/*

Copyright (c) 2008-2009, 2012-2022, Arvid Norberg
Copyright (c) 2016, Andrei Kurushin
Copyright (c) 2018, 2020, Alden Torres
All rights reserved.

You may use, distribute and modify this code under the terms of the BSD license,
see LICENSE file.
*/

#include "libtorrent/session.hpp"
#include "libtorrent/session_settings.hpp"
#include "libtorrent/session_params.hpp"
#include "libtorrent/alert_types.hpp"
#include "libtorrent/ip_filter.hpp"
#include "libtorrent/aux_/path.hpp"
#include <tuple>
#include <iostream>

#include "test.hpp"
#include "test_utils.hpp"
#include "setup_transfer.hpp"
#include "settings.hpp"

namespace {

void test_swarm()
{
	using namespace lt;

	// these are declared before the session objects
	// so that they are destructed last. This enables
	// the sessions to destruct in parallel
	session_proxy p1;
	session_proxy p2;
	session_proxy p3;

	// this is to avoid everything finish from a single peer
	// immediately. To make the swarm actually connect all
	// three peers before finishing.
	float rate_limit = 50000;

	settings_pack pack = settings();
	// run the choker once per second, to make it more likely to actually trigger
	// during the test.
	pack.set_int(settings_pack::unchoke_interval, 1);

	pack.set_bool(settings_pack::allow_multiple_connections_per_ip, true);
	pack.set_int(settings_pack::choking_algorithm, settings_pack::rate_based_choker);
	pack.set_int(settings_pack::upload_rate_limit, int(rate_limit));
	pack.set_int(settings_pack::unchoke_slots_limit, 1);
	pack.set_int(settings_pack::max_retry_port_bind, 900);
	pack.set_str(settings_pack::listen_interfaces, test_listen_interface());
	pack.set_bool(settings_pack::enable_natpmp, false);
	pack.set_bool(settings_pack::enable_upnp, false);
	pack.set_bool(settings_pack::enable_dht, false);
#if TORRENT_ABI_VERSION == 1
	pack.set_bool(settings_pack::rate_limit_utp, true);
#endif

	pack.set_int(settings_pack::out_enc_policy, settings_pack::pe_forced);
	pack.set_int(settings_pack::in_enc_policy, settings_pack::pe_forced);

	lt::session ses1(pack);

	pack.set_int(settings_pack::upload_rate_limit, int(rate_limit / 10));
	pack.set_int(settings_pack::download_rate_limit, int(rate_limit / 5));
	pack.set_int(settings_pack::unchoke_slots_limit, 0);
	pack.set_int(settings_pack::choking_algorithm, settings_pack::fixed_slots_choker);
	pack.set_str(settings_pack::listen_interfaces, test_listen_interface());

	lt::session ses2(pack);

	pack.set_str(settings_pack::listen_interfaces, test_listen_interface());

	lt::session ses3(pack);

	auto const [tor1, tor2, tor3] = setup_transfer(&ses1, &ses2, &ses3, true, false, true, "_unchoke");

	std::map<std::string, std::int64_t> cnt = get_counters(ses1);

	std::printf("allowed_upload_slots: %d\n", int(cnt["ses.num_unchoke_slots"]));
	TEST_EQUAL(cnt["ses.num_unchoke_slots"], 1);
	auto const start_time = lt::clock_type::now();
	for (int i = 0; i < 200; ++i)
	{
		print_alerts(ses1, "ses1");
		print_alerts(ses2, "ses2");
		print_alerts(ses3, "ses3");

		cnt = get_counters(ses1);
		std::printf("allowed unchoked: %d\n", int(cnt["ses.num_unchoke_slots"]));
		if (cnt["ses.num_unchoke_slots"] >= 2) break;

		torrent_status st1 = tor1.status();
		torrent_status st2 = tor2.status();
		torrent_status st3 = tor3.status();

		print_ses_rate(start_time, &st1, &st2, &st3);

		std::this_thread::sleep_for(lt::milliseconds(100));
	}

	TEST_CHECK(cnt["ses.num_unchoke_slots"] >= 2);

	// make sure the files are deleted
	ses1.remove_torrent(tor1, lt::session::delete_files);
	ses2.remove_torrent(tor2, lt::session::delete_files);
	ses3.remove_torrent(tor3, lt::session::delete_files);

	// this allows shutting down the sessions in parallel
	p1 = ses1.abort();
	p2 = ses2.abort();
	p3 = ses3.abort();
}

} // anonymous namespace

TORRENT_TEST(auto_unchoke)
{
	using namespace lt;

	// in case the previous run was terminated
	error_code ec;
	remove_all("./tmp1_unchoke", ec);
	remove_all("./tmp2_unchoke", ec);
	remove_all("./tmp3_unchoke", ec);

	test_swarm();

	TEST_CHECK(!exists("./tmp1_unchoke/temporary"));
	TEST_CHECK(!exists("./tmp2_unchoke/temporary"));
	TEST_CHECK(!exists("./tmp3_unchoke/temporary"));

	remove_all("./tmp1_unchoke", ec);
	remove_all("./tmp2_unchoke", ec);
	remove_all("./tmp3_unchoke", ec);
}