/**************************************************************************/
/*  test_udp_server.h                                                     */
/**************************************************************************/
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#pragma once

#include "core/io/packet_peer_udp.h"
#include "core/io/udp_server.h"
#include "tests/test_macros.h"

namespace TestUDPServer {

const int PORT = 12345;
const IPAddress LOCALHOST("127.0.0.1");
const uint32_t SLEEP_DURATION = 1000;
const uint64_t MAX_WAIT_USEC = 100000;

void wait_for_condition(std::function<bool()> f_test) {
	const uint64_t time = OS::get_singleton()->get_ticks_usec();
	while (!f_test() && (OS::get_singleton()->get_ticks_usec() - time) < MAX_WAIT_USEC) {
		OS::get_singleton()->delay_usec(SLEEP_DURATION);
	}
}

Ref<UDPServer> create_server(const IPAddress &p_address, int p_port) {
	Ref<UDPServer> server;
	server.instantiate();

	Error err = server->listen(PORT, LOCALHOST);
	REQUIRE_EQ(Error::OK, err);
	REQUIRE(server->is_listening());
	CHECK_FALSE(server->is_connection_available());
	CHECK_EQ(server->get_max_pending_connections(), 16);

	return server;
}

Ref<PacketPeerUDP> create_client(const IPAddress &p_address, int p_port) {
	Ref<PacketPeerUDP> client;
	client.instantiate();

	Error err = client->connect_to_host(LOCALHOST, PORT);
	REQUIRE_EQ(Error::OK, err);
	CHECK(client->is_bound());
	CHECK(client->is_socket_connected());

	return client;
}

Ref<PacketPeerUDP> accept_connection(Ref<UDPServer> &p_server) {
	wait_for_condition([&]() {
		return p_server->poll() != Error::OK || p_server->is_connection_available();
	});

	CHECK_EQ(p_server->poll(), Error::OK);
	REQUIRE(p_server->is_connection_available());
	Ref<PacketPeerUDP> client_from_server = p_server->take_connection();
	REQUIRE(client_from_server.is_valid());
	CHECK(client_from_server->is_bound());
	CHECK(client_from_server->is_socket_connected());

	return client_from_server;
}

TEST_CASE("[UDPServer] Instantiation") {
	Ref<UDPServer> server;
	server.instantiate();

	REQUIRE(server.is_valid());
	CHECK_EQ(false, server->is_listening());
}

TEST_CASE("[UDPServer] Accept a connection and receive/send data") {
	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
	Ref<PacketPeerUDP> client = create_client(LOCALHOST, PORT);

	// Sending data from client to server.
	const String hello_world = "Hello World!";
	CHECK_EQ(client->put_var(hello_world), Error::OK);

	Variant hello_world_received;
	Ref<PacketPeerUDP> client_from_server = accept_connection(server);
	CHECK_EQ(client_from_server->get_var(hello_world_received), Error::OK);
	CHECK_EQ(String(hello_world_received), hello_world);

	// Sending data from server to client.
	const Variant pi = 3.1415;
	CHECK_EQ(client_from_server->put_var(pi), Error::OK);

	wait_for_condition([&]() {
		return client->get_available_packet_count() > 0;
	});

	CHECK_GT(client->get_available_packet_count(), 0);

	Variant pi_received;
	CHECK_EQ(client->get_var(pi_received), Error::OK);
	CHECK_EQ(pi_received, pi);

	client->close();
	server->stop();
	CHECK_FALSE(server->is_listening());
}

TEST_CASE("[UDPServer] Handle multiple clients at the same time") {
	Ref<UDPServer> server = create_server(LOCALHOST, PORT);

	Vector<Ref<PacketPeerUDP>> clients;
	for (int i = 0; i < 5; i++) {
		Ref<PacketPeerUDP> c = create_client(LOCALHOST, PORT);

		// Sending data from client to server.
		const String hello_client = itos(i);
		CHECK_EQ(c->put_var(hello_client), Error::OK);

		clients.push_back(c);
	}

	Array packets;
	for (int i = 0; i < clients.size(); i++) {
		Ref<PacketPeerUDP> cfs = accept_connection(server);

		Variant received_var;
		CHECK_EQ(cfs->get_var(received_var), Error::OK);
		CHECK_EQ(received_var.get_type(), Variant::STRING);
		packets.push_back(received_var);

		// Sending data from server to client.
		const float sent_float = 3.1415 + received_var.operator String().to_float();
		CHECK_EQ(cfs->put_var(sent_float), Error::OK);
	}

	CHECK_EQ(packets.size(), clients.size());

	packets.sort();
	for (int i = 0; i < clients.size(); i++) {
		CHECK_EQ(packets[i].operator String(), itos(i));
	}

	wait_for_condition([&]() {
		bool should_exit = true;
		for (Ref<PacketPeerUDP> &c : clients) {
			int count = c->get_available_packet_count();
			if (count < 0) {
				return true;
			}
			if (count == 0) {
				should_exit = false;
			}
		}
		return should_exit;
	});

	for (int i = 0; i < clients.size(); i++) {
		CHECK_GT(clients[i]->get_available_packet_count(), 0);

		Variant received_var;
		const float expected = 3.1415 + i;
		CHECK_EQ(clients[i]->get_var(received_var), Error::OK);
		CHECK_EQ(received_var.get_type(), Variant::FLOAT);
		CHECK_EQ(received_var.operator float(), expected);
	}

	for (Ref<PacketPeerUDP> &c : clients) {
		c->close();
	}
	server->stop();
}

TEST_CASE("[UDPServer] Should not accept new connections after stop") {
	Ref<UDPServer> server = create_server(LOCALHOST, PORT);
	Ref<PacketPeerUDP> client = create_client(LOCALHOST, PORT);

	// Sending data from client to server.
	const String hello_world = "Hello World!";
	CHECK_EQ(client->put_var(hello_world), Error::OK);

	wait_for_condition([&]() {
		return server->poll() != Error::OK || server->is_connection_available();
	});

	REQUIRE(server->is_connection_available());

	server->stop();

	CHECK_FALSE(server->is_listening());
	CHECK_FALSE(server->is_connection_available());
}

} // namespace TestUDPServer