/*
 * Copyright (c) 2017 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <logging/log.h>
LOG_MODULE_REGISTER(net_mqtt_publisher_sample, LOG_LEVEL_DBG);

#include <zephyr.h>
#include <net/socket.h>
#include <net/mqtt.h>

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

#include "config.h"

/* Buffers for MQTT client. */
static u8_t rx_buffer[APP_MQTT_BUFFER_SIZE];
static u8_t tx_buffer[APP_MQTT_BUFFER_SIZE];

#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
/* Making RX buffer large enough that the full IPv6 packet can fit into it */
#define MQTT_LIB_WEBSOCKET_RECV_BUF_LEN 1280

/* Websocket needs temporary buffer to store partial packets */
static u8_t temp_ws_rx_buf[MQTT_LIB_WEBSOCKET_RECV_BUF_LEN];
#endif

/* The mqtt client struct */
static struct mqtt_client client_ctx;

/* MQTT Broker details. */
static struct sockaddr_storage broker;

#if defined(CONFIG_SOCKS)
static struct sockaddr socks5_proxy;
#endif

static struct pollfd fds[1];
static int nfds;

static bool connected;

#if defined(CONFIG_MQTT_LIB_TLS)

#include "test_certs.h"

#define TLS_SNI_HOSTNAME "localhost"
#define APP_CA_CERT_TAG 1
#define APP_PSK_TAG 2

static sec_tag_t m_sec_tags[] = {
#if defined(MBEDTLS_X509_CRT_PARSE_C) || defined(CONFIG_NET_SOCKETS_OFFLOAD)
		APP_CA_CERT_TAG,
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
		APP_PSK_TAG,
#endif
};

static int tls_init(void)
{
	int err = -EINVAL;

#if defined(MBEDTLS_X509_CRT_PARSE_C) || defined(CONFIG_NET_SOCKETS_OFFLOAD)
	err = tls_credential_add(APP_CA_CERT_TAG, TLS_CREDENTIAL_CA_CERTIFICATE,
				 ca_certificate, sizeof(ca_certificate));
	if (err < 0) {
		LOG_ERR("Failed to register public certificate: %d", err);
		return err;
	}
#endif

#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
	err = tls_credential_add(APP_PSK_TAG, TLS_CREDENTIAL_PSK,
				 client_psk, sizeof(client_psk));
	if (err < 0) {
		LOG_ERR("Failed to register PSK: %d", err);
		return err;
	}

	err = tls_credential_add(APP_PSK_TAG, TLS_CREDENTIAL_PSK_ID,
				 client_psk_id, sizeof(client_psk_id) - 1);
	if (err < 0) {
		LOG_ERR("Failed to register PSK ID: %d", err);
	}
#endif

	return err;
}

#endif /* CONFIG_MQTT_LIB_TLS */

static void prepare_fds(struct mqtt_client *client)
{
	if (client->transport.type == MQTT_TRANSPORT_NON_SECURE) {
		fds[0].fd = client->transport.tcp.sock;
	}
#if defined(CONFIG_MQTT_LIB_TLS)
	else if (client->transport.type == MQTT_TRANSPORT_SECURE) {
		fds[0].fd = client->transport.tls.sock;
	}
#endif

	fds[0].events = ZSOCK_POLLIN;
	nfds = 1;
}

static void clear_fds(void)
{
	nfds = 0;
}

static void wait(int timeout)
{
	if (nfds > 0) {
		if (poll(fds, nfds, timeout) < 0) {
			LOG_ERR("poll error: %d", errno);
		}
	}
}

void mqtt_evt_handler(struct mqtt_client *const client,
		      const struct mqtt_evt *evt)
{
	int err;

	switch (evt->type) {
	case MQTT_EVT_CONNACK:
		if (evt->result != 0) {
			LOG_ERR("MQTT connect failed %d", evt->result);
			break;
		}

		connected = true;
		LOG_INF("MQTT client connected!");

		break;

	case MQTT_EVT_DISCONNECT:
		LOG_INF("MQTT client disconnected %d", evt->result);

		connected = false;
		clear_fds();

		break;

	case MQTT_EVT_PUBACK:
		if (evt->result != 0) {
			LOG_ERR("MQTT PUBACK error %d", evt->result);
			break;
		}

		LOG_INF("PUBACK packet id: %u", evt->param.puback.message_id);

		break;

	case MQTT_EVT_PUBREC:
		if (evt->result != 0) {
			LOG_ERR("MQTT PUBREC error %d", evt->result);
			break;
		}

		LOG_INF("PUBREC packet id: %u", evt->param.pubrec.message_id);

		const struct mqtt_pubrel_param rel_param = {
			.message_id = evt->param.pubrec.message_id
		};

		err = mqtt_publish_qos2_release(client, &rel_param);
		if (err != 0) {
			LOG_ERR("Failed to send MQTT PUBREL: %d", err);
		}

		break;

	case MQTT_EVT_PUBCOMP:
		if (evt->result != 0) {
			LOG_ERR("MQTT PUBCOMP error %d", evt->result);
			break;
		}

		LOG_INF("PUBCOMP packet id: %u",
			evt->param.pubcomp.message_id);

		break;

	default:
		break;
	}
}

static char *get_mqtt_payload(enum mqtt_qos qos)
{
#if APP_BLUEMIX_TOPIC
	static char payload[30];

	snprintk(payload, sizeof(payload), "{d:{temperature:%d}}",
		 (u8_t)sys_rand32_get());
#else
	static char payload[] = "DOORS:OPEN_QoSx";

	payload[strlen(payload) - 1] = '0' + qos;
#endif

	return payload;
}

static char *get_mqtt_topic(void)
{
#if APP_BLUEMIX_TOPIC
	return "iot-2/type/"BLUEMIX_DEVTYPE"/id/"BLUEMIX_DEVID
	       "/evt/"BLUEMIX_EVENT"/fmt/"BLUEMIX_FORMAT;
#else
	return "sensors";
#endif
}

static int publish(struct mqtt_client *client, enum mqtt_qos qos)
{
	struct mqtt_publish_param param;

	param.message.topic.qos = qos;
	param.message.topic.topic.utf8 = (u8_t *)get_mqtt_topic();
	param.message.topic.topic.size =
			strlen(param.message.topic.topic.utf8);
	param.message.payload.data = get_mqtt_payload(qos);
	param.message.payload.len =
			strlen(param.message.payload.data);
	param.message_id = sys_rand32_get();
	param.dup_flag = 0U;
	param.retain_flag = 0U;

	return mqtt_publish(client, &param);
}

#define RC_STR(rc) ((rc) == 0 ? "OK" : "ERROR")

#define PRINT_RESULT(func, rc) \
	LOG_INF("%s: %d <%s>", (func), rc, RC_STR(rc))

static void broker_init(void)
{
#if defined(CONFIG_NET_IPV6)
	struct sockaddr_in6 *broker6 = (struct sockaddr_in6 *)&broker;

	broker6->sin6_family = AF_INET6;
	broker6->sin6_port = htons(SERVER_PORT);
	inet_pton(AF_INET6, SERVER_ADDR, &broker6->sin6_addr);

#if defined(CONFIG_SOCKS)
	struct sockaddr_in6 *proxy6 = (struct sockaddr_in6 *)&socks5_proxy;

	proxy6->sin6_family = AF_INET6;
	proxy6->sin6_port = htons(SOCKS5_PROXY_PORT);
	inet_pton(AF_INET6, SOCKS5_PROXY_ADDR, &proxy6->sin6_addr);
#endif
#else
	struct sockaddr_in *broker4 = (struct sockaddr_in *)&broker;

	broker4->sin_family = AF_INET;
	broker4->sin_port = htons(SERVER_PORT);
	inet_pton(AF_INET, SERVER_ADDR, &broker4->sin_addr);
#if defined(CONFIG_SOCKS)
	struct sockaddr_in *proxy4 = (struct sockaddr_in *)&socks5_proxy;

	proxy4->sin_family = AF_INET;
	proxy4->sin_port = htons(SOCKS5_PROXY_PORT);
	inet_pton(AF_INET, SOCKS5_PROXY_ADDR, &proxy4->sin_addr);
#endif
#endif
}

static void client_init(struct mqtt_client *client)
{
	mqtt_client_init(client);

	broker_init();

	/* MQTT client configuration */
	client->broker = &broker;
	client->evt_cb = mqtt_evt_handler;
	client->client_id.utf8 = (u8_t *)MQTT_CLIENTID;
	client->client_id.size = strlen(MQTT_CLIENTID);
	client->password = NULL;
	client->user_name = NULL;
	client->protocol_version = MQTT_VERSION_3_1_1;

	/* MQTT buffers configuration */
	client->rx_buf = rx_buffer;
	client->rx_buf_size = sizeof(rx_buffer);
	client->tx_buf = tx_buffer;
	client->tx_buf_size = sizeof(tx_buffer);

	/* MQTT transport configuration */
#if defined(CONFIG_MQTT_LIB_TLS)
#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
	client->transport.type = MQTT_TRANSPORT_SECURE_WEBSOCKET;
#else
	client->transport.type = MQTT_TRANSPORT_SECURE;
#endif

	struct mqtt_sec_config *tls_config = &client->transport.tls.config;

	tls_config->peer_verify = 2;
	tls_config->cipher_list = NULL;
	tls_config->sec_tag_list = m_sec_tags;
	tls_config->sec_tag_count = ARRAY_SIZE(m_sec_tags);
#if defined(MBEDTLS_X509_CRT_PARSE_C) || defined(CONFIG_NET_SOCKETS_OFFLOAD)
	tls_config->hostname = TLS_SNI_HOSTNAME;
#else
	tls_config->hostname = NULL;
#endif

#else
#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
	client->transport.type = MQTT_TRANSPORT_NON_SECURE_WEBSOCKET;
#else
	client->transport.type = MQTT_TRANSPORT_NON_SECURE;
#endif
#endif

#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
	client->transport.websocket.config.host = SERVER_ADDR;
	client->transport.websocket.config.url = "/mqtt";
	client->transport.websocket.config.tmp_buf = temp_ws_rx_buf;
	client->transport.websocket.config.tmp_buf_len =
						sizeof(temp_ws_rx_buf);
	client->transport.websocket.timeout = K_SECONDS(5);
#endif

#if defined(CONFIG_SOCKS)
	mqtt_client_set_proxy(client, &socks5_proxy,
			      socks5_proxy.sa_family == AF_INET ?
			      sizeof(struct sockaddr_in) :
			      sizeof(struct sockaddr_in6));
#endif
}

/* In this routine we block until the connected variable is 1 */
static int try_to_connect(struct mqtt_client *client)
{
	int rc, i = 0;

	while (i++ < APP_CONNECT_TRIES && !connected) {

		client_init(client);

		rc = mqtt_connect(client);
		if (rc != 0) {
			PRINT_RESULT("mqtt_connect", rc);
			k_sleep(APP_SLEEP_MSECS);
			continue;
		}

		prepare_fds(client);

		wait(APP_SLEEP_MSECS);
		mqtt_input(client);

		if (!connected) {
			mqtt_abort(client);
		}
	}

	if (connected) {
		return 0;
	}

	return -EINVAL;
}

static int process_mqtt_and_sleep(struct mqtt_client *client, int timeout)
{
	s64_t remaining = timeout;
	s64_t start_time = k_uptime_get();
	int rc;

	while (remaining > 0 && connected) {
		wait(remaining);

		rc = mqtt_live(client);
		if (rc != 0) {
			PRINT_RESULT("mqtt_live", rc);
			return rc;
		}

		rc = mqtt_input(client);
		if (rc != 0) {
			PRINT_RESULT("mqtt_input", rc);
			return rc;
		}

		remaining = timeout + start_time - k_uptime_get();
	}

	return 0;
}

#define SUCCESS_OR_EXIT(rc) { if (rc != 0) { return; } }
#define SUCCESS_OR_BREAK(rc) { if (rc != 0) { break; } }

static void publisher(void)
{
	int i, rc;

	LOG_INF("attempting to connect: ");
	rc = try_to_connect(&client_ctx);
	PRINT_RESULT("try_to_connect", rc);
	SUCCESS_OR_EXIT(rc);

	i = 0;
	while (i++ < APP_MAX_ITERATIONS && connected) {
		rc = mqtt_ping(&client_ctx);
		PRINT_RESULT("mqtt_ping", rc);
		SUCCESS_OR_BREAK(rc);

		rc = process_mqtt_and_sleep(&client_ctx, APP_SLEEP_MSECS);
		SUCCESS_OR_BREAK(rc);

		rc = publish(&client_ctx, MQTT_QOS_0_AT_MOST_ONCE);
		PRINT_RESULT("mqtt_publish", rc);
		SUCCESS_OR_BREAK(rc);

		rc = process_mqtt_and_sleep(&client_ctx, APP_SLEEP_MSECS);
		SUCCESS_OR_BREAK(rc);

		rc = publish(&client_ctx, MQTT_QOS_1_AT_LEAST_ONCE);
		PRINT_RESULT("mqtt_publish", rc);
		SUCCESS_OR_BREAK(rc);

		rc = process_mqtt_and_sleep(&client_ctx, APP_SLEEP_MSECS);
		SUCCESS_OR_BREAK(rc);

		rc = publish(&client_ctx, MQTT_QOS_2_EXACTLY_ONCE);
		PRINT_RESULT("mqtt_publish", rc);
		SUCCESS_OR_BREAK(rc);

		rc = process_mqtt_and_sleep(&client_ctx, APP_SLEEP_MSECS);
		SUCCESS_OR_BREAK(rc);
	}

	rc = mqtt_disconnect(&client_ctx);
	PRINT_RESULT("mqtt_disconnect", rc);

	wait(APP_SLEEP_MSECS);
	rc = mqtt_input(&client_ctx);
	PRINT_RESULT("mqtt_input", rc);

	LOG_INF("Bye!");
}

void main(void)
{
#if defined(CONFIG_MQTT_LIB_TLS)
	int rc;

	rc = tls_init();
	PRINT_RESULT("tls_init", rc);
#endif

	while (1) {
		publisher();
		k_sleep(K_MSEC(5000));
	}
}