// =================================================================================================
// Copyright Adobe
// Copyright 2010 Adobe
// All Rights Reserved
//
// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it. 
// =================================================================================================

#include "public/include/XMP_Environment.h"	// ! This must be the first include.

#include "source/Host_IO.hpp"
#include "source/XMP_LibUtils.hpp"
#include "source/XIO.hpp"
#include "source/UnicodeConversions.hpp"

#if XMP_WinBuild
	#pragma warning ( disable : 4800 )	// forcing value to bool 'true' or 'false' (performance warning)
#endif

// =================================================================================================
// Host_IO implementations for Windows
// ===================================

#if ! XMP_WinBuild
	#error "This is the Windows implementation of Host_IO."
#endif

static bool IsLongPath ( const std::string& path );
static bool IsNetworkPath ( const std::string& path );
static bool IsRelativePath ( const std::string& path );
static bool GetWidePath ( const char* path, std::string & widePath );
static std::string & CorrectSlashes ( std::string & path );

static bool Exists ( const std::string & widePath );
static Host_IO::FileRef Open ( const std::string & widePath, bool readOnly );
static Host_IO::FileRef OpenWithWriteShare ( const std::string & widePath, bool readOnly );
static Host_IO::FileMode GetFileMode ( const std::string & widePath );

// =================================================================================================
// File operations
// =================================================================================================

// =================================================================================================
// Host_IO::Exists
// ===============

bool Host_IO::Exists ( const char* filePath )
{
	std::string wideName;
	if ( GetWidePath(filePath, wideName) ) {
		return ::Exists(wideName);
	}
	return false;
}

// =================================================================================================
// Host_IO::Writable
// ===============
bool Host_IO::Writable( const char * path, bool checkCreationPossible )
{
	std::string widePath;
	if ( ! GetWidePath(path, widePath) || widePath.length() == 0)
		XMP_Throw ( "Host_IO::Writable, cannot convert path", kXMPErr_ExternalFailure );

	if ( ::Exists( widePath ) )
	{
		switch ( ::GetFileMode( widePath ) )
		{
		case kFMode_IsFile:
			// open the file in write mode but with file_share_read | file_share_write
			try
			{
				Host_IO::FileRef fileRef = Host_IO::noFileRef;
				fileRef = ::OpenWithWriteShare( widePath, false );
				if ( fileRef == Host_IO::noFileRef )
					return false;// can not open in write mode.
				Host_IO::Close ( fileRef );
				return true;
			}
			catch ( ... )
			{
				return false;
			}
			break;

		default:
			return false;
			break;
		}
	} 
	else if ( checkCreationPossible )
	{
		// file doesn't exist. Let's check if we can create it temporarily.
		bool created = false;
		try
		{
			created = Host_IO::Create ( path );
			if ( created )
				Host_IO::Delete ( path );
		}
		catch ( ... )
		{
			return false;
		}
		return created;
	}
	else
		return true;
}

// =================================================================================================
// Host_IO::Create
// ===============

bool Host_IO::Create ( const char* filePath )
{
	std::string wideName;
	if ( !GetWidePath ( filePath, wideName ) || wideName.length() == 0 )
		 XMP_Throw ( "Host_IO::Create, cannot convert path", kXMPErr_ExternalFailure );

	if ( ::Exists ( wideName ) ) {
		if ( ::GetFileMode ( wideName ) == kFMode_IsFile ) return false;
		XMP_Throw ( "Host_IO::Create, path exists but is not a file", kXMPErr_InternalFailure );
	}

	Host_IO::FileRef fileHandle;
#ifdef WIN_UNIVERSAL_ENV
	CREATEFILE2_EXTENDED_PARAMETERS params;
	params.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
	params.dwFileAttributes = (FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS);
	params.lpSecurityAttributes = 0;
	params.hTemplateFile = 0;
	params.dwFileFlags = 0;
	params.dwSecurityQosFlags = 0;
	fileHandle = CreateFile2((LPCWSTR)wideName.data(), (GENERIC_READ | GENERIC_WRITE), 0, CREATE_ALWAYS, &params);
#else
	fileHandle = CreateFileW ( (LPCWSTR)wideName.data(), (GENERIC_READ | GENERIC_WRITE), 0, 0, CREATE_ALWAYS,
 							   (FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS), 0 );
#endif
	if ( fileHandle == INVALID_HANDLE_VALUE ) XMP_Throw ( "Host_IO::Create, cannot create file", kXMPErr_InternalFailure );;

	CloseHandle ( fileHandle );
	return true;
}	// Host_IO::Create

// =================================================================================================
// FillXMPTime
// ===========

static void FillXMPTime ( const SYSTEMTIME & winTime, XMP_DateTime * xmpTime )
{

	// Ignore the fractional seconds for consistency with UNIX and to avoid false newness even on
	// Windows. Some other sources of time only resolve to seconds, we don't want 25.3 looking
	// newer than 25.

	xmpTime->year = winTime.wYear;
	xmpTime->month = winTime.wMonth;
	xmpTime->day = winTime.wDay;
	xmpTime->hasDate = true;

	xmpTime->hour = winTime.wHour;
	xmpTime->minute = winTime.wMinute;
	xmpTime->second = winTime.wSecond;
	xmpTime->nanoSecond = 0;	// See note above; winTime.wMilliseconds * 1000*1000;
	xmpTime->hasTime = true;

	xmpTime->tzSign = kXMP_TimeIsUTC;
	xmpTime->tzHour = 0;
	xmpTime->tzMinute = 0;
	xmpTime->hasTimeZone = true;

}

// =================================================================================================
// Host_IO::GetModifyDate
// ======================

bool Host_IO::GetModifyDate ( const char* filePath, XMP_DateTime * modifyDate )
{
	BOOL ok;
	Host_IO::FileRef fileHandle;

	try {	// Host_IO::Open should not throw - fix after CS6.
		fileHandle = Host_IO::Open ( filePath, Host_IO::openReadOnly );
		if ( fileHandle == Host_IO::noFileRef ) return false;
	} catch ( ... ) {
		return false;
	}

	FILETIME binTime;
	ok = GetFileTime ( fileHandle, 0, 0, &binTime );
	Host_IO::Close ( fileHandle );
	if ( ! ok ) return false;
	
	SYSTEMTIME utcTime;
	ok = FileTimeToSystemTime ( &binTime, &utcTime );
	if ( ! ok ) return false;
	
	FillXMPTime ( utcTime, modifyDate );
	return true;

}	// Host_IO::GetModifyDate

// =================================================================================================
// ConjureDerivedPath
// ==================

static std::string ConjureDerivedPath ( const char* basePath )
{
	std::string tempPath = basePath;
	tempPath += "._nn_";
	char * indexPart = (char*) tempPath.c_str() + strlen(basePath) + 2;

	for ( char ten = '0'; ten <= '9' ; ++ten ) {
		indexPart[0] = ten;
		for ( char one = '0'; one <= '9' ; ++one ) {
			indexPart[1] = one;
			if ( ! Host_IO::Exists ( tempPath.c_str() ) ) return tempPath;
		}
	}

	return "";

}	// ConjureDerivedPath

// =================================================================================================
// Host_IO::CreateTemp
// ===================

std::string Host_IO::CreateTemp ( const char* sourcePath )
{
	std::string tempPath = ConjureDerivedPath ( sourcePath );
	if ( tempPath.empty() ) XMP_Throw ( "Host_IO::CreateTemp, cannot create temp file path", kXMPErr_InternalFailure );
	XMP_Assert ( ! Host_IO::Exists ( tempPath.c_str() ) );

	Host_IO::Create ( tempPath.c_str() );
	return tempPath;

}	// Host_IO::CreateTemp

// =================================================================================================
// Host_IO::Open
// =============
//
// Returns Host_IO::noFileRef (0) if the file does not exist, throws for other errors.

Host_IO::FileRef Host_IO::Open ( const char* filePath, bool readOnly )
{
	std::string wideName;
	if ( !GetWidePath ( filePath, wideName ) || wideName.length() == 0 )
		XMP_Throw ( "Host_IO::Open, GetWidePath failure", kXMPErr_ExternalFailure );

	return ::Open( wideName, readOnly );

}	// Host_IO::Open

// =================================================================================================
// Host_IO::Close
// ==============

void Host_IO::Close ( Host_IO::FileRef fileHandle )
{
	if ( fileHandle == Host_IO::noFileRef ) return;

	BOOL ok = CloseHandle ( fileHandle );
	if ( ! ok ) XMP_Throw ( "Host_IO::Close, CloseHandle failure", kXMPErr_ExternalFailure );

}	// Host_IO::Close

// =================================================================================================
// Host_IO::SwapData
// =================

void Host_IO::SwapData ( const char* sourcePath, const char* destPath )
{

	// For lack of a better approach, do a 3-way rename.

	std::string thirdPath = ConjureDerivedPath ( sourcePath );
	if ( thirdPath.empty() ) XMP_Throw ( "Cannot create temp file path", kXMPErr_InternalFailure );
	XMP_Assert ( ! Host_IO::Exists ( thirdPath.c_str() ) );

	Host_IO::Rename ( sourcePath, thirdPath.c_str() );
	
	try {
		Host_IO::Rename ( destPath, sourcePath );
	} catch ( ... ) {
		Host_IO::Rename ( thirdPath.c_str(), sourcePath );
		throw;
	}
	
	try {
		Host_IO::Rename ( thirdPath.c_str(), destPath );
	} catch ( ... ) {
		Host_IO::Rename ( sourcePath, destPath );
		Host_IO::Rename ( thirdPath.c_str(), sourcePath );
		throw;
	}

}	// Host_IO::SwapData

// =================================================================================================
// Host_IO::Rename
// ===============

void Host_IO::Rename ( const char* oldPath, const char* newPath )
{
	std::string wideOldPath, wideNewPath;
	if ( !GetWidePath ( oldPath, wideOldPath ) || wideOldPath.length() == 0 )
		XMP_Throw ( "Host_IO::Rename, GetWidePath failure", kXMPErr_ExternalFailure );

	if ( !GetWidePath ( newPath, wideNewPath ) || wideNewPath.length() == 0 )
		XMP_Throw ( "Host_IO::Rename, GetWidePath failure", kXMPErr_ExternalFailure );

	if ( ::Exists ( wideNewPath ) ) XMP_Throw ( "Host_IO::Rename, new path exists", kXMPErr_InternalFailure );

#if XMP_UWP
	BOOL ok = MoveFileExW((LPCWSTR)wideOldPath.data(), (LPCWSTR)wideNewPath.data(), MOVEFILE_REPLACE_EXISTING);
	if (!ok) XMP_Throw("Host_IO::Rename, MoveFileExW failure", kXMPErr_ExternalFailure);
#else
	BOOL ok = MoveFileW((LPCWSTR)wideOldPath.data(), (LPCWSTR)wideNewPath.data());
	if (!ok) XMP_Throw("Host_IO::Rename, MoveFileW failure", kXMPErr_ExternalFailure);
#endif
}	// Host_IO::Rename

// =================================================================================================
// Host_IO::Delete
// ===============

void Host_IO::Delete ( const char* filePath )
{
	std::string wideName;
	if ( !GetWidePath ( filePath, wideName ) || wideName.length() == 0 )
		XMP_Throw ( "Host_IO::Delete, GetWidePath failure", kXMPErr_ExternalFailure );
	
	if ( !::Exists ( wideName ) ) return;

	

	BOOL ok = DeleteFileW ( (LPCWSTR)wideName.data() );
	if ( ! ok ) {
		DWORD errCode = GetLastError();
		if ( errCode != ERROR_FILE_NOT_FOUND ) {
			XMP_Throw ( "Host_IO::Delete, DeleteFileW failure", kXMPErr_ExternalFailure );
		}
	}

}	// Host_IO::Delete

// =================================================================================================
// Host_IO::Seek
// =============

XMP_Int64 Host_IO::Seek ( Host_IO::FileRef fileHandle, XMP_Int64 offset, SeekMode mode )
{
	DWORD method;
	switch ( mode ) {
		case kXMP_SeekFromStart :
			method = FILE_BEGIN;
			break;
		case kXMP_SeekFromCurrent :
			method = FILE_CURRENT;
			break;
		case kXMP_SeekFromEnd :
			method = FILE_END;
			break;
		default :
			XMP_Throw ( "Invalid seek mode", kXMPErr_InternalFailure );
			break;
	}

	LARGE_INTEGER seekOffset, newPos;
	seekOffset.QuadPart = offset;

	BOOL ok = SetFilePointerEx ( fileHandle, seekOffset, &newPos, method );
	if ( ! ok ) XMP_Throw ( "Host_IO::Seek, SetFilePointerEx failure", kXMPErr_ExternalFailure );

	return newPos.QuadPart;

}	// Host_IO::Seek

// =================================================================================================
// Host_IO::Read
// =============

#define TwoGB (XMP_Uns32)(2*1024*1024*1024UL)

XMP_Uns32 Host_IO::Read ( Host_IO::FileRef fileHandle, void * buffer, XMP_Uns32 count )
{
	if ( count >= TwoGB ) XMP_Throw ( "Host_IO::Read, request too large", kXMPErr_EnforceFailure );

	DWORD bytesRead;
	BOOL ok = ReadFile ( fileHandle, buffer, count, &bytesRead, 0 );
	if ( ! ok ) XMP_Throw ( "Host_IO::Read, ReadFile failure", kXMPErr_ReadError );

	return bytesRead;

}	// Host_IO::Read

// =================================================================================================
// Host_IO::Write
// ==============

void Host_IO::Write ( Host_IO::FileRef fileHandle, const void * buffer, XMP_Uns32 count )
{
	if ( count >= TwoGB ) XMP_Throw ( "Host_IO::Write, request too large", kXMPErr_EnforceFailure );

	DWORD bytesWritten;
	BOOL ok = WriteFile ( fileHandle, buffer, count, &bytesWritten, 0 );
	if ( (! ok) || (bytesWritten != count) ) {
		DWORD osCode = GetLastError();
		if ( osCode == ERROR_DISK_FULL ) {
			XMP_Throw ( "Host_IO::Write, disk full", kXMPErr_DiskSpace );
		} else {
			XMP_Throw ( "Host_IO::Write, WriteFile failure", kXMPErr_WriteError );
		}
	}

}	// Host_IO::Write

// =================================================================================================
// Host_IO::Length
// ===============

XMP_Int64 Host_IO::Length ( Host_IO::FileRef fileHandle )
{
	LARGE_INTEGER length;
	BOOL ok = GetFileSizeEx ( fileHandle, &length );
	if ( ! ok ) XMP_Throw ( "Host_IO::Length, GetFileSizeEx failure", kXMPErr_ExternalFailure );

	return length.QuadPart;

}	// Host_IO::Length

// =================================================================================================
// Host_IO::SetEOF
// ===============

void Host_IO::SetEOF ( Host_IO::FileRef fileHandle, XMP_Int64 length )
{
	LARGE_INTEGER winLength;
	winLength.QuadPart = length;

	BOOL ok = SetFilePointerEx ( fileHandle, winLength, 0, FILE_BEGIN );
	if ( ! ok ) XMP_Throw ( "Host_IO::SetEOF, SetFilePointerEx failure", kXMPErr_ExternalFailure );
	ok = SetEndOfFile ( fileHandle );
	if ( ! ok ) XMP_Throw ( "Host_IO::SetEOF, SetEndOfFile failure", kXMPErr_ExternalFailure );

}	// Host_IO::SetEOF

// =================================================================================================
// Folder operations
// =================================================================================================

// =================================================================================================
// Host_IO::GetFileMode
// ====================

static DWORD kOtherAttrs = (FILE_ATTRIBUTE_DEVICE);

Host_IO::FileMode Host_IO::GetFileMode ( const char * path )
{
	std::string utf16;	// GetFileAttributes wants native UTF-16.
	if ( !GetWidePath ( path, utf16 ) )
		XMP_Throw ( "Host_IO::GetFileMode, GetWidePath failure", kXMPErr_ExternalFailure );
	
	return ::GetFileMode( utf16 );
}	// Host_IO::GetFileMode

// =================================================================================================
// Host_IO::GetChildMode
// =====================

Host_IO::FileMode Host_IO::GetChildMode ( const char * parentPath, const char * childName )
{
	std::string fullPath = parentPath;
	char lastChar = fullPath[fullPath.length() - 1];
	if ( lastChar != '\\' && lastChar != '/' )
		fullPath += '\\';
	fullPath += childName;

	return GetFileMode ( fullPath.c_str() );

}	// Host_IO::GetChildMode

// =================================================================================================
// Host_IO::OpenFolder
// ===================

Host_IO::FolderRef Host_IO::OpenFolder ( const char* folderPath )
{
	switch ( Host_IO::GetFileMode ( folderPath ) ) {

	case Host_IO::kFMode_IsFolder :
		{
			WIN32_FIND_DATAW childInfo;
			std::string findPath = folderPath;
			// Looking for all children of that folder, add * as search criteria
			findPath += findPath[findPath.length() - 1] == '\\' ? "*" : "\\*";

			std::string utf16;	// FindFirstFile wants native UTF-16.
			if ( !GetWidePath ( findPath.c_str(), utf16 ) )
				XMP_Throw ( "Host_IO::OpenFolder, GetWidePath failure", kXMPErr_ExternalFailure );
#if XMP_UWP
			Host_IO::FolderRef folder = FindFirstFileExW((LPCWSTR)utf16.c_str(), FindExInfoStandard,&childInfo, FindExSearchNameMatch,NULL, FIND_FIRST_EX_CASE_SENSITIVE);
#else
			Host_IO::FolderRef folder = FindFirstFileW ( (LPCWSTR) utf16.c_str(), &childInfo );
#endif
			if ( folder == noFolderRef ) XMP_Throw ( "Host_IO::OpenFolder - FindFirstFileW failed", kXMPErr_ExternalFailure );
			// The first child should be ".", which we want to ignore anyway.
			XMP_Assert ( (folder == noFolderRef) || (childInfo.cFileName[0] == '.') );

			return folder;
		}

	case Host_IO::kFMode_DoesNotExist :
		return Host_IO::noFolderRef;

	default :
		XMP_Throw ( "Host_IO::OpenFolder, path is not a folder", kXMPErr_ExternalFailure );

	}

	XMP_Throw ( "Host_IO::OpenFolder, should not get here", kXMPErr_InternalFailure );

}	// Host_IO::OpenFolder

// =================================================================================================
// Host_IO::CloseFolder
// ====================

void Host_IO::CloseFolder ( Host_IO::FolderRef folder )
{
	if ( folder == noFolderRef ) return;

	BOOL ok = FindClose ( folder );
	if ( ! ok ) XMP_Throw ( "Host_IO::CloseFolder, FindClose failure", kXMPErr_ExternalFailure );

}	// Host_IO::CloseFolder

// =================================================================================================
// Host_IO::GetNextChild
// =====================

bool Host_IO::GetNextChild ( Host_IO::FolderRef folder, std::string* childName )
{
	bool found;
	WIN32_FIND_DATAW childInfo;

	if ( folder == Host_IO::noFolderRef ) return false;

	do {	// Ignore all children with names starting in '.'. This covers ., .., .DS_Store, etc.
		found = (bool) FindNextFile ( folder, &childInfo );
	} while ( found && (childInfo.cFileName[0] == '.') );
	if ( ! found ) return false;

	if ( childName != 0 ) {
		size_t len16 = 0;	// The cFileName field is native UTF-16.
		while ( childInfo.cFileName[len16] != 0 ) ++len16;
		FromUTF16Native ( (UTF16Unit*)childInfo.cFileName, len16, childName );
	}

	return true;

}	// Host_IO::GetNextChild

// =================================================================================================
// IsLongPath
// =====================

bool IsLongPath ( const std::string& path ) {
	if ( path.find ( "\\\\?\\" ) == 0 ) return true;
	return false;
}

// =================================================================================================
// IsNetworkPath
// =====================

bool IsNetworkPath ( const std::string& path ) {
	if ( path.find ( "\\\\" ) == 0 ) return true;
	return false;
}

// =================================================================================================
// IsRelativePath
// =====================

bool IsRelativePath ( const std::string& path ) {
	if ( path.length() > 2) {
		char driveLetter = path[0];
		if ( ( driveLetter >= 'a' && driveLetter <= 'z' ) || ( driveLetter >= 'A' && driveLetter <= 'Z' ) ) {
			if (path[1] == ':' && path[2] == '\\' ) {
				if ( path.find(".\\") == std::string::npos )
					return false;
			}
		}
	}
	return true;
}

// =================================================================================================
// GetWidePath
// =====================

bool GetWidePath( const char* path, std::string & widePath ) {
	std::string utfPath ( path );
	CorrectSlashes ( utfPath);

	if ( !IsLongPath ( utfPath ) ) {
		if ( IsNetworkPath ( utfPath ) ) {
			utfPath = "\\\\?\\UNC\\" + utfPath.substr ( 2 );
		} else if ( IsRelativePath ( utfPath ) ) {
			//don't do anything
		} else { // absolute path
			utfPath = "\\\\?\\" + utfPath;
		}
	}

	widePath.clear();
	const size_t maxLen =  MultiByteToWideChar ( CP_UTF8, 0, utfPath.c_str(), -1, (LPWSTR)0, (int)0 );

	widePath.reserve ( maxLen * sizeof (WCHAR) );
	widePath.assign ( maxLen * sizeof (WCHAR) , '\0' );
	int wideLen = MultiByteToWideChar ( CP_UTF8, 0, utfPath.c_str(), -1, (LPWSTR)widePath.data(), (int)maxLen );
	if ( wideLen == 0 ) return false;
	return true;
}

// =================================================================================================
// CorrectSlashes
// =====================

std::string & CorrectSlashes ( std::string & path ) {
	size_t idx = 0;

	while( (idx = path.find_first_of('/',idx)) != std::string::npos )
		path.replace( idx, 1, "\\" );
	return path;
}

bool Exists ( const std::string & widePath )
{
	DWORD attrs = INVALID_FILE_ATTRIBUTES;
#if XMP_UWP
	_WIN32_FILE_ATTRIBUTE_DATA fileDataAttr;
	fileDataAttr.dwFileAttributes = INVALID_FILE_ATTRIBUTES;
	if(GetFileAttributesExW((LPCWSTR)widePath.data(), GetFileExInfoStandard, &fileDataAttr))
		attrs = fileDataAttr.dwFileAttributes;
#else
	attrs = GetFileAttributesW ( (LPCWSTR)widePath.data() );
#endif 

	return ( attrs != INVALID_FILE_ATTRIBUTES);
}


Host_IO::FileMode GetFileMode ( const std::string & widePath )
{
	// ! A shortcut is seen as a file, we would need extra code to recognize it and find the target.
	DWORD fileAttrs = INVALID_FILE_ATTRIBUTES;
#if XMP_UWP
	_WIN32_FILE_ATTRIBUTE_DATA fileDataAttr;
	if(GetFileAttributesExW((LPCWSTR)widePath.data(), GetFileExInfoStandard, &fileDataAttr))
		fileAttrs = fileDataAttr.dwFileAttributes;
#else
	fileAttrs =  GetFileAttributesW ( (LPCWSTR) widePath.c_str() );
#endif
	if ( fileAttrs == INVALID_FILE_ATTRIBUTES ) return Host_IO::kFMode_DoesNotExist;	// ! Any failure turns into does-not-exist.

	if ( fileAttrs & FILE_ATTRIBUTE_DIRECTORY ) return Host_IO::kFMode_IsFolder;
	if ( fileAttrs & kOtherAttrs ) return Host_IO::kFMode_IsOther;
	return Host_IO::kFMode_IsFile;

}

Host_IO::FileRef Open ( const std::string & widePath, bool readOnly )
{
	DWORD access = GENERIC_READ;	// Assume read mode.
	DWORD share  = FILE_SHARE_READ | FILE_SHARE_WRITE;

	if ( ! readOnly ) {
		access |= GENERIC_WRITE;
		share = 0;
	}

	Host_IO::FileRef fileHandle;

#if XMP_UWP
	CREATEFILE2_EXTENDED_PARAMETERS params;
	params.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
	params.dwFileAttributes = (FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS);
	params.lpSecurityAttributes = 0;
	params.hTemplateFile = 0;
	params.dwFileFlags = 0;
	params.dwSecurityQosFlags = 0;
	fileHandle = CreateFile2((LPCWSTR)widePath.data(), access, share, OPEN_EXISTING, &params);
#else
	fileHandle = CreateFileW ( (LPCWSTR)widePath.data(), access, share, 0, OPEN_EXISTING,
		(FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS), 0 );
#endif

	if ( fileHandle == INVALID_HANDLE_VALUE ) {
		DWORD osCode = GetLastError();
		if ( (osCode == ERROR_FILE_NOT_FOUND) || (osCode == ERROR_PATH_NOT_FOUND) || (osCode == ERROR_FILE_OFFLINE) ) {
			return Host_IO::noFileRef;
		} else if ( osCode == ERROR_ACCESS_DENIED ) {
			XMP_Throw ( "Open, file permission error", kXMPErr_FilePermission );
		} else {
			XMP_Throw ( "Open, other failure", kXMPErr_ExternalFailure );
		}
	}

	return fileHandle;
}

Host_IO::FileRef OpenWithWriteShare ( const std::string & widePath, bool readOnly )
{
	DWORD access = GENERIC_READ;	// Assume read mode.
	DWORD share  = FILE_SHARE_READ | FILE_SHARE_WRITE;

	if ( ! readOnly ) {
		access |= GENERIC_WRITE;
	}

	Host_IO::FileRef fileHandle;

#if WIN_UNIVERSAL_ENV
	CREATEFILE2_EXTENDED_PARAMETERS params;
	params.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
	params.dwFileAttributes = (FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS);
	params.lpSecurityAttributes = 0;
	params.hTemplateFile = 0;
	params.dwFileFlags = 0;
	params.dwSecurityQosFlags = 0;
	fileHandle = CreateFile2((LPCWSTR)widePath.data(), access, share, OPEN_EXISTING, &params);
#else
	fileHandle = CreateFileW ( (LPCWSTR)widePath.data(), access, share, 0, OPEN_EXISTING,
		(FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS), 0 );
#endif
	if ( fileHandle == INVALID_HANDLE_VALUE ) {
		DWORD osCode = GetLastError();
		if ( (osCode == ERROR_FILE_NOT_FOUND) || (osCode == ERROR_PATH_NOT_FOUND) || (osCode == ERROR_FILE_OFFLINE) ) {
			return Host_IO::noFileRef;
		} else if ( osCode == ERROR_ACCESS_DENIED ) {
			XMP_Throw ( "Open, file permission error", kXMPErr_FilePermission );
		} else {
			XMP_Throw ( "Open, other failure", kXMPErr_ExternalFailure );
		}
	}

	return fileHandle;
}

static std::string ConstructPreservedPath( const std::string& inputPath )
{
	DWORD allocate_size,retValue;
	std::string longpathname="\\\\?\\";
	std::string networkpathsuffix="UNC\\";
	std::string pathSep="\\";
	std::string casePreservedPath,systempath,widePath,leafname;

	if ( !  Host_IO::Exists( inputPath.c_str() ) )
		XMP_Throw ( "Host_IO::GetCasePresevedLeafName, Invalid Path-Doesn't Exist", kXMPErr_ExternalFailure );
	std::string utfPath ( inputPath );
	CorrectSlashes ( utfPath);

	size_t pos = 0;
	bool isNetworkPath=false;
	int skipServerAndShareName=0;
	if ( ! longpathname.compare ( utfPath.substr ( 0, longpathname.length() ) ) )
	{
		pos = longpathname.length() ;
		if ( ! networkpathsuffix.compare ( utfPath.substr ( pos, networkpathsuffix.length() ) ))
		{
			pos += networkpathsuffix.length() ;
			isNetworkPath=true;
		}
		casePreservedPath = utfPath.substr ( 0 , pos ) ;
	}
	else
	{
		isNetworkPath=IsNetworkPath(utfPath);
		if (isNetworkPath){ pos =2;casePreservedPath="\\\\";}
	}
	if (isNetworkPath) skipServerAndShareName=2;
	bool loopvar=true;
	while(loopvar) 
	{
		size_t newpos = utfPath.find_first_of( pathSep, pos );
		if ( newpos ==  std::string::npos )
		{
			newpos = utfPath.length();
			loopvar= false;
		}
		WIN32_FIND_DATAW fileInfo;
		HANDLE  searchNext;
		leafname=utfPath.substr(pos,newpos-pos );
		skipServerAndShareName=(skipServerAndShareName<0)?0:skipServerAndShareName;
		if (!( leafname=="" || leafname=="." || leafname==".." || leafname[newpos-pos-1]==':' || skipServerAndShareName-- ) )
		{
			std::string partialPath=utfPath.substr(0,newpos);
			if ( ! GetWidePath(partialPath.c_str(), widePath) || widePath.length() == 0)
				XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );
#if XMP_UWP
			searchNext = FindFirstFileExW((LPCWSTR)widePath.c_str(), FindExInfoStandard, &fileInfo, FindExSearchNameMatch, NULL, FIND_FIRST_EX_CASE_SENSITIVE);
#else
			searchNext = ::FindFirstFileW((LPCWSTR)widePath.c_str(), &fileInfo);
#endif
			if( searchNext == INVALID_HANDLE_VALUE || ! ::FindClose(searchNext) )
				XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );
			
			allocate_size=::WideCharToMultiByte(CP_UTF8,0,fileInfo.cFileName,-1,NULL,0,NULL,NULL);
			leafname.reserve(allocate_size);
			leafname.assign ( allocate_size , 0 );
			retValue=::WideCharToMultiByte(CP_UTF8,0,fileInfo.cFileName,-1,(LPSTR)leafname.data(),(int)(leafname.length()),NULL,NULL);
			if ( ! retValue )
				XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );
		}
		casePreservedPath += leafname.c_str() ;
		if (loopvar)
			casePreservedPath+=pathSep;
		pos=newpos+1;
	}
	return casePreservedPath.c_str();
}
static bool ContainsNonASCIICodePoints( const std::string & value )
{
	size_t vallen=value.length();
	for (size_t index=0;index<vallen;index++)
	{
		if ((unsigned char)value[index]>127)
		{
			return true;
		}
	}
	return false;
}
// =================================================================================================
// Host_IO::GetCasePreservedName
// =============================
std::string Host_IO::GetCasePreservedName( const std::string& inputPath )
{
#ifndef XMP_UWP
	if ( ! ContainsNonASCIICodePoints( inputPath ) )
	{
		DWORD allocate_size,retValue;
		std::string widePath,systempath,longPathName,shortPathName;
		if ( ! GetWidePath(inputPath.c_str(), widePath) || widePath.length() == 0)
			XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );

		allocate_size = ::GetShortPathNameW((LPCWSTR)(widePath.c_str()),NULL,0);
		shortPathName.reserve ( allocate_size* sizeof(TCHAR) );
		shortPathName.assign ( allocate_size* sizeof(TCHAR) , 0 );
		retValue = ::GetShortPathNameW( ( LPCWSTR)(widePath.c_str()),(LPWSTR)shortPathName.data(),allocate_size);
		if ( ! retValue )
			XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );

		allocate_size = ::GetLongPathNameW((LPCWSTR)(shortPathName.c_str()),NULL,0);
		longPathName.reserve ( allocate_size* sizeof(TCHAR) );
		longPathName.assign ( allocate_size* sizeof(TCHAR) , 0 );
		retValue = ::GetLongPathNameW( ( LPCWSTR)(shortPathName.c_str()),(LPWSTR)longPathName.data(),allocate_size);
		if ( ! retValue )
			XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );

		allocate_size=::WideCharToMultiByte(CP_UTF8,0,(LPWSTR)&longPathName[0],-1,NULL,0,NULL,NULL);
		systempath.reserve(allocate_size+1);
		systempath.assign ( allocate_size+1 , 0 );
		retValue=::WideCharToMultiByte(CP_UTF8,0,(LPWSTR)&longPathName[0],-1,(LPSTR)systempath.data(),systempath.size(),NULL,NULL);
		if ( ! retValue )
			XMP_Throw ( "Host_IO::GetCasePresevedLeafName, cannot convert path", kXMPErr_ExternalFailure );

		return systempath.c_str();
	}
	else
#endif
	{
		 return ConstructPreservedPath( inputPath );
	}
}