/*
 * Copyright (c) 2018-2020 O.S.Systems
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(updatehub, CONFIG_UPDATEHUB_LOG_LEVEL);

#include <zephyr/kernel.h>

#include <zephyr/logging/log_ctrl.h>
#include <zephyr/net/socket.h>
#include <zephyr/net/net_mgmt.h>
#include <zephyr/net/net_ip.h>
#include <zephyr/net/udp.h>
#include <zephyr/net/coap.h>
#include <zephyr/net/dns_resolve.h>
#include <zephyr/drivers/flash.h>
#include <zephyr/sys/reboot.h>
#include <tinycrypt/sha256.h>
#include <zephyr/data/json.h>
#include <zephyr/storage/flash_map.h>

#include "include/updatehub.h"
#include "updatehub_priv.h"
#include "updatehub_firmware.h"
#include "updatehub_device.h"
#include "updatehub_timer.h"

#if defined(CONFIG_UPDATEHUB_DTLS)
#define CA_CERTIFICATE_TAG 1
#include <zephyr/net/tls_credentials.h>
#endif

#define NETWORK_TIMEOUT (2 * MSEC_PER_SEC)
#define UPDATEHUB_POLL_INTERVAL K_MINUTES(CONFIG_UPDATEHUB_POLL_INTERVAL)
#define MAX_PATH_SIZE 255
/* MAX_PAYLOAD_SIZE must reflect size COAP_BLOCK_x option */
#define MAX_PAYLOAD_SIZE 1024
/* MAX_DOWNLOAD_DATA must be equal or bigger than:
 * MAX_PAYLOAD_SIZE + (len + header + options)
 * otherwise download size will be less than real size.
 */
#define MAX_DOWNLOAD_DATA (MAX_PAYLOAD_SIZE + 32)
#define MAX_IP_SIZE 30

#define SHA256_HEX_DIGEST_SIZE	((TC_SHA256_DIGEST_SIZE * 2) + 1)

#if defined(CONFIG_UPDATEHUB_CE)
#define UPDATEHUB_SERVER CONFIG_UPDATEHUB_SERVER
#else
#define UPDATEHUB_SERVER "coap.updatehub.io"
#endif

#ifdef CONFIG_UPDATEHUB_DOWNLOAD_SHA256_VERIFICATION
#define _DOWNLOAD_SHA256_VERIFICATION
#elif defined(CONFIG_UPDATEHUB_DOWNLOAD_STORAGE_SHA256_VERIFICATION)
#define _DOWNLOAD_SHA256_VERIFICATION
#define _STORAGE_SHA256_VERIFICATION
#elif defined(CONFIG_UPDATEHUB_STORAGE_SHA256_VERIFICATION)
#define _STORAGE_SHA256_VERIFICATION
#endif

static struct updatehub_context {
	struct coap_block_context block;
	struct k_sem semaphore;
	struct flash_img_context flash_ctx;
	struct tc_sha256_state_struct sha256sum;
	enum updatehub_response code_status;
	uint8_t hash[TC_SHA256_DIGEST_SIZE];
	uint8_t uri_path[MAX_PATH_SIZE];
	uint8_t payload[MAX_PAYLOAD_SIZE];
	int downloaded_size;
	struct pollfd fds[1];
	int sock;
	int nfds;
} ctx;

static struct update_info {
	char package_uid[SHA256_HEX_DIGEST_SIZE];
	char sha256sum_image[SHA256_HEX_DIGEST_SIZE];
	int image_size;
} update_info;

static struct k_work_delayable updatehub_work_handle;

static int bin2hex_str(uint8_t *bin, size_t bin_len, char *str, size_t str_buf_len)
{
	if (bin == NULL || str == NULL) {
		return -1;
	}

	/* ensures at least an empty string */
	if (str_buf_len < 1) {
		return -2;
	}

	memset(str, 0, str_buf_len);
	bin2hex(bin, bin_len, str, str_buf_len);

	return 0;
}

static void wait_fds(void)
{
	if (poll(ctx.fds, ctx.nfds, NETWORK_TIMEOUT) < 0) {
		LOG_ERR("Error in poll");
	}
}

static void prepare_fds(void)
{
	ctx.fds[ctx.nfds].fd = ctx.sock;
	ctx.fds[ctx.nfds].events = POLLIN;
	ctx.nfds++;
}

static int metadata_hash_get(char *metadata)
{
	struct tc_sha256_state_struct sha256sum;

	if (tc_sha256_init(&sha256sum) == 0) {
		return -1;
	}

	if (tc_sha256_update(&sha256sum, metadata, strlen(metadata)) == 0) {
		return -1;
	}

	if (tc_sha256_final(ctx.hash, &sha256sum) == 0) {
		return -1;
	}

	if (bin2hex_str(ctx.hash, TC_SHA256_DIGEST_SIZE,
		update_info.package_uid, SHA256_HEX_DIGEST_SIZE)) {
		return -1;
	}

	return 0;
}

static bool
is_compatible_hardware(struct resp_probe_some_boards *metadata_some_boards)
{
	int i;

	for (i = 0; i < metadata_some_boards->supported_hardware_len; i++) {
		if (strncmp(metadata_some_boards->supported_hardware[i],
			    CONFIG_BOARD, strlen(CONFIG_BOARD)) == 0) {
			return true;
		}
	}
	return false;
}

static void cleanup_connection(void)
{
	int i;

	if (close(ctx.sock) < 0) {
		LOG_ERR("Could not close the socket");
	}

	for (i = 0; i < ctx.nfds; i++) {
		memset(&ctx.fds[i], 0, sizeof(ctx.fds[i]));
	}

	ctx.nfds = 0;
	ctx.sock = 0;
}

static bool start_coap_client(void)
{
	struct addrinfo *addr;
	struct addrinfo hints;
	int resolve_attempts = 10;
	int ret = -1;

	memset(&hints, 0, sizeof(hints));

	if (IS_ENABLED(CONFIG_NET_IPV6)) {
		hints.ai_family = AF_INET6;
		hints.ai_socktype = SOCK_STREAM;
	} else if (IS_ENABLED(CONFIG_NET_IPV4)) {
		hints.ai_family = AF_INET;
		hints.ai_socktype = SOCK_STREAM;
	}

#if defined(CONFIG_UPDATEHUB_DTLS)
	int verify = TLS_PEER_VERIFY_REQUIRED;
	sec_tag_t sec_list[] = { CA_CERTIFICATE_TAG };
	int protocol = IPPROTO_DTLS_1_2;
	char port[] = "5684";
#else
	int protocol = IPPROTO_UDP;
	char port[] = "5683";
#endif

	while (resolve_attempts--) {
		ret = getaddrinfo(UPDATEHUB_SERVER, port, &hints, &addr);
		if (ret == 0) {
			break;
		}
		k_sleep(K_SECONDS(1));
	}
	if (ret < 0) {
		LOG_ERR("Could not resolve dns");
		return false;
	}

	ret = 1;

	ctx.sock = socket(addr->ai_family, SOCK_DGRAM, protocol);
	if (ctx.sock < 0) {
		LOG_ERR("Failed to create UDP socket");
		goto error;
	}

	ret = -1;

#if defined(CONFIG_UPDATEHUB_DTLS)
	if (setsockopt(ctx.sock, SOL_TLS, TLS_SEC_TAG_LIST,
		       sec_list, sizeof(sec_list)) < 0) {
		LOG_ERR("Failed to set TLS_TAG option");
		goto error;
	}

	if (setsockopt(ctx.sock, SOL_TLS, TLS_PEER_VERIFY, &verify, sizeof(int)) < 0) {
		LOG_ERR("Failed to set TLS_PEER_VERIFY option");
		goto error;
	}
#endif

	if (connect(ctx.sock, addr->ai_addr, addr->ai_addrlen) < 0) {
		LOG_ERR("Cannot connect to UDP remote");
		goto error;
	}

	prepare_fds();

	ret = 0;
error:
	freeaddrinfo(addr);

	if (ret > 0) {
		cleanup_connection();
	}

	return (ret == 0) ? true : false;
}

static int send_request(enum coap_msgtype msgtype, enum coap_method method,
			enum updatehub_uri_path type)
{
	struct coap_packet request_packet;
	int ret = -1;
	uint8_t *data = k_malloc(MAX_PAYLOAD_SIZE);

	if (data == NULL) {
		LOG_ERR("Could not alloc data memory");
		goto error;
	}

	ret = coap_packet_init(&request_packet, data, MAX_PAYLOAD_SIZE,
			       COAP_VERSION_1, COAP_TYPE_CON,
			       COAP_TOKEN_MAX_LEN, coap_next_token(), method,
			       coap_next_id());
	if (ret < 0) {
		LOG_ERR("Could not init packet");
		goto error;
	}

	switch (method) {
	case COAP_METHOD_GET:
		snprintk(ctx.uri_path, MAX_PATH_SIZE,
			 "%s/%s/packages/%s/objects/%s", uri_path(type),
			 CONFIG_UPDATEHUB_PRODUCT_UID, update_info.package_uid,
			 update_info.sha256sum_image);

		ret = coap_packet_append_option(&request_packet,
						COAP_OPTION_URI_PATH,
						ctx.uri_path,
						strlen(ctx.uri_path));
		if (ret < 0) {
			LOG_ERR("Unable add option to request path");
			goto error;
		}

		ret = coap_append_block2_option(&request_packet,
						&ctx.block);
		if (ret < 0) {
			LOG_ERR("Unable coap append block 2");
			goto error;
		}

		ret = coap_packet_append_option(&request_packet, 2048,
						UPDATEHUB_API_HEADER, strlen(UPDATEHUB_API_HEADER));
		if (ret < 0) {
			LOG_ERR("Unable add option to add updatehub header");
			goto error;
		}

		break;

	case COAP_METHOD_POST:
		ret = coap_packet_append_option(&request_packet,
						COAP_OPTION_URI_PATH,
						uri_path(type),
						strlen(uri_path(type)));
		if (ret < 0) {
			LOG_ERR("Unable add option to request path");
			goto error;
		}

		ret = coap_append_option_int(&request_packet,
					     COAP_OPTION_CONTENT_FORMAT,
					     COAP_CONTENT_FORMAT_APP_JSON);
		if (ret < 0) {
			LOG_ERR("Unable add option to request format");
			goto error;
		}

		ret = coap_packet_append_option(&request_packet, 2048,
						UPDATEHUB_API_HEADER, strlen(UPDATEHUB_API_HEADER));
		if (ret < 0) {
			LOG_ERR("Unable add option to add updatehub header");
			goto error;
		}

		ret = coap_packet_append_payload_marker(&request_packet);
		if (ret < 0) {
			LOG_ERR("Unable to append payload marker");
			goto error;
		}

		ret = coap_packet_append_payload(&request_packet,
						 ctx.payload,
						 strlen(ctx.payload));
		if (ret < 0) {
			LOG_ERR("Not able to append payload");
			goto error;
		}

		break;

	default:
		LOG_ERR("Invalid method");
		ret = -1;
		goto error;
	}

	ret = send(ctx.sock, request_packet.data, request_packet.offset, 0);
	if (ret < 0) {
		LOG_ERR("Could not send request");
		goto error;
	}

error:
	k_free(data);

	return ret;
}

#ifdef _DOWNLOAD_SHA256_VERIFICATION
static bool install_update_cb_sha256(void)
{
	char sha256[SHA256_HEX_DIGEST_SIZE];

	if (tc_sha256_final(ctx.hash, &ctx.sha256sum) < 1) {
		LOG_ERR("Could not finish sha256sum");
		return false;
	}

	if (bin2hex_str(ctx.hash, TC_SHA256_DIGEST_SIZE,
		sha256, SHA256_HEX_DIGEST_SIZE)) {
		LOG_ERR("Could not create sha256sum hex representation");
		return false;
	}

	if (strncmp(sha256, update_info.sha256sum_image,
		    SHA256_HEX_DIGEST_SIZE) != 0) {
		LOG_ERR("SHA256SUM of image are not the same");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		return false;
	}

	return true;
}
#endif

static int install_update_cb_check_blk_num(const struct coap_packet *resp)
{
	int blk_num;
	int blk2_opt;
	uint16_t payload_len;

	blk2_opt = coap_get_option_int(resp, COAP_OPTION_BLOCK2);
	(void)coap_packet_get_payload(resp, &payload_len);

	if ((payload_len == 0) || (blk2_opt < 0)) {
		LOG_DBG("Invalid data received or block number is < 0");
		return -ENOENT;
	}

	blk_num = GET_BLOCK_NUM(blk2_opt);

	if (blk_num == updatehub_blk_get(UPDATEHUB_BLK_INDEX)) {
		updatehub_blk_inc(UPDATEHUB_BLK_INDEX);

		return 0;
	}

	return -EAGAIN;
}

static void install_update_cb(void)
{
	struct coap_packet response_packet;
#ifdef _STORAGE_SHA256_VERIFICATION
	struct flash_img_check fic;
#endif
	uint8_t *data = k_malloc(MAX_DOWNLOAD_DATA);
	const uint8_t *payload_start;
	uint16_t payload_len;
	int rcvd = -1;

	if (data == NULL) {
		LOG_ERR("Could not alloc data memory");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto cleanup;
	}

	wait_fds();

	rcvd = recv(ctx.sock, data, MAX_DOWNLOAD_DATA, MSG_DONTWAIT);
	if (rcvd <= 0) {
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		LOG_ERR("Could not receive data");
		goto cleanup;
	}

	if (coap_packet_parse(&response_packet, data, rcvd, NULL, 0) < 0) {
		LOG_ERR("Invalid data received");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto cleanup;
	}

	if (install_update_cb_check_blk_num(&response_packet) < 0) {
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto cleanup;
	}

	/* payload_len is > 0, checked at install_update_cb_check_blk_num */
	payload_start = coap_packet_get_payload(&response_packet, &payload_len);

	updatehub_tmr_stop();
	updatehub_blk_set(UPDATEHUB_BLK_ATTEMPT, 0);
	updatehub_blk_set(UPDATEHUB_BLK_TX_AVAILABLE, 1);

	ctx.downloaded_size = ctx.downloaded_size + payload_len;

#ifdef _DOWNLOAD_SHA256_VERIFICATION
	if (tc_sha256_update(&ctx.sha256sum,
			     payload_start,
			     payload_len) < 1) {
		LOG_ERR("Could not update sha256sum");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto cleanup;
	}
#endif

	LOG_DBG("Flash: Address: 0x%08x, Size: %d, Flush: %s",
		ctx.flash_ctx.stream.bytes_written, payload_len,
		(ctx.downloaded_size == ctx.block.total_size ?
			"True" : "False"));

	if (flash_img_buffered_write(&ctx.flash_ctx,
				     payload_start, payload_len,
				     ctx.downloaded_size == ctx.block.total_size) < 0) {
		LOG_ERR("Error to write on the flash");
		ctx.code_status = UPDATEHUB_INSTALL_ERROR;
		goto cleanup;
	}

	if (coap_update_from_block(&response_packet, &ctx.block) < 0) {
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto cleanup;
	}

	if (coap_next_block(&response_packet, &ctx.block) == 0) {
		if (ctx.downloaded_size != ctx.block.total_size) {
			LOG_ERR("Could not get the next coap block");
			ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
			goto cleanup;
		}

		LOG_INF("Firmware download complete");

#ifdef _DOWNLOAD_SHA256_VERIFICATION
		if (!install_update_cb_sha256()) {
			LOG_ERR("Firmware - download validation has failed");
			ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
			goto cleanup;
		}
#else
		if (hex2bin(update_info.sha256sum_image,
			    SHA256_HEX_DIGEST_SIZE - 1, ctx.hash,
			    TC_SHA256_DIGEST_SIZE) != TC_SHA256_DIGEST_SIZE) {
			LOG_ERR("Firmware - metadata validation has failed");
			ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
			goto cleanup;
		}
#endif

#ifdef _STORAGE_SHA256_VERIFICATION
		fic.match = ctx.hash;
		fic.clen = ctx.downloaded_size;

		if (flash_img_check(&ctx.flash_ctx, &fic,
				    FIXED_PARTITION_ID(slot1_partition))) {
			LOG_ERR("Firmware - flash validation has failed");
			ctx.code_status = UPDATEHUB_INSTALL_ERROR;
			goto cleanup;
		}
#endif
	}

	ctx.code_status = UPDATEHUB_OK;

cleanup:
	k_free(data);
}

static enum updatehub_response install_update(void)
{
	if (boot_erase_img_bank(FIXED_PARTITION_ID(slot1_partition)) != 0) {
		LOG_ERR("Failed to init flash and erase second slot");
		ctx.code_status = UPDATEHUB_FLASH_INIT_ERROR;
		goto error;
	}

#ifdef _DOWNLOAD_SHA256_VERIFICATION
	if (tc_sha256_init(&ctx.sha256sum) < 1) {
		LOG_ERR("Could not start sha256sum");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		goto error;
	}
#endif

	if (!start_coap_client()) {
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		goto error;
	}

	if (coap_block_transfer_init(&ctx.block,
				     CONFIG_UPDATEHUB_COAP_BLOCK_SIZE_EXP,
				     update_info.image_size) < 0) {
		LOG_ERR("Unable init block transfer");
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		goto cleanup;
	}

	if (flash_img_init(&ctx.flash_ctx)) {
		LOG_ERR("Unable init flash");
		ctx.code_status = UPDATEHUB_FLASH_INIT_ERROR;
		goto cleanup;
	}

	ctx.downloaded_size = 0;
	updatehub_blk_set(UPDATEHUB_BLK_ATTEMPT, 0);
	updatehub_blk_set(UPDATEHUB_BLK_INDEX, 0);
	updatehub_blk_set(UPDATEHUB_BLK_TX_AVAILABLE, 1);

	while (ctx.downloaded_size != ctx.block.total_size) {
		if (updatehub_blk_get(UPDATEHUB_BLK_TX_AVAILABLE)) {
			if (send_request(COAP_TYPE_CON, COAP_METHOD_GET,
					 UPDATEHUB_DOWNLOAD) < 0) {
				ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
				goto cleanup;
			}

			updatehub_blk_set(UPDATEHUB_BLK_TX_AVAILABLE, 0);
			updatehub_blk_inc(UPDATEHUB_BLK_ATTEMPT);
			updatehub_tmr_start();
		}

		install_update_cb();

		if (ctx.code_status == UPDATEHUB_OK) {
			continue;
		}

		if (ctx.code_status != UPDATEHUB_DOWNLOAD_ERROR &&
		    ctx.code_status != UPDATEHUB_NETWORKING_ERROR) {
			LOG_DBG("status: %d", ctx.code_status);
			goto cleanup;
		}

		if (updatehub_blk_get(UPDATEHUB_BLK_ATTEMPT) ==
		    CONFIG_UPDATEHUB_COAP_MAX_RETRY) {
			updatehub_tmr_stop();

			LOG_ERR("Could not get the packet");
			ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
			goto cleanup;
		}
	}

cleanup:
	cleanup_connection();

error:
	ctx.downloaded_size = 0;

	return ctx.code_status;
}

static int report(enum updatehub_state state)
{
	struct report report;
	int ret = -1;
	const char *exec = state_name(state);
	char *device_id = k_malloc(DEVICE_ID_HEX_MAX_SIZE);
	char *firmware_version = k_malloc(BOOT_IMG_VER_STRLEN_MAX);

	if (device_id == NULL || firmware_version == NULL) {
		LOG_ERR("Could not alloc device_id or firmware_version memory");
		goto error;
	}

	if (!updatehub_get_device_identity(device_id, DEVICE_ID_HEX_MAX_SIZE)) {
		goto error;
	}

	if (!updatehub_get_firmware_version(firmware_version, BOOT_IMG_VER_STRLEN_MAX)) {
		goto error;
	}

	memset(&report, 0, sizeof(report));
	report.product_uid = CONFIG_UPDATEHUB_PRODUCT_UID;
	report.device_identity.id = device_id;
	report.version = firmware_version;
	report.hardware = CONFIG_BOARD;
	report.status = exec;
	report.package_uid = update_info.package_uid;

	switch (ctx.code_status) {
	case UPDATEHUB_INSTALL_ERROR:
		report.previous_state =
			state_name(UPDATEHUB_STATE_INSTALLING);
		break;
	case UPDATEHUB_DOWNLOAD_ERROR:
		report.previous_state =
			state_name(UPDATEHUB_STATE_DOWNLOADING);
		break;
	case UPDATEHUB_FLASH_INIT_ERROR:
		report.previous_state =
			state_name(UPDATEHUB_FLASH_INIT_ERROR);
		break;
	default:
		report.previous_state = "";
		break;
	}

	if (strncmp(report.previous_state, "", sizeof("") - 1) != 0) {
		report.error_message = updatehub_response(ctx.code_status);
	} else {
		report.error_message = "";
	}

	memset(&ctx.payload, 0, MAX_PAYLOAD_SIZE);
	ret = json_obj_encode_buf(send_report_descr,
				  ARRAY_SIZE(send_report_descr),
				  &report, ctx.payload,
				  MAX_PAYLOAD_SIZE - 1);
	if (ret < 0) {
		LOG_ERR("Could not encode metadata");
		goto error;
	}

	if (!start_coap_client()) {
		goto error;
	}

	ret = send_request(COAP_TYPE_NON_CON, COAP_METHOD_POST,
			   UPDATEHUB_REPORT);
	if (ret < 0) {
		goto cleanup;
	}

	wait_fds();

cleanup:
	cleanup_connection();

error:
	k_free(firmware_version);
	k_free(device_id);

	return ret;
}

static void probe_cb(char *metadata, size_t metadata_size)
{
	struct coap_packet reply;
	char tmp[MAX_DOWNLOAD_DATA];
	const uint8_t *payload_start;
	uint16_t payload_len;
	size_t tmp_len;
	int rcvd = -1;

	wait_fds();

	rcvd = recv(ctx.sock, tmp, MAX_DOWNLOAD_DATA, MSG_DONTWAIT);
	if (rcvd <= 0) {
		LOG_ERR("Could not receive data");
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		return;
	}

	if (coap_packet_parse(&reply, tmp, rcvd, NULL, 0) < 0) {
		LOG_ERR("Invalid data received");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		return;
	}

	if (coap_header_get_code(&reply) == COAP_RESPONSE_CODE_NOT_FOUND) {
		LOG_INF("No update available");
		ctx.code_status = UPDATEHUB_NO_UPDATE;
		return;
	}

	payload_start = coap_packet_get_payload(&reply, &payload_len);
	if (payload_len == 0) {
		LOG_ERR("Invalid payload received");
		ctx.code_status = UPDATEHUB_DOWNLOAD_ERROR;
		return;
	}

	if (metadata_size < payload_len) {
		LOG_ERR("There is no buffer available");
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		return;
	}

	memset(metadata, 0, metadata_size);
	memcpy(metadata, payload_start, payload_len);

	/* ensures payload have a valid string with size lower
	 * than metadata_size
	 */
	tmp_len = strlen(metadata);
	if (tmp_len >= metadata_size) {
		LOG_ERR("Invalid metadata data received");
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		return;
	}

	ctx.code_status = UPDATEHUB_OK;

	LOG_INF("Probe metadata received");
}

enum updatehub_response updatehub_probe(void)
{
	struct probe request;
	struct resp_probe_some_boards metadata_some_boards = { 0 };
	struct resp_probe_any_boards metadata_any_boards = { 0 };

	char *metadata = k_malloc(MAX_DOWNLOAD_DATA);
	char *metadata_copy = k_malloc(MAX_DOWNLOAD_DATA);
	char *device_id = k_malloc(DEVICE_ID_HEX_MAX_SIZE);
	char *firmware_version = k_malloc(BOOT_IMG_VER_STRLEN_MAX);

	size_t sha256size;

	if (device_id == NULL || firmware_version == NULL ||
	    metadata == NULL || metadata_copy == NULL) {
		LOG_ERR("Could not alloc probe memory");
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		goto error;
	}

	if (!boot_is_img_confirmed()) {
		LOG_ERR("The current image is not confirmed");
		ctx.code_status = UPDATEHUB_UNCONFIRMED_IMAGE;
		goto error;
	}

	if (!updatehub_get_firmware_version(firmware_version, BOOT_IMG_VER_STRLEN_MAX)) {
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		goto error;
	}

	if (!updatehub_get_device_identity(device_id, DEVICE_ID_HEX_MAX_SIZE)) {
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		goto error;
	}

	memset(&request, 0, sizeof(request));
	request.product_uid = CONFIG_UPDATEHUB_PRODUCT_UID;
	request.device_identity.id = device_id;
	request.version = firmware_version;
	request.hardware = CONFIG_BOARD;

	memset(&ctx.payload, 0, MAX_PAYLOAD_SIZE);
	if (json_obj_encode_buf(send_probe_descr,
				ARRAY_SIZE(send_probe_descr),
				&request, ctx.payload,
				MAX_PAYLOAD_SIZE - 1) < 0) {
		LOG_ERR("Could not encode metadata");
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		goto error;
	}

	ctx.nfds = 0;

	if (!start_coap_client()) {
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		goto error;
	}

	if (send_request(COAP_TYPE_CON, COAP_METHOD_POST, UPDATEHUB_PROBE) < 0) {
		ctx.code_status = UPDATEHUB_NETWORKING_ERROR;
		goto cleanup;
	}

	probe_cb(metadata, MAX_DOWNLOAD_DATA);

	if (ctx.code_status != UPDATEHUB_OK) {
		goto cleanup;
	}

	memset(&update_info, 0, sizeof(update_info));
	if (metadata_hash_get(metadata) < 0) {
		LOG_ERR("Could not get metadata hash");
		ctx.code_status = UPDATEHUB_METADATA_ERROR;
		goto cleanup;
	}

	LOG_DBG("metadata size: %d", strlen(metadata));
	LOG_HEXDUMP_DBG(metadata, MAX_DOWNLOAD_DATA, "metadata");

	memcpy(metadata_copy, metadata, strlen(metadata));
	if (json_obj_parse(metadata, strlen(metadata),
			   recv_probe_sh_array_descr,
			   ARRAY_SIZE(recv_probe_sh_array_descr),
			   &metadata_some_boards) < 0) {

		if (json_obj_parse(metadata_copy, strlen(metadata_copy),
				   recv_probe_sh_string_descr,
				   ARRAY_SIZE(recv_probe_sh_string_descr),
				   &metadata_any_boards) < 0) {
			LOG_ERR("Could not parse json");
			ctx.code_status = UPDATEHUB_METADATA_ERROR;
			goto cleanup;
		}

		if (metadata_any_boards.objects_len != 2) {
			LOG_ERR("Could not parse json");
			ctx.code_status = UPDATEHUB_METADATA_ERROR;
			goto cleanup;
		}

		sha256size = strlen(
			metadata_any_boards.objects[1].objects.sha256sum) + 1;

		if (sha256size != SHA256_HEX_DIGEST_SIZE) {
			LOG_ERR("SHA256 size is invalid");
			ctx.code_status = UPDATEHUB_METADATA_ERROR;
			goto cleanup;
		}

		memcpy(update_info.sha256sum_image,
		       metadata_any_boards.objects[1].objects.sha256sum,
		       SHA256_HEX_DIGEST_SIZE);
		update_info.image_size = metadata_any_boards.objects[1].objects.size;
		LOG_DBG("metadata_any: %s",
			update_info.sha256sum_image);
	} else {
		if (metadata_some_boards.objects_len != 2) {
			LOG_ERR("Could not parse json");
			ctx.code_status = UPDATEHUB_METADATA_ERROR;
			goto cleanup;
		}

		if (!is_compatible_hardware(&metadata_some_boards)) {
			LOG_ERR("Incompatible hardware");
			ctx.code_status =
				UPDATEHUB_INCOMPATIBLE_HARDWARE;
			goto cleanup;
		}

		sha256size = strlen(
			metadata_some_boards.objects[1].objects.sha256sum) + 1;

		if (sha256size != SHA256_HEX_DIGEST_SIZE) {
			LOG_ERR("SHA256 size is invalid");
			ctx.code_status = UPDATEHUB_METADATA_ERROR;
			goto cleanup;
		}

		memcpy(update_info.sha256sum_image,
		       metadata_some_boards.objects[1].objects.sha256sum,
		       SHA256_HEX_DIGEST_SIZE);
		update_info.image_size =
			metadata_some_boards.objects[1].objects.size;
		LOG_DBG("metadata_some: %s",
			update_info.sha256sum_image);
	}

	ctx.code_status = UPDATEHUB_HAS_UPDATE;

cleanup:
	cleanup_connection();

error:
	k_free(metadata);
	k_free(metadata_copy);
	k_free(firmware_version);
	k_free(device_id);

	return ctx.code_status;
}

enum updatehub_response updatehub_update(void)
{
	if (report(UPDATEHUB_STATE_DOWNLOADING) < 0) {
		LOG_ERR("Could not reporting downloading state");
		goto error;
	}

	if (report(UPDATEHUB_STATE_INSTALLING) < 0) {
		LOG_ERR("Could not reporting installing state");
		goto error;
	}

	if (install_update() != UPDATEHUB_OK) {
		goto error;
	}

	if (report(UPDATEHUB_STATE_DOWNLOADED) < 0) {
		LOG_ERR("Could not reporting downloaded state");
		goto error;
	}

	if (boot_request_upgrade(BOOT_UPGRADE_TEST)) {
		LOG_ERR("Could not reporting downloaded state");
		ctx.code_status = UPDATEHUB_INSTALL_ERROR;
		goto error;
	}

	if (report(UPDATEHUB_STATE_INSTALLED) < 0) {
		LOG_ERR("Could not reporting installed state");
		goto error;
	}

	if (report(UPDATEHUB_STATE_REBOOTING) < 0) {
		LOG_ERR("Could not reporting rebooting state");
		goto error;
	}

	LOG_INF("Image flashed successfully, you can reboot now");

	return ctx.code_status;

error:
	if (ctx.code_status != UPDATEHUB_NETWORKING_ERROR) {
		if (report(UPDATEHUB_STATE_ERROR) < 0) {
			LOG_ERR("Could not reporting error state");
		}
	}

	return ctx.code_status;
}

static void autohandler(struct k_work *work)
{
	switch (updatehub_probe()) {
	case UPDATEHUB_UNCONFIRMED_IMAGE:
		LOG_ERR("Image is unconfirmed. Rebooting to revert back to previous"
			"confirmed image.");

		LOG_PANIC();
		sys_reboot(SYS_REBOOT_WARM);
		break;

	case UPDATEHUB_HAS_UPDATE:
		switch (updatehub_update()) {
		case UPDATEHUB_OK:
			LOG_PANIC();
			sys_reboot(SYS_REBOOT_WARM);
			break;

		default:
			break;
		}

		break;

	case UPDATEHUB_NO_UPDATE:
		break;

	default:
		break;
	}

	k_work_reschedule(&updatehub_work_handle, UPDATEHUB_POLL_INTERVAL);
}

void updatehub_autohandler(void)
{
#if defined(CONFIG_UPDATEHUB_DOWNLOAD_SHA256_VERIFICATION)
	LOG_INF("SHA-256 verification on download only");
#endif
#if defined(CONFIG_UPDATEHUB_STORAGE_SHA256_VERIFICATION)
	LOG_INF("SHA-256 verification from flash only");
#endif
#if defined(CONFIG_UPDATEHUB_DOWNLOAD_STORAGE_SHA256_VERIFICATION)
	LOG_INF("SHA-256 verification on download and from flash");
#endif

	k_work_init_delayable(&updatehub_work_handle, autohandler);
	k_work_reschedule(&updatehub_work_handle, K_NO_WAIT);
}