/*
 * ============================================================================
 *
 *                                  Preamble
 *
 * ============================================================================
 */


/*
 * stuff from the C library
 */


#include <string.h>


/*
 *  stuff from gobject/gstreamer
 */


#include <glib.h>
#include <gst/gst.h>
#include <gst/base/gstadapter.h>
#include <gst/base/gstbasetransform.h>


/*
 * stuff from gstlal
 */


#include <gstlal_mean.h>


/*
 * ============================================================================
 *
 *                           GStreamer Boiler Plate
 *
 * ============================================================================
 */


static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE(
	GST_BASE_TRANSFORM_SINK_NAME,
	GST_PAD_SINK,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS(
		"audio/x-raw-float, " \
		"rate = (int) [1, MAX], " \
		"channels = (int) 1, " \
		"endianness = (int) BYTE_ORDER, " \
		"width = (int) 64"
	)
);


static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE(
	GST_BASE_TRANSFORM_SRC_NAME,
	GST_PAD_SRC,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS(
		"audio/x-raw-float, " \
		"rate = (int) [1, MAX], " \
		"channels = (int) 1, " \
		"endianness = (int) BYTE_ORDER, " \
		"width = (int) 64"
	)
);


GST_BOILERPLATE(
	GSTLALMean,
	gstlal_mean,
	GstBaseTransform,
	GST_TYPE_BASE_TRANSFORM
);


enum property {
	ARG_N = 1
};


#define DEFAULT_N 1


/*
 * ============================================================================
 *
 *                          GObject Method Overrides
 *
 * ============================================================================
 */


/*
 * set_property()
 */


static void set_property(GObject *object, enum property prop_id, const GValue *value, GParamSpec *pspec)
{
	GSTLALMean *element = GSTLAL_MEAN(object);

	GST_OBJECT_LOCK(element);

	switch (prop_id) {
	case ARG_N: {
		guint32 old_n = element->n;
		element->n = g_value_get_uint(value);
		if(element->n != old_n)
			g_object_notify(object, "n");
		break;
	}

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
		break;
	}

	GST_OBJECT_UNLOCK(element);
}


/*
 * get_property()
 */


static void get_property(GObject *object, enum property prop_id, GValue *value, GParamSpec *pspec)
{
	GSTLALMean *element = GSTLAL_MEAN(object);

	GST_OBJECT_LOCK(element);

	switch (prop_id) {
	case ARG_N:
		g_value_set_uint(value, element->n);
		break;

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
		break;
	}

	GST_OBJECT_UNLOCK(element);
}


/*
 * finalize()
 */


static void finalize(GObject *object)
{
	GSTLALMean *element = GSTLAL_MEAN(object);

	/*
	 * free resources
	 */

	/*
	 * chain to parent class' finalize() method
	 */

	G_OBJECT_CLASS(parent_class)->finalize(object);
}


/*
 * base_init()
 */


static void gstlal_mean_base_init(gpointer gclass)
{
	GstElementClass *element_class = GST_ELEMENT_CLASS(gclass);
	GstBaseTransformClass *transform_class = GST_BASE_TRANSFORM_CLASS(gclass);

	gst_element_class_set_details_simple(element_class, "Average of last N samples", "Filter/Audio", "Each output sample is the average of the N most recent samples", "Kipp Cannon <kipp.cannon@ligo.org>");

	gst_element_class_add_pad_template(element_class, gst_static_pad_template_get(&src_factory));
	gst_element_class_add_pad_template(element_class, gst_static_pad_template_get(&sink_factory));
}


/*
 * class_init()
 */


static void gstlal_mean_class_init(GSTLALMeanClass *klass)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(klass);

	gobject_class->set_property = GST_DEBUG_FUNCPTR(set_property);
	gobject_class->get_property = GST_DEBUG_FUNCPTR(get_property);
	gobject_class->finalize = GST_DEBUG_FUNCPTR(finalize);

	g_object_class_install_property(
		gobject_class,
		ARG_N,
		g_param_spec_uint(
			"n",
			"n",
			"Number of samples to average.",
			0, G_MAXUINT, DEFAULT_N,
			G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS
		)
	);
}


/*
 * init()
 */


static void gstlal_mean_init(GSTLALMean *filter, GSTLALMeanClass *kclass)
{
	filter->n = DEFAULT_N;
	gst_base_transform_set_gap_aware(GST_BASE_TRANSFORM(filter), TRUE);
}