#include "Utils.hpp"
#include "I18N.hpp"

#include <locale>
#include <ctime>
#include <cstdarg>
#include <stdio.h>

#include "Time.hpp"

#ifdef WIN32
	#include <windows.h>
	#include <psapi.h>
#else
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/param.h>
    #include <sys/resource.h>
	#ifdef BSD
		#include <sys/sysctl.h>
	#endif
    #ifdef __APPLE__
        #include <mach/mach.h>
    #endif
#endif

#include <boost/log/core.hpp>
#include <boost/log/trivial.hpp>
#include <boost/log/expressions.hpp>

#include <boost/locale.hpp>

#include <boost/algorithm/string/predicate.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/nowide/fstream.hpp>
#include <boost/nowide/convert.hpp>
#include <boost/nowide/cstdio.hpp>

#include <tbb/task_scheduler_init.h>

#if defined(__linux) || defined(__GNUC__ )
#include <strings.h>
#endif /* __linux */

#ifdef _MSC_VER 
    #define strcasecmp _stricmp
#endif

namespace Slic3r {

static boost::log::trivial::severity_level logSeverity = boost::log::trivial::error;

static boost::log::trivial::severity_level level_to_boost(unsigned level)
{
    switch (level) {
    // Report fatal errors only.
    case 0: return boost::log::trivial::fatal;
    // Report fatal errors and errors.
    case 1: return boost::log::trivial::error;
    // Report fatal errors, errors and warnings.
    case 2: return boost::log::trivial::warning;
    // Report all errors, warnings and infos.
    case 3: return boost::log::trivial::info;
    // Report all errors, warnings, infos and debugging.
    case 4: return boost::log::trivial::debug;
    // Report everyting including fine level tracing information.
    default: return boost::log::trivial::trace;
    }
}

void set_logging_level(unsigned int level)
{
    logSeverity = level_to_boost(level);

    boost::log::core::get()->set_filter
    (
        boost::log::trivial::severity >= logSeverity
    );
}

unsigned get_logging_level()
{
    switch (logSeverity) {
    case boost::log::trivial::fatal : return 0;
    case boost::log::trivial::error : return 1;
    case boost::log::trivial::warning : return 2;
    case boost::log::trivial::info : return 3;
    case boost::log::trivial::debug : return 4;
    case boost::log::trivial::trace : return 5;
    default: return 1;
    }
}

// Force set_logging_level(<=error) after loading of the DLL.
// This is currently only needed if libslic3r is loaded as a shared library into Perl interpreter
// to perform unit and integration tests.
static struct RunOnInit {
    RunOnInit() { 
        set_logging_level(1);
    }
} g_RunOnInit;

void trace(unsigned int level, const char *message)
{
    boost::log::trivial::severity_level severity = level_to_boost(level);

    BOOST_LOG_STREAM_WITH_PARAMS(::boost::log::trivial::logger::get(),\
        (::boost::log::keywords::severity = severity)) << message;
}

void disable_multi_threading()
{
    // Disable parallelization so the Shiny profiler works
    static tbb::task_scheduler_init *tbb_init = nullptr;
    if (tbb_init == nullptr)
        tbb_init = new tbb::task_scheduler_init(1);
}

static std::string g_var_dir;

void set_var_dir(const std::string &dir)
{
    g_var_dir = dir;
}

const std::string& var_dir()
{
    return g_var_dir;
}

std::string var(const std::string &file_name)
{
    auto file = (boost::filesystem::path(g_var_dir) / file_name).make_preferred();
    return file.string();
}

static std::string g_resources_dir;

void set_resources_dir(const std::string &dir)
{
    g_resources_dir = dir;
}

const std::string& resources_dir()
{
    return g_resources_dir;
}

static std::string g_local_dir;

void set_local_dir(const std::string &dir)
{
    g_local_dir = dir;
}

const std::string& localization_dir()
{
	return g_local_dir;
}

// Translate function callback, to call wxWidgets translate function to convert non-localized UTF8 string to a localized one.
Slic3r::I18N::translate_fn_type Slic3r::I18N::translate_fn = nullptr;

static std::string g_data_dir;

void set_data_dir(const std::string &dir)
{
    g_data_dir = dir;
}

const std::string& data_dir()
{
    return g_data_dir;
}

#ifdef _WIN32
// The following helpers are borrowed from the LLVM project https://github.com/llvm
namespace WindowsSupport
{
	template <typename HandleTraits>
	class ScopedHandle {
		typedef typename HandleTraits::handle_type handle_type;
		handle_type Handle;
		ScopedHandle(const ScopedHandle &other) = delete;
		void operator=(const ScopedHandle &other) = delete;
	public:
		ScopedHandle() : Handle(HandleTraits::GetInvalid()) {}
	  	explicit ScopedHandle(handle_type h) : Handle(h) {}
	  	~ScopedHandle() { if (HandleTraits::IsValid(Handle)) HandleTraits::Close(Handle); }
	  	handle_type take() {
	    	handle_type t = Handle;
	    	Handle = HandleTraits::GetInvalid();
	    	return t;
	  	}
	  	ScopedHandle &operator=(handle_type h) {
	    	if (HandleTraits::IsValid(Handle))
	      		HandleTraits::Close(Handle);
	    	Handle = h;
	    	return *this;
	  	}
	  	// True if Handle is valid.
	  	explicit operator bool() const { return HandleTraits::IsValid(Handle) ? true : false; }
	  	operator handle_type() const { return Handle; }
	};

	struct CommonHandleTraits {
	  	typedef HANDLE handle_type;
	  	static handle_type GetInvalid() { return INVALID_HANDLE_VALUE; }
	  	static void Close(handle_type h) { ::CloseHandle(h); }
	  	static bool IsValid(handle_type h) { return h != GetInvalid(); }
	};

	typedef ScopedHandle<CommonHandleTraits> ScopedFileHandle;

	std::error_code map_windows_error(unsigned windows_error_code)
	{
		#define MAP_ERR_TO_COND(x, y) case x: return std::make_error_code(std::errc::y)
		switch (windows_error_code) {
			MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
			MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
			MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
			MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
			MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
			MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
			MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
			MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
			MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
			MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
			MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
			MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
			MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
			MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
			MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
			MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
			MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
			MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
			MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
			MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
			MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
			MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
			MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
			MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
			MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
			MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
			MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
			MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
			MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
			MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
			MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
			MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
			MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
			MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
			MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
			MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
			MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
			MAP_ERR_TO_COND(ERROR_SEEK, io_error);
			MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
			MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
			MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
			MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
			MAP_ERR_TO_COND(WSAEACCES, permission_denied);
			MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
			MAP_ERR_TO_COND(WSAEFAULT, bad_address);
			MAP_ERR_TO_COND(WSAEINTR, interrupted);
			MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
			MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
			MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
		default:
			return std::error_code(windows_error_code, std::system_category());
		}
		#undef MAP_ERR_TO_COND
	}

	static std::error_code rename_internal(HANDLE from_handle, const std::wstring &wide_to, bool replace_if_exists)
	{
		std::vector<char> rename_info_buf(sizeof(FILE_RENAME_INFO) - sizeof(wchar_t) + (wide_to.size() * sizeof(wchar_t)));
		FILE_RENAME_INFO &rename_info = *reinterpret_cast<FILE_RENAME_INFO*>(rename_info_buf.data());
		rename_info.ReplaceIfExists = replace_if_exists;
		rename_info.RootDirectory = 0;
		rename_info.FileNameLength = DWORD(wide_to.size() * sizeof(wchar_t));
		std::copy(wide_to.begin(), wide_to.end(), &rename_info.FileName[0]);

		::SetLastError(ERROR_SUCCESS);
		if (! ::SetFileInformationByHandle(from_handle, FileRenameInfo, &rename_info, (DWORD)rename_info_buf.size())) {
			unsigned Error = GetLastError();
			if (Error == ERROR_SUCCESS)
		  		Error = ERROR_CALL_NOT_IMPLEMENTED; // Wine doesn't always set error code.
			return map_windows_error(Error);
		}

		return std::error_code();
	}

	static std::error_code real_path_from_handle(HANDLE H, std::wstring &buffer)
	{
		buffer.resize(MAX_PATH + 1);
		DWORD CountChars = ::GetFinalPathNameByHandleW(H, (LPWSTR)buffer.data(), (DWORD)buffer.size() - 1, FILE_NAME_NORMALIZED);
	  	if (CountChars > buffer.size()) {
	    	// The buffer wasn't big enough, try again.  In this case the return value *does* indicate the size of the null terminator.
	    	buffer.resize((size_t)CountChars);
	    	CountChars = ::GetFinalPathNameByHandleW(H, (LPWSTR)buffer.data(), (DWORD)buffer.size() - 1, FILE_NAME_NORMALIZED);
	  	}
	  	if (CountChars == 0)
	    	return map_windows_error(GetLastError());
	  	buffer.resize(CountChars);
	  	return std::error_code();
	}

	std::error_code rename(const std::string &from, const std::string &to)
	{
		// Convert to utf-16.
		std::wstring wide_from = boost::nowide::widen(from);
		std::wstring wide_to   = boost::nowide::widen(to);

		ScopedFileHandle from_handle;
		// Retry this a few times to defeat badly behaved file system scanners.
		for (unsigned retry = 0; retry != 200; ++ retry) {
			if (retry != 0)
		  		::Sleep(10);
			from_handle = ::CreateFileW((LPWSTR)wide_from.data(), GENERIC_READ | DELETE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
			if (from_handle)
		  		break;
		}
		if (! from_handle)
			return map_windows_error(GetLastError());

		// We normally expect this loop to succeed after a few iterations. If it
		// requires more than 200 tries, it's more likely that the failures are due to
		// a true error, so stop trying.
		for (unsigned retry = 0; retry != 200; ++ retry) {
			auto errcode = rename_internal(from_handle, wide_to, true);

			if (errcode == std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category())) {
		  		// Wine doesn't support SetFileInformationByHandle in rename_internal.
		  		// Fall back to MoveFileEx.
		  		if (std::error_code errcode2 = real_path_from_handle(from_handle, wide_from))
		    		return errcode2;
		  		if (::MoveFileExW((LPCWSTR)wide_from.data(), (LPCWSTR)wide_to.data(), MOVEFILE_REPLACE_EXISTING))
		    		return std::error_code();
		  		return map_windows_error(GetLastError());
			}

			if (! errcode || errcode != std::errc::permission_denied)
		  		return errcode;

			// The destination file probably exists and is currently open in another
			// process, either because the file was opened without FILE_SHARE_DELETE or
			// it is mapped into memory (e.g. using MemoryBuffer). Rename it in order to
			// move it out of the way of the source file. Use FILE_FLAG_DELETE_ON_CLOSE
			// to arrange for the destination file to be deleted when the other process
			// closes it.
			ScopedFileHandle to_handle(::CreateFileW((LPCWSTR)wide_to.data(), GENERIC_READ | DELETE, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE, NULL));
			if (! to_handle) {
				auto errcode = map_windows_error(GetLastError());
				// Another process might have raced with us and moved the existing file
				// out of the way before we had a chance to open it. If that happens, try
				// to rename the source file again.
				if (errcode == std::errc::no_such_file_or_directory)
					continue;
				return errcode;
			}

			BY_HANDLE_FILE_INFORMATION FI;
			if (! ::GetFileInformationByHandle(to_handle, &FI))
		  		return map_windows_error(GetLastError());

			// Try to find a unique new name for the destination file.
			for (unsigned unique_id = 0; unique_id != 200; ++ unique_id) {
				std::wstring tmp_filename = wide_to + L".tmp" + std::to_wstring(unique_id);
				std::error_code errcode = rename_internal(to_handle, tmp_filename, false);
				if (errcode) {
					if (errcode == std::make_error_code(std::errc::file_exists) || errcode == std::make_error_code(std::errc::permission_denied)) {
						// Again, another process might have raced with us and moved the file
						// before we could move it. Check whether this is the case, as it
						// might have caused the permission denied error. If that was the
						// case, we don't need to move it ourselves.
						ScopedFileHandle to_handle2(::CreateFileW((LPCWSTR)wide_to.data(), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
						if (! to_handle2) {
							auto errcode = map_windows_error(GetLastError());
							if (errcode == std::errc::no_such_file_or_directory)
						  		break;
							return errcode;
						}
						BY_HANDLE_FILE_INFORMATION FI2;
						if (! ::GetFileInformationByHandle(to_handle2, &FI2))
							return map_windows_error(GetLastError());
						if (FI.nFileIndexHigh != FI2.nFileIndexHigh || FI.nFileIndexLow != FI2.nFileIndexLow || FI.dwVolumeSerialNumber != FI2.dwVolumeSerialNumber)
							break;
						continue;
					}
					return errcode;
				}
				break;
			}

			// Okay, the old destination file has probably been moved out of the way at
			// this point, so try to rename the source file again. Still, another
			// process might have raced with us to create and open the destination
			// file, so we need to keep doing this until we succeed.
		}

		// The most likely root cause.
		return std::make_error_code(std::errc::permission_denied);
	}
} // namespace WindowsSupport
#endif /* _WIN32 */

// borrowed from LVVM lib/Support/Windows/Path.inc
std::error_code rename_file(const std::string &from, const std::string &to)
{
#ifdef _WIN32
	return WindowsSupport::rename(from, to);
#else
	boost::nowide::remove(to.c_str());
	return std::make_error_code(static_cast<std::errc>(boost::nowide::rename(from.c_str(), to.c_str())));
#endif
}

CopyFileResult copy_file_inner(const std::string& from, const std::string& to)
{
	const boost::filesystem::path source(from);
	const boost::filesystem::path target(to);
	static const auto perms = boost::filesystem::owner_read | boost::filesystem::owner_write | boost::filesystem::group_read | boost::filesystem::others_read;   // aka 644

	// Make sure the file has correct permission both before and after we copy over it.
	// NOTE: error_code variants are used here to supress expception throwing.
	// Error code of permission() calls is ignored on purpose - if they fail,
	// the copy_file() function will fail appropriately and we don't want the permission()
	// calls to cause needless failures on permissionless filesystems (ie. FATs on SD cards etc.)
	// or when the target file doesn't exist.
	boost::system::error_code ec;
	boost::filesystem::permissions(target, perms, ec);
	boost::filesystem::copy_file(source, target, boost::filesystem::copy_option::overwrite_if_exists, ec);
	if (ec) {
		return FAIL_COPY_FILE;
	}
	boost::filesystem::permissions(target, perms, ec);
	return SUCCESS;
}

CopyFileResult copy_file(const std::string &from, const std::string &to, const bool with_check)
{
	std::string to_temp = to + ".tmp";
	CopyFileResult ret_val = copy_file_inner(from,to_temp);
    if(ret_val == SUCCESS)
	{
        if (with_check)
            ret_val = check_copy(from, to_temp);

        if (ret_val == 0 && rename_file(to_temp, to))
        	ret_val = FAIL_RENAMING;
	}
	return ret_val;
}

CopyFileResult check_copy(const std::string &origin, const std::string &copy)
{
	boost::nowide::ifstream f1(origin, std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
	boost::nowide::ifstream f2(copy, std::ifstream::in | std::ifstream::binary | std::ifstream::ate);

	if (f1.fail())
		return FAIL_CHECK_ORIGIN_NOT_OPENED;
	if (f2.fail())
		return FAIL_CHECK_TARGET_NOT_OPENED;

	std::streampos fsize = f1.tellg();
	if (fsize != f2.tellg())
		return FAIL_FILES_DIFFERENT;

	f1.seekg(0, std::ifstream::beg);
	f2.seekg(0, std::ifstream::beg);

	// Compare by reading 8 MiB buffers one at a time.
	size_t 			  buffer_size = 8 * 1024 * 1024;
	std::vector<char> buffer_origin(buffer_size, 0);
	std::vector<char> buffer_copy(buffer_size, 0);
	do {
		f1.read(buffer_origin.data(), buffer_size);
        f2.read(buffer_copy.data(), buffer_size);
		std::streampos origin_cnt = f1.gcount();
		std::streampos copy_cnt   = f2.gcount();
		if (origin_cnt != copy_cnt ||
			(origin_cnt > 0 && std::memcmp(buffer_origin.data(), buffer_copy.data(), origin_cnt) != 0))
			// Files are different.
			return FAIL_FILES_DIFFERENT;
		fsize -= origin_cnt;
    } while (f1.good() && f2.good());

    // All data has been read and compared equal.
    return (f1.eof() && f2.eof() && fsize == 0) ? SUCCESS : FAIL_FILES_DIFFERENT;
}

// Ignore system and hidden files, which may be created by the DropBox synchronisation process.
// https://github.com/prusa3d/PrusaSlicer/issues/1298
bool is_plain_file(const boost::filesystem::directory_entry &dir_entry)
{
    if (! boost::filesystem::is_regular_file(dir_entry.status()))
        return false;
#ifdef _MSC_VER
    DWORD attributes = GetFileAttributesW(boost::nowide::widen(dir_entry.path().string()).c_str());
    return (attributes & (FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_SYSTEM)) == 0;
#else
    return true;
#endif
}

bool is_ini_file(const boost::filesystem::directory_entry &dir_entry)
{
    return is_plain_file(dir_entry) && strcasecmp(dir_entry.path().extension().string().c_str(), ".ini") == 0;
}

bool is_idx_file(const boost::filesystem::directory_entry &dir_entry)
{
	return is_plain_file(dir_entry) && strcasecmp(dir_entry.path().extension().string().c_str(), ".idx") == 0;
}

} // namespace Slic3r

#ifdef WIN32
    #ifndef NOMINMAX
    # define NOMINMAX
    #endif
    #include <windows.h>
#endif /* WIN32 */

namespace Slic3r {

// Encode an UTF-8 string to the local code page.
std::string encode_path(const char *src)
{    
#ifdef WIN32
    // Convert the source utf8 encoded string to a wide string.
    std::wstring wstr_src = boost::nowide::widen(src);
    if (wstr_src.length() == 0)
        return std::string();
    // Convert a wide string to a local code page.
    int size_needed = ::WideCharToMultiByte(0, 0, wstr_src.data(), (int)wstr_src.size(), nullptr, 0, nullptr, nullptr);
    std::string str_dst(size_needed, 0);
    ::WideCharToMultiByte(0, 0, wstr_src.data(), (int)wstr_src.size(), str_dst.data(), size_needed, nullptr, nullptr);
    return str_dst;
#else /* WIN32 */
    return src;
#endif /* WIN32 */
}

// Encode an 8-bit string from a local code page to UTF-8.
std::string decode_path(const char *src)
{  
#ifdef WIN32
    int len = int(strlen(src));
    if (len == 0)
        return std::string();
    // Convert the string encoded using the local code page to a wide string.
    int size_needed = ::MultiByteToWideChar(0, 0, src, len, nullptr, 0);
    std::wstring wstr_dst(size_needed, 0);
    ::MultiByteToWideChar(0, 0, src, len, wstr_dst.data(), size_needed);
    // Convert a wide string to utf8.
    return boost::nowide::narrow(wstr_dst.c_str());
#else /* WIN32 */
    return src;
#endif /* WIN32 */
}

std::string normalize_utf8_nfc(const char *src)
{
    static std::locale locale_utf8(boost::locale::generator().generate(""));
    return boost::locale::normalize(src, boost::locale::norm_nfc, locale_utf8);
}

namespace PerlUtils {
    // Get a file name including the extension.
    std::string path_to_filename(const char *src)       { return boost::filesystem::path(src).filename().string(); }
    // Get a file name without the extension.
    std::string path_to_stem(const char *src)           { return boost::filesystem::path(src).stem().string(); }
    // Get just the extension.
    std::string path_to_extension(const char *src)      { return boost::filesystem::path(src).extension().string(); }
    // Get a directory without the trailing slash.
    std::string path_to_parent_path(const char *src)    { return boost::filesystem::path(src).parent_path().string(); }
};


std::string string_printf(const char *format, ...)
{
    va_list args1;
    va_start(args1, format);
    va_list args2;
    va_copy(args2, args1);
    
    static const size_t INITIAL_LEN = 200;
    std::string buffer(INITIAL_LEN, '\0');
    
    int bufflen = ::vsnprintf(buffer.data(), INITIAL_LEN - 1, format, args1);
    
    if (bufflen >= int(INITIAL_LEN)) {
        buffer.resize(size_t(bufflen) + 1);
        ::vsnprintf(buffer.data(), buffer.size(), format, args2);
    }
    
    buffer.resize(bufflen);
    
    return buffer;
}

std::string header_slic3r_generated()
{
    return std::string("generated by " SLIC3R_APP_NAME " " SLIC3R_VERSION " on " ) + Utils::utc_timestamp();
}

unsigned get_current_pid()
{
#ifdef WIN32
    return GetCurrentProcessId();
#else
    return ::getpid();
#endif
}

std::string xml_escape(std::string text)
{
    std::string::size_type pos = 0;
    for (;;)
    {
        pos = text.find_first_of("\"\'&<>", pos);
        if (pos == std::string::npos)
            break;

        std::string replacement;
        switch (text[pos])
        {
        case '\"': replacement = "&quot;"; break;
        case '\'': replacement = "&apos;"; break;
        case '&':  replacement = "&amp;";  break;
        case '<':  replacement = "&lt;";   break;
        case '>':  replacement = "&gt;";   break;
        default: break;
        }

        text.replace(pos, 1, replacement);
        pos += replacement.size();
    }

    return text;
}

std::string format_memsize_MB(size_t n) 
{
    std::string out;
    size_t n2 = 0;
    size_t scale = 1;
    // Round to MB
    n +=  500000;
    n /= 1000000;
    while (n >= 1000) {
        n2 = n2 + scale * (n % 1000);
        n /= 1000;
        scale *= 1000;
    }
    char buf[8];
    sprintf(buf, "%d", (int)n);
    out = buf;
    while (scale != 1) {
        scale /= 1000;
        n = n2 / scale;
        n2 = n2  % scale;
        sprintf(buf, ",%03d", (int)n);
        out += buf;
    }
    return out + "MB";
}

// Returns platform-specific string to be used as log output or parsed in SysInfoDialog.
// The latter parses the string with (semi)colons as separators, it should look about as
// "desc1: value1; desc2: value2" or similar (spaces should not matter).
std::string log_memory_info(bool ignore_loglevel)
{
    std::string out;
    if (ignore_loglevel || logSeverity <= boost::log::trivial::info) {
#ifdef WIN32
    #ifndef PROCESS_MEMORY_COUNTERS_EX
        // MingW32 doesn't have this struct in psapi.h
        typedef struct _PROCESS_MEMORY_COUNTERS_EX {
          DWORD  cb;
          DWORD  PageFaultCount;
          SIZE_T PeakWorkingSetSize;
          SIZE_T WorkingSetSize;
          SIZE_T QuotaPeakPagedPoolUsage;
          SIZE_T QuotaPagedPoolUsage;
          SIZE_T QuotaPeakNonPagedPoolUsage;
          SIZE_T QuotaNonPagedPoolUsage;
          SIZE_T PagefileUsage;
          SIZE_T PeakPagefileUsage;
          SIZE_T PrivateUsage;
        } PROCESS_MEMORY_COUNTERS_EX, *PPROCESS_MEMORY_COUNTERS_EX;
    #endif /* PROCESS_MEMORY_COUNTERS_EX */


        HANDLE hProcess = ::OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, ::GetCurrentProcessId());
        if (hProcess != nullptr) {
            PROCESS_MEMORY_COUNTERS_EX pmc;
            if (GetProcessMemoryInfo(hProcess, (PROCESS_MEMORY_COUNTERS*)&pmc, sizeof(pmc)))
                out = " WorkingSet: " + format_memsize_MB(pmc.WorkingSetSize) + "; PrivateBytes: " + format_memsize_MB(pmc.PrivateUsage) + "; Pagefile(peak): " + format_memsize_MB(pmc.PagefileUsage) + "(" + format_memsize_MB(pmc.PeakPagefileUsage) + ")";
            else
                out += " Used memory: N/A";
            CloseHandle(hProcess);
        }
#elif defined(__linux__) or defined(__APPLE__)
        // Get current memory usage.
    #ifdef __APPLE__
        struct mach_task_basic_info info;
        mach_msg_type_number_t infoCount = MACH_TASK_BASIC_INFO_COUNT;
        out += " Resident memory: ";
        if ( task_info( mach_task_self( ), MACH_TASK_BASIC_INFO, (task_info_t)&info, &infoCount ) == KERN_SUCCESS )
            out += format_memsize_MB((size_t)info.resident_size);
        else
            out += "N/A";
    #else // i.e. __linux__
        size_t tSize = 0, resident = 0, share = 0;
        std::ifstream buffer("/proc/self/statm");
        if (buffer && (buffer >> tSize >> resident >> share)) {
            size_t page_size = (size_t)sysconf(_SC_PAGE_SIZE); // in case x86-64 is configured to use 2MB pages
            size_t rss = resident * page_size;
            out += " Resident memory: " + format_memsize_MB(rss);
            out += "; Shared memory: " + format_memsize_MB(share * page_size);
            out += "; Private memory: " + format_memsize_MB(rss - share * page_size);
        }
        else
            out += " Used memory: N/A";
    #endif
        // Now get peak memory usage.
        out += "; Peak memory usage: ";
        rusage memory_info;
        if (getrusage(RUSAGE_SELF, &memory_info) == 0)
        {
            size_t peak_mem_usage = (size_t)memory_info.ru_maxrss;
            #ifdef __linux__
                peak_mem_usage *= 1024;// getrusage returns the value in kB on linux
            #endif
            out += format_memsize_MB(peak_mem_usage);
        }
        else
            out += "N/A";
#endif
    }
    return out;
}

// Returns the size of physical memory (RAM) in bytes.
// http://nadeausoftware.com/articles/2012/09/c_c_tip_how_get_physical_memory_size_system
size_t total_physical_memory()
{
#if defined(_WIN32) && (defined(__CYGWIN__) || defined(__CYGWIN32__))
	// Cygwin under Windows. ------------------------------------
	// New 64-bit MEMORYSTATUSEX isn't available.  Use old 32.bit
	MEMORYSTATUS status;
	status.dwLength = sizeof(status);
	GlobalMemoryStatus( &status );
	return (size_t)status.dwTotalPhys;
#elif defined(_WIN32)
	// Windows. -------------------------------------------------
	// Use new 64-bit MEMORYSTATUSEX, not old 32-bit MEMORYSTATUS
	MEMORYSTATUSEX status;
	status.dwLength = sizeof(status);
	GlobalMemoryStatusEx( &status );
	return (size_t)status.ullTotalPhys;
#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))
	// UNIX variants. -------------------------------------------
	// Prefer sysctl() over sysconf() except sysctl() HW_REALMEM and HW_PHYSMEM

#if defined(CTL_HW) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM64))
	int mib[2];
	mib[0] = CTL_HW;
#if defined(HW_MEMSIZE)
	mib[1] = HW_MEMSIZE;            // OSX. ---------------------
#elif defined(HW_PHYSMEM64)
	mib[1] = HW_PHYSMEM64;          // NetBSD, OpenBSD. ---------
#endif
	int64_t size = 0;               // 64-bit
	size_t len = sizeof( size );
	if ( sysctl( mib, 2, &size, &len, NULL, 0 ) == 0 )
		return (size_t)size;
	return 0L;			// Failed?

#elif defined(_SC_AIX_REALMEM)
	// AIX. -----------------------------------------------------
	return (size_t)sysconf( _SC_AIX_REALMEM ) * (size_t)1024L;

#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
	// FreeBSD, Linux, OpenBSD, and Solaris. --------------------
	return (size_t)sysconf( _SC_PHYS_PAGES ) *
		(size_t)sysconf( _SC_PAGESIZE );

#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGE_SIZE)
	// Legacy. --------------------------------------------------
	return (size_t)sysconf( _SC_PHYS_PAGES ) *
		(size_t)sysconf( _SC_PAGE_SIZE );

#elif defined(CTL_HW) && (defined(HW_PHYSMEM) || defined(HW_REALMEM))
	// DragonFly BSD, FreeBSD, NetBSD, OpenBSD, and OSX. --------
	int mib[2];
	mib[0] = CTL_HW;
#if defined(HW_REALMEM)
	mib[1] = HW_REALMEM;		// FreeBSD. -----------------
#elif defined(HW_PYSMEM)
	mib[1] = HW_PHYSMEM;		// Others. ------------------
#endif
	unsigned int size = 0;		// 32-bit
	size_t len = sizeof( size );
	if ( sysctl( mib, 2, &size, &len, NULL, 0 ) == 0 )
		return (size_t)size;
	return 0L;			// Failed?
#endif // sysctl and sysconf variants

#else
	return 0L;			// Unknown OS.
#endif
}

}; // namespace Slic3r