/*
 * SHAppBarMessage implementation
 *
 * Copyright 2008 Vincent Povirk for CodeWeavers
 *
 * 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
 *
 * TODO: freedesktop _NET_WM_STRUT integration
 *
 * TODO: find when a fullscreen app is in the foreground and send FULLSCREENAPP
 *  notifications
 *
 * TODO: detect changes in the screen size and send ABN_POSCHANGED ?
 *
 * TODO: multiple monitor support
 */

//
// Adapted from Wine appbar.c .
//

#include "precomp.h"

#include <wine/list.h>

struct appbar_cmd
{
    DWORD  dwMsg;
    ULONG  return_map;
    DWORD  return_process;
    struct _AppBarData abd;
};

struct appbar_response
{
    ULONGLONG result;
    struct _AppBarData abd;
};

struct appbar_data
{
    struct list entry;
    HWND hwnd;
    UINT callback_msg;
    UINT edge;
    RECT rc;
    BOOL space_reserved;
    /* BOOL autohide; */
};

static struct list appbars = LIST_INIT(appbars);

static struct appbar_data* get_appbar(HWND hwnd)
{
    struct appbar_data* data;

    LIST_FOR_EACH_ENTRY(data, &appbars, struct appbar_data, entry)
    {
        if (data->hwnd == hwnd)
            return data;
    }

    return NULL;
}

void appbar_notify_all(HMONITOR hMon, UINT uMsg, HWND hwndExclude, LPARAM lParam)
{
    struct appbar_data* data;

    LIST_FOR_EACH_ENTRY(data, &appbars, struct appbar_data, entry)
    {
        if (data->hwnd == hwndExclude)
            continue;

        if (hMon && hMon != MonitorFromWindow(data->hwnd, MONITOR_DEFAULTTONULL))
            continue;

        SendMessageW(data->hwnd, data->callback_msg, uMsg, lParam);
    }
}

/* send_poschanged: send ABN_POSCHANGED to every appbar except one */
static void send_poschanged(HWND hwnd)
{
    appbar_notify_all(NULL, ABN_POSCHANGED, hwnd, 0);
}

/* appbar_cliprect: cut out parts of the rectangle that interfere with existing appbars */
static void appbar_cliprect( HWND hwnd, RECT *rect )
{
    struct appbar_data* data;
    LIST_FOR_EACH_ENTRY(data, &appbars, struct appbar_data, entry)
    {
        if (data->hwnd == hwnd)
        {
            /* we only care about appbars that were added before this one */
            return;
        }
        if (data->space_reserved)
        {
            /* move in the side that corresponds to the other appbar's edge */
            switch (data->edge)
            {
            case ABE_BOTTOM:
                rect->bottom = min(rect->bottom, data->rc.top);
                break;
            case ABE_LEFT:
                rect->left = max(rect->left, data->rc.right);
                break;
            case ABE_RIGHT:
                rect->right = min(rect->right, data->rc.left);
                break;
            case ABE_TOP:
                rect->top = max(rect->top, data->rc.bottom);
                break;
            }
        }
    }
}

static UINT_PTR handle_appbarmessage(DWORD msg, _AppBarData *abd)
{
    struct appbar_data* data;
    HWND hwnd = abd->hWnd;

    switch (msg)
    {
    case ABM_NEW:
        if (get_appbar(hwnd))
        {
            /* fail when adding an hwnd the second time */
            return FALSE;
        }

        data = (struct appbar_data*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(struct appbar_data));
        if (!data)
        {
            ERR("out of memory\n");
            return FALSE;
        }
        data->hwnd = hwnd;
        data->callback_msg = abd->uCallbackMessage;

        list_add_tail(&appbars, &data->entry);

        return TRUE;
    case ABM_REMOVE:
        if ((data = get_appbar(hwnd)))
        {
            list_remove(&data->entry);

            send_poschanged(hwnd);

            HeapFree(GetProcessHeap(), 0, data);
        }
        else
            WARN("removing hwnd %p not on the list\n", hwnd);
        return TRUE;
    case ABM_QUERYPOS:
        if (abd->uEdge > ABE_BOTTOM)
            WARN("invalid edge %i for %p\n", abd->uEdge, hwnd);
        appbar_cliprect( hwnd, &abd->rc );
        return TRUE;
    case ABM_SETPOS:
        if (abd->uEdge > ABE_BOTTOM)
        {
            WARN("invalid edge %i for %p\n", abd->uEdge, hwnd);
            return TRUE;
        }
        if ((data = get_appbar(hwnd)))
        {
            /* calculate acceptable space */
            appbar_cliprect( hwnd, &abd->rc );

            if (!EqualRect(&abd->rc, &data->rc))
                send_poschanged(hwnd);

            /* reserve that space for this appbar */
            data->edge = abd->uEdge;
            data->rc = abd->rc;
            data->space_reserved = TRUE;
        }
        else
        {
            WARN("app sent ABM_SETPOS message for %p without ABM_ADD\n", hwnd);
        }
        return TRUE;
    case ABM_GETSTATE:
        FIXME("SHAppBarMessage(ABM_GETSTATE): stub\n");
        return ABS_ALWAYSONTOP | ABS_AUTOHIDE;
    case ABM_GETTASKBARPOS:
        FIXME("SHAppBarMessage(ABM_GETTASKBARPOS, hwnd=%p): stub\n", hwnd);
        /* Report the taskbar is at the bottom of the screen. */
        abd->rc.left = 0;
        abd->rc.right = GetSystemMetrics(SM_CXSCREEN);
        abd->rc.bottom = GetSystemMetrics(SM_CYSCREEN);
        abd->rc.top = abd->rc.bottom-1;
        abd->uEdge = ABE_BOTTOM;
        return TRUE;
    case ABM_ACTIVATE:
        return TRUE;
    case ABM_GETAUTOHIDEBAR:
        FIXME("SHAppBarMessage(ABM_GETAUTOHIDEBAR, hwnd=%p, edge=%x): stub\n", hwnd, abd->uEdge);
        return 0;
    case ABM_SETAUTOHIDEBAR:
        FIXME("SHAppBarMessage(ABM_SETAUTOHIDEBAR, hwnd=%p, edge=%x, lparam=%s): stub\n",
                   hwnd, abd->uEdge, wine_dbgstr_longlong(abd->lParam));
        return TRUE;
    case ABM_WINDOWPOSCHANGED:
        return TRUE;
    default:
        FIXME("SHAppBarMessage(%x) unimplemented\n", msg);
        return FALSE;
    }
}

LRESULT appbar_message ( COPYDATASTRUCT* cds )
{
    struct appbar_cmd cmd;
    UINT_PTR result;
    HANDLE return_hproc;
    HANDLE return_map;
    LPVOID return_view;
    struct appbar_response* response;

    if (cds->cbData != sizeof(struct appbar_cmd))
        return TRUE;

    RtlCopyMemory(&cmd, cds->lpData, cds->cbData);

    result = handle_appbarmessage(cmd.dwMsg, &cmd.abd);

    return_hproc = OpenProcess(PROCESS_DUP_HANDLE, FALSE, cmd.return_process);
    if (return_hproc == NULL)
    {
        ERR("couldn't open calling process\n");
        return TRUE;
    }

    if (!DuplicateHandle(return_hproc, UlongToHandle(cmd.return_map), GetCurrentProcess(), &return_map, 0, FALSE, DUPLICATE_SAME_ACCESS))
    {
        ERR("couldn't duplicate handle\n");
        CloseHandle(return_hproc);
        return TRUE;
    }
    CloseHandle(return_hproc);

    return_view = MapViewOfFile(return_map, FILE_MAP_WRITE, 0, 0, sizeof(struct appbar_response));

    if (return_view)
    {
        response = (struct appbar_response*)return_view;
        response->result = result;
        response->abd = cmd.abd;

        UnmapViewOfFile(return_view);
    }
    else
    {
        ERR("couldn't map view of file\n");
    }

    CloseHandle(return_map);
    return TRUE;
}