/* Spa
 *
 * Copyright © 2018 Wim Taymans
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <limits.h>

#include <spa/support/log.h>
#include <spa/utils/list.h>
#include <spa/node/node.h>
#include <spa/node/io.h>
#include <spa/param/audio/format-utils.h>
#include <spa/param/param.h>
#include <spa/pod/filter.h>
#include <spa/debug/types.h>
#include <spa/debug/mem.h>

#define NAME "splitter"

#define DEFAULT_RATE		48000
#define DEFAULT_CHANNELS	2
#define DEFAULT_MASK		(1LL << SPA_AUDIO_CHANNEL_FL) | (1LL << SPA_AUDIO_CHANNEL_FR)

#define MAX_SAMPLES	1024
#define MAX_BUFFERS	64
#define MAX_PORTS	128

struct buffer {
#define BUFFER_FLAG_QUEUED	(1<<0)
	uint32_t flags;
	struct spa_list link;
	struct spa_buffer *buf;
};

struct port {
	uint32_t id;

	struct spa_io_buffers *io;
	struct spa_io_range *ctrl;

	struct spa_port_info info;
	struct spa_dict info_props;
	struct spa_dict_item info_props_items[2];
	char position[8];

	bool have_format;
	struct spa_audio_info format;
	uint32_t blocks;
	uint32_t stride;

	struct buffer buffers[MAX_BUFFERS];
	uint32_t n_buffers;

	struct spa_list queue;
};

#include "fmt-ops.c"

struct impl {
	struct spa_handle handle;
	struct spa_node node;

	struct spa_log *log;

	const struct spa_node_callbacks *callbacks;
	void *user_data;

	struct port in_ports[1];
	struct port out_ports[MAX_PORTS];
	int port_count;

	bool started;
	convert_func_t convert;

	bool have_profile;

	float empty[MAX_SAMPLES];
};

#define CHECK_OUT_PORT(this,d,p)	((d) == SPA_DIRECTION_OUTPUT && (p) < this->port_count)
#define CHECK_IN_PORT(this,d,p)		((d) == SPA_DIRECTION_INPUT && (p) == 0)
#define CHECK_PORT(this,d,p)		(CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
#define GET_IN_PORT(this,p)		(&this->in_ports[p])
#define GET_OUT_PORT(this,p)		(&this->out_ports[p])
#define GET_PORT(this,d,p)		(d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))

static int init_port(struct impl *this, uint32_t port_id, uint32_t rate, uint32_t position)
{
	struct port *port = GET_OUT_PORT(this, port_id);

	port->id = port_id;

	snprintf(port->position, 7, "%s", rindex(spa_type_audio_channel[position].name, ':')+1);

	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;
	port->info_props_items[0] = SPA_DICT_ITEM_INIT("port.dsp", "32 bit float mono audio");
	port->info_props_items[1] = SPA_DICT_ITEM_INIT("port.channel", port->position);
	port->info_props = SPA_DICT_INIT(port->info_props_items, 2);
	port->info.props = &port->info_props;

	spa_list_init(&port->queue);

	port->n_buffers = 0;
	port->have_format = false;
	port->format.media_type = SPA_MEDIA_TYPE_audio;
	port->format.media_subtype = SPA_MEDIA_SUBTYPE_raw;
	port->format.info.raw.format = SPA_AUDIO_FORMAT_F32P;
	port->format.info.raw.rate = rate;
	port->format.info.raw.channels = 1;
	port->format.info.raw.position[0] = position;

	spa_log_debug(this->log, NAME " %p: init port %d %s", this, port_id, port->position);

	return 0;
}

static int impl_node_enum_params(struct spa_node *node,
				 uint32_t id, uint32_t *index,
				 const struct spa_pod *filter,
				 struct spa_pod **param,
				 struct spa_pod_builder *builder)
{
	spa_return_val_if_fail(node != NULL, -EINVAL);

	switch (id) {
	case SPA_PARAM_List:
	{
		uint32_t list[] = { SPA_PARAM_Profile };

		if (*index < SPA_N_ELEMENTS(list))
			param = spa_pod_builder_object(builder,
					SPA_TYPE_OBJECT_ParamList, id,
					SPA_PARAM_LIST_id, &SPA_POD_Id(list[*index]),
					0);
		else
			return 0;
		break;
	}
	default:
		return 0;
	}
	(*index)++;

	return 1;
}

static int impl_node_set_io(struct spa_node *node, uint32_t id, void *data, size_t size)
{
	return -ENOTSUP;
}

static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flags,
			       const struct spa_pod *param)
{
	struct impl *this;
	int res;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	switch (id) {
	case SPA_PARAM_Profile:
	{
		struct port *port;
		struct spa_audio_info info = { 0, };
		struct spa_pod *format;
		int i;

		if (spa_pod_object_parse(param,
					":", SPA_PARAM_PROFILE_format, "P", &format,
					NULL) < 0)
			return -EINVAL;

		if (!SPA_POD_IS_OBJECT_TYPE(format, SPA_TYPE_OBJECT_Format))
			return -EINVAL;

		if ((res = spa_format_parse(format, &info.media_type, &info.media_subtype)) < 0)
			return res;

		if (info.media_type != SPA_MEDIA_TYPE_audio ||
		    info.media_subtype != SPA_MEDIA_SUBTYPE_raw)
			return -EINVAL;

		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
			return -EINVAL;

		port = GET_IN_PORT(this, 0);
		if (port->have_format && memcmp(&port->format, &info, sizeof(info)) == 0)
			return 0;

		this->have_profile = true;
		this->port_count = info.info.raw.channels;
		for (i = 0; i < this->port_count; i++) {
			init_port(this, i, info.info.raw.rate,
					info.info.raw.position[i]);
		}
		port->have_format = true;
		port->format = info;

		if (this->callbacks && this->callbacks->event)
			this->callbacks->event(this->user_data,
				&SPA_NODE_EVENT_INIT(SPA_NODE_EVENT_PortsChanged));
		return 0;
	}
	default:
		return -ENOENT;
	}
	return 0;
}

static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
{
	struct impl *this;

	spa_return_val_if_fail(node != NULL, -EINVAL);
	spa_return_val_if_fail(command != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	switch (SPA_NODE_COMMAND_ID(command)) {
	case SPA_NODE_COMMAND_Start:
		this->started = true;
		break;
	case SPA_NODE_COMMAND_Pause:
		this->started = false;
		break;
	default:
		return -ENOTSUP;
	}
	return 0;
}

static int
impl_node_set_callbacks(struct spa_node *node,
			const struct spa_node_callbacks *callbacks,
			void *user_data)
{
	struct impl *this;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	this->callbacks = callbacks;
	this->user_data = user_data;

	return 0;
}

static int
impl_node_get_n_ports(struct spa_node *node,
		      uint32_t *n_input_ports,
		      uint32_t *max_input_ports,
		      uint32_t *n_output_ports,
		      uint32_t *max_output_ports)
{
	struct impl *this;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	if (n_input_ports)
		*n_input_ports = 1;
	if (max_input_ports)
		*max_input_ports = 1;
	if (n_output_ports)
		*n_output_ports = this->port_count;
	if (max_output_ports)
		*max_output_ports = this->port_count;

	return 0;
}

static int
impl_node_get_port_ids(struct spa_node *node,
		       uint32_t *input_ids,
		       uint32_t n_input_ids,
		       uint32_t *output_ids,
		       uint32_t n_output_ids)
{
	struct impl *this;
	int i;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	if (n_input_ids > 0 && input_ids)
		input_ids[0] = 0;
	if (output_ids) {
		n_output_ids = SPA_MIN(n_output_ids, this->port_count);
		for (i = 0; i < n_output_ids; i++)
			output_ids[i] = i;
	}
	return 0;
}

static int impl_node_add_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
{
	spa_return_val_if_fail(node != NULL, -EINVAL);
	return -ENOTSUP;
}

static int
impl_node_remove_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
{
	spa_return_val_if_fail(node != NULL, -EINVAL);
	return -ENOTSUP;
}

static int
impl_node_port_get_info(struct spa_node *node,
			enum spa_direction direction,
			uint32_t port_id,
			const struct spa_port_info **info)
{
	struct impl *this;
	struct port *port;

	spa_return_val_if_fail(node != NULL, -EINVAL);
	spa_return_val_if_fail(info != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);

	port = GET_PORT(this, direction, port_id);

	*info = &port->info;

	return 0;
}

static int port_enum_formats(struct spa_node *node,
			     enum spa_direction direction, uint32_t port_id,
			     uint32_t *index,
			     struct spa_pod **param,
			     struct spa_pod_builder *builder)
{
	struct impl *this = SPA_CONTAINER_OF(node, struct impl, node);
	struct port *port = GET_PORT(this, direction, port_id);

	switch (*index) {
	case 0:
		if (direction == SPA_DIRECTION_OUTPUT || port->have_format) {
			*param = spa_format_audio_raw_build(builder,
					SPA_PARAM_EnumFormat, &port->format.info.raw);
		}
		else {
			*param = spa_pod_builder_object(builder,
				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
				SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
				SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
				SPA_FORMAT_AUDIO_format,   &SPA_POD_CHOICE_ENUM_Id(18,
							SPA_AUDIO_FORMAT_F32,
							SPA_AUDIO_FORMAT_F32P,
							SPA_AUDIO_FORMAT_F32,
							SPA_AUDIO_FORMAT_F32_OE,
							SPA_AUDIO_FORMAT_S32P,
							SPA_AUDIO_FORMAT_S32,
							SPA_AUDIO_FORMAT_S32_OE,
							SPA_AUDIO_FORMAT_S24_32P,
							SPA_AUDIO_FORMAT_S24_32,
							SPA_AUDIO_FORMAT_S24_32_OE,
							SPA_AUDIO_FORMAT_S24P,
							SPA_AUDIO_FORMAT_S24,
							SPA_AUDIO_FORMAT_S24_OE,
							SPA_AUDIO_FORMAT_S16P,
							SPA_AUDIO_FORMAT_S16,
							SPA_AUDIO_FORMAT_S16_OE,
							SPA_AUDIO_FORMAT_U8P,
							SPA_AUDIO_FORMAT_U8),
				SPA_FORMAT_AUDIO_rate,     &SPA_POD_CHOICE_RANGE_Int(
						DEFAULT_RATE, 1, INT32_MAX),
				SPA_FORMAT_AUDIO_channels, &SPA_POD_CHOICE_RANGE_Int(
						DEFAULT_CHANNELS, 1, MAX_PORTS),
				0);
		}
		break;
	default:
		return 0;
	}
	return 1;
}

static int
impl_node_port_enum_params(struct spa_node *node,
			   enum spa_direction direction, uint32_t port_id,
			   uint32_t id, uint32_t *index,
			   const struct spa_pod *filter,
			   struct spa_pod **result,
			   struct spa_pod_builder *builder)
{
	struct impl *this;
	struct port *port;
	struct spa_pod *param;
	struct spa_pod_builder b = { 0 };
	uint8_t buffer[1024];
	int res;

	spa_return_val_if_fail(node != NULL, -EINVAL);
	spa_return_val_if_fail(index != NULL, -EINVAL);
	spa_return_val_if_fail(builder != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);

	port = GET_PORT(this, direction, port_id);

      next:
	spa_pod_builder_init(&b, buffer, sizeof(buffer));

	spa_log_debug(this->log, NAME " %p: enum param %d", this, id);

	switch (id) {
	case SPA_PARAM_List:
	{
		uint32_t list[] = { SPA_PARAM_EnumFormat,
				    SPA_PARAM_Format,
				    SPA_PARAM_Buffers,
				    SPA_PARAM_Meta,
				    SPA_PARAM_IO };

		if (*index < SPA_N_ELEMENTS(list))
			param = spa_pod_builder_object(&b,
					SPA_TYPE_OBJECT_ParamList, id,
					SPA_PARAM_LIST_id, &SPA_POD_Id(list[*index]),
					0);
		else
			return 0;
		break;
	}
	case SPA_PARAM_EnumFormat:
		if ((res = port_enum_formats(node, direction, port_id, index, &param, &b)) <= 0)
			return res;
		break;
	case SPA_PARAM_Format:
		if (!port->have_format)
			return -EIO;
		if (*index > 0)
			return 0;

		param = spa_format_audio_raw_build(&b, id, &port->format.info.raw);
		break;
	case SPA_PARAM_Buffers:
		if (!port->have_format)
			return -EIO;
		if (*index > 0)
			return 0;

		param = spa_pod_builder_object(&b,
			SPA_TYPE_OBJECT_ParamBuffers, id,
			SPA_PARAM_BUFFERS_buffers, &SPA_POD_CHOICE_RANGE_Int(1, 1, MAX_BUFFERS),
			SPA_PARAM_BUFFERS_blocks,  &SPA_POD_Int(port->blocks),
			SPA_PARAM_BUFFERS_size,    &SPA_POD_CHOICE_RANGE_Int(
							1024 * port->stride,
							16 * port->stride,
							MAX_SAMPLES * port->stride),
			SPA_PARAM_BUFFERS_stride,  &SPA_POD_Int(port->stride),
			SPA_PARAM_BUFFERS_align,   &SPA_POD_Int(16),
			0);
		break;

	case SPA_PARAM_Meta:
		if (!port->have_format)
			return -EIO;

		switch (*index) {
		case 0:
			param = spa_pod_builder_object(&b,
				SPA_TYPE_OBJECT_ParamMeta, id,
				SPA_PARAM_META_type, &SPA_POD_Id(SPA_META_Header),
				SPA_PARAM_META_size, &SPA_POD_Int(sizeof(struct spa_meta_header)),
				0);
			break;
		default:
			return 0;
		}
		break;
	case SPA_PARAM_IO:
		switch (*index) {
		case 0:
			param = spa_pod_builder_object(&b,
				SPA_TYPE_OBJECT_ParamIO, id,
				SPA_PARAM_IO_id,   &SPA_POD_Id(SPA_IO_Buffers),
				SPA_PARAM_IO_size, &SPA_POD_Int(sizeof(struct spa_io_buffers)),
				0);
			break;
		default:
			return 0;
		}
		break;
	default:
		return -ENOENT;
	}

	(*index)++;

	if (spa_pod_filter(builder, result, param, filter) < 0)
		goto next;

	return 1;
}

static int clear_buffers(struct impl *this, struct port *port)
{
	if (port->n_buffers > 0) {
		spa_log_debug(this->log, NAME " %p: clear buffers %p", this, port);
		port->n_buffers = 0;
		spa_list_init(&port->queue);
	}
	return 0;
}

static int setup_convert(struct impl *this)
{
	const struct conv_info *conv;
	struct port *inport;
	uint32_t src_fmt, dst_fmt;

	inport = GET_IN_PORT(this, 0);

	src_fmt = inport->format.info.raw.format;
	dst_fmt = SPA_AUDIO_FORMAT_F32P;

	spa_log_info(this->log, NAME " %p: %s/%d@%d->%s/%d@%dx%d", this,
			spa_debug_type_find_name(spa_type_audio_format, src_fmt),
			inport->format.info.raw.channels,
			inport->format.info.raw.rate,
			spa_debug_type_find_name(spa_type_audio_format, dst_fmt),
			1,
			inport->format.info.raw.rate,
			this->port_count);

	conv = find_conv_info(src_fmt, dst_fmt, FEATURE_SSE);
	if (conv != NULL) {
		spa_log_info(this->log, NAME " %p: got converter features %08x", this,
				conv->features);

		this->convert = conv->func;
		return 0;
	}
	return -ENOTSUP;
}

static int calc_width(struct spa_audio_info *info)
{
	switch (info->info.raw.format) {
	case SPA_AUDIO_FORMAT_U8:
	case SPA_AUDIO_FORMAT_U8P:
		return 1;
	case SPA_AUDIO_FORMAT_S16P:
	case SPA_AUDIO_FORMAT_S16:
	case SPA_AUDIO_FORMAT_S16_OE:
		return 2;
	case SPA_AUDIO_FORMAT_S24P:
	case SPA_AUDIO_FORMAT_S24:
	case SPA_AUDIO_FORMAT_S24_OE:
		return 3;
	default:
		return 4;
	}
}

static int port_set_format(struct spa_node *node,
			   enum spa_direction direction,
			   uint32_t port_id,
			   uint32_t flags,
			   const struct spa_pod *format)
{
	struct impl *this = SPA_CONTAINER_OF(node, struct impl, node);
	struct port *port;
	int res;

	port = GET_PORT(this, direction, port_id);

	spa_log_debug(this->log, NAME " %p: set format", this);

	if (format == NULL) {
		if (port->have_format) {
			if (direction == SPA_DIRECTION_INPUT)
				port->have_format = this->have_profile;
			else
				port->have_format = false;
			clear_buffers(this, port);
		}
	} else {
		struct spa_audio_info info = { 0 };

		if ((res = spa_format_parse(format, &info.media_type, &info.media_subtype)) < 0)
			return res;

		if (info.media_type != SPA_MEDIA_TYPE_audio ||
		    info.media_subtype != SPA_MEDIA_SUBTYPE_raw)
			return -EINVAL;

		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
			return -EINVAL;

		if (direction == SPA_DIRECTION_OUTPUT) {
			if (info.info.raw.rate != port->format.info.raw.rate)
				return -EINVAL;
			if (info.info.raw.format != SPA_AUDIO_FORMAT_F32P)
				return -EINVAL;
			if (info.info.raw.channels != 1)
				return -EINVAL;
		}
		else {
			if (info.info.raw.channels != this->port_count)
				return -EINVAL;
		}

		port->format = info;
		port->stride = calc_width(&info);

		if (SPA_AUDIO_FORMAT_IS_PLANAR(info.info.raw.format)) {
			port->blocks = info.info.raw.channels;
		} else {
			port->stride *= info.info.raw.channels;
			port->blocks = 1;
		}
		spa_log_debug(this->log, NAME " %p: %d %d %d", this, port_id, port->stride, port->blocks);

		if (direction == SPA_DIRECTION_INPUT)
			setup_convert(this);

		port->have_format = true;
	}

	return 0;
}


static int
impl_node_port_set_param(struct spa_node *node,
			 enum spa_direction direction, uint32_t port_id,
			 uint32_t id, uint32_t flags,
			 const struct spa_pod *param)
{
	struct impl *this;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);

	switch (id) {
	case SPA_PARAM_Format:
		return port_set_format(node, direction, port_id, flags, param);
	default:
		return -ENOENT;
	}
}

static void queue_buffer(struct impl *this, struct port *port, uint32_t id)
{
	struct buffer *b = &port->buffers[id];

	spa_log_trace(this->log, NAME " %p: queue buffer %d on port %d %d",
			this, id, port->id, b->flags);
	if (SPA_FLAG_CHECK(b->flags, BUFFER_FLAG_QUEUED))
		return;

	spa_list_append(&port->queue, &b->link);
	SPA_FLAG_SET(b->flags, BUFFER_FLAG_QUEUED);
}

static struct buffer *dequeue_buffer(struct impl *this, struct port *port)
{
	struct buffer *b;

	if (spa_list_is_empty(&port->queue))
		return NULL;

	b = spa_list_first(&port->queue, struct buffer, link);
	spa_list_remove(&b->link);
	SPA_FLAG_UNSET(b->flags, BUFFER_FLAG_QUEUED);
	spa_log_trace(this->log, NAME " %p: dequeue buffer %d on port %d %u",
			this, b->buf->id, port->id, b->flags);

	return b;
}

static int
impl_node_port_use_buffers(struct spa_node *node,
			   enum spa_direction direction,
			   uint32_t port_id,
			   struct spa_buffer **buffers,
			   uint32_t n_buffers)
{
	struct impl *this;
	struct port *port;
	uint32_t i;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);

	port = GET_PORT(this, direction, port_id);

	spa_return_val_if_fail(port->have_format, -EIO);

	spa_log_debug(this->log, NAME " %p: use buffers %d on port %d", this, n_buffers, port_id);

	clear_buffers(this, port);

	for (i = 0; i < n_buffers; i++) {
		struct buffer *b;
		struct spa_data *d = buffers[i]->datas;

		b = &port->buffers[i];
		b->buf = buffers[i];
		b->flags = 0;

		if (!((d[0].type == SPA_DATA_MemPtr ||
		       d[0].type == SPA_DATA_MemFd ||
		       d[0].type == SPA_DATA_DmaBuf) && d[0].data != NULL)) {
			spa_log_error(this->log, NAME " %p: invalid memory on buffer %p %d %p", this,
				      buffers[i], d[0].type, d[0].data);
			return -EINVAL;
		}
		if (direction == SPA_DIRECTION_OUTPUT)
			queue_buffer(this, port, i);
	}
	port->n_buffers = n_buffers;

	return 0;
}

static int
impl_node_port_alloc_buffers(struct spa_node *node,
			     enum spa_direction direction,
			     uint32_t port_id,
			     struct spa_pod **params,
			     uint32_t n_params,
			     struct spa_buffer **buffers,
			     uint32_t *n_buffers)
{
	return -ENOTSUP;
}

static int
impl_node_port_set_io(struct spa_node *node,
		      enum spa_direction direction, uint32_t port_id,
		      uint32_t id, void *data, size_t size)
{
	struct impl *this;
	struct port *port;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);

	port = GET_PORT(this, direction, port_id);

	switch (id) {
	case SPA_IO_Buffers:
		port->io = data;
		break;
	case SPA_IO_Range:
		port->ctrl = data;
		break;
	default:
		return -ENOENT;
	}
	return 0;
}

static int impl_node_port_reuse_buffer(struct spa_node *node, uint32_t port_id, uint32_t buffer_id)
{
	struct impl *this;
	struct port *port;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	spa_return_val_if_fail(CHECK_PORT(this, SPA_DIRECTION_OUTPUT, port_id), -EINVAL);

	port = GET_OUT_PORT(this, port_id);
	queue_buffer(this, port, buffer_id);

	return 0;
}

static int
impl_node_port_send_command(struct spa_node *node,
			    enum spa_direction direction,
			    uint32_t port_id,
			    const struct spa_command *command)
{
	return -ENOTSUP;
}

static int impl_node_process(struct spa_node *node)
{
	struct impl *this;
	struct port *inport;
	struct spa_io_buffers *inio;
	int i, j, maxsize, res = 0, n_samples, n_bytes = 0;
	struct spa_data *sd, *dd;
	struct buffer *sbuf, *dbuf;
	uint32_t n_src_datas, n_dst_datas;
	const void **src_datas;
	void **dst_datas;

	spa_return_val_if_fail(node != NULL, -EINVAL);

	this = SPA_CONTAINER_OF(node, struct impl, node);

	inport = GET_IN_PORT(this, 0);
	inio = inport->io;
	spa_return_val_if_fail(inio != NULL, -EIO);
	spa_return_val_if_fail(this->convert != NULL, -EIO);

	spa_log_trace(this->log, NAME " %p: status %p %d %d", this,
			inio, inio->status, inio->buffer_id);

	if (inio->status != SPA_STATUS_HAVE_BUFFER)
		return SPA_STATUS_NEED_BUFFER;
	if (inio->buffer_id >= inport->n_buffers)
		return inio->status = -EINVAL;

	sbuf = &inport->buffers[inio->buffer_id];
	sd = sbuf->buf->datas;

	n_src_datas = sbuf->buf->n_datas;
	src_datas = alloca(sizeof(void*) * n_src_datas);

	maxsize = INT_MAX;
	for (i = 0; i < n_src_datas; i++) {
		src_datas[i] = SPA_MEMBER(sd[i].data,
				sd[i].chunk->offset, void);
		maxsize = SPA_MIN(sd[i].chunk->size, maxsize);
	}
	n_bytes = maxsize;
	n_samples = maxsize / inport->stride;

	dst_datas = alloca(sizeof(void*) * MAX_PORTS);

	n_dst_datas = 0;
	for (i = 0; i < this->port_count; i++) {
		struct port *outport = GET_OUT_PORT(this, i);
		struct spa_io_buffers *outio;

		if ((outio = outport->io) == NULL)
			goto empty;

		spa_log_trace(this->log, NAME " %p: %d %p %d %d %d", this, i,
				outio, outio->status, outio->buffer_id, outport->stride);

		if (outio->status == SPA_STATUS_HAVE_BUFFER) {
			res |= SPA_STATUS_HAVE_BUFFER;
			goto empty;
		}

		if (outio->buffer_id < outport->n_buffers) {
			queue_buffer(this, outport, outio->buffer_id);
			outio->buffer_id = SPA_ID_INVALID;
		}

		if ((dbuf = dequeue_buffer(this, outport)) == NULL) {
			outio->status = -EPIPE;
          empty:
			dst_datas[n_dst_datas++] = this->empty;
			continue;
		}

		dd = dbuf->buf->datas;

		maxsize = dd->maxsize;
		if (outport->ctrl)
			maxsize = SPA_MIN(outport->ctrl->max_size, maxsize);

		for (j = 0; j < dbuf->buf->n_datas; j++) {
			dst_datas[n_dst_datas++] = dd[j].data;
			dd[j].chunk->offset = 0;
			dd[j].chunk->size = n_samples * outport->stride;
		}
		outio->status = SPA_STATUS_HAVE_BUFFER;
		outio->buffer_id = dbuf->buf->id;
		res |= SPA_STATUS_HAVE_BUFFER;
	}

	spa_log_trace(this->log, NAME " %p: %d %d %d %d %d", this,
			n_src_datas, n_dst_datas, n_bytes, maxsize, inport->stride);

	this->convert(this, n_dst_datas, dst_datas, n_src_datas, src_datas, n_bytes);

	inio->status = SPA_STATUS_NEED_BUFFER;
	res |= SPA_STATUS_NEED_BUFFER;

	return res;
}

static const struct spa_node impl_node = {
	SPA_VERSION_NODE,
	NULL,
	impl_node_enum_params,
	impl_node_set_param,
	impl_node_set_io,
	impl_node_send_command,
	impl_node_set_callbacks,
	impl_node_get_n_ports,
	impl_node_get_port_ids,
	impl_node_add_port,
	impl_node_remove_port,
	impl_node_port_get_info,
	impl_node_port_enum_params,
	impl_node_port_set_param,
	impl_node_port_use_buffers,
	impl_node_port_alloc_buffers,
	impl_node_port_set_io,
	impl_node_port_reuse_buffer,
	impl_node_port_send_command,
	impl_node_process,
};

static int impl_get_interface(struct spa_handle *handle, uint32_t type, void **interface)
{
	struct impl *this;

	spa_return_val_if_fail(handle != NULL, -EINVAL);
	spa_return_val_if_fail(interface != NULL, -EINVAL);

	this = (struct impl *) handle;

	if (type == SPA_TYPE_INTERFACE_Node)
		*interface = &this->node;
	else
		return -ENOENT;

	return 0;
}

static int impl_clear(struct spa_handle *handle)
{
	return 0;
}

static size_t
impl_get_size(const struct spa_handle_factory *factory,
	      const struct spa_dict *params)
{
	return sizeof(struct impl);
}

static int
impl_init(const struct spa_handle_factory *factory,
	  struct spa_handle *handle,
	  const struct spa_dict *info,
	  const struct spa_support *support,
	  uint32_t n_support)
{
	struct impl *this;
	struct port *port;
	int i;

	spa_return_val_if_fail(factory != NULL, -EINVAL);
	spa_return_val_if_fail(handle != NULL, -EINVAL);

	handle->get_interface = impl_get_interface;
	handle->clear = impl_clear;

	this = (struct impl *) handle;

	for (i = 0; i < n_support; i++) {
		if (support[i].type == SPA_TYPE_INTERFACE_Log)
			this->log = support[i].data;
	}

	this->node = impl_node;

	port = GET_IN_PORT(this, 0);
	port->id = 0;
	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;

	return 0;
}

static const struct spa_interface_info impl_interfaces[] = {
	{SPA_TYPE_INTERFACE_Node,},
};

static int
impl_enum_interface_info(const struct spa_handle_factory *factory,
			 const struct spa_interface_info **info,
			 uint32_t *index)
{
	spa_return_val_if_fail(factory != NULL, -EINVAL);
	spa_return_val_if_fail(info != NULL, -EINVAL);
	spa_return_val_if_fail(index != NULL, -EINVAL);

	switch (*index) {
	case 0:
		*info = &impl_interfaces[*index];
		break;
	default:
		return 0;
	}
	(*index)++;
	return 1;
}

const struct spa_handle_factory spa_splitter_factory = {
	SPA_VERSION_HANDLE_FACTORY,
	NAME,
	NULL,
	impl_get_size,
	impl_init,
	impl_enum_interface_info,
};