/*
 * Copyright © 2006 Novell, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of
 * Novell, Inc. not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior permission.
 * Novell, Inc. makes no representations about the suitability of this
 * software for any purpose. It is provided "as is" without express or
 * implied warranty.
 *
 * NOVELL, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
 * NO EVENT SHALL NOVELL, INC. BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author: David Reveman <davidr@novell.com>
 */

#include <stdlib.h>
#include <unistd.h>
#include <poll.h>
#include <sys/inotify.h>

#include <compiz-core.h>

static CompMetadata inotifyMetadata;

static int corePrivateIndex;

typedef struct _CompInotifyWatch {
    struct _CompInotifyWatch *next;
    CompFileWatchHandle	     handle;
    int			     wd;
} CompInotifyWatch;

typedef struct _InotifyCore {
    int		      fd;
    CompInotifyWatch  *watch;
    CompWatchFdHandle watchFdHandle;

    FileWatchAddedProc   fileWatchAdded;
    FileWatchRemovedProc fileWatchRemoved;
} InotifyCore;

#define GET_INOTIFY_CORE(c)				       \
    ((InotifyCore *) (c)->base.privates[corePrivateIndex].ptr)

#define INOTIFY_CORE(c)			   \
    InotifyCore *ic = GET_INOTIFY_CORE (c)


static Bool
inotifyProcessEvents (void *data)
{
    char buf[256 * (sizeof (struct inotify_event) + 16)];
    int	 len;

    INOTIFY_CORE (&core);

    len = read (ic->fd, buf, sizeof (buf));
    if (len < 0)
    {
	perror ("read");
    }
    else
    {
	struct inotify_event *event;
	CompInotifyWatch     *iw;
	CompFileWatch	     *fw;
	int		     i = 0;

	while (i < len)
	{
	    event = (struct inotify_event *) &buf[i];

	    for (iw = ic->watch; iw; iw = iw->next)
		if (iw->wd == event->wd)
		    break;

	    if (iw)
	    {
		for (fw = core.fileWatch; fw; fw = fw->next)
		    if (fw->handle == iw->handle)
			break;

		if (fw)
		{
		    if (event->len)
			(*fw->callBack) (event->name, fw->closure);
		    else
			(*fw->callBack) (NULL, fw->closure);
		}
	    }

	    i += sizeof (*event) + event->len;
	}
    }

    return TRUE;
}

static int
inotifyMask (CompFileWatch *fileWatch)
{
    int mask = 0;

    if (fileWatch->mask & NOTIFY_CREATE_MASK)
	mask |= IN_CREATE;

    if (fileWatch->mask & NOTIFY_DELETE_MASK)
	mask |= IN_DELETE;

    if (fileWatch->mask & NOTIFY_MOVE_MASK)
	mask |= IN_MOVE;

    if (fileWatch->mask & NOTIFY_MODIFY_MASK)
	mask |= IN_MODIFY;

    return mask;
}

static void
inotifyFileWatchAdded (CompCore      *c,
		       CompFileWatch *fileWatch)
{
    CompInotifyWatch *iw;

    INOTIFY_CORE (c);

    iw = malloc (sizeof (CompInotifyWatch));
    if (!iw)
	return;

    iw->handle = fileWatch->handle;
    iw->wd     = inotify_add_watch (ic->fd,
				    fileWatch->path,
				    inotifyMask (fileWatch));
    if (iw->wd < 0)
    {
	perror ("inotify_add_watch");
	free (iw);
	return;
    }

    iw->next  = ic->watch;
    ic->watch = iw;
}

static void
inotifyFileWatchRemoved (CompCore      *c,
			 CompFileWatch *fileWatch)
{
    CompInotifyWatch *p = 0, *iw;

    INOTIFY_CORE (c);

    for (iw = ic->watch; iw; iw = iw->next)
    {
	if (iw->handle == fileWatch->handle)
	    break;

	p = iw;
    }

    if (iw)
    {
	if (p)
	    p->next = iw->next;
	else
	    ic->watch = iw->next;

	if (inotify_rm_watch (ic->fd, iw->wd))
	    perror ("inotify_rm_watch");

	free (iw);
    }
}

static Bool
inotifyInitCore (CompPlugin *p,
		 CompCore   *c)
{
    InotifyCore   *ic;
    CompFileWatch *fw;

    if (!checkPluginABI ("core", CORE_ABIVERSION))
	return FALSE;

    ic = malloc (sizeof (InotifyCore));
    if (!ic)
	return FALSE;

    ic->fd = inotify_init ();
    if (ic->fd < 0)
    {
	perror ("inotify_init");
	free (ic);
	return FALSE;
    }

    ic->watch = NULL;

    ic->watchFdHandle = compAddWatchFd (ic->fd,
					POLLIN | POLLPRI | POLLHUP | POLLERR,
					inotifyProcessEvents,
					NULL);

    WRAP (ic, c, fileWatchAdded, inotifyFileWatchAdded);
    WRAP (ic, c, fileWatchRemoved, inotifyFileWatchRemoved);

    c->base.privates[corePrivateIndex].ptr = ic;

    for (fw = c->fileWatch; fw; fw = fw->next)
	inotifyFileWatchAdded (c, fw);

    return TRUE;
}

static void
inotifyFiniCore (CompPlugin *p,
		 CompCore   *c)
{
    CompFileWatch *fw;

    INOTIFY_CORE (c);

    compRemoveWatchFd (ic->watchFdHandle);

    for (fw = c->fileWatch; fw; fw = fw->next)
	inotifyFileWatchRemoved (c, fw);

    close (ic->fd);

    UNWRAP (ic, c, fileWatchAdded);
    UNWRAP (ic, c, fileWatchRemoved);

    free (ic);
}

static CompBool
inotifyInitObject (CompPlugin *p,
		   CompObject *o)
{
    static InitPluginObjectProc dispTab[] = {
	(InitPluginObjectProc) inotifyInitCore
    };

    RETURN_DISPATCH (o, dispTab, ARRAY_SIZE (dispTab), TRUE, (p, o));
}

static void
inotifyFiniObject (CompPlugin *p,
		   CompObject *o)
{
    static FiniPluginObjectProc dispTab[] = {
	(FiniPluginObjectProc) inotifyFiniCore
    };

    DISPATCH (o, dispTab, ARRAY_SIZE (dispTab), (p, o));
}

static Bool
inotifyInit (CompPlugin *p)
{
    if (!compInitPluginMetadataFromInfo (&inotifyMetadata, p->vTable->name,
					 0, 0, 0, 0))
	return FALSE;

    corePrivateIndex = allocateCorePrivateIndex ();
    if (corePrivateIndex < 0)
    {
	compFiniMetadata (&inotifyMetadata);
	return FALSE;
    }

    compAddMetadataFromFile (&inotifyMetadata, p->vTable->name);

    return TRUE;
}

static void
inotifyFini (CompPlugin *p)
{
    freeCorePrivateIndex (corePrivateIndex);
    compFiniMetadata (&inotifyMetadata);
}

static CompMetadata *
inotifyGetMetadata (CompPlugin *plugin)
{
    return &inotifyMetadata;
}

CompPluginVTable inotifyVTable = {
    "inotify",
    inotifyGetMetadata,
    inotifyInit,
    inotifyFini,
    inotifyInitObject,
    inotifyFiniObject,
    0, /* GetObjectOptions */
    0  /* SetObjectOption */
};

CompPluginVTable *
getCompPluginInfo20070830 (void)
{
    return &inotifyVTable;
}