/* GStreamer
 * Copyright (C) 1999,2000,2001,2002 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000,2001,2002 Wim Taymans <wtay@chello.be>
 *                              2002 Steve Baker <steve@stevebaker.org>
 *								2003 Julien Moutte <julien@moutte.net>
 *
 * play.c: GstPlay object code
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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.
 */

#include "play.h"

enum {
	STREAM_END,
	INFORMATION,
	STATE_CHANGE,
	STREAM_LENGTH,
	TIME_TICK,
	HAVE_XID,
	HAVE_VIS_XID,
	HAVE_VIDEO_SIZE,
	LAST_SIGNAL,
};

/* this struct is used to decouple signals coming out of threaded pipelines */

typedef struct _GstPlaySignal    GstPlaySignal;

struct _GstPlaySignal
{
	gint signal_id;
	union {
		struct {
			gint width;
			gint height;
		} video_size;
		struct {
			gint xid;
		} video_xid;
		struct {
			GstElementState old_state;
			GstElementState new_state;
		} state;
		struct {
			GstElement* element;
			GParamSpec* param;
		} info;
	} signal_data;
};

enum
{
	ARG_0,
	ARG_LOCATION,
	ARG_VOLUME,
	ARG_MUTE,
	/* FILL ME */
};

static guint gst_play_signals [LAST_SIGNAL] = { 0 };

static GstElementClass *parent_class = NULL;

/* ============================================================= */
/*                                                               */
/*                       Private Methods                         */
/*                                                               */
/* ============================================================= */

/* =========================================== */
/*                                             */
/*                  Tool Box                   */
/*                                             */
/* =========================================== */

static GQuark
gst_play_error_quark (void)
{
	static GQuark quark = 0;
	if (quark == 0) {
		quark = g_quark_from_static_string ("gst-play-error-quark");
	}

	return quark;
}

/* GError creation when plugin is missing
 * If we want to make error messages less
 * generic and have more errors than only
 * plug-ins, move the message creation to the switch */
static void
gst_play_error_plugin (	GstPlayError type,
						GError **error)
{
        gchar *name;

        if (error == NULL) return;

        switch (type)
        {
                case GST_PLAY_ERROR_THREAD:
                        name = g_strdup ("thread");
                        break;
                case GST_PLAY_ERROR_QUEUE:
                        name = g_strdup ("queue");
                        break;
                case GST_PLAY_ERROR_FAKESINK:
                        name = g_strdup ("fakesink");
                        break;
                case GST_PLAY_ERROR_VOLUME:
                        name = g_strdup ("volume");
                        break;
                case GST_PLAY_ERROR_COLORSPACE:
                        name = g_strdup ("colorspace");
                        break;
                case GST_PLAY_ERROR_GNOMEVFSSRC:
                        name = g_strdup ("gnomevfssrc");
                        break;
                default:
                        name = g_strdup ("unknown");
                        break;
        }
		
        *error = g_error_new (	GST_PLAY_ERROR,
								type,
								"The %s plug-in could not be found. "
								"This plug-in is essential for gst-player. "
								"Please install it and verify that it works "
								"by running 'gst-inspect %s'",
								name, name);
        g_free (name);
        return;
}

static void
gst_play_set_property (	GObject *object,
						guint prop_id,
						const GValue *value,
						GParamSpec *pspec)
{
	GstPlay *play;
	g_return_if_fail (object != NULL);
	g_return_if_fail (GST_IS_PLAY (object));
	play = GST_PLAY (object);
	
	switch (prop_id) {
	case ARG_LOCATION:
		gst_play_set_location(play, g_value_get_string (value));
		break;
	case ARG_VOLUME:
		gst_play_set_volume(play, g_value_get_float (value));
		break;
	case ARG_MUTE:
		gst_play_set_mute(play, g_value_get_boolean (value));
		break;
	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
		break;
	}
}

static void
gst_play_get_property (	GObject *object,
						guint prop_id,
						GValue *value,
						GParamSpec *pspec)
{
	GstPlay *play;
	g_return_if_fail (object != NULL);
	g_return_if_fail (GST_IS_PLAY (object));
	play = GST_PLAY (object);

	switch (prop_id) {
	case ARG_LOCATION:
		g_value_set_string (value, gst_play_get_location(play));
		break;
	case ARG_VOLUME:
		g_value_set_float(value, gst_play_get_volume(play));
		break;
	case ARG_MUTE:
		g_value_set_boolean (value, gst_play_get_mute(play));
		break;
	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
		break;
	}
}

/* =========================================== */
/*                                             */
/*          Event Handlers, Callbacks          */
/*                                             */
/* =========================================== */

static gboolean
gst_play_get_length_callback (GstPlay *play)
{
	gint64 value;
	GstFormat format = GST_FORMAT_TIME;
	gboolean query_worked = FALSE;

	g_print("trying to get length\n");
	if (	(play->audio_sink_element != NULL) &&
			(GST_IS_ELEMENT (play->audio_sink_element)) ) {
		g_mutex_lock(play->audio_bin_mutex);
		query_worked = gst_element_query (play->audio_sink_element, GST_QUERY_TOTAL, &format, &value);
		g_mutex_unlock(play->audio_bin_mutex);
	}
	else if (	(play->video_sink_element != NULL) &&
				(GST_IS_ELEMENT (play->video_sink_element)) ) {
		g_mutex_lock(play->video_bin_mutex);
		query_worked = gst_element_query (play->video_sink_element, GST_QUERY_TOTAL, &format, &value);
		g_mutex_unlock(play->video_bin_mutex);
	}
	if (query_worked){
		g_print("got length %" G_GINT64_FORMAT "\n", value);
		g_signal_emit (G_OBJECT (play), gst_play_signals [STREAM_LENGTH], 0, value);
		play->length_nanos = value;
		return FALSE;
	}
	else {
		if (play->get_length_attempt-- < 1){
			/* we've tried enough times, give up */
			return FALSE;
		}
	}
	return (gst_element_get_state(play->pipeline) == GST_STATE_PLAYING);
}

static gboolean
gst_play_tick_callback (GstPlay *play)
{
	gint secs;
	
	g_return_val_if_fail (play != NULL, FALSE); 
	g_return_val_if_fail (GST_IS_PLAY(play), FALSE);
	
	play->clock = gst_bin_get_clock (GST_BIN (play->pipeline));
	play->time_nanos = gst_clock_get_time(play->clock);
	secs = (gint) (play->time_nanos / GST_SECOND);
	if (secs != play->time_seconds){
		play->time_seconds = secs;
		g_signal_emit (G_OBJECT (play), gst_play_signals [TIME_TICK], 0, play->time_nanos);
	}

	return (gst_element_get_state(play->pipeline) == GST_STATE_PLAYING);
}

static gboolean
gst_play_default_idle (GstPlayIdleData *idle_data)
{
	if(idle_data->func(idle_data->data)){
		/* call this function again in the future */
		return TRUE;
	}
	/* this function should no longer be called */
	g_free(idle_data);
	return FALSE;
}

static guint
gst_play_default_timeout_add (	guint interval,
								GSourceFunc function,
								gpointer data)
{
	GstPlayIdleData *idle_data = g_new0(GstPlayIdleData, 1);
	idle_data->func = function;
	idle_data->data = data;

	return g_timeout_add (interval, (GSourceFunc)gst_play_default_idle, idle_data);
}

static guint
gst_play_default_idle_add (	GSourceFunc function,
							gpointer data)
{
	GstPlayIdleData *idle_data = g_new0(GstPlayIdleData, 1);
	idle_data->func = function;
	idle_data->data = data;
	
	return g_idle_add ((GSourceFunc)gst_play_default_idle, idle_data);
}

static gboolean
gst_play_idle_callback (GstPlay *play)
{
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY(play), FALSE);
	
	return gst_bin_iterate (GST_BIN (play->pipeline));
}

static gboolean
gst_play_idle_signal (GstPlay *play)
{
	GstPlaySignal *signal;
	gint queue_length;
	
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY(play), FALSE);
	
	signal = g_async_queue_try_pop(play->signal_queue);
	if (signal == NULL){
		return FALSE;
	}

	switch (signal->signal_id){
	case HAVE_XID:
		g_signal_emit (G_OBJECT (play), gst_play_signals[HAVE_XID], 0,
		               signal->signal_data.video_xid.xid);
		break;
	case HAVE_VIS_XID:
		g_signal_emit (G_OBJECT (play), gst_play_signals[HAVE_VIS_XID], 0,
		               signal->signal_data.video_xid.xid);
		break;
	case HAVE_VIDEO_SIZE:
		g_signal_emit (G_OBJECT (play), gst_play_signals[HAVE_VIDEO_SIZE], 0, 
		               signal->signal_data.video_size.width, signal->signal_data.video_size.height);
		break;
	case STATE_CHANGE:
		g_signal_emit (G_OBJECT (play), gst_play_signals[STATE_CHANGE], 0, 
		               signal->signal_data.state.old_state, signal->signal_data.state.new_state);
		break;
	case INFORMATION:
		g_signal_emit (G_OBJECT (play), gst_play_signals[INFORMATION], 0, 
		               signal->signal_data.info.element, signal->signal_data.info.param);
		break;
	default:
		break;
	}

	g_free(signal);
	queue_length = g_async_queue_length (play->signal_queue);
		
	return (queue_length > 0);
}

static gboolean
gst_play_idle_eos (GstPlay* play)
{
	g_signal_emit (G_OBJECT (play), gst_play_signals [STREAM_END], 0);
	return FALSE;
}

static void
callback_audio_sink_eos (	GstElement *element,
							GstPlay *play)
{
	play->idle_add_func ((GSourceFunc) gst_play_idle_eos, play);
}

static void
callback_video_have_xid (	GstElement *element,
							gint xid,
							GstPlay *play)
{
	GstPlaySignal *signal;
	
	signal = g_new0(GstPlaySignal, 1);
	signal->signal_id = HAVE_XID;
	signal->signal_data.video_xid.xid = xid;
	
	g_async_queue_push(play->signal_queue, signal);
	
	play->idle_add_func ((GSourceFunc) gst_play_idle_signal, play);
}

static void
callback_video_have_vis_xid (	GstElement *element,
								gint xid,
								GstPlay *play)
{
	GstPlaySignal *signal;
	
	signal = g_new0(GstPlaySignal, 1);
	signal->signal_id = HAVE_VIS_XID;
	signal->signal_data.video_xid.xid = xid;
	
	g_async_queue_push(play->signal_queue, signal);
	
	play->idle_add_func ((GSourceFunc) gst_play_idle_signal, play);
}

static void
callback_video_have_size (	GstElement *element,
							gint width,
							gint height,
							GstPlay *play)
{
	GstPlaySignal *signal;
	
	signal = g_new0(GstPlaySignal, 1);
	signal->signal_id = HAVE_VIDEO_SIZE;
	signal->signal_data.video_size.width = width;
	signal->signal_data.video_size.height = height;
	
	g_async_queue_push(play->signal_queue, signal);
	
	play->idle_add_func ((GSourceFunc) gst_play_idle_signal, play);
}

static void 
callback_bin_pre_iterate (	GstBin *bin,
							GMutex *mutex)
{
	g_mutex_lock(mutex);
}

static void 
callback_bin_post_iterate (	GstBin *bin,
							GMutex *mutex)
{
	g_mutex_unlock(mutex);
}

static void
callback_pipeline_error (	GObject *object,
							GstObject *orig,
							gchar *error,
							GstPlay* play)
{ 
	g_print ("Pipeline error: %s\n", error);
	if (gst_element_get_state(play->pipeline) == GST_STATE_PLAYING)
		gst_element_set_state(play->pipeline, GST_STATE_READY);
} 

static void
callback_pipeline_deep_notify (	GstElement *element,
								GstElement *orig,
								GParamSpec *param,
								GstPlay* play)
{
	GstPlaySignal *signal;
	
	signal = g_new0(GstPlaySignal, 1);
	signal->signal_id = INFORMATION;
	signal->signal_data.info.element = orig;
	signal->signal_data.info.param = param;
	
	g_async_queue_push(play->signal_queue, signal);
	
	play->idle_add_func ((GSourceFunc) gst_play_idle_signal, play);
}

static void
callback_pipeline_state_change (	GstElement *element,
									GstElementState old,
									GstElementState state,
									GstPlay* play)
{
	GstPlaySignal *signal;

	g_return_if_fail (play != NULL);
	g_return_if_fail (element != NULL);
	g_return_if_fail (GST_IS_ELEMENT (element));
	g_return_if_fail (GST_IS_PLAY (play));
	g_return_if_fail (element == play->pipeline);

	/*g_print ("got state change %s to %s\n", gst_element_state_get_name (old), gst_element_state_get_name (state));*/

	/* do additional stuff depending on state */
	if (GST_IS_PIPELINE (play->pipeline)){
		switch (state) {
		case GST_STATE_PLAYING:
			play->idle_add_func (	(GSourceFunc) gst_play_idle_callback,
									play);
			play->timeout_add_func (	200,
										(GSourceFunc) gst_play_tick_callback,
										play);
			if (play->length_nanos == 0LL){
				/* try to get the length up to 16 times */
				play->get_length_attempt = 16;
				play->timeout_add_func (200, (GSourceFunc) gst_play_get_length_callback, play); 
			}
			break;
		default:
			break;
		}
	}	
	signal = g_new0(GstPlaySignal, 1);
	signal->signal_id = STATE_CHANGE;
	signal->signal_data.state.old_state = old;
	signal->signal_data.state.new_state = state;

	g_async_queue_push(play->signal_queue, signal);

	play->idle_add_func ((GSourceFunc) gst_play_idle_signal, play);
}

/* split static pipeline functions to a seperate file */
#include "playpipelines.c"

/* =========================================== */
/*                                             */
/*              Init & Class init              */
/*                                             */
/* =========================================== */

static void
gst_play_dispose (GObject *object)
{
	g_return_if_fail (object != NULL);
	g_return_if_fail (GST_IS_PLAY(object));
	GstPlay *play = GST_PLAY (object);

	/* Removing all sources */
	while (g_source_remove_by_user_data (play));
		
	G_OBJECT_CLASS (parent_class)->dispose (object);
	g_mutex_free(play->audio_bin_mutex);
	g_mutex_free(play->video_bin_mutex);
}

static void
gst_play_class_init (GstPlayClass *klass)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  
	parent_class = g_type_class_ref(GST_TYPE_OBJECT);

	klass->information = NULL;
	klass->state_changed = NULL;
	klass->stream_end = NULL;
  
	gobject_class->dispose = gst_play_dispose;
	gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_play_set_property);
	gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_play_get_property);

	g_object_class_install_property (
			gobject_class,
			ARG_LOCATION,
			g_param_spec_string (
						"location",
						"location of file", 
						"location of the file to play",
						NULL, G_PARAM_READWRITE));
	
	g_object_class_install_property (
			gobject_class,
			ARG_VOLUME,
			g_param_spec_float (
						"volume",
						"Playing volume", 
			            "Playing volume", 
						0, 1.0, 0, G_PARAM_READWRITE));
						
	g_object_class_install_property (
			gobject_class,
			ARG_MUTE,
			g_param_spec_boolean (
						"mute",
						"Volume muted",
						"Playing volume muted",
						FALSE, G_PARAM_READWRITE));
  
	gst_play_signals [INFORMATION] = 
		g_signal_new ("information", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, information), 
			      NULL, NULL,
			      gst_marshal_VOID__OBJECT_PARAM, 
			      G_TYPE_NONE, 2, 
			      G_TYPE_OBJECT, G_TYPE_PARAM);
	
	gst_play_signals [STATE_CHANGE] = 
		g_signal_new ("state_change", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, state_changed), 
			      NULL, NULL,
			      gst_marshal_VOID__INT_INT,
			      G_TYPE_NONE, 2, 
			      G_TYPE_INT, G_TYPE_INT);
	
	gst_play_signals [STREAM_END] =
		g_signal_new ("stream_end",
			      G_TYPE_FROM_CLASS (klass),
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, stream_end),
			      NULL, NULL,
			      gst_marshal_VOID__VOID,
			      G_TYPE_NONE, 0);

	gst_play_signals [TIME_TICK] = 
		g_signal_new ("time_tick", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, time_tick), 
			      NULL, NULL,
			      gst_marshal_VOID__INT64,
			      G_TYPE_NONE, 1, 
			      G_TYPE_INT64);

	gst_play_signals [STREAM_LENGTH] = 
		g_signal_new ("stream_length", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, stream_length), 
			      NULL, NULL,
			      gst_marshal_VOID__INT64,
			      G_TYPE_NONE, 1, 
			      G_TYPE_INT64);

	gst_play_signals [HAVE_XID] = 
		g_signal_new ("have_xid", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, have_xid), 
			      NULL, NULL,
			      gst_marshal_VOID__INT,
			      G_TYPE_NONE, 1, 
			      G_TYPE_INT);
				  
	gst_play_signals [HAVE_VIS_XID] = 
		g_signal_new ("have_vis_xid", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, have_vis_xid), 
			      NULL, NULL,
			      gst_marshal_VOID__INT,
			      G_TYPE_NONE, 1, 
			      G_TYPE_INT);

	gst_play_signals [HAVE_VIDEO_SIZE] = 
		g_signal_new ("have_video_size", 
			      G_TYPE_FROM_CLASS (klass), 
			      G_SIGNAL_RUN_FIRST,
			      G_STRUCT_OFFSET (GstPlayClass, have_video_size), 
			      NULL, NULL,
			      gst_marshal_VOID__INT_INT,
			      G_TYPE_NONE, 2, 
			      G_TYPE_INT, G_TYPE_INT);

	gst_control_init(NULL,NULL);
}



static void 
gst_play_init (GstPlay *play) 
{
	play->pipeline				= NULL;
	play->source				= NULL;
	play->autoplugger			= NULL;
	play->audio_sink			= NULL;
	play->audio_sink_element	= NULL;
	play->video_sink			= NULL;
	play->video_sink_element	= NULL;
	play->volume				= NULL;
	play->other_elements		= g_hash_table_new(g_str_hash, g_str_equal);
	play->audio_bin_mutex		= g_mutex_new();
	play->video_bin_mutex		= g_mutex_new();
	
	gst_play_set_idle_timeout_funcs(	play,
										gst_play_default_timeout_add,
										gst_play_default_idle_add);
}

/* ============================================================= */
/*                                                               */
/*                       Public Methods                          */
/*                                                               */
/* ============================================================= */

/* =========================================== */
/*                                             */
/*                   Toolbox                   */
/*                                             */
/* =========================================== */

/**
 * gst_play_seek_to_time:
 * @play: a #GstPlay.
 * @time_nanos: a #gint64 indicating a time position.
 *
 * Performs a seek on @play until @time_nanos.
 */
void
gst_play_seek_to_time (	GstPlay *play,
						gint64 time_nanos)
{
	GstEvent *s_event;
        guint8   prev_state;
	gboolean audio_seek_worked = FALSE;
	gboolean video_seek_worked = FALSE;
	gboolean visualisation_seek_worked = FALSE;

	g_return_if_fail (play != NULL);
	g_return_if_fail (GST_IS_PLAY (play));
	if (time_nanos < 0LL){
		play->seek_time = 0LL;
	}
	else if (time_nanos < 0LL){
		play->seek_time = play->length_nanos;
	}
	else {
		play->seek_time = time_nanos;
	}

	/*g_print("doing seek to %lld\n", play->seek_time);*/
        prev_state = GST_STATE(play->pipeline);
	gst_element_set_state(play->pipeline, GST_STATE_PAUSED);

	s_event = gst_event_new_seek (GST_FORMAT_TIME |
	                              GST_SEEK_METHOD_SET |
	                              GST_SEEK_FLAG_FLUSH, play->seek_time);
	if (play->audio_sink_element != NULL){
		gst_event_ref (s_event);
		audio_seek_worked = gst_element_send_event (
										play->audio_sink_element, s_event);
	}
	if (play->visualisation_sink_element != NULL){
		gst_event_ref (s_event);
		visualisation_seek_worked = gst_element_send_event (
										play->visualisation_sink_element, s_event);
	}
	if (play->video_sink_element != NULL){
		gst_event_ref (s_event);
		video_seek_worked = gst_element_send_event (
										play->video_sink_element, s_event);
	}
	gst_event_unref (s_event);

	if (audio_seek_worked || video_seek_worked){
		play->time_nanos = gst_clock_get_time(play->clock);
		g_signal_emit (G_OBJECT (play), gst_play_signals [TIME_TICK], 0, play->time_nanos);
	}
	gst_element_set_state(play->pipeline, prev_state);
}

/**
 * gst_play_need_new_video_window:
 * @play: a #GstPlay.
 *
 * Request a new video window for @play.
 */
void
gst_play_need_new_video_window (GstPlay *play)
{
	g_return_if_fail (play != NULL);
	g_return_if_fail (GST_IS_PLAY (play));
	if (GST_IS_ELEMENT(play->video_sink_element)){
		g_object_set(	G_OBJECT(play->video_sink_element),
						"need_new_window", TRUE, NULL);
	}
	if (GST_IS_ELEMENT(play->visualisation_sink_element)){
		g_object_set(	G_OBJECT(play->visualisation_sink_element),
						"need_new_window", TRUE, NULL);
	}
}

void
gst_play_set_idle_timeout_funcs (	GstPlay *play,
									GstPlayTimeoutAdd timeout_add_func,
									GstPlayIdleAdd idle_add_func)
{
	g_return_if_fail (play != NULL);
	g_return_if_fail (GST_IS_PLAY (play));
	play->timeout_add_func = timeout_add_func;
	play->idle_add_func = idle_add_func;
}

/**
 * gst_play_get_sink_element:
 * @play: a #GstPlay.
 * @element: a #GstElement.
 * @sink_type: a #GstPlaySinkType.
 *
 * Searches recursively for a sink #GstElement with
 * type @sink_type in @element which is supposed to be a #GstBin.
 *
 * Returns: the sink #GstElement of @element.
 */
GstElement*
gst_play_get_sink_element (	GstPlay *play,
							GstElement *element,
							GstPlaySinkType sink_type)
{
	GList *elements = NULL;
	const GList *pads = NULL;
	gboolean has_src, has_correct_type;

	g_return_val_if_fail (play != NULL, NULL);
	g_return_val_if_fail (element != NULL, NULL);
	g_return_val_if_fail (GST_IS_PLAY (play), NULL);
	g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);

	if (!GST_IS_BIN(element)){
		/* since its not a bin, we'll presume this 
		 * element is a sink element */		
		return element;
	}
	
	elements = (GList *) gst_bin_get_list (GST_BIN(element));
	
	/* traverse all elements looking for a src pad */
	
	while (elements) {
		
		element = GST_ELEMENT (elements->data);
		
		/* Recursivity :) */
		
		if (GST_IS_BIN(element)) {
			element = gst_play_get_sink_element(play,element,sink_type);
			if (GST_IS_ELEMENT (element)) {
				return element;
			}
		}
		else {
		
			pads = gst_element_get_pad_list (element);
			has_src = FALSE;
			has_correct_type = FALSE;
			while (pads) {
				/* check for src pad */
				if (GST_PAD_DIRECTION (GST_PAD (pads->data)) == GST_PAD_SRC) {
					has_src = TRUE;
					break;
				}
				else {
					/* If not a src pad checking caps */
					GstCaps *caps;
					caps = gst_pad_get_caps (GST_PAD (pads->data));
					while (caps) {
						gboolean has_video_cap = FALSE, has_audio_cap = FALSE;
						if (g_ascii_strcasecmp(	gst_caps_get_mime (caps),
														"audio/raw") == 0)
						{
							has_audio_cap = TRUE;
						}
						if (g_ascii_strcasecmp(	gst_caps_get_mime (caps),
														"video/raw") == 0)
						{
							has_video_cap = TRUE;
						}
					
						switch (sink_type) {
							case GST_PLAY_SINK_TYPE_AUDIO:
								if (has_audio_cap)
									has_correct_type = TRUE;
								break;;
							case GST_PLAY_SINK_TYPE_VIDEO:
								if (has_video_cap)
									has_correct_type = TRUE;
								break;;
							case GST_PLAY_SINK_TYPE_ANY:
								if ( (has_video_cap) || (has_audio_cap) )
									has_correct_type = TRUE;
								break;;
							default:
								has_correct_type = FALSE;
						}
						caps = caps->next;
					}
				}
				pads = g_list_next (pads);
			}
			if ( (!has_src) && (has_correct_type) ){
				return element;
			}
		}
		elements = g_list_next (elements);
	}
	/* we didn't find a sink element */
	return NULL;
}

/* =========================================== */
/*                                             */
/*      State, Mute, Volume, Location          */
/*                                             */
/* =========================================== */

/**
 * gst_play_set_state:
 * @play: a #GstPlay.
 * @state: a #GstElementState.
 *
 * Set state of @play 's pipeline to @state.
 *
 * Returns: a #GstElementStateReturn indicating if the operation succeeded.
 */
GstElementStateReturn
gst_play_set_state (	GstPlay *play,
						GstElementState state)
{
	g_return_val_if_fail (play != NULL, GST_STATE_FAILURE);
	g_return_val_if_fail (GST_IS_PLAY (play), GST_STATE_FAILURE);
	g_return_val_if_fail (GST_IS_ELEMENT(play->pipeline), GST_STATE_FAILURE);

	return gst_element_set_state(play->pipeline, state);
}

/**
 * gst_play_get_state:
 * @play: a #GstPlay.
 *
 * Get state of @play 's pipeline.
 *
 * Returns: a #GstElementState indicating @play 's pipeline current state.
 */
GstElementState
gst_play_get_state (GstPlay *play)
{
	g_return_val_if_fail (play != NULL, GST_STATE_FAILURE);
	g_return_val_if_fail (GST_IS_PLAY (play), GST_STATE_FAILURE);
	g_return_val_if_fail (play->pipeline, GST_STATE_FAILURE);

	return gst_element_get_state(play->pipeline);
}

/**
 * gst_play_set_location:
 * @play: a #GstPlay.
 * @location: a const #gchar indicating location to play
 *
 * Set location of @play to @location.
 *
 * Returns: TRUE if location was set successfully.
 */
gboolean
gst_play_set_location (	GstPlay *play,
						const gchar *location)
{
	GstElementState current_state;
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY (play), FALSE);
	g_return_val_if_fail (location != NULL, FALSE);

	current_state = gst_play_get_state (play);
	if (current_state != GST_STATE_READY){
		gst_play_set_state (play, GST_STATE_READY);
	}

	if (play->set_autoplugger){
		if (! play->set_autoplugger(play, gst_element_factory_make ("spider", "autoplugger"))){
			g_warning ("couldn't replace autoplugger\n");
			return FALSE;
		}
	}

	/* FIXME check for valid location (somehow) */
	g_object_set (G_OBJECT (play->source), "location", location, NULL);

	/* reset time/length values */
	play->time_seconds = 0;
	play->length_nanos = 0LL;
	play->time_nanos = 0LL;
	g_signal_emit (G_OBJECT (play), gst_play_signals [STREAM_LENGTH], 0, 0LL);
	g_signal_emit (G_OBJECT (play), gst_play_signals [TIME_TICK], 0, 0LL);
	play->need_stream_length = TRUE;

	return TRUE;
}

/**
 * gst_play_get_location:
 * @play: a #GstPlay.
 *
 * Get current location of @play.
 *
 * Returns: a #gchar pointer to current location.
 */
gchar*
gst_play_get_location (GstPlay *play)
{
	gchar* location;
	g_return_val_if_fail (play != NULL, NULL);
	g_return_val_if_fail (GST_IS_PLAY (play), NULL);
	g_return_val_if_fail (GST_IS_ELEMENT(play->source), NULL);
	g_object_get (G_OBJECT (play->source), "location", &location, NULL);
	return location;
}

/**
 * gst_play_set_volume:
 * @play: a #GstPlay.
 * @volume: a #gfloat indicating volume level.
 *
 * Set current volume of @play.
 */
void
gst_play_set_volume (	GstPlay *play,
						gfloat volume)
{
	g_return_if_fail (play != NULL);
	g_return_if_fail (GST_IS_PLAY (play));

	g_object_set(G_OBJECT(play->vol_dparam), "value_float", volume, NULL);
}

/**
 * gst_play_get_volume:
 * @play: a #GstPlay.
 *
 * Get current volume of @play.
 *
 * Returns: a #gfloat indicating current volume level.
 */
gfloat
gst_play_get_volume (GstPlay *play)
{
	gfloat volume;

	g_return_val_if_fail (play != NULL, 0);
	g_return_val_if_fail (GST_IS_PLAY (play), 0);

	g_object_get(G_OBJECT(play->vol_dparam), "value_float", &volume, NULL);

	return volume;
}

/**
 * gst_play_set_mute:
 * @play: a #GstPlay.
 * @mute: a #gboolean indicating wether audio is muted or not.
 *
 * Mutes/Unmutes audio playback of @play.
 */
void
gst_play_set_mute (	GstPlay *play,
					gboolean mute)
{
	g_return_if_fail (play != NULL);
	g_return_if_fail (GST_IS_PLAY (play));

	g_object_set (G_OBJECT (play->volume), "mute", mute, NULL);
}

/**
 * gst_play_get_mute:
 * @play: a #GstPlay.
 *
 * Get current muted status of @play.
 *
 * Returns: a #gboolean indicating if audio is muted or not.
 */
gboolean
gst_play_get_mute (GstPlay *play)
{
	gboolean mute;

	g_return_val_if_fail (play != NULL, 0);
	g_return_val_if_fail (GST_IS_PLAY (play), 0);

	g_object_get (G_OBJECT (play->volume), "mute", &mute, NULL);

	return mute;
}

/* =========================================== */
/*                                             */
/*    Audio sink, Video sink, Data src         */
/*                                             */
/* =========================================== */

/**
 * gst_play_set_data_src:
 * @play: a #GstPlay.
 * @data_src: a #GstElement.
 *
 * Set @data_src as the source element of @play.
 *
 * Returns: TRUE if call succeeded.
 */
gboolean
gst_play_set_data_src (	GstPlay *play,
						GstElement *data_src)
{
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (data_src != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY (play), FALSE);
	g_return_val_if_fail (GST_IS_ELEMENT (data_src), FALSE);

	if (gst_play_get_state (play) != GST_STATE_READY){
		gst_play_set_state (play, GST_STATE_READY);
	}

	if (play->set_data_src){
		return play->set_data_src(play, data_src);
	}

	/* if there is no set_data_src func, fail quietly */
	return FALSE;
}

/**
 * gst_play_set_video_sink:
 * @play: a #GstPlay.
 * @video_sink: a #GstElement.
 *
 * Set @video_sink as the video sink element of @play.
 *
 * Returns: TRUE if call succeeded.
 */
gboolean
gst_play_set_video_sink (	GstPlay *play,
							GstElement *video_sink)
{
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (video_sink != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY (play), FALSE);
	g_return_val_if_fail (GST_IS_ELEMENT (video_sink), FALSE);

	if (gst_play_get_state (play) != GST_STATE_READY){
		gst_play_set_state (play, GST_STATE_READY);
	}

	if (play->set_video_sink){
		return play->set_video_sink(play, video_sink);
	}

	/* if there is no set_video_sink func, fail quietly */
	return FALSE;
}

/**
 * gst_play_set_audio_sink:
 * @play: a #GstPlay.
 * @audio_sink: a #GstElement.
 *
 * Set @audio_sink as the audio sink element of @play.
 *
 * Returns: TRUE if call succeeded.
 */
gboolean
gst_play_set_audio_sink (	GstPlay *play,
							GstElement *audio_sink)
{
	g_return_val_if_fail (play != NULL, FALSE);
	g_return_val_if_fail (audio_sink != NULL, FALSE);
	g_return_val_if_fail (GST_IS_PLAY (play), FALSE);
	g_return_val_if_fail (GST_IS_ELEMENT (audio_sink), FALSE);

	if (gst_play_get_state (play) != GST_STATE_READY){
		gst_play_set_state (play, GST_STATE_READY);
	}

	if (play->set_audio_sink){
		return play->set_audio_sink(play, audio_sink);
	}

	/* if there is no set_audio_sink func, fail quietly */
	return FALSE;
}

/* =========================================== */
/*                                             */
/*          Object typing & Creation           */
/*                                             */
/* =========================================== */

GType
gst_play_get_type (void)
{
	static GType play_type = 0;
	
	if (!play_type)
	{
		static const GTypeInfo play_info = {
			sizeof (GstPlayClass),
			(GBaseInitFunc) NULL,
			(GBaseFinalizeFunc) NULL,
			(GClassInitFunc) gst_play_class_init,
			NULL, NULL, sizeof (GstPlay),
			0, (GInstanceInitFunc) gst_play_init,
			NULL
		};
      
		play_type = g_type_register_static (G_TYPE_OBJECT, "GstPlay", &play_info, 0);
	}

	return play_type;
}


GstPlay *
gst_play_new (	GstPlayPipeType pipe_type,
				GError **error)
{
	GstPlay *play;

	play = g_object_new (GST_TYPE_PLAY, NULL);

	/* FIXME: looks like only VIDEO ever gets used ! */
	switch (pipe_type){
		case GST_PLAY_PIPE_VIDEO:
			play->setup_pipeline = gst_play_video_setup;
			play->teardown_pipeline = NULL;
			play->set_data_src = gst_play_video_set_data_src;
			play->set_autoplugger = gst_play_video_set_auto;
			play->set_video_sink = gst_play_video_set_video;
			play->set_audio_sink = gst_play_video_set_audio;
			break;
		case GST_PLAY_PIPE_VIDEO_VISUALISATION:
			play->setup_pipeline = gst_play_video_vis_setup;
			play->teardown_pipeline = NULL;
			play->set_data_src = gst_play_video_set_data_src;
			play->set_autoplugger = gst_play_video_set_auto;
			play->set_video_sink = gst_play_video_vis_set_video;
			play->set_audio_sink = gst_play_video_vis_set_audio;
			break;
		case GST_PLAY_PIPE_AUDIO:
			/* we can reuse the threaded set functions */
			play->setup_pipeline = gst_play_audio_setup;
			play->teardown_pipeline = NULL;
			play->set_data_src = gst_play_simple_set_data_src;
			play->set_autoplugger = gst_play_audiot_set_auto;
			play->set_video_sink = NULL;
			play->set_audio_sink = gst_play_audiot_set_audio;
			break;
		case GST_PLAY_PIPE_AUDIO_THREADED:
			play->setup_pipeline = gst_play_audiot_setup;
			play->teardown_pipeline = NULL;
			play->set_data_src = gst_play_simple_set_data_src;
			play->set_autoplugger = gst_play_audiot_set_auto;
			play->set_video_sink = NULL;
			play->set_audio_sink = gst_play_audiot_set_audio;
			break;
		case GST_PLAY_PIPE_AUDIO_HYPER_THREADED:
			play->setup_pipeline = gst_play_audioht_setup;
			play->teardown_pipeline = NULL;
			play->set_data_src = gst_play_simple_set_data_src;
			play->set_autoplugger = gst_play_audioht_set_auto;
			play->set_video_sink = NULL;
			play->set_audio_sink = gst_play_audioht_set_audio;
			break;
		default:
			g_warning("unknown pipeline type: %d\n", pipe_type);
	}

	/* init pipeline */
	if ((play->setup_pipeline) &&
	    (! play->setup_pipeline (play, error)))
	{
		g_object_unref (play);
		return NULL;
	}


	if (play->pipeline) {
		/* connect to pipeline events */
		g_signal_connect (	G_OBJECT (play->pipeline),
							"deep_notify",
							G_CALLBACK (callback_pipeline_deep_notify),
							play);
		g_signal_connect (	G_OBJECT (play->pipeline),
							"state_change",
							G_CALLBACK (callback_pipeline_state_change),
							play);
		g_signal_connect (	G_OBJECT (play->pipeline),
							"error",
							G_CALLBACK (callback_pipeline_error),
							play);
	}

	if (play->volume) {
		play->vol_dpman =  gst_dpman_get_manager(play->volume);
		play->vol_dparam = gst_dpsmooth_new(G_TYPE_FLOAT);
  
		g_object_set(	G_OBJECT(play->vol_dparam),
						"update_period", 2000000LL, NULL);
  
		g_object_set(	G_OBJECT(play->vol_dparam),
						"slope_delta_float", 0.1F, NULL);
		g_object_set(	G_OBJECT(play->vol_dparam),
						"slope_time", 10000000LL, NULL); 
 
		if (!gst_dpman_attach_dparam (	play->vol_dpman,
										"volume",
										play->vol_dparam))
			g_warning("could not attach dparam to volume element\n");
		
		gst_dpman_set_mode(play->vol_dpman, "asynchronous");
		gst_play_set_volume(play, 0.9);
	}
	
	play->signal_queue = g_async_queue_new();

	return play;
}