// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
// * Copyright (C) ZenJu (zhnmju123 AT gmx DOT de) - All Rights Reserved    *
// **************************************************************************

#ifndef FIND_FIRST_FILE_PLUS_HEADER_087483434
#define FIND_FIRST_FILE_PLUS_HEADER_087483434

#ifdef FIND_FILE_PLUS_DLL_EXPORTS
#define DLL_FUNCTION_DECLARATION extern "C" __declspec(dllexport)
#else
#define DLL_FUNCTION_DECLARATION extern "C" __declspec(dllimport)
#endif


#ifdef FIND_FILE_PLUS_DLL_EXPORTS
#include <Ntifs.h>  //driver level headers must be included *before* windows api headers!
#endif
#include <windef.h> //
#undef min
#undef max

#include <zen/build_info.h>

namespace findplus
{
/*--------------
  |declarations|
  --------------*/

struct FileInformation
{
    FILETIME creationTime;
    FILETIME lastWriteTime;
    ULARGE_INTEGER fileSize;
    ULARGE_INTEGER fileId; //optional: may be 0 if not supported
    DWORD fileAttributes;
    DWORD shortNameLength;
    WCHAR shortName[MAX_PATH + 1]; //shortName is 0-terminated
}; //no need for #pragma pack -> all members are perfectly 4, 8 byte aligned!

class FileSearcher;
typedef FileSearcher* FindHandle;

DLL_FUNCTION_DECLARATION
FindHandle openDir(const wchar_t* dirname); //returns nullptr on error, call ::GetLastError()
//note: do NOT place an asterisk at end, e.g. C:\SomeDir\*, as you would do for ::FindFirstFile()

DLL_FUNCTION_DECLARATION
bool readDir(FindHandle hnd, FileInformation& output); //returns false on error or if there are no more files; ::GetLastError() returns ERROR_NO_MORE_FILES in this case
/*
warning:; this may also return file system implementation dependent error codes like ERROR_NOT_SUPPORTED, ERROR_INVALID_LEVEL,
ect. if "FileIdBothDirectoryInformation" is not supported! We need a fallback:

    sometimes it's *not* sufficient to use fallback for NtQueryDirectoryFile() alone, we need to reset "hDir", since it may be fucked up by some poor file system layer implementation:
    - Samba before v3.0.22 (Mar 30, 2006) seems to have a bug which sucessfully returns 128 elements via NtQueryDirectoryFile() and FileIdBothDirectoryInformation,
    then fails with STATUS_INVALID_LEVEL. Fallback to FileBothDirectoryInformation will return STATUS_NO_MORE_FILES, even if there *are* more files
    - NtQueryDirectoryFile() may *not* respect "restartScan" for some weird Win2000 file system drivers, so we cannot rely on this as a replacement for a "hDir" reset
    - Windows 7 Remote Desktop sharing does not work unless "hDir" is reset!
	=> let's assume worst case in general and do a reset!
	perf note: implementing this reset at a folder level is possible, but a huge perf-killer (additional open/close handle), therefore fallback must apply to a complete folder (sub-)tree!
	=> caller needs to handle this and implement FindFirstFile()/FindNextFile() fallback!
*/

DLL_FUNCTION_DECLARATION
void closeDir(FindHandle hnd);

/*----------
  |typedefs|
  ----------*/
typedef FindHandle (*FunType_openDir )(const wchar_t* dirname);
typedef bool       (*FunType_readDir )(FindHandle hnd, FileInformation& dirInfo);
typedef void       (*FunType_closeDir)(FindHandle hnd);

/*--------------
  |symbol names|
  --------------*/
//const pointers ensure internal linkage
const char funName_openDir [] = "openDir";
const char funName_readDir [] = "readDir";
const char funName_closeDir[] = "closeDir";

/*---------------
  |library names|
  ---------------*/
inline const wchar_t* getDllName() { return zen::is64BitBuild ? L"FindFilePlus_x64.dll" : L"FindFilePlus_Win32.dll"; }
}


#endif //FIND_FIRST_FILE_PLUS_HEADER_087483434