/*
 * Window related functions
 *
 * Copyright 1993, 1994 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */


#if 0
#pragma makedep unix
#endif

#include <pthread.h>
#include <assert.h>

#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "win32u_private.h"
#include "ntuser_private.h"
#include "wine/server.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(win);

#define NB_USER_HANDLES  ((LAST_USER_HANDLE - FIRST_USER_HANDLE + 1) >> 1)
#define USER_HANDLE_TO_INDEX(hwnd) ((LOWORD(hwnd) - FIRST_USER_HANDLE) >> 1)

static void *user_handles[NB_USER_HANDLES];

static struct list window_surfaces = LIST_INIT( window_surfaces );
static pthread_mutex_t surfaces_lock = PTHREAD_MUTEX_INITIALIZER;

/***********************************************************************
 *           alloc_user_handle
 */
HANDLE alloc_user_handle( struct user_object *ptr, unsigned int type )
{
    HANDLE handle = 0;

    SERVER_START_REQ( alloc_user_handle )
    {
        if (!wine_server_call_err( req )) handle = wine_server_ptr_handle( reply->handle );
    }
    SERVER_END_REQ;

    if (handle)
    {
        UINT index = USER_HANDLE_TO_INDEX( handle );

        assert( index < NB_USER_HANDLES );
        ptr->handle = handle;
        ptr->type = type;
        InterlockedExchangePointer( &user_handles[index], ptr );
    }
    return handle;
}

/***********************************************************************
 *           get_user_handle_ptr
 */
void *get_user_handle_ptr( HANDLE handle, unsigned int type )
{
    struct user_object *ptr;
    WORD index = USER_HANDLE_TO_INDEX( handle );

    if (index >= NB_USER_HANDLES) return NULL;

    user_lock();
    if ((ptr = user_handles[index]))
    {
        if (ptr->type == type &&
            ((UINT)(UINT_PTR)ptr->handle == (UINT)(UINT_PTR)handle ||
             !HIWORD(handle) || HIWORD(handle) == 0xffff))
            return ptr;
        ptr = NULL;
    }
    else ptr = OBJ_OTHER_PROCESS;
    user_unlock();
    return ptr;
}

/***********************************************************************
 *           set_user_handle_ptr
 */
void set_user_handle_ptr( HANDLE handle, struct user_object *ptr )
{
    WORD index = USER_HANDLE_TO_INDEX(handle);
    assert( index < NB_USER_HANDLES );
    InterlockedExchangePointer( &user_handles[index], ptr );
}

/***********************************************************************
 *           release_user_handle_ptr
 */
void release_user_handle_ptr( void *ptr )
{
    assert( ptr && ptr != OBJ_OTHER_PROCESS );
    user_unlock();
}

/***********************************************************************
 *           free_user_handle
 */
void *free_user_handle( HANDLE handle, unsigned int type )
{
    struct user_object *ptr;
    WORD index = USER_HANDLE_TO_INDEX( handle );

    if ((ptr = get_user_handle_ptr( handle, type )) && ptr != OBJ_OTHER_PROCESS)
    {
        SERVER_START_REQ( free_user_handle )
        {
            req->handle = wine_server_user_handle( handle );
            if (wine_server_call( req )) ptr = NULL;
            else InterlockedCompareExchangePointer( &user_handles[index], NULL, ptr );
        }
        SERVER_END_REQ;
        user_unlock();
    }
    return ptr;
}

/***********************************************************************
 *           next_thread_window
 */
WND *next_thread_window_ptr( HWND *hwnd )
{
    struct user_object *ptr;
    WND *win;
    WORD index = *hwnd ? USER_HANDLE_TO_INDEX( *hwnd ) + 1 : 0;

    while (index < NB_USER_HANDLES)
    {
        if (!(ptr = user_handles[index++])) continue;
        if (ptr->type != NTUSER_OBJ_WINDOW) continue;
        win = (WND *)ptr;
        if (win->tid != GetCurrentThreadId()) continue;
        *hwnd = ptr->handle;
        return win;
    }
    return NULL;
}

/*******************************************************************
 *           get_hwnd_message_parent
 *
 * Return the parent for HWND_MESSAGE windows.
 */
static HWND get_hwnd_message_parent(void)
{
    struct user_thread_info *thread_info = get_user_thread_info();

    if (!thread_info->msg_window && user_callbacks)
        user_callbacks->pGetDesktopWindow();  /* trigger creation */
    return thread_info->msg_window;
}

/***********************************************************************
 *           get_full_window_handle
 *
 * Convert a possibly truncated window handle to a full 32-bit handle.
 */
static HWND get_full_window_handle( HWND hwnd )
{
    WND *win;

    if (!hwnd || (ULONG_PTR)hwnd >> 16) return hwnd;
    if (LOWORD(hwnd) <= 1 || LOWORD(hwnd) == 0xffff) return hwnd;
    /* do sign extension for -2 and -3 */
    if (LOWORD(hwnd) >= (WORD)-3) return (HWND)(LONG_PTR)(INT16)LOWORD(hwnd);

    if (!(win = get_win_ptr( hwnd ))) return hwnd;

    if (win == WND_DESKTOP)
    {
        if (user_callbacks && LOWORD(hwnd) == LOWORD(user_callbacks->pGetDesktopWindow()))
            return user_callbacks->pGetDesktopWindow();
        else return get_hwnd_message_parent();
    }

    if (win != WND_OTHER_PROCESS)
    {
        hwnd = win->obj.handle;
        release_win_ptr( win );
    }
    else  /* may belong to another process */
    {
        SERVER_START_REQ( get_window_info )
        {
            req->handle = wine_server_user_handle( hwnd );
            if (!wine_server_call_err( req )) hwnd = wine_server_ptr_handle( reply->full_handle );
        }
        SERVER_END_REQ;
    }
    return hwnd;
}

/*******************************************************************
 *           register_window_surface
 *
 * Register a window surface in the global list, possibly replacing another one.
 */
void register_window_surface( struct window_surface *old, struct window_surface *new )
{
    if (old == new) return;
    pthread_mutex_lock( &surfaces_lock );
    if (old) list_remove( &old->entry );
    if (new) list_add_tail( &window_surfaces, &new->entry );
    pthread_mutex_unlock( &surfaces_lock );
}

/*******************************************************************
 *           flush_window_surfaces
 *
 * Flush pending output from all window surfaces.
 */
void flush_window_surfaces( BOOL idle )
{
    static DWORD last_idle;
    DWORD now;
    struct window_surface *surface;

    pthread_mutex_lock( &surfaces_lock );
    now = NtGetTickCount();
    if (idle) last_idle = now;
    /* if not idle, we only flush if there's evidence that the app never goes idle */
    else if ((int)(now - last_idle) < 50) goto done;

    LIST_FOR_EACH_ENTRY( surface, &window_surfaces, struct window_surface, entry )
        surface->funcs->flush( surface );
done:
    pthread_mutex_unlock( &surfaces_lock );
}

/*******************************************************************
 *           is_desktop_window
 *
 * Check if window is the desktop or the HWND_MESSAGE top parent.
 */
static BOOL is_desktop_window( HWND hwnd )
{
    struct user_thread_info *thread_info = get_user_thread_info();

    if (!hwnd) return FALSE;
    if (hwnd == thread_info->top_window) return TRUE;
    if (hwnd == thread_info->msg_window) return TRUE;

    if (!HIWORD(hwnd) || HIWORD(hwnd) == 0xffff)
    {
        if (LOWORD(thread_info->top_window) == LOWORD(hwnd)) return TRUE;
        if (LOWORD(thread_info->msg_window) == LOWORD(hwnd)) return TRUE;
    }
    return FALSE;
}

/***********************************************************************
 *           win_get_ptr
 *
 * Return a pointer to the WND structure if local to the process,
 * or WND_OTHER_PROCESS if handle may be valid in other process.
 * If ret value is a valid pointer, it must be released with WIN_ReleasePtr.
 */
WND *get_win_ptr( HWND hwnd )
{
    WND *win;

    if ((win = get_user_handle_ptr( hwnd, NTUSER_OBJ_WINDOW )) == WND_OTHER_PROCESS)
    {
        if (is_desktop_window( hwnd )) win = WND_DESKTOP;
    }
    return win;
}

/***********************************************************************
 *           is_current_thread_window
 *
 * Check whether a given window belongs to the current process (and return the full handle).
 */
HWND is_current_thread_window( HWND hwnd )
{
    WND *win;
    HWND ret = 0;

    if (!(win = get_win_ptr( hwnd )) || win == WND_OTHER_PROCESS || win == WND_DESKTOP)
        return 0;
    if (win->tid == GetCurrentThreadId()) ret = win->obj.handle;
    release_win_ptr( win );
    return ret;
}

/* see IsWindow */
BOOL is_window( HWND hwnd )
{
    WND *win;
    BOOL ret;

    if (!(win = get_win_ptr( hwnd ))) return FALSE;
    if (win == WND_DESKTOP) return TRUE;

    if (win != WND_OTHER_PROCESS)
    {
        release_win_ptr( win );
        return TRUE;
    }

    /* check other processes */
    SERVER_START_REQ( get_window_info )
    {
        req->handle = wine_server_user_handle( hwnd );
        ret = !wine_server_call_err( req );
    }
    SERVER_END_REQ;
    return ret;
}

/* see GetWindowThreadProcessId */
static DWORD get_window_thread( HWND hwnd, DWORD *process )
{
    WND *ptr;
    DWORD tid = 0;

    if (!(ptr = get_win_ptr( hwnd )))
    {
        SetLastError( ERROR_INVALID_WINDOW_HANDLE);
        return 0;
    }

    if (ptr != WND_OTHER_PROCESS && ptr != WND_DESKTOP)
    {
        /* got a valid window */
        tid = ptr->tid;
        if (process) *process = GetCurrentProcessId();
        release_win_ptr( ptr );
        return tid;
    }

    /* check other processes */
    SERVER_START_REQ( get_window_info )
    {
        req->handle = wine_server_user_handle( hwnd );
        if (!wine_server_call_err( req ))
        {
            tid = (DWORD)reply->tid;
            if (process) *process = (DWORD)reply->pid;
        }
    }
    SERVER_END_REQ;
    return tid;
}

/* see GetParent */
static HWND get_parent( HWND hwnd )
{
    HWND retval = 0;
    WND *win;

    if (!(win = get_win_ptr( hwnd )))
    {
        SetLastError( ERROR_INVALID_WINDOW_HANDLE );
        return 0;
    }
    if (win == WND_DESKTOP) return 0;
    if (win == WND_OTHER_PROCESS)
    {
        LONG style = get_window_long( hwnd, GWL_STYLE );
        if (style & (WS_POPUP | WS_CHILD))
        {
            SERVER_START_REQ( get_window_tree )
            {
                req->handle = wine_server_user_handle( hwnd );
                if (!wine_server_call_err( req ))
                {
                    if (style & WS_POPUP) retval = wine_server_ptr_handle( reply->owner );
                    else if (style & WS_CHILD) retval = wine_server_ptr_handle( reply->parent );
                }
            }
            SERVER_END_REQ;
        }
    }
    else
    {
        if (win->dwStyle & WS_POPUP) retval = win->owner;
        else if (win->dwStyle & WS_CHILD) retval = win->parent;
        release_win_ptr( win );
    }
    return retval;
}

/* see GetWindow */
static HWND get_window_relative( HWND hwnd, UINT rel )
{
    HWND retval = 0;

    if (rel == GW_OWNER)  /* this one may be available locally */
    {
        WND *win = get_win_ptr( hwnd );
        if (!win)
        {
            SetLastError( ERROR_INVALID_HANDLE );
            return 0;
        }
        if (win == WND_DESKTOP) return 0;
        if (win != WND_OTHER_PROCESS)
        {
            retval = win->owner;
            release_win_ptr( win );
            return retval;
        }
        /* else fall through to server call */
    }

    SERVER_START_REQ( get_window_tree )
    {
        req->handle = wine_server_user_handle( hwnd );
        if (!wine_server_call_err( req ))
        {
            switch(rel)
            {
            case GW_HWNDFIRST:
                retval = wine_server_ptr_handle( reply->first_sibling );
                break;
            case GW_HWNDLAST:
                retval = wine_server_ptr_handle( reply->last_sibling );
                break;
            case GW_HWNDNEXT:
                retval = wine_server_ptr_handle( reply->next_sibling );
                break;
            case GW_HWNDPREV:
                retval = wine_server_ptr_handle( reply->prev_sibling );
                break;
            case GW_OWNER:
                retval = wine_server_ptr_handle( reply->owner );
                break;
            case GW_CHILD:
                retval = wine_server_ptr_handle( reply->first_child );
                break;
            }
        }
    }
    SERVER_END_REQ;
    return retval;
}

/*******************************************************************
 *           list_window_parents
 *
 * Build an array of all parents of a given window, starting with
 * the immediate parent. The array must be freed with free().
 */
static HWND *list_window_parents( HWND hwnd )
{
    WND *win;
    HWND current, *list;
    int i, pos = 0, size = 16, count;

    if (!(list = malloc( size * sizeof(HWND) ))) return NULL;

    current = hwnd;
    for (;;)
    {
        if (!(win = get_win_ptr( current ))) goto empty;
        if (win == WND_OTHER_PROCESS) break;  /* need to do it the hard way */
        if (win == WND_DESKTOP)
        {
            if (!pos) goto empty;
            list[pos] = 0;
            return list;
        }
        list[pos] = current = win->parent;
        release_win_ptr( win );
        if (!current) return list;
        if (++pos == size - 1)
        {
            /* need to grow the list */
            HWND *new_list = realloc( list, (size + 16) * sizeof(HWND) );
            if (!new_list) goto empty;
            list = new_list;
            size += 16;
        }
    }

    /* at least one parent belongs to another process, have to query the server */

    for (;;)
    {
        count = 0;
        SERVER_START_REQ( get_window_parents )
        {
            req->handle = wine_server_user_handle( hwnd );
            wine_server_set_reply( req, list, (size-1) * sizeof(user_handle_t) );
            if (!wine_server_call( req )) count = reply->count;
        }
        SERVER_END_REQ;
        if (!count) goto empty;
        if (size > count)
        {
            /* start from the end since HWND is potentially larger than user_handle_t */
            for (i = count - 1; i >= 0; i--)
                list[i] = wine_server_ptr_handle( ((user_handle_t *)list)[i] );
            list[count] = 0;
            return list;
        }
        free( list );
        size = count + 1;
        if (!(list = malloc( size * sizeof(HWND) ))) return NULL;
    }

empty:
    free( list );
    return NULL;
}

/*****************************************************************
 *           NtUserGetAncestor (win32u.@)
 */
HWND WINAPI NtUserGetAncestor( HWND hwnd, UINT type )
{
    HWND *list, ret = 0;
    WND *win;

    switch(type)
    {
    case GA_PARENT:
        if (!(win = get_win_ptr( hwnd )))
        {
            SetLastError( ERROR_INVALID_WINDOW_HANDLE );
            return 0;
        }
        if (win == WND_DESKTOP) return 0;
        if (win != WND_OTHER_PROCESS)
        {
            ret = win->parent;
            release_win_ptr( win );
        }
        else /* need to query the server */
        {
            SERVER_START_REQ( get_window_tree )
            {
                req->handle = wine_server_user_handle( hwnd );
                if (!wine_server_call_err( req )) ret = wine_server_ptr_handle( reply->parent );
            }
            SERVER_END_REQ;
        }
        break;

    case GA_ROOT:
        if (!(list = list_window_parents( hwnd ))) return 0;

        if (!list[0] || !list[1]) ret = get_full_window_handle( hwnd );  /* top-level window */
        else
        {
            int count = 2;
            while (list[count]) count++;
            ret = list[count - 2];  /* get the one before the desktop */
        }
        free( list );
        break;

    case GA_ROOTOWNER:
        if (is_desktop_window( hwnd )) return 0;
        ret = get_full_window_handle( hwnd );
        for (;;)
        {
            HWND parent = get_parent( ret );
            if (!parent) break;
            ret = parent;
        }
        break;
    }
    return ret;
}

static LONG_PTR get_win_data( const void *ptr, UINT size )
{
    if (size == sizeof(WORD))
    {
        WORD ret;
        memcpy( &ret, ptr, sizeof(ret) );
        return ret;
    }
    else if (size == sizeof(DWORD))
    {
        DWORD ret;
        memcpy( &ret, ptr, sizeof(ret) );
        return ret;
    }
    else
    {
        LONG_PTR ret;
        memcpy( &ret, ptr, sizeof(ret) );
        return ret;
    }
}

static LONG_PTR get_window_long_size( HWND hwnd, INT offset, UINT size, BOOL ansi )
{
    LONG_PTR retval = 0;
    WND *win;

    if (offset == GWLP_HWNDPARENT)
    {
        FIXME( "GWLP_HWNDPARENT not supported\n" );
        return 0;
    }

    if (!(win = get_win_ptr( hwnd )))
    {
        SetLastError( ERROR_INVALID_WINDOW_HANDLE );
        return 0;
    }

    if (win == WND_DESKTOP)
    {
        switch (offset)
        {
        case GWL_STYLE:
            retval = WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN; /* message parent is not visible */
            if (user_callbacks && get_full_window_handle( hwnd ) == user_callbacks->pGetDesktopWindow())
                retval |= WS_VISIBLE;
            return retval;
        case GWL_EXSTYLE:
        case GWLP_USERDATA:
        case GWLP_ID:
        case GWLP_HINSTANCE:
            return 0;
        case GWLP_WNDPROC:
            SetLastError( ERROR_ACCESS_DENIED );
            return 0;
        }
        SetLastError( ERROR_INVALID_INDEX );
        return 0;
    }

    if (win == WND_OTHER_PROCESS)
    {
        if (offset == GWLP_WNDPROC)
        {
            SetLastError( ERROR_ACCESS_DENIED );
            return 0;
        }
        SERVER_START_REQ( set_window_info )
        {
            req->handle = wine_server_user_handle( hwnd );
            req->flags  = 0;  /* don't set anything, just retrieve */
            req->extra_offset = (offset >= 0) ? offset : -1;
            req->extra_size = (offset >= 0) ? size : 0;
            if (!wine_server_call_err( req ))
            {
                switch(offset)
                {
                case GWL_STYLE:      retval = reply->old_style; break;
                case GWL_EXSTYLE:    retval = reply->old_ex_style; break;
                case GWLP_ID:        retval = reply->old_id; break;
                case GWLP_HINSTANCE: retval = (ULONG_PTR)wine_server_get_ptr( reply->old_instance ); break;
                case GWLP_USERDATA:  retval = reply->old_user_data; break;
                default:
                    if (offset >= 0) retval = get_win_data( &reply->old_extra_value, size );
                    else SetLastError( ERROR_INVALID_INDEX );
                    break;
                }
            }
        }
        SERVER_END_REQ;
        return retval;
    }

    /* now we have a valid win */

    if (offset >= 0)
    {
        if (offset > (int)(win->cbWndExtra - size))
        {
            WARN("Invalid offset %d\n", offset );
            release_win_ptr( win );
            SetLastError( ERROR_INVALID_INDEX );
            return 0;
        }
        retval = get_win_data( (char *)win->wExtra + offset, size );

        /* Special case for dialog window procedure */
        if ((offset == DWLP_DLGPROC) && (size == sizeof(LONG_PTR)) && win->dlgInfo)
            retval = (LONG_PTR)get_winproc( (WNDPROC)retval, ansi );
        release_win_ptr( win );
        return retval;
    }

    switch(offset)
    {
    case GWLP_USERDATA:  retval = win->userdata; break;
    case GWL_STYLE:      retval = win->dwStyle; break;
    case GWL_EXSTYLE:    retval = win->dwExStyle; break;
    case GWLP_ID:        retval = win->wIDmenu; break;
    case GWLP_HINSTANCE: retval = (ULONG_PTR)win->hInstance; break;
    case GWLP_WNDPROC:
        /* This looks like a hack only for the edit control (see tests). This makes these controls
         * more tolerant to A/W mismatches. The lack of W->A->W conversion for such a mismatch suggests
         * that the hack is in GetWindowLongPtr[AW], not in winprocs.
         */
        if (win->winproc == BUILTIN_WINPROC(WINPROC_EDIT) && (!!ansi != !(win->flags & WIN_ISUNICODE)))
            retval = (ULONG_PTR)win->winproc;
        else
            retval = (ULONG_PTR)get_winproc( win->winproc, ansi );
        break;
    default:
        WARN("Unknown offset %d\n", offset );
        SetLastError( ERROR_INVALID_INDEX );
        break;
    }
    release_win_ptr( win );
    return retval;
}

/* see GetWindowLongW */
DWORD get_window_long( HWND hwnd, INT offset )
{
    return get_window_long_size( hwnd, offset, sizeof(LONG), FALSE );
}

/* see GetWindowLongPtr */
static ULONG_PTR get_window_long_ptr( HWND hwnd, INT offset, BOOL ansi )
{
    return get_window_long_size( hwnd, offset, sizeof(LONG_PTR), ansi );
}

/* see GetWindowWord */
static WORD get_window_word( HWND hwnd, INT offset )
{
    switch(offset)
    {
    case GWLP_ID:
    case GWLP_HINSTANCE:
    case GWLP_HWNDPARENT:
        break;
    default:
        if (offset < 0)
        {
            WARN("Invalid offset %d\n", offset );
            SetLastError( ERROR_INVALID_INDEX );
            return 0;
        }
        break;
    }
    return get_window_long_size( hwnd, offset, sizeof(WORD), TRUE );
}

/***********************************************************************
 *           NtUserGetProp   (win32u.@)
 *
 * NOTE Native allows only ATOMs as the second argument. We allow strings
 *      to save extra server call in GetPropW.
 */
HANDLE WINAPI NtUserGetProp( HWND hwnd, const WCHAR *str )
{
    ULONG_PTR ret = 0;

    SERVER_START_REQ( get_window_property )
    {
        req->window = wine_server_user_handle( hwnd );
        if (IS_INTRESOURCE(str)) req->atom = LOWORD(str);
        else wine_server_add_data( req, str, lstrlenW(str) * sizeof(WCHAR) );
        if (!wine_server_call_err( req )) ret = reply->data;
    }
    SERVER_END_REQ;
    return (HANDLE)ret;
}

/*****************************************************************************
 *           NtUserSetProp    (win32u.@)
 *
 * NOTE Native allows only ATOMs as the second argument. We allow strings
 *      to save extra server call in SetPropW.
 */
BOOL WINAPI NtUserSetProp( HWND hwnd, const WCHAR *str, HANDLE handle )
{
    BOOL ret;

    SERVER_START_REQ( set_window_property )
    {
        req->window = wine_server_user_handle( hwnd );
        req->data   = (ULONG_PTR)handle;
        if (IS_INTRESOURCE(str)) req->atom = LOWORD(str);
        else wine_server_add_data( req, str, lstrlenW(str) * sizeof(WCHAR) );
        ret = !wine_server_call_err( req );
    }
    SERVER_END_REQ;
    return ret;
}


/***********************************************************************
 *           NtUserRemoveProp   (win32u.@)
 *
 * NOTE Native allows only ATOMs as the second argument. We allow strings
 *      to save extra server call in RemovePropW.
 */
HANDLE WINAPI NtUserRemoveProp( HWND hwnd, const WCHAR *str )
{
    ULONG_PTR ret = 0;

    SERVER_START_REQ( remove_window_property )
    {
        req->window = wine_server_user_handle( hwnd );
        if (IS_INTRESOURCE(str)) req->atom = LOWORD(str);
        else wine_server_add_data( req, str, lstrlenW(str) * sizeof(WCHAR) );
        if (!wine_server_call_err( req )) ret = reply->data;
    }
    SERVER_END_REQ;

    return (HANDLE)ret;
}


/*****************************************************************************
 *           NtUserGetLayeredWindowAttributes (win32u.@)
 */
BOOL WINAPI NtUserGetLayeredWindowAttributes( HWND hwnd, COLORREF *key, BYTE *alpha, DWORD *flags )
{
    BOOL ret;

    SERVER_START_REQ( get_window_layered_info )
    {
        req->handle = wine_server_user_handle( hwnd );
        if ((ret = !wine_server_call_err( req )))
        {
            if (key) *key = reply->color_key;
            if (alpha) *alpha = reply->alpha;
            if (flags) *flags = reply->flags;
        }
    }
    SERVER_END_REQ;

    return ret;
}

/*****************************************************************************
 *           NtUserBuildHwndList (win32u.@)
 */
NTSTATUS WINAPI NtUserBuildHwndList( HDESK desktop, ULONG unk2, ULONG unk3, ULONG unk4,
                                     ULONG thread_id, ULONG count, HWND *buffer, ULONG *size )
{
    user_handle_t *list = (user_handle_t *)buffer;
    int i;
    NTSTATUS status;

    SERVER_START_REQ( get_window_children )
    {
        req->desktop = wine_server_obj_handle( desktop );
        req->tid = thread_id;
        if (count) wine_server_set_reply( req, list, (count - 1) * sizeof(user_handle_t) );
        status = wine_server_call( req );
        if (status && status != STATUS_BUFFER_TOO_SMALL) return status;
        *size = reply->count + 1;
    }
    SERVER_END_REQ;
    if (*size > count) return STATUS_BUFFER_TOO_SMALL;

    /* start from the end since HWND is potentially larger than user_handle_t */
    for (i = *size - 2; i >= 0; i--)
        buffer[i] = wine_server_ptr_handle( list[i] );
    buffer[*size - 1] = HWND_BOTTOM;
    return STATUS_SUCCESS;
}

/* Retrieve the window text from the server. */
static data_size_t get_server_window_text( HWND hwnd, WCHAR *text, data_size_t count )
{
    data_size_t len = 0, needed = 0;

    SERVER_START_REQ( get_window_text )
    {
        req->handle = wine_server_user_handle( hwnd );
        if (count) wine_server_set_reply( req, text, (count - 1) * sizeof(WCHAR) );
        if (!wine_server_call_err( req ))
        {
            needed = reply->length;
            len = wine_server_reply_size(reply);
        }
    }
    SERVER_END_REQ;
    if (text) text[len / sizeof(WCHAR)] = 0;
    return needed;
}

/*******************************************************************
 *           NtUserInternalGetWindowText (win32u.@)
 */
INT WINAPI NtUserInternalGetWindowText( HWND hwnd, WCHAR *text, INT count )
{
    WND *win;

    if (count <= 0) return 0;
    if (!(win = get_win_ptr( hwnd ))) return 0;
    if (win == WND_DESKTOP) text[0] = 0;
    else if (win != WND_OTHER_PROCESS)
    {
        if (win->text) lstrcpynW( text, win->text, count );
        else text[0] = 0;
        release_win_ptr( win );
    }
    else
    {
        get_server_window_text( hwnd, text, count );
    }
    return lstrlenW(text);
}

/*****************************************************************************
 *           NtUserCallHwnd (win32u.@)
 */
DWORD WINAPI NtUserCallHwnd( HWND hwnd, DWORD code )
{
    switch (code)
    {
    case NtUserGetParent:
        return HandleToUlong( get_parent( hwnd ));
    case NtUserGetWindowTextLength:
        return get_server_window_text( hwnd, NULL, 0 );
    case NtUserIsWindow:
        return is_window( hwnd );
    default:
        FIXME( "invalid code %u\n", code );
        return 0;
    }
}

/*****************************************************************************
 *           NtUserCallHwndParam (win32u.@)
 */
ULONG_PTR WINAPI NtUserCallHwndParam( HWND hwnd, DWORD_PTR param, DWORD code )
{
    switch (code)
    {
    case NtUserGetClassLongA:
        return get_class_long( hwnd, param, TRUE );
    case NtUserGetClassLongW:
        return get_class_long( hwnd, param, FALSE );
    case NtUserGetClassLongPtrA:
        return get_class_long_ptr( hwnd, param, TRUE );
    case NtUserGetClassLongPtrW:
        return get_class_long_ptr( hwnd, param, FALSE );
    case NtUserGetClassWord:
        return get_class_word( hwnd, param );
    case NtUserGetWindowLongA:
        return get_window_long_size( hwnd, param, sizeof(LONG), TRUE );
    case NtUserGetWindowLongW:
        return get_window_long( hwnd, param );
    case NtUserGetWindowLongPtrA:
        return get_window_long_ptr( hwnd, param, TRUE );
    case NtUserGetWindowLongPtrW:
        return get_window_long_ptr( hwnd, param, FALSE );
    case NtUserGetWindowRelative:
        return HandleToUlong( get_window_relative( hwnd, param ));
    case NtUserGetWindowThread:
        return get_window_thread( hwnd, (DWORD *)param );
    case NtUserGetWindowWord:
        return get_window_word( hwnd, param );
    default:
        FIXME( "invalid code %u\n", code );
        return 0;
    }
}