/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

/*
	Random portability stuff

	See comments in porting.h
*/

#include "porting.h"

#if defined(__APPLE__)
	#include <mach-o/dyld.h>
	#include "CoreFoundation/CoreFoundation.h"
#elif defined(__FreeBSD__)
	#include <sys/types.h>
	#include <sys/sysctl.h>
#elif defined(_WIN32)
	#include <algorithm>
#elif defined(__LINUX)
	#include <sys/types.h>
#endif
#if !defined(_WIN32)
	#include <sys/stat.h>
	#include <unistd.h>
	#include <sys/utsname.h>
#endif

#include "config.h"
#include "debug.h"
#include "filesys.h"
#include "log.h"
#include "util/string.h"
#include "main.h"
#include "settings.h"
#include <list>

namespace porting
{

/*
	Signal handler (grabs Ctrl-C on POSIX systems)
*/

bool g_killed = false;

bool * signal_handler_killstatus(void)
{
	return &g_killed;
}

#if !defined(_WIN32) // POSIX
	#include <signal.h>

void sigint_handler(int sig)
{
	if(g_killed == false)
	{
		dstream<<DTIME<<"INFO: sigint_handler(): "
				<<"Ctrl-C pressed, shutting down."<<std::endl;

		// Comment out for less clutter when testing scripts
		/*dstream<<DTIME<<"INFO: sigint_handler(): "
				<<"Printing debug stacks"<<std::endl;
		debug_stacks_print();*/

		g_killed = true;
	}
	else
	{
		(void)signal(SIGINT, SIG_DFL);
	}
}

void signal_handler_init(void)
{
	(void)signal(SIGINT, sigint_handler);
}

#else // _WIN32
	#include <signal.h>

	BOOL WINAPI event_handler(DWORD sig)
	{
		switch(sig)
		{
		case CTRL_C_EVENT:
		case CTRL_CLOSE_EVENT:
		case CTRL_LOGOFF_EVENT:
		case CTRL_SHUTDOWN_EVENT:

			if(g_killed == false)
			{
				dstream<<DTIME<<"INFO: event_handler(): "
						<<"Ctrl+C, Close Event, Logoff Event or Shutdown Event, shutting down."<<std::endl;
				// Comment out for less clutter when testing scripts
				/*dstream<<DTIME<<"INFO: event_handler(): "
						<<"Printing debug stacks"<<std::endl;
				debug_stacks_print();*/

				g_killed = true;
			}
			else
			{
				(void)signal(SIGINT, SIG_DFL);
			}

			break;
		case CTRL_BREAK_EVENT:
			break;
		}

		return TRUE;
	}

void signal_handler_init(void)
{
	SetConsoleCtrlHandler( (PHANDLER_ROUTINE)event_handler,TRUE);
}

#endif


/*
	Multithreading support
*/
int getNumberOfProcessors()
{
#if defined(_SC_NPROCESSORS_ONLN)

	return sysconf(_SC_NPROCESSORS_ONLN);

#elif defined(__FreeBSD__) || defined(__APPLE__)

	unsigned int len, count;
	len = sizeof(count);
	return sysctlbyname("hw.ncpu", &count, &len, NULL, 0);

#elif defined(_GNU_SOURCE)

	return get_nprocs();

#elif defined(_WIN32)

	SYSTEM_INFO sysinfo;
	GetSystemInfo(&sysinfo);
	return sysinfo.dwNumberOfProcessors;

#elif defined(PTW32_VERSION) || defined(__hpux)

	return pthread_num_processors_np();

#else

	return 1;

#endif
}


bool threadBindToProcessor(threadid_t tid, int pnumber)
{
#if defined(_WIN32)

	HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, 0, tid);
	if (!hThread)
		return false;

	bool success = SetThreadAffinityMask(hThread, 1 << pnumber) != 0;

	CloseHandle(hThread);
	return success;

#elif (defined(__FreeBSD__) && (__FreeBSD_version >= 702106)) \
	|| defined(__linux) || defined(linux)

	cpu_set_t cpuset;

	CPU_ZERO(&cpuset);
	CPU_SET(pnumber, &cpuset);
	return pthread_setaffinity_np(tid, sizeof(cpuset), &cpuset) == 0;

#elif defined(__sun) || defined(sun)

	return processor_bind(P_LWPID, MAKE_LWPID_PTHREAD(tid),
						pnumber, NULL) == 0;

#elif defined(_AIX)
	
	return bindprocessor(BINDTHREAD, (tid_t)tid, pnumber) == 0;

#elif defined(__hpux) || defined(hpux)

	pthread_spu_t answer;

	return pthread_processor_bind_np(PTHREAD_BIND_ADVISORY_NP,
									&answer, pnumber, tid) == 0;
	
#elif defined(__APPLE__)

	struct thread_affinity_policy tapol;
	
	thread_port_t threadport = pthread_mach_thread_np(tid);
	tapol.affinity_tag = pnumber + 1;
	return thread_policy_set(threadport, THREAD_AFFINITY_POLICY,
			(thread_policy_t)&tapol, THREAD_AFFINITY_POLICY_COUNT) == KERN_SUCCESS;

#else

	return false;

#endif
}


bool threadSetPriority(threadid_t tid, int prio)
{
#if defined(_WIN32)

	HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, 0, tid);
	if (!hThread)
		return false;

	bool success = SetThreadPriority(hThread, prio) != 0;

	CloseHandle(hThread);
	return success;
	
#else

	struct sched_param sparam;
	int policy;
	
	if (pthread_getschedparam(tid, &policy, &sparam) != 0)
		return false;
		
	int min = sched_get_priority_min(policy);
	int max = sched_get_priority_max(policy);

	sparam.sched_priority = min + prio * (max - min) / THREAD_PRIORITY_HIGHEST;
	return pthread_setschedparam(tid, policy, &sparam) == 0;
	
#endif
}


/*
	Path mangler
*/

// Default to RUN_IN_PLACE style relative paths
std::string path_share = "..";
std::string path_user = "..";

std::string getDataPath(const char *subpath)
{
	return path_share + DIR_DELIM + subpath;
}

void pathRemoveFile(char *path, char delim)
{
	// Remove filename and path delimiter
	int i;
	for(i = strlen(path)-1; i>=0; i--)
	{
		if(path[i] == delim)
			break;
	}
	path[i] = 0;
}

bool detectMSVCBuildDir(char *c_path)
{
	std::string path(c_path);
	const char *ends[] = {"bin\\Release", "bin\\Build", NULL};
	return (removeStringEnd(path, ends) != "");
}

std::string get_sysinfo()
{
#ifdef _WIN32
	OSVERSIONINFO osvi;
	std::ostringstream oss;
	std::string tmp;
	ZeroMemory(&osvi, sizeof(OSVERSIONINFO));
	osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
	GetVersionEx(&osvi);
	tmp = osvi.szCSDVersion;
	std::replace(tmp.begin(), tmp.end(), ' ', '_');

	oss << "Windows/" << osvi.dwMajorVersion << "."
		<< osvi.dwMinorVersion;
	if(osvi.szCSDVersion[0])
		oss << "-" << tmp;
	oss << " ";
	#ifdef _WIN64
	oss << "x86_64";
	#else
	BOOL is64 = FALSE;
	if(IsWow64Process(GetCurrentProcess(), &is64) && is64)
		oss << "x86_64"; // 32-bit app on 64-bit OS
	else
		oss << "x86";
	#endif

	return oss.str();
#else
	struct utsname osinfo;
	uname(&osinfo);
	return std::string(osinfo.sysname) + "/"
		+ osinfo.release + " " + osinfo.machine;
#endif
}

void initializePaths()
{
#if RUN_IN_PLACE
	/*
		Use relative paths if RUN_IN_PLACE
	*/

	infostream<<"Using relative paths (RUN_IN_PLACE)"<<std::endl;

	/*
		Windows
	*/
	#if defined(_WIN32)

	const DWORD buflen = 1000;
	char buf[buflen];
	DWORD len;

	// Find path of executable and set path_share relative to it
	len = GetModuleFileName(GetModuleHandle(NULL), buf, buflen);
	assert(len < buflen);
	pathRemoveFile(buf, '\\');

	if(detectMSVCBuildDir(buf)){
		infostream<<"MSVC build directory detected"<<std::endl;
		path_share = std::string(buf) + "\\..\\..";
		path_user = std::string(buf) + "\\..\\..";
	}
	else{
		path_share = std::string(buf) + "\\..";
		path_user = std::string(buf) + "\\..";
	}

	/*
		Linux
	*/
	#elif defined(linux)

	char buf[BUFSIZ];
	memset(buf, 0, BUFSIZ);
	// Get path to executable
	assert(readlink("/proc/self/exe", buf, BUFSIZ-1) != -1);

	pathRemoveFile(buf, '/');

	path_share = std::string(buf) + "/..";
	path_user = std::string(buf) + "/..";

	/*
		OS X
	*/
	#elif defined(__APPLE__)

	//https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man3/dyld.3.html
	//TODO: Test this code
	char buf[BUFSIZ];
	uint32_t len = sizeof(buf);
	assert(_NSGetExecutablePath(buf, &len) != -1);

	pathRemoveFile(buf, '/');

	path_share = std::string(buf) + "/..";
	path_user = std::string(buf) + "/..";

	/*
		FreeBSD
	*/
	#elif defined(__FreeBSD__)

	int mib[4];
	char buf[BUFSIZ];
	size_t len = sizeof(buf);

	mib[0] = CTL_KERN;
	mib[1] = KERN_PROC;
	mib[2] = KERN_PROC_PATHNAME;
	mib[3] = -1;
	assert(sysctl(mib, 4, buf, &len, NULL, 0) != -1);

	pathRemoveFile(buf, '/');

	path_share = std::string(buf) + "/..";
	path_user = std::string(buf) + "/..";

	#else

	//TODO: Get path of executable. This assumes working directory is bin/
	dstream<<"WARNING: Relative path not properly supported on this platform"
			<<std::endl;

	/* scriptapi no longer allows paths that start with "..", so assuming that
	   the current working directory is bin/, strip off the last component. */
	char *cwd = getcwd(NULL, 0);
	pathRemoveFile(cwd, '/');
	path_share = std::string(cwd);
	path_user = std::string(cwd);

	#endif

#else // RUN_IN_PLACE

	/*
		Use platform-specific paths otherwise
	*/

	infostream<<"Using system-wide paths (NOT RUN_IN_PLACE)"<<std::endl;

	/*
		Windows
	*/
	#if defined(_WIN32)

	const DWORD buflen = 1000;
	char buf[buflen];
	DWORD len;

	// Find path of executable and set path_share relative to it
	len = GetModuleFileName(GetModuleHandle(NULL), buf, buflen);
	assert(len < buflen);
	pathRemoveFile(buf, '\\');

	// Use ".\bin\.."
	path_share = std::string(buf) + "\\..";

	// Use "C:\Documents and Settings\user\Application Data\<PROJECT_NAME>"
	len = GetEnvironmentVariable("APPDATA", buf, buflen);
	assert(len < buflen);
	path_user = std::string(buf) + DIR_DELIM + PROJECT_NAME;

	/*
		Linux
	*/
	#elif defined(linux)

	// Get path to executable
	std::string bindir = "";
	{
		char buf[BUFSIZ];
		memset(buf, 0, BUFSIZ);
		assert(readlink("/proc/self/exe", buf, BUFSIZ-1) != -1);
		pathRemoveFile(buf, '/');
		bindir = buf;
	}

	// Find share directory from these.
	// It is identified by containing the subdirectory "builtin".
	std::list<std::string> trylist;
	std::string static_sharedir = STATIC_SHAREDIR;
	if(static_sharedir != "" && static_sharedir != ".")
		trylist.push_back(static_sharedir);
	trylist.push_back(
			bindir + DIR_DELIM + ".." + DIR_DELIM + "share" + DIR_DELIM + PROJECT_NAME);
	trylist.push_back(bindir + DIR_DELIM + "..");

	for(std::list<std::string>::const_iterator i = trylist.begin();
			i != trylist.end(); i++)
	{
		const std::string &trypath = *i;
		if(!fs::PathExists(trypath) || !fs::PathExists(trypath + DIR_DELIM + "builtin")){
			dstream<<"WARNING: system-wide share not found at \""
					<<trypath<<"\""<<std::endl;
			continue;
		}
		// Warn if was not the first alternative
		if(i != trylist.begin()){
			dstream<<"WARNING: system-wide share found at \""
					<<trypath<<"\""<<std::endl;
		}
		path_share = trypath;
		break;
	}

	path_user = std::string(getenv("HOME")) + DIR_DELIM + "." + PROJECT_NAME;

	/*
		OS X
	*/
	#elif defined(__APPLE__)

	// Code based on
	// http://stackoverflow.com/questions/516200/relative-paths-not-working-in-xcode-c
	CFBundleRef main_bundle = CFBundleGetMainBundle();
	CFURLRef resources_url = CFBundleCopyResourcesDirectoryURL(main_bundle);
	char path[PATH_MAX];
	if(CFURLGetFileSystemRepresentation(resources_url, TRUE, (UInt8 *)path, PATH_MAX))
	{
		dstream<<"Bundle resource path: "<<path<<std::endl;
		//chdir(path);
		path_share = std::string(path) + DIR_DELIM + "share";
	}
	else
	{
		// error!
		dstream<<"WARNING: Could not determine bundle resource path"<<std::endl;
	}
	CFRelease(resources_url);

	path_user = std::string(getenv("HOME")) + "/Library/Application Support/" + PROJECT_NAME;

	#else // FreeBSD, and probably many other POSIX-like systems.

	path_share = STATIC_SHAREDIR;
	path_user = std::string(getenv("HOME")) + DIR_DELIM + "." + PROJECT_NAME;

	#endif

#endif // RUN_IN_PLACE
}

static irr::IrrlichtDevice* device;

void initIrrlicht(irr::IrrlichtDevice * _device)
{
	device = _device;
}

#ifndef SERVER
v2u32 getWindowSize()
{
	return device->getVideoDriver()->getScreenSize();
}


float getDisplayDensity()
{
	float gui_scaling = g_settings->getFloat("gui_scaling");
	// using Y here feels like a bug, this needs to be discussed later!
	if (getWindowSize().Y <= 800) {
		return (2.0/3.0) * gui_scaling;
	}
	if (getWindowSize().Y <= 1280) {
		return 1.0 * gui_scaling;
	}

	return (4.0/3.0) * gui_scaling;
}

v2u32 getDisplaySize()
{
	IrrlichtDevice *nulldevice = createDevice(video::EDT_NULL);

	core::dimension2d<u32> deskres = nulldevice->getVideoModeList()->getDesktopResolution();
	nulldevice -> drop();

	return deskres;
}
#endif

#ifdef SERVER
#ifdef _WIN32
void daemonize()
{
	errorstream << "daemonize not implemented on windows" << std::endl;
}
#else // assume posix like os

static std::string get_pidfile_path()
{
	// make it static to make sure it won't change after first call to this fct
	static std::string path_pidfile = "";
	static bool initialized = false;

	if (initialized)
	{
		return path_pidfile;
	}

	g_settings->getNoEx("pidfile", path_pidfile);

	if (path_pidfile == "") {
#ifdef RUN_IN_PLACE
		path_pidfile = "pidfile.pid";
#else
		path_pidfile = "/var/run/minetest.pid";
#endif
	}
	initialized = true;
	return path_pidfile;
}


void daemonize()
{
	std::string path_pidfile = get_pidfile_path();

	FILE* pidfile = fopen(path_pidfile.c_str(),"r");

	if (pidfile) {
		int pid = 0;
		if (fscanf(pidfile, "%i", &pid) == 1) {
			if (kill(pid, 0) == 0) {
				errorstream <<
						"Minetestserver is already running with pid: "
						<< pid << std::endl;
				exit(-1);
			}
		} else {
			errorstream << "Pidfile \"" << path_pidfile << "\" "
					"already exists but content is invalid" << std::endl <<
					"Delete it manually if you're sure minetest isn't running!"
					<< std::endl;
			exit(-1);
		}
		fclose(pidfile);
		pidfile = 0;
	}

	pid_t pid = fork();

	if (pid > 0) {
		pidfile = fopen(path_pidfile.c_str(),"w+");
		if (pidfile) {
			fprintf(pidfile,"%i",pid);
			fclose(pidfile);
		} else {
			errorstream << "Failed to create pidfile: \"" << path_pidfile
					<< "\""<< std::endl;
		}
		exit (0);
	} else if (pid == 0) {
		fclose(stdout);
		fclose(stderr);
		return;
	}

	errorstream << "Failed to daemonize minetest, exiting" << std::endl;
	exit(-1);
}

void cleanup_pid()
{
	unlink(get_pidfile_path().c_str());
}
#endif
#endif

} //namespace porting