/* Message related functions.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <cstring>
#include <arpa/inet.h>

#include <villas/formats/villas_binary.hpp>
#include <villas/formats/msg.hpp>
#include <villas/formats/msg_format.hpp>
#include <villas/exceptions.hpp>
#include <villas/sample.hpp>
#include <villas/utils.hpp>

using namespace villas;
using namespace villas::node;

int VillasBinaryFormat::sprint(char *buf, size_t len, size_t *wbytes, const struct Sample * const smps[], unsigned cnt)
{
	int ret;
	unsigned i = 0;
	char *ptr = buf;

	for (i = 0; i < cnt; i++) {
		struct Message *msg = (struct Message *) ptr;
		const struct Sample *smp = smps[i];

		if (ptr + MSG_LEN(smp->length) > buf + len)
			break;

		ret = msg_from_sample(msg, smp, smp->signals, source_index);
		if (ret)
			return ret;

		if (web) {
			// TODO: convert to little endian
		}
		else
			msg_hton(msg);

		ptr += MSG_LEN(smp->length);
	}

	if (wbytes)
		*wbytes = ptr - buf;

	return i;
}

int VillasBinaryFormat::sscan(const char *buf, size_t len, size_t *rbytes, struct Sample * const smps[], unsigned cnt)
{
	int ret, values;
	unsigned i, j;
	const char *ptr = buf;
	uint8_t sid; // source_index

	if (len % 4 != 0)
		return -1; // Packet size is invalid: Must be multiple of 4 bytes

	for (i = 0, j = 0; i < cnt; i++) {
		struct Message *msg = (struct Message *) ptr;
		struct Sample *smp = smps[j];

		smp->signals = signals;

		// Complete buffer has been parsed
		if (ptr == buf + len)
			break;

		// Check if header is still in buffer bounaries
		if (ptr + sizeof(struct Message) > buf + len)
			return -2; // Invalid msg received

		values = web ? msg->length : ntohs(msg->length);

		// Check if remainder of message is in buffer boundaries
		if (ptr + MSG_LEN(values) > buf + len)
			return -3; // Invalid msg receive

		if (web) {
			// TODO: convert from little endian
		}
		else
			msg_ntoh(msg);

		ret = msg_to_sample(msg, smp, signals, &sid);
		if (ret)
			return ret; // Invalid msg received

		if (validate_source_index && sid != source_index) {
			// source index mismatch: we skip this sample
		}
		else
			j++;

		ptr += MSG_LEN(smp->length);
	}

	if (rbytes)
		*rbytes = ptr - buf;

	return j;
}

void VillasBinaryFormat::parse(json_t *json)
{
	int ret;
	json_error_t err;
	int sid = -1;
	int vsi = -1;

	ret = json_unpack_ex(json, &err, 0, "{ s?: i, s?: b }",
		"source_index", &sid,
		"validate_source_index", &vsi
	);
	if (ret)
		throw ConfigError(json, err, "node-config-format-villas-binary", "Failed to parse format configuration");

	if (vsi >= 0)
		validate_source_index = vsi != 0;

	if (sid >= 0)
		source_index = sid;

	Format::parse(json);
}

// Register formats
static
VillasBinaryFormatPlugin<false> p1;
static
VillasBinaryFormatPlugin<true> p2;