/*
 *
 *  D-Bus++ - C++ bindings for D-Bus
 *
 *  Copyright (C) 2005-2007  Paolo Durante <shackan@gmail.com>
 *
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <dbus-c++/glib-integration.h>

#include <dbus/dbus.h> // for DBUS_WATCH_*

using namespace DBus;

Glib::BusTimeout::BusTimeout(Timeout::Internal *ti, GMainContext *ctx, int priority)
: Timeout(ti), _ctx(ctx), _priority(priority), _source(NULL)
{
	if (Timeout::enabled())
		_enable();
}

Glib::BusTimeout::~BusTimeout()
{
	_disable();
}

void Glib::BusTimeout::toggle()
{
	debug_log("glib: timeout %p toggled (%s)", this, Timeout::enabled() ? "on":"off");

	if (Timeout::enabled())	_enable();
	else			_disable();
}

gboolean Glib::BusTimeout::timeout_handler(gpointer data)
{
	Glib::BusTimeout *t = reinterpret_cast<Glib::BusTimeout *>(data);

	t->handle();

	return TRUE;
}

void Glib::BusTimeout::_enable()
{
	if (_source)
		_disable(); // be sane

	_source = g_timeout_source_new(Timeout::interval());
	g_source_set_priority(_source, _priority);
	g_source_set_callback(_source, timeout_handler, this, NULL);
	g_source_attach(_source, _ctx);
}

void Glib::BusTimeout::_disable()
{
	if (_source)
	{
		g_source_destroy(_source);
		_source = NULL;
	}
}

struct BusSource
{
	GSource source;
	GPollFD poll;
};

static gboolean watch_prepare(GSource *source, gint *timeout)
{
	//debug_log("glib: watch_prepare");

	*timeout = -1;
	return FALSE;
}

static gboolean watch_check(GSource *source)
{
	//debug_log("glib: watch_check");

	BusSource *io = (BusSource *)source;
	return io->poll.revents ? TRUE : FALSE;
}

static gboolean watch_dispatch(GSource *source, GSourceFunc callback, gpointer data)
{
	debug_log("glib: watch_dispatch");

	gboolean cb = callback(data);
	return cb;
}

static GSourceFuncs watch_funcs = {
	watch_prepare,
	watch_check,
	watch_dispatch,
	NULL
};

Glib::BusWatch::BusWatch(Watch::Internal *wi, GMainContext *ctx, int priority)
: Watch(wi), _ctx(ctx), _priority(priority), _source(NULL)
{
	if (Watch::enabled())
		_enable();
}

Glib::BusWatch::~BusWatch()
{
	_disable();
}

void Glib::BusWatch::toggle()
{
	debug_log("glib: watch %p toggled (%s)", this, Watch::enabled() ? "on":"off");

	if (Watch::enabled())	_enable();
	else			_disable();
}

gboolean Glib::BusWatch::watch_handler(gpointer data)
{
	Glib::BusWatch *w = reinterpret_cast<Glib::BusWatch *>(data);

	BusSource *io = (BusSource *)(w->_source);

	int flags = 0;
	if (io->poll.revents &G_IO_IN)
	     flags |= DBUS_WATCH_READABLE;
	if (io->poll.revents &G_IO_OUT)
	     flags |= DBUS_WATCH_WRITABLE;
	if (io->poll.revents &G_IO_ERR)
	     flags |= DBUS_WATCH_ERROR;
	if (io->poll.revents &G_IO_HUP)
	     flags |= DBUS_WATCH_HANGUP;

	w->handle(flags);

	return TRUE;
}

void Glib::BusWatch::_enable()
{
	if (_source)
		_disable(); // be sane
	_source = g_source_new(&watch_funcs, sizeof(BusSource));
	g_source_set_priority(_source, _priority);
	g_source_set_callback(_source, watch_handler, this, NULL);

	int flags = Watch::flags();
	int condition = 0;

	if (flags &DBUS_WATCH_READABLE)
		condition |= G_IO_IN;
	if (flags &DBUS_WATCH_WRITABLE)
		condition |= G_IO_OUT;
	if (flags &DBUS_WATCH_ERROR)
		condition |= G_IO_ERR;
	if (flags &DBUS_WATCH_HANGUP)
		condition |= G_IO_HUP;

	GPollFD *poll = &(((BusSource *)_source)->poll);
	poll->fd = Watch::descriptor();
	poll->events = condition;
	poll->revents = 0;

	g_source_add_poll(_source, poll);
	g_source_attach(_source, _ctx);
}

void Glib::BusWatch::_disable()
{
	if (!_source)
		return;
	GPollFD *poll = &(((BusSource *)_source)->poll);
	g_source_remove_poll(_source, poll);
	g_source_destroy(_source);
	_source = NULL;
}

/*
 * We need this on top of the IO handlers, because sometimes
 * there are messages to dispatch queued up but no IO pending.
 * (fixes also a previous problem of code not working in case of multiple dispatchers)
*/
struct DispatcherSource
{
	GSource source;
	Dispatcher *dispatcher;
};


static gboolean dispatcher_prepare(GSource *source, gint *timeout)
{
	Dispatcher *dispatcher = ((DispatcherSource*)source)->dispatcher;
  
  	*timeout = -1;

  	return dispatcher->has_something_to_dispatch()? TRUE:FALSE;
}

static gboolean dispatcher_check(GSource *source)
{
  	return FALSE;
}

static gboolean
dispatcher_dispatch(GSource *source,
                    GSourceFunc callback,
                    gpointer user_data)
{
  	Dispatcher *dispatcher = ((DispatcherSource*)source)->dispatcher;

	dispatcher->dispatch_pending();
  	return TRUE;
}

static const GSourceFuncs dispatcher_funcs = {
	dispatcher_prepare,
	dispatcher_check,
	dispatcher_dispatch,
	NULL
};

Glib::BusDispatcher::BusDispatcher()
: _ctx(NULL), _priority(G_PRIORITY_DEFAULT), _source(NULL)
{
}

Glib::BusDispatcher::~BusDispatcher()
{
	if (_source)
	{
		GSource *temp = _source;
		_source = NULL;

		g_source_destroy (temp);
		g_source_unref (temp);
	}

	if (_ctx)
		g_main_context_unref(_ctx);
}

void Glib::BusDispatcher::attach(GMainContext *ctx)
{
	g_assert(_ctx == NULL); // just to be sane

	_ctx = ctx ? ctx : g_main_context_default();
 	g_main_context_ref(_ctx);
	
	// create the source for dispatching messages
	_source = g_source_new((GSourceFuncs *) &dispatcher_funcs,
	                       sizeof(DispatcherSource));

	((DispatcherSource*)_source)->dispatcher = this;
	g_source_attach (_source, _ctx);
}

Timeout *Glib::BusDispatcher::add_timeout(Timeout::Internal *wi)
{
	Timeout *t = new Glib::BusTimeout(wi, _ctx, _priority);

	debug_log("glib: added timeout %p (%s)", t, t->enabled() ? "on":"off");

	return t;
}

void Glib::BusDispatcher::rem_timeout(Timeout *t)
{
	debug_log("glib: removed timeout %p", t);

	delete t;
}

Watch *Glib::BusDispatcher::add_watch(Watch::Internal *wi)
{
	Watch *w = new Glib::BusWatch(wi, _ctx, _priority);

	debug_log("glib: added watch %p (%s) fd=%d flags=%d",
		w, w->enabled() ? "on":"off", w->descriptor(), w->flags()
	);
	return w;
}

void Glib::BusDispatcher::rem_watch(Watch *w)
{
	debug_log("glib: removed watch %p", w);

	delete w;
}

void Glib::BusDispatcher::set_priority(int priority)
{
	_priority = priority;
}