#include <algorithm>

#include <boost/test/unit_test.hpp>

#include <boost/asio/io_context.hpp>

#include <async_mqtt5/mqtt_client.hpp>

#include "test_common/message_exchange.hpp"
#include "test_common/test_service.hpp"
#include "test_common/test_stream.hpp"

using namespace async_mqtt5;

BOOST_AUTO_TEST_SUITE(ping/*, *boost::unit_test::disabled()*/)

struct shared_test_data {
	error_code success {};
	error_code fail = asio::error::not_connected;

	const std::string connack_no_ka = encoders::encode_connack(
		false, reason_codes::success.value(), {}
	);

	const std::string pingreq = encoders::encode_pingreq();
	const std::string pingresp = encoders::encode_pingresp();
};

using test::after;
using namespace std::chrono;

std::string connect_with_keep_alive(uint16_t keep_alive) {
	return encoders::encode_connect(
		"", std::nullopt, std::nullopt, keep_alive, false, {}, std::nullopt
	);
}

std::string connack_with_keep_alive(uint16_t keep_alive) {
	connack_props cprops;
	cprops[prop::server_keep_alive] = keep_alive;

	return encoders::encode_connack(
		false, reason_codes::success.value(), cprops
	);
}

void run_test(
	test::msg_exchange broker_side,
	std::chrono::milliseconds cancel_timeout,
	uint16_t keep_alive = std::numeric_limits<uint16_t>::max()
) {
	asio::io_context ioc;
	auto executor = ioc.get_executor();
	auto& broker = asio::make_service<test::test_broker>(
		ioc, executor, std::move(broker_side)
	);

	using client_type = mqtt_client<test::test_stream>;
	client_type c(executor, "");
	c.brokers("127.0.0.1,127.0.0.1") // to avoid reconnect backoff
		.keep_alive(keep_alive)
		.async_run(asio::detached);

	asio::steady_timer timer(c.get_executor());
	timer.expires_after(cancel_timeout);
	timer.async_wait([&c](error_code) {
		c.cancel();
	});

	ioc.run();
	BOOST_CHECK(broker.received_all_expected());
}

BOOST_FIXTURE_TEST_CASE(ping_pong_client_ka, shared_test_data) {
	// data
	uint16_t keep_alive = 1;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_no_ka, after(2ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
			.reply_with(pingresp, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(keep_alive * 1000 + 100),
		keep_alive
	);
}

BOOST_FIXTURE_TEST_CASE(ping_pong_server_ka, shared_test_data) {
	// data
	uint16_t keep_alive = 10;
	uint16_t server_keep_alive = 1;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_with_keep_alive(server_keep_alive), after(2ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
			.reply_with(pingresp, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(server_keep_alive * 1000 + 100),
		keep_alive
	);
}

BOOST_FIXTURE_TEST_CASE(disable_ping, shared_test_data) {
	// data
	uint16_t keep_alive = 0;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_no_ka, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(1000),
		keep_alive
	);
}

BOOST_FIXTURE_TEST_CASE(ping_timeout, shared_test_data) {
	// observation in test cases with a real broker:
	// old stream_ptr will receive disconnect with rc: session taken over
	// when the new stream_ptr sends a connect packet

	// data
	uint16_t keep_alive = 1;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_no_ka, after(2ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_no_ka, after(2ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
			.reply_with(pingresp, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(2700),
		keep_alive
	);
}

BOOST_FIXTURE_TEST_CASE(keep_alive_change_while_waiting, shared_test_data) {
	// data
	uint16_t keep_alive = 0;
	uint16_t server_keep_alive = 1;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_with_keep_alive(server_keep_alive), after(2ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
			.reply_with(fail, after(2ms))
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_no_ka, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(1500), keep_alive
	);
}

BOOST_FIXTURE_TEST_CASE(keep_alive_change_during_writing, shared_test_data) {
	// data
	uint16_t keep_alive = 1;
	uint16_t server_keep_alive = 1;

	test::msg_exchange broker_side;
	broker_side
		.expect(connect_with_keep_alive(keep_alive))
			.complete_with(success, after(1ms))
			.reply_with(connack_with_keep_alive(server_keep_alive), after(1500ms))
		.expect(pingreq)
			.complete_with(success, after(1ms))
			.reply_with(pingresp, after(2ms));

	run_test(
		std::move(broker_side),
		std::chrono::milliseconds(2700), keep_alive
	);
}

BOOST_AUTO_TEST_SUITE_END();