/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <time.h>
#ifdef POSIX
#include <sys/time.h>
#include <unistd.h>
#include <signal.h>
// sighandler_t is a GNU extension exposed when _GNU_SOURCE is defined
#ifndef _GNU_SOURCE
typedef void (*sighandler_t)(int);
#endif
#elif defined(WIN32)
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef main
#endif

// We use some stdio.h functionality here thus we need to allow some
// symbols. Alternatively, we could simply allow everything by defining
// FORBIDDEN_SYMBOL_ALLOW_ALL
#define FORBIDDEN_SYMBOL_EXCEPTION_FILE
#define FORBIDDEN_SYMBOL_EXCEPTION_stdout
#define FORBIDDEN_SYMBOL_EXCEPTION_stderr
#define FORBIDDEN_SYMBOL_EXCEPTION_fputs
#define FORBIDDEN_SYMBOL_EXCEPTION_exit
#define FORBIDDEN_SYMBOL_EXCEPTION_time_h

#include "common/scummsys.h"

#if defined(USE_NULL_DRIVER)
#include "backends/modular-backend.h"
#include "backends/mutex/null/null-mutex.h"
#include "base/main.h"

#ifndef NULL_DRIVER_USE_FOR_TEST
#include "backends/saves/default/default-saves.h"
#include "backends/timer/default/default-timer.h"
#include "backends/events/default/default-events.h"
#include "backends/mixer/null/null-mixer.h"
#include "backends/graphics/null/null-graphics.h"
#include "gui/debugger.h"
#endif

/*
 * Include header files needed for the getFilesystemFactory() method.
 */
#if defined(__amigaos4__)
	#include "backends/fs/amigaos/amigaos-fs-factory.h"
#elif defined(__MORPHOS__)
	#include "backends/fs/morphos/morphos-fs-factory.h"
#elif defined(POSIX)
	#include "backends/fs/posix/posix-fs-factory.h"
#elif defined(RISCOS)
	#include "backends/fs/riscos/riscos-fs-factory.h"
#elif defined(WIN32)
	#include "backends/fs/windows/windows-fs-factory.h"
#endif

class OSystem_NULL : public ModularMixerBackend, public ModularGraphicsBackend, Common::EventSource {
public:
	OSystem_NULL(bool silenceLogs);
	virtual ~OSystem_NULL();

	virtual void initBackend();

	virtual bool pollEvent(Common::Event &event);

	virtual Common::MutexInternal *createMutex();
	virtual uint32 getMillis(bool skipRecord = false);
	virtual void delayMillis(uint msecs);
	virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const;

	virtual void quit();

	virtual void logMessage(LogMessageType::Type type, const char *message);

	virtual void addSysArchivesToSearchSet(Common::SearchSet &s, int priority);

private:
#ifdef POSIX
	timeval _startTime;
#elif defined(WIN32)
	DWORD _startTime;
#endif
	bool _silenceLogs;
};

OSystem_NULL::OSystem_NULL(bool silenceLogs) :
	_silenceLogs(silenceLogs) {
	#if defined(__amigaos4__)
		_fsFactory = new AmigaOSFilesystemFactory();
	#elif defined(__MORPHOS__)
		_fsFactory = new MorphOSFilesystemFactory();
	#elif defined(POSIX)
		_fsFactory = new POSIXFilesystemFactory();
	#elif defined(RISCOS)
		_fsFactory = new RISCOSFilesystemFactory();
	#elif defined(WIN32)
		_fsFactory = new WindowsFilesystemFactory();
	#else
		#error Unknown and unsupported FS backend
	#endif
}

OSystem_NULL::~OSystem_NULL() {
}

#if defined(POSIX) && !defined(NULL_DRIVER_USE_FOR_TEST)
static volatile bool intReceived = false;

static sighandler_t last_handler;

void intHandler(int dummy) {
	signal(SIGINT, last_handler);
	intReceived = true;
}
#endif

void OSystem_NULL::initBackend() {
#ifdef POSIX
	gettimeofday(&_startTime, 0);
#elif defined(WIN32)
	_startTime = GetTickCount();
#endif

#ifndef NULL_DRIVER_USE_FOR_TEST
#ifdef POSIX
	last_handler = signal(SIGINT, intHandler);
#endif

	_timerManager = new DefaultTimerManager();
	_eventManager = new DefaultEventManager(this);
	_savefileManager = new DefaultSaveFileManager();
	_graphicsManager = new NullGraphicsManager();
	_mixerManager = new NullMixerManager();
	// Setup and start mixer
	_mixerManager->init();
#endif

	BaseBackend::initBackend();
}

bool OSystem_NULL::pollEvent(Common::Event &event) {
#ifndef NULL_DRIVER_USE_FOR_TEST
	((DefaultTimerManager *)getTimerManager())->checkTimers();
	((NullMixerManager *)_mixerManager)->update(1);

#ifdef POSIX
	if (intReceived) {
		intReceived = false;

#ifdef USE_TEXT_CONSOLE_FOR_DEBUGGER
		GUI::Debugger *debugger = g_engine ? g_engine->getOrCreateDebugger() : nullptr;
		if (debugger && !debugger->isActive()) {
			last_handler = signal(SIGINT, intHandler);
			event.type = Common::EVENT_DEBUGGER;
			return true;
		}
#endif

		event.type = Common::EVENT_QUIT;
		return true;
	}
#endif
#endif

	return false;
}

Common::MutexInternal *OSystem_NULL::createMutex() {
	return new NullMutexInternal();
}

uint32 OSystem_NULL::getMillis(bool skipRecord) {
#ifdef POSIX
	timeval curTime;

	gettimeofday(&curTime, 0);

	return (uint32)(((curTime.tv_sec - _startTime.tv_sec) * 1000) +
			((curTime.tv_usec - _startTime.tv_usec) / 1000));
#elif defined(WIN32)
	return GetTickCount() - _startTime;
#else
	return 0;
#endif
}

void OSystem_NULL::delayMillis(uint msecs) {
#ifdef POSIX
	usleep(msecs * 1000);
#elif defined(WIN32)
	Sleep(msecs);
#endif
}

void OSystem_NULL::getTimeAndDate(TimeDate &td, bool skipRecord) const {
	time_t curTime = time(0);
	struct tm t = *localtime(&curTime);
	td.tm_sec = t.tm_sec;
	td.tm_min = t.tm_min;
	td.tm_hour = t.tm_hour;
	td.tm_mday = t.tm_mday;
	td.tm_mon = t.tm_mon;
	td.tm_year = t.tm_year;
	td.tm_wday = t.tm_wday;
}

#ifndef NULL_DRIVER_USE_FOR_TEST
void OSystem_NULL::quit() {
	exit(0);
}
#endif

void OSystem_NULL::logMessage(LogMessageType::Type type, const char *message) {
	if (_silenceLogs)
		return;

	FILE *output = 0;

	if (type == LogMessageType::kInfo || type == LogMessageType::kDebug)
		output = stdout;
	else
		output = stderr;

	fputs(message, output);
	fflush(output);
}

void OSystem_NULL::addSysArchivesToSearchSet(Common::SearchSet &s, int priority) {
	s.add("test/engine-data", new Common::FSDirectory("test/engine-data", 4), priority);
	s.add("gui/themes", new Common::FSDirectory("gui/themes", 4), priority);
}

OSystem *OSystem_NULL_create(bool silenceLogs) {
	return new OSystem_NULL(silenceLogs);
}

#ifndef NULL_DRIVER_USE_FOR_TEST
int main(int argc, char *argv[]) {
	g_system = OSystem_NULL_create(false);
	assert(g_system);

	// Invoke the actual ScummVM main entry point:
	int res = scummvm_main(argc, argv);
	g_system->destroy();
	return res;
}
#endif

#else /* USE_NULL_DRIVER */

OSystem *OSystem_NULL_create(bool silenceLogs) {
	(void)silenceLogs;
	return NULL;
}

#endif