"""Windows API helpers for window management (ctypes, no extra dependencies)."""
from __future__ import annotations

import ctypes
import ctypes.wintypes as wt
import sys

if sys.platform != "win32":
    # Stub for non-Windows development/testing
    def find_window_by_pid(pid: int) -> int | None:
        return None

    def move_and_maximize(hwnd: int, x: int, y: int, w: int, h: int) -> None:
        pass

    def is_window_alive(hwnd: int) -> bool:
        return False

else:
    _user32 = ctypes.windll.user32  # type: ignore[attr-defined]

    # Constants
    _HWND_TOP = 0
    _SW_RESTORE = 9
    _SW_MAXIMIZE = 3
    _SWP_SHOWWINDOW = 0x0040
    _SWP_FRAMECHANGED = 0x0020
    _GW_OWNER = 4

    # Callback type for EnumWindows
    _WNDENUMPROC = ctypes.WINFUNCTYPE(ctypes.c_bool, wt.HWND, wt.LPARAM)

    def find_window_by_pid(pid: int) -> int | None:
        """Return the first visible top-level HWND belonging to *pid*."""
        found: list[int] = []

        def _cb(hwnd: int, _: int) -> bool:
            if not _user32.IsWindowVisible(hwnd):
                return True
            # Skip windows with an owner (child dialogs, etc.)
            if _user32.GetWindow(hwnd, _GW_OWNER):
                return True
            lp_pid = wt.DWORD()
            _user32.GetWindowThreadProcessId(hwnd, ctypes.byref(lp_pid))
            if lp_pid.value == pid:
                found.append(hwnd)
                return False   # stop enumeration
            return True

        _user32.EnumWindows(_WNDENUMPROC(_cb), 0)
        return found[0] if found else None

    def find_window_by_title_hint(hint: str) -> int | None:
        """Return the first visible top-level HWND whose title contains *hint*."""
        if not hint:
            return None
        found: list[int] = []

        def _cb(hwnd: int, _: int) -> bool:
            if not _user32.IsWindowVisible(hwnd):
                return True
            buf = ctypes.create_unicode_buffer(512)
            _user32.GetWindowTextW(hwnd, buf, 512)
            if hint.lower() in buf.value.lower():
                found.append(hwnd)
                return False
            return True

        _user32.EnumWindows(_WNDENUMPROC(_cb), 0)
        return found[0] if found else None

    def move_and_maximize(hwnd: int, x: int, y: int, w: int, h: int) -> None:
        """Move a window to (x, y, w, h) then maximize it on that monitor."""
        _user32.ShowWindow(hwnd, _SW_RESTORE)
        _user32.SetWindowPos(
            hwnd, _HWND_TOP,
            x, y, w, h,
            _SWP_SHOWWINDOW | _SWP_FRAMECHANGED,
        )
        _user32.ShowWindow(hwnd, _SW_MAXIMIZE)
        _user32.SetForegroundWindow(hwnd)

    def is_window_alive(hwnd: int) -> bool:
        return bool(_user32.IsWindow(hwnd))