/*

Copyright (c) 2005, 2008, 2010, 2012-2022, Arvid Norberg
Copyright (c) 2017, Andrei Kurushin
Copyright (c) 2018, Steven Siloti
Copyright (c) 2021, Alden Torres
All rights reserved.

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

#include <iostream>
#include <boost/config.hpp>
#include <fcntl.h>
#include <cstdio>
#include <cstdlib> // for exit()
#include "libtorrent/address.hpp"
#include "libtorrent/socket.hpp"
#include "setup_transfer.hpp" // for unit_test::g_test_failures
#include "test.hpp"
#include "dht_server.hpp" // for stop_dht
#include "peer_server.hpp" // for stop_peer
#include "udp_tracker.hpp" // for stop_udp_tracker
#include <boost/system/system_error.hpp>

#include "libtorrent/assert.hpp"
#include "libtorrent/aux_/path.hpp"
#include "libtorrent/aux_/random.hpp"
#include "libtorrent/aux_/escape_string.hpp"
#include <csignal>

#ifdef _WIN32
#include "libtorrent/aux_/windows.hpp" // for SetErrorMode
#include <io.h> // for _dup and _dup2
#include <process.h> // for _getpid
#include <crtdbg.h>

#define dup _dup
#define dup2 _dup2

#else

#include <unistd.h> // for getpid()

#endif

using namespace lt;

namespace {

// these are global so we can restore them on abnormal exits and print stuff
// out, such as the log
int old_stdout = -1;
int old_stderr = -1;
#ifdef _WIN32
bool redirect_stdout = !IsDebuggerPresent();
#else
bool redirect_stdout = true;
#endif
// sanitizer output will go to stderr and we won't get an opportunity to print
// it, so don't redirect stderr by default
bool redirect_stderr = false;
bool keep_files = false;

// the current tests file descriptor
unit_test::unit_test_t* current_test = nullptr;

void output_test_log_to_terminal()
{
	if (current_test == nullptr
		|| current_test->output == nullptr)
		return;

	fflush(stdout);
	fflush(stderr);
	if (old_stdout != -1)
	{
		dup2(old_stdout, fileno(stdout));
		old_stdout = -1;
	}
	if (old_stderr != -1)
	{
		dup2(old_stderr, fileno(stderr));
		old_stderr = -1;
	}

	fseek(current_test->output, 0, SEEK_SET);
	std::printf("::group::%s\n", current_test->name);
	std::printf("\x1b[1m[%s]\x1b[0m\n\n", current_test->name);
	char buf[4096];
	std::size_t size = 0;
	do {
		size = fread(buf, 1, sizeof(buf), current_test->output);
		if (size > 0) fwrite(buf, 1, size, stdout);
	} while (size > 0);
	std::printf("::endgroup::\n");
}

#ifdef _WIN32
LONG WINAPI seh_exception_handler(LPEXCEPTION_POINTERS p)
{
	char stack_text[10000];

#if TORRENT_USE_ASSERTS \
	|| defined TORRENT_ASIO_DEBUGGING \
	|| defined TORRENT_PROFILE_CALLS \
	|| defined TORRENT_DEBUG_BUFFERS
	print_backtrace(stack_text, sizeof(stack_text), 30
		, p->ContextRecord);
#elif defined __FUNCTION__
	strcpy(stack_text, __FUNCTION__);
#else
	strcpy(stack_text, "<stack traces disabled>");
#endif

	DWORD const code = p->ExceptionRecord->ExceptionCode;
	char const* name = "<unknown exception>";
	switch (code)
	{
#define EXC(x) case x: name = #x; break
		EXC(EXCEPTION_ACCESS_VIOLATION);
		EXC(EXCEPTION_ARRAY_BOUNDS_EXCEEDED);
		EXC(EXCEPTION_BREAKPOINT);
		EXC(EXCEPTION_DATATYPE_MISALIGNMENT);
		EXC(EXCEPTION_FLT_DENORMAL_OPERAND);
		EXC(EXCEPTION_FLT_DIVIDE_BY_ZERO);
		EXC(EXCEPTION_FLT_INEXACT_RESULT);
		EXC(EXCEPTION_FLT_INVALID_OPERATION);
		EXC(EXCEPTION_FLT_OVERFLOW);
		EXC(EXCEPTION_FLT_STACK_CHECK);
		EXC(EXCEPTION_FLT_UNDERFLOW);
		EXC(EXCEPTION_ILLEGAL_INSTRUCTION);
		EXC(EXCEPTION_IN_PAGE_ERROR);
		EXC(EXCEPTION_INT_DIVIDE_BY_ZERO);
		EXC(EXCEPTION_INT_OVERFLOW);
		EXC(EXCEPTION_INVALID_DISPOSITION);
		EXC(EXCEPTION_NONCONTINUABLE_EXCEPTION);
		EXC(EXCEPTION_PRIV_INSTRUCTION);
		EXC(EXCEPTION_SINGLE_STEP);
		EXC(EXCEPTION_STACK_OVERFLOW);
#undef EXC
	};

	std::printf("exception: (0x%x) %s caught:\n%s\n"
		, code, name, stack_text);

	output_test_log_to_terminal();

	exit(code);
}

#endif

[[noreturn]] void sig_handler(int sig)
{
	char stack_text[10000];

#if TORRENT_USE_ASSERTS \
	|| defined TORRENT_ASIO_DEBUGGING \
	|| defined TORRENT_PROFILE_CALLS \
	|| defined TORRENT_DEBUG_BUFFERS
	print_backtrace(stack_text, sizeof(stack_text), 30);
#elif defined __FUNCTION__
	strcpy(stack_text, __FUNCTION__);
#else
	strcpy(stack_text, "<stack traces disabled>");
#endif
	char const* name = "<unknown signal>";
	switch (sig)
	{
#define SIG(x) case x: name = #x; break
		SIG(SIGSEGV);
#ifdef SIGBUS
		SIG(SIGBUS);
#endif
		SIG(SIGINT);
		SIG(SIGTERM);
		SIG(SIGILL);
		SIG(SIGABRT);
		SIG(SIGFPE);
#ifdef SIGSYS
		SIG(SIGSYS);
#endif
#undef SIG
	}
	std::printf("signal: (%d) %s caught:\n%s\n", sig, name, stack_text);

	output_test_log_to_terminal();

	std::exit(128 + sig);
}

[[noreturn]] void term_handler()
{
	char stack_text[10000];
#if TORRENT_USE_ASSERTS \
	|| defined TORRENT_ASIO_DEBUGGING \
	|| defined TORRENT_PROFILE_CALLS \
	|| defined TORRENT_DEBUG_BUFFERS
	print_backtrace(stack_text, sizeof(stack_text), 30);
#elif defined __FUNCTION__
	strcpy(stack_text, __FUNCTION__);
#else
	strcpy(stack_text, "<stack traces disabled>");
#endif
	std::printf("\n\nterminate called:\n%s\n\n\n", stack_text);
	std::exit(-1);
}

void print_usage(char const* executable)
{
	std::printf("%s [options] [tests...]\n"
		"\n"
		"OPTIONS:\n"
		"-h,--help            show this help\n"
		"-l,--list            list the tests available to run\n"
		"-k,--keep            keep files created by the test\n"
		"                     regardless of whether it passed or not\n"
		"-n,--no-redirect     don't redirect test output to\n"
		"                     temporary file, but let it go straight\n"
		"                     to stdout\n"
		"--stderr-redirect    also redirect stderr in addition to stdout\n"
		"\n"
		"for tests, specify one or more test names as printed\n"
		"by -l. If no test is specified, all tests are run\n", executable);
}

void change_directory(std::string const& f, error_code& ec)
{
	ec.clear();

	native_path_string const n = convert_to_native_path_string(f);

#ifdef TORRENT_WINDOWS
	if (SetCurrentDirectoryW(n.c_str()) == 0)
		ec.assign(GetLastError(), system_category());
#else
	int ret = ::chdir(n.c_str());
	if (ret != 0)
		ec.assign(errno, system_category());
#endif
}

} // anonymous namespace

struct unit_directory_guard
{
	explicit unit_directory_guard(std::string d) : dir(std::move(d)) {}
	unit_directory_guard(unit_directory_guard const&) = delete;
	unit_directory_guard& operator=(unit_directory_guard const&) = delete;
	~unit_directory_guard()
	{
		if (keep_files) return;
		error_code ec;
		std::string const parent_dir = parent_path(dir);
		// windows will not allow to remove current dir, so let's change it to root
		change_directory(parent_dir, ec);
		if (ec)
		{
			TEST_ERROR("Failed to change directory: " + ec.message());
			return;
		}
		remove_all(dir, ec);
#ifdef TORRENT_WINDOWS
		if (ec.value() == ERROR_SHARING_VIOLATION)
		{
			// on windows, files are removed in the background, and we may need
			// to wait a little bit
			std::this_thread::sleep_for(milliseconds(400));
			remove_all(dir, ec);
		}
#endif
		if (ec) std::cerr << "Failed to remove unit test directory: " << ec.message() << "\n";
	}
private:
	std::string dir;
};

namespace unit_test {

void EXPORT reset_output()
{
	if (current_test == nullptr || current_test->output == nullptr) return;
	fflush(stdout);
	fflush(stderr);
	rewind(current_test->output);
#ifdef TORRENT_WINDOWS
	int const r = _chsize(fileno(current_test->output), 0);
#else
	int const r = ftruncate(fileno(current_test->output), 0);
#endif
	if (r != 0)
	{
		// this is best effort, it's not the end of the world if we fail
		std::cerr << "ftruncate of temporary test output file failed: " << strerror(errno) << "\n";
	}
}

}

int EXPORT main(int argc, char const* argv[])
{
	char const* executable = argv[0];
	// skip executable name
	++argv;
	--argc;

	// pick up options
	while (argc > 0 && argv[0][0] == '-')
	{
		if (argv[0] == "-h"_sv || argv[0] == "--help"_sv)
		{
			print_usage(executable);
			return 0;
		}

		if (argv[0] == "-l"_sv || argv[0] == "--list"_sv)
		{
			std::printf("TESTS:\n");
			for (int i = 0; i < ::unit_test::g_num_unit_tests; ++i)
			{
				std::printf(" - %s\n", ::unit_test::g_unit_tests[i].name);
			}
			return 0;
		}

		if (argv[0] == "-n"_sv || argv[0] == "--no-redirect"_sv)
		{
			redirect_stdout = false;
			redirect_stderr = false;
		}

		if (argv[0] == "--stderr-redirect"_sv)
		{
			redirect_stderr = true;
		}

		if (argv[0] == "-k"_sv || argv[0] == "--keep"_sv)
		{
			keep_files = true;
		}
		++argv;
		--argc;
	}

	std::set<std::string> tests_to_run;
	bool filter = false;

	for (int i = 0; i < argc; ++i)
	{
		tests_to_run.insert(argv[i]);
		filter = true;
	}

#ifdef O_NONBLOCK
	// on darwin, stdout is set to non-blocking mode by default
	// which sometimes causes tests to fail with EAGAIN just
	// by printing logs
	int flags = fcntl(fileno(stdout), F_GETFL, 0);
	fcntl(fileno(stdout), F_SETFL, flags & ~O_NONBLOCK);
	flags = fcntl(fileno(stderr), F_GETFL, 0);
	fcntl(fileno(stderr), F_SETFL, flags & ~O_NONBLOCK);
#endif

#ifdef _WIN32
	// try to suppress hanging the process by windows displaying
	// modal dialogs.
	SetErrorMode(SEM_NOALIGNMENTFAULTEXCEPT
		| SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX);

	SetUnhandledExceptionFilter(&seh_exception_handler);

#ifdef _DEBUG
	_CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE);
	_CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
#endif

#endif

	std::set_terminate(term_handler);

	signal(SIGSEGV, &sig_handler);
#ifdef SIGBUS
	signal(SIGBUS, &sig_handler);
#endif
	signal(SIGILL, &sig_handler);
	signal(SIGINT, &sig_handler);
	signal(SIGABRT, &sig_handler);
	signal(SIGFPE, &sig_handler);
#ifdef SIGSYS
	signal(SIGSYS, &sig_handler);
#endif

	int process_id = -1;
#ifdef _WIN32
	process_id = _getpid();
#else
	process_id = getpid();
#endif
	std::string const root_dir = current_working_directory();
	std::string const unit_dir_prefix = combine_path(root_dir, "test_tmp_" + std::to_string(process_id) + "_");
	std::printf("test: %s\ncwd_prefix = \"%s\"\n", executable, unit_dir_prefix.c_str());

	if (unit_test::g_num_unit_tests == 0)
	{
		std::printf("\x1b[31mTEST_ERROR: no unit tests registered\x1b[0m\n");
		return 1;
	}

	if (redirect_stdout) old_stdout = dup(fileno(stdout));
	if (redirect_stderr) old_stderr = dup(fileno(stderr));

	int num_run = 0;
	for (int i = 0; i < unit_test::g_num_unit_tests; ++i)
	{
		if (filter && tests_to_run.count(unit_test::g_unit_tests[i].name) == 0)
			continue;

		std::string const unit_dir = unit_dir_prefix + std::to_string(i);
		error_code ec;
		create_directory(unit_dir, ec);
		if (ec)
		{
			std::printf("Failed to create unit test directory: %s\n", ec.message().c_str());
			output_test_log_to_terminal();
			return 1;
		}
		unit_directory_guard unit_dir_guard{unit_dir};
		change_directory(unit_dir, ec);
		if (ec)
		{
			std::printf("Failed to change unit test directory: %s\n", ec.message().c_str());
			output_test_log_to_terminal();
			return 1;
		}

		auto& t = ::unit_test::g_unit_tests[i];

		if (redirect_stdout || redirect_stderr)
		{
			// redirect test output to a temporary file
			fflush(stdout);
			fflush(stderr);
			FILE* f = tmpfile();
			if (f != nullptr)
			{
				int ret1 = 0;
				if (redirect_stdout) ret1 |= dup2(fileno(f), fileno(stdout));
				if (redirect_stderr) ret1 |= dup2(fileno(f), fileno(stderr));
				if (ret1 >= 0)
				{
					t.output = f;
				}
				else
				{
					std::printf("failed to redirect output: (%d) %s\n"
						, errno, strerror(errno));
				}
			}
			else
			{
				std::printf("failed to create temporary file for redirecting "
					"output: (%d) %s\n", errno, strerror(errno));
			}
		}

		// get proper interleaving of stderr and stdout
		setbuf(stdout, nullptr);
		setbuf(stderr, nullptr);

		::unit_test::g_test_idx = i;
		current_test = &t;

		std::printf("cwd: %s\n", unit_dir.c_str());
		std::printf("test-case: %s\n", t.name);
		std::mt19937 rng(0x82daf973);
		lt::aux::random_engine() = rng;
		std::printf("rnd = %x\n", lt::aux::random(0xffffffff));

#ifndef BOOST_NO_EXCEPTIONS
		try
		{
#endif

			std::srand(0x82daf973);
			lt::aux::random_engine().seed(0x82daf973);

			::unit_test::g_test_failures = 0;
			(*t.fun)();
#ifndef BOOST_NO_EXCEPTIONS
		}
		catch (boost::system::system_error const& e)
		{
			char buf[200];
			std::snprintf(buf, sizeof(buf), "TEST_ERROR: Terminated with system_error: (%d) [%s] \"%s\""
				, e.code().value()
				, e.code().category().name()
				, e.code().message().c_str());
			unit_test::report_failure(buf, __FILE__, __LINE__);
		}
		catch (std::exception const& e)
		{
			char buf[200];
			std::snprintf(buf, sizeof(buf), "TEST_ERROR: Terminated with exception: \"%s\"", e.what());
			unit_test::report_failure(buf, __FILE__, __LINE__);
		}
		catch (...)
		{
			unit_test::report_failure("TEST_ERROR: Terminated with unknown exception", __FILE__, __LINE__);
		}
#endif

		if (!tests_to_run.empty()) tests_to_run.erase(t.name);

		if (::unit_test::g_test_failures > 0)
		{
			output_test_log_to_terminal();
		}

		t.num_failures = ::unit_test::g_test_failures;
		t.run = true;
		++num_run;

		if (redirect_stdout && t.output)
			fclose(t.output);
	}

	if (redirect_stdout && old_stdout != -1) dup2(old_stdout, fileno(stdout));
	if (redirect_stderr && old_stderr != -1) dup2(old_stderr, fileno(stderr));

	if (!tests_to_run.empty())
	{
		std::printf("\x1b[1mUNKNOWN tests:\x1b[0m\n");
		for (std::set<std::string>::iterator i = tests_to_run.begin()
			, end(tests_to_run.end()); i != end; ++i)
		{
			std::printf("  %s\n", i->c_str());
		}
	}

	if (num_run == 0)
	{
		std::printf("\x1b[31mTEST_ERROR: no unit tests run\x1b[0m\n");
		output_test_log_to_terminal();
		return 1;
	}

	// just in case of premature exits
	// make sure we try to clean up some
	stop_udp_tracker();
	stop_all_proxies();
	stop_web_server();
	stop_peer();
	stop_dht();

	if (redirect_stdout) fflush(stdout);
	if (redirect_stderr) fflush(stderr);

	return unit_test::print_failures() ? 333 : 0;
}