self._local_h,
            )
            ax, ay = int(round(cg_x)), int(round(cg_y))
            click_state = 1
            if int(button) == 1:
                if pressed:
                    now = time.monotonic()
                    if now - getattr(self, "_mac_last_down_at", 0.0) > 0.35:
                        self._mac_click_state = 0
                    self._mac_last_down_at = now
                    self._mac_click_state = max(1, int(self._mac_click_state) + 1)
                click_state = max(1, int(self._mac_click_state))
            _mac_inject_mouse_pos(ax, ay)
            _mac_inject_mouse_button(
                ax, ay, button, pressed, click_state=click_state
            )
            return
        from pynput.mouse import Button

        btn = Button.left
        if button == 2:
            btn = Button.right
        elif button == 3:
            btn = Button.middle
        if self._mouse_ctl is None:
            return
        if pressed:
            self._mouse_ctl.press(btn)
        else:
            self._mouse_ctl.release(btn)

    def _on_peer_move(self, x: int, y: int) -> None:
        """Apply peer's absolute virtual cursor position on this screen."""
        release = False
        session = None
        w = h = 0
        ax = ay = 0
        with self._lock:
            if not self.being_controlled:
                return
            now = time.monotonic()
            session = self.session
            w, h = self._local_w, self._local_h
            ax = max(0, min(max(1, w - 1), int(x)))
            ay = max(0, min(max(1, h - 1), int(y)))
            self._vx = float(ax)
            self._vy = float(ay)
            release = self._should_peer_return_left(float(ax), now)
        try:
            # Absolute inject is more reliable than stacking relative SendInput
            self._inject_mouse_pos(ax, ay)
        except Exception as exc:
            self._log(f"마우스 주입 실패: {exc}")
            return
        if release:
            with self._lock:
                if self.being_controlled:
                    self._stop_being_controlled_locked()
                    if session:
                        try:
                            session.send_input_ctrl(INPUT_CTRL_LOCAL, w, h)
                        except Exception:
                            pass
                    self._log("왼쪽 가장자리 — 상대에게 제어권 반환 요청")
                    _force_release_os_input()

    def _peer_perform_click(self, button: int, x: int, y: int) -> None:
        """Peer-side: warp to position and deliver one full click (down+up)."""
        if x >= 0 and y >= 0:
            with self._lock:
                w, h = self._local_w, self._local_h
                self._vx = float(max(0, min(max(1, w - 1), int(x))))
                self._vy = float(max(0, min(max(1, h - 1), int(y))))
        self._local_size()
        if _IS_MAC:
            cg_x, cg_y = _mac_virtual_to_cg(
                float(self._vx), float(self._vy),
                self._desk_ox, self._desk_oy, self._local_h,
            )
            ax, ay = int(round(cg_x)), int(round(cg_y))
            if not _mac_accessibility_ok():
                _mac_request_accessibility()
            if not _mac_click_at(ax, ay, int(button)):
                raise RuntimeError(
                    "Mac 클릭 주입 실패 — 시스템 설정 → 손쉬운 사용에서 "
                    "Python/Terminal 허용 후 재시도"
                )
        else:
            ax = int(round(self._desk_ox + float(self._vx)))
            ay = int(round(self._desk_oy + float(self._vy)))
            self._inject_mouse_pos(int(self._vx), int(self._vy))
            ok, err = self._ensure_controllers()
            if not ok:
                raise RuntimeError(err or "입력 컨트롤러 없음")
            from pynput.mouse import Button

            pbtn = {1: Button.left, 2: Button.right, 3: Button.middle}.get(
                int(button), Button.left
            )
            if self._mouse_ctl is None:
                raise RuntimeError("마우스 컨트롤러 없음")
            try:
                self._mouse_ctl.position = (ax, ay)
                with self._mouse_ctl:
                    self._mouse_ctl.click(pbtn, 1)
            except Exception:
                if _IS_WIN:
                    self._inject_mouse_button(button, True, x, y)
                    self._inject_mouse_button(button, False, x, y)
                else:
                    raise

        session = self.session
        if session is not None:
            try:
                session.send_input_ctrl(
                    INPUT_CTRL_PEER_CLICK,
                    int(button),
                    max(0, min(65535, int(x if x >= 0 else self._vx))),
                )
            except Exception:
                pass

    def _on_peer_button(
        self, button: int, pressed: bool, x: int = -1, y: int = -1
    ) -> None:
        # Hold the button between press and release so title-bar / selection
        # drags work: press = button-down (held), release = button-up. A quick
        # down+up at the same spot is still a normal click.
        with self._lock:
            if not self.being_controlled:
                return
            self._peer_click_recv += 1
            n = self._peer_click_recv
        if not pressed and int(button) not in self._injected_buttons_down:
            # Release with no matching press we injected — nothing to do, but
            # still push a safety up event so a stuck button can't linger.
            try:
                self._inject_mouse_button(button, False, x, y)
            except Exception:
                pass
            return
        try:
            # Land the cursor at the event location first, then press/release.
            if x >= 0 and y >= 0:
                with self._lock:
                    w, h = self._local_w, self._local_h
                    self._vx = float(max(0, min(max(1, w - 1), int(x))))
                    self._vy = float(max(0, min(max(1, h - 1), int(y))))
                self._inject_mouse_pos(int(self._vx), int(self._vy))
            if not _IS_MAC:
                self._ensure_controllers()
            self._inject_mouse_button(button, pressed, x, y)
        except Exception as exc:
            self._log(f"클릭 주입 실패: {exc}")
            return
        if pressed:
            session = self.session
            if session is not None:
                try:
                    session.send_input_ctrl(
                        INPUT_CTRL_PEER_CLICK,
                        int(button),
                        max(0, min(65535, int(x if x >= 0 else self._vx))),
                    )
                except Exception:
                    pass
        if n <= 3 or n % 20 == 0:
            act = "누름" if pressed else "뗌"
            self._log(f"클릭 주입 ({act}, btn={button}, {x},{y}) — {n}회")

    def _on_peer_wheel(self, dx: int, dy: int) -> None:
        with self._lock:
            if not self.being_controlled:
                return
        if _IS_WIN:
            # Inject natively — clicks use mouse_event, so _mouse_ctl (pynput)
            # is often never created on the peer, which silently dropped scroll.
            try:
                import ctypes

                MOUSEEVENTF_WHEEL = 0x0800
                MOUSEEVENTF_HWHEEL = 0x01000
                WHEEL_DELTA = 120
                user32 = ctypes.windll.user32
                if dy:
                    user32.mouse_event(
                        MOUSEEVENTF_WHEEL, 0, 0, ctypes.c_int(int(dy) * WHEEL_DELTA), 0
                    )
                if dx:
                    user32.mouse_event(
                        MOUSEEVENTF_HWHEEL, 0, 0, ctypes.c_int(int(dx) * WHEEL_DELTA), 0
                    )
                return
            except Exception as exc:
                self._log(f"스크롤 주입 실패(Win): {exc}")
                return
        # macOS / other: use the pynput controller (create it if needed).
        self._ensure_controllers()
        if self._mouse_ctl is not None:
            try:
                self._mouse_ctl.scroll(int(dx), int(dy))
            except Exception as exc:
                self._log(f"스크롤 주입 실패: {exc}")

    def _on_peer_key(self, name: str, pressed: bool) -> None:
        inject_name = name
        active_mods: set[str]
        key_ctl = None
        with self._lock:
            if not self.being_controlled:
                return
            self._key_recv_count += 1
            recv_n = self._key_recv_count
            if _IS_WIN and name.lower() in (
                "cmd",
                "cmd_l",
                "cmd_r",
                "command",
                "super",
                "windows",
                "win",
            ):
                inject_name = "ctrl"
            low = inject_name.lower()
            if low in _MAC_MODIFIER_NAMES:
                if pressed:
                    self._peer_modifiers.add(low)
                else:
                    self._peer_modifiers.discard(low)
            active_mods = set(self._peer_modifiers)
            key_ctl = self._key_ctl
        if recv_n == 1 or recv_n % 50 == 0:
            self._log(
                f"상대 키 수신 → 이 PC 주입 ('{inject_name}' "
                f"{'누름' if pressed else '뗌'}, {recv_n}회)"
            )
        if _IS_MAC:
            if _mac_inject_key(inject_name, pressed, active_mods):
                with self._lock:
                    if pressed:
                        self._injected_keys_down.add(inject_name)
                    else:
                        self._injected_keys_down.discard(inject_name)
                return
            self._log(f"Mac 키 주입 실패 — '{inject_name}' (권한/매핑 확인)")
        if _IS_WIN:
            low_inj = inject_name.lower()
            if pressed and low_inj in ("caps_lock", "hangul", "hanja"):
                self._log(f"Windows 토글 주입 시도 — '{inject_name}'")
            if _win_inject_key(inject_name, pressed, active_mods):
                with self._lock:
                    if pressed:
                        self._injected_keys_down.add(inject_name)
                    else:
                        self._injected_keys_down.discard(inject_name)
                if pressed and low_inj in ("caps_lock", "hangul", "hanja"):
                    self._log(f"Windows 토글 주입 완료 — '{inject_name}'")
                return
            self._log(f"Windows 키 주입 실패 — '{inject_name}' (VK 매핑 없음)")
        if key_ctl is None:
            return
        key = _key_from_name(inject_name)
        if key is None:
            return
        try:
            if pressed:
                with self._lock:
                    self._injected_keys_down.add(inject_name)
                key_ctl.press(key)
            else:
                with self._lock:
                    self._injected_keys_down.discard(inject_name)
                key_ctl.release(key)
        except Exception as exc:
            self._log(f"키 주입 실패: {exc}")


# Process-wide singleton for GUI
SHARE = InputShare()