/*
	PIP - Platform Independent Primitives
	MQTT Client
	Ivan Pelipenko peri4ko@yandex.ru

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "pimqttclient.h"

#include "MQTTClient.h"


STATIC_INITIALIZER_BEGIN
	MQTTClient_init_options opts = MQTTClient_init_options_initializer;
	MQTTClient_global_init(&opts);
STATIC_INITIALIZER_END


PRIVATE_DEFINITION_START(PIMQTT::Client)
	MQTTClient client = nullptr;
	bool connected    = false;

	static void connectionLost_callback(void * context, char *) {
		((PIMQTT::Client *)context)->mqtt_connectionLost();
	}

	static void deliveryComplete_callback(void * context, MQTTClient_deliveryToken dt) {
		((PIMQTT::Client *)context)->mqtt_deliveryComplete(dt);
	}

	static int messageArrived_callback(void * context, char * topicName, int topicLen, MQTTClient_message * message) {
		PIMQTT::Message msg;
		msg.topic        = PIString::fromUTF8(topicName);
		msg.payload      = PIByteArray(message->payload, message->payloadlen);
		msg.msg_id       = message->msgid;
		msg.is_duplicate = message->dup != 0;
		msg.qos          = static_cast<PIMQTT::QoS>(message->qos);
		MQTTClient_freeMessage(&message);
		MQTTClient_free(topicName);
		((PIMQTT::Client *)context)->mqtt_messageArrived(msg);
		return 1;
	}

PRIVATE_DEFINITION_END(PIMQTT::Client)


PIMQTT::Client::Client() {
	thread = new PIThread([this] { run(); });
	thread->start();
}


PIMQTT::Client::~Client() {
	thread->stop();
	disconnect();
	thread->waitForFinish();
	piDeleteSafety(thread);
}


void PIMQTT::Client::connect(const PIString & address, const PIString & client, const PIString & username, const PIString & password) {
	auto ci      = connect_info.getRef();
	ci->address  = address;
	ci->clientID = client;
	ci->username = username;
	ci->password = password;
	changeStatus(Connecting);
}


void PIMQTT::Client::disconnect() {
	changeStatus(Disconnecting);
}


void PIMQTT::Client::subscribe(const PIString & topic, QoS qos) {
	sub_queue.getRef()->enqueue({topic, qos});
	notifier.notify();
}


void PIMQTT::Client::unsubscribe(const PIString & topic) {
	unsub_queue.getRef()->enqueue(topic);
	notifier.notify();
}


void PIMQTT::Client::publish(const PIString & topic, const PIByteArray & msg, QoS qos) {
	Message m;
	m.topic   = topic;
	m.payload = msg;
	m.qos     = qos;
	pub_queue.getRef()->enqueue(m);
	notifier.notify();
}


void PIMQTT::Client::mqtt_connectionLost() {
	piCoutObj << "mqtt_connectionLost";
	PRIVATE->connected = false;
	changeStatus(Idle);
	disconnected(Error::ServerUnavailable);
}


void PIMQTT::Client::mqtt_deliveryComplete(int token) {}


void PIMQTT::Client::mqtt_messageArrived(const Message & msg) {
	piCoutObj << "mqtt_messageArrived";
	received(msg);
}


void PIMQTT::Client::connectInternal() {
	destroy();
	PRIVATE->connected        = false;
	auto ci                   = connect_info.get();
	PINetworkAddress net_addr = PINetworkAddress::resolve(ci.address);
	if (net_addr.port() == 0) net_addr.setPort(1883);
	PIString server_uri = "tcp://" + net_addr.toString();
	MQTTClient_create(&PRIVATE->client, server_uri.dataAscii(), ci.clientID.dataUTF8(), MQTTCLIENT_PERSISTENCE_NONE, nullptr);
	MQTTClient_setCallbacks(PRIVATE->client,
							this,
							PRIVATE->connectionLost_callback,
							PRIVATE->messageArrived_callback,
							PRIVATE->deliveryComplete_callback);
	MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
	conn_opts.keepAliveInterval         = 9;
	conn_opts.cleansession              = 1;
	conn_opts.connectTimeout            = piRound(connect_timeout.toSeconds());
	if (ci.username.isNotEmpty()) conn_opts.username = ci.username.dataAscii();
	if (ci.password.isNotEmpty()) conn_opts.password = ci.password.dataAscii();
	int ret = MQTTClient_connect(PRIVATE->client, &conn_opts);
	if (ret != MQTTCLIENT_SUCCESS) {
		piCoutObj << "Failed to connect to " + server_uri << ", code" << ret;
		changeStatus(Idle);
		if (ret < 0) ret = static_cast<int>(Error::ServerUnavailable);
		disconnected(static_cast<Error>(ret));
		return;
	}
	PRIVATE->connected = true;
	changeStatus(Connected);
	connected();
}


void PIMQTT::Client::publishInternal(const Message & m) {
	if (!PRIVATE->client) return;
	MQTTClient_message pubmsg = MQTTClient_message_initializer;
	pubmsg.payload            = const_cast<void *>(static_cast<const void *>(m.payload.data()));
	pubmsg.payloadlen         = m.payload.size_s();
	pubmsg.qos                = static_cast<int>(m.qos);
	int ret                   = MQTTClient_publishMessage(PRIVATE->client, m.topic.dataAscii(), &pubmsg, nullptr);
	if (ret != MQTTCLIENT_SUCCESS) {
		piCoutObj << "Failed to publishMessage, code" << ret;
	}
}


void PIMQTT::Client::subscribeInternal(const Subscribe & sub) {
	if (!PRIVATE->client) return;
	int ret = MQTTClient_subscribe(PRIVATE->client, sub.topic.dataUTF8(), static_cast<int>(sub.qos));
	if (ret != MQTTCLIENT_SUCCESS) {
		piCoutObj << "Failed to subscribe" << sub.topic << ", code" << ret;
	}
}


void PIMQTT::Client::unsubscribeInternal(const PIString & topic) {
	if (!PRIVATE->client) return;
	int ret = MQTTClient_unsubscribe(PRIVATE->client, topic.dataUTF8());
	if (ret != MQTTCLIENT_SUCCESS) {
		piCoutObj << "Failed to unsubscribe" << topic << ", code" << ret;
	}
}


void PIMQTT::Client::destroy() {
	if (!PRIVATE->client) return;
	if (PRIVATE->connected) MQTTClient_disconnect(PRIVATE->client, 1000);
	MQTTClient_destroy(&PRIVATE->client);
	PRIVATE->connected = false;
	PRIVATE->client    = nullptr;
}


void PIMQTT::Client::changeStatus(Status s) {
	m_status = s;
	notifier.notify();
}


void PIMQTT::Client::run() {
	notifier.wait();
	piCoutObj << "run" << (int)m_status;
	if (thread->isStopping() || m_status == Disconnecting) {
		bool was_connected = PRIVATE->connected;
		changeStatus(Idle);
		destroy();
		if (was_connected) disconnected(Error::Unknown);
		PRIVATE->connected = false;
		return;
	}
	if (m_status == Connecting) {
		connectInternal();
		return;
	}
	if (m_status == Connected) {
		Subscribe sub;
		{
			auto ref = sub_queue.getRef();
			if (!ref->isEmpty()) sub = ref->dequeue();
		}
		if (sub.topic.isNotEmpty()) {
			subscribeInternal(sub);
			notifier.notify();
			return;
		}

		PIString topic;
		{
			auto ref = unsub_queue.getRef();
			if (!ref->isEmpty()) topic = ref->dequeue();
		}
		if (topic.isNotEmpty()) {
			unsubscribeInternal(topic);
			notifier.notify();
			return;
		}

		Message msg;
		{
			auto ref = pub_queue.getRef();
			if (!ref->isEmpty()) msg = ref->dequeue();
		}
		if (msg.isValid()) {
			publishInternal(msg);
			notifier.notify();
			return;
		}
	}
}