/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.

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/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/Win32/pnUtW32Path.cpp
*   
***/

#include "../../Pch.h"
#pragma hdrstop


/*****************************************************************************
*
*   Local functions
*
***/

// make sure our definition is at least as big as the compiler's definition
COMPILER_ASSERT(MAX_PATH >= _MAX_PATH);


//===========================================================================
static inline bool IsSlash (wchar c) {
    return (c == L'\\') || (c == L'/');
}

//===========================================================================
static inline wchar ConvertSlash (wchar c) {
    return c != L'/' ? c : L'\\';
}

//===========================================================================
static inline bool IsUncPath (const wchar path[]) {
    return IsSlash(path[0]) && IsSlash(path[1]);
}

//===========================================================================
static const wchar * SkipUncDrive (const wchar path[]) {
    // UNC drive: "//server/share"

    // skip over leading "//"
    path += 2;

    // scan forward to end of server name
    for (;; ++path) {
        if (!*path)
            return path;
        if (IsSlash(*path))
            break;
    }

    // skip over '/'
    ++path;

    // skip over share name
    for (;; ++path) {
        if (!*path)
            return path;
        if (IsSlash(*path))
            return path;
    }
}

//===========================================================================
static wchar * PathSkipOverSeparator (wchar * path) {
    for (; *path; ++path) {
        if (IsSlash(*path))
            return path + 1;
    }

    return path;
}

//===========================================================================
static unsigned CommonPrefixLength (
    const wchar src1[],
    const wchar src2[]
) {
    ASSERT(src1);
    ASSERT(src2);

    wchar const * const base    = src1;
    const wchar * common        = nil;
    for (;;) {
        // Are the next components equal in length?
        const wchar * next1 = PathSkipOverSeparator(const_cast<wchar *>(src1));
        const wchar * next2 = PathSkipOverSeparator(const_cast<wchar *>(src2));
        const int componentLen = next1 - src1;
        if (componentLen != (next2 - src2))
            break;

        // Are the next components equal in value?
        if (!StrCmpI(src1, src2, componentLen))
            common = next1;
        else
            break;

        if (!*next1)
            break;
        src1 = next1 + 1;

        if (!*next2)
            break;
        src2 = next2 + 1;
    }

    if (!common)
        return 0;

    // Compute length of common subchunk;
    // if it is "C:" convert it to "C:\"
    unsigned commonLen = common - base;
    if ((commonLen == 2) && (base[1] == L':'))
        ++commonLen;
    return commonLen;
}

//===========================================================================
static void GetProgramName (
    void *      instance,
    wchar *     dst,
    unsigned    dstChars
) {
    ASSERT(dst);
    ASSERT(dstChars);

    if (!GetModuleFileNameW((HINSTANCE) instance, dst, dstChars)) {
        ErrorAssert(__LINE__, __FILE__, "GetModuleName failed");
        *dst = 0;
    }
}


/****************************************************************************
*
*   Exports
*
***/

//===========================================================================
void PathGetModuleName (
    wchar *     dst,
    unsigned    dstChars
) {
    GetProgramName(ModuleGetInstance(), dst, dstChars);
}

//===========================================================================
void PathGetProgramName (
    wchar *      dst,
    unsigned     dstChars
) {
    GetProgramName(nil, dst, dstChars);
}

//===========================================================================
bool PathFromString (
    wchar *      dst, 
    const wchar  src[], 
    unsigned     dstChars
) {
    ASSERT(dst);
    ASSERT(src);
    ASSERT(dstChars);

    for (;;) {
        // enable src and dst to be the same buffer
        wchar temp[MAX_PATH];
        if (dst == src) {
            StrCopy(temp, src, arrsize(temp));
            src = temp;
        }

        DWORD const result = GetFullPathNameW(src, dstChars, dst, 0);
        if (!result)
            break;
        if (dstChars < result)
            break;
        if (!dst[0])
            break;

        return true;
    }

    *dst = 0;
    return false;
}

//===========================================================================
bool PathFromString (
    wchar *     dst,                // ASSERT(dst);
    const wchar src[],              // ASSERT(src);
    unsigned    dstChars,           // ASSERT(dstChars);
    const wchar baseDir[]           // ASSERT(baseDir);
) {
    ASSERT(baseDir);
    ASSERT(dstChars);

    // Save current directory
    wchar curr[MAX_PATH];
    PathGetCurrentDirectory(curr, arrsize(curr));

    // Perform string conversion from specified directory
    bool result;
    if (0 != (result = PathSetCurrentDirectory(baseDir)))
        result = PathFromString(dst, src, dstChars);
    else
        *dst = 0;

    // Restore directory
    PathSetCurrentDirectory(curr);
    return result;
}

//===========================================================================
// this function was originally derived from _tsplitpath in the MSVCRT library,
// but has been updated to support UNC paths and to avoid blasting off the end
// of the buffers.
void PathSplitPath (
    const wchar     path[],
    wchar *         drive,
    wchar *         dir,
    wchar *         fname,
    wchar *         ext
) {
    ASSERT(path);
    ASSERT(path != drive);
    ASSERT(path != dir);
    ASSERT(path != fname);
    ASSERT(path != ext);

    // check for UNC path
    if (IsUncPath(path)) {
        const wchar * pathStart = path;
        path = SkipUncDrive(path);

        if (drive)
            StrCopy(drive, pathStart, min(MAX_DRIVE, path - pathStart + 1));
    }
    // regular DOS path
    else if (path[0] && (path[1] == L':')) {
        if (drive) {
            ASSERT(MAX_DRIVE >= 3);
            drive[0] = path[0];
            drive[1] = L':';
            drive[2] = L'\0';
        }

        path += 2; // skip over 'C' ':'
    }
    else if (drive) {
        *drive = 0;
    }

    // extract path string, if any.  Path now points to the first character
    // of the path, if any, or the filename or extension, if no path was
    // specified.  Scan ahead for the last occurence, if any, of a '/' or
    // '\' path separator character.  If none is found, there is no path.
    // We will also note the last '.' character found, if any, to aid in
    // handling the extension.
    const wchar *last_slash = nil, *last_dot = nil, *p = path;
    for (; *p; p++) {
        if (IsSlash(*p))
            last_slash = p + 1; // point to one beyond for later copy
        else if (*p == L'.')
            last_dot = p;
    }

    if (last_slash) {
        if (dir)
            StrCopy(dir, path, min(MAX_DIR, last_slash - path + 1));
        path = last_slash;
    }
    else if (dir) {
        *dir = 0;
    }

    // extract file name and extension, if any.  Path now points to the
    // first character of the file name, if any, or the extension if no
    // file name was given.  Dot points to the '.' beginning the extension,
    // if any.
    if (last_dot && (last_dot >= path)) {
        if (fname)
            StrCopy(fname, path, min(MAX_FNAME, last_dot - path + 1));
        if (ext)
            StrCopy(ext, last_dot, MAX_EXT);
    }
    else {
        if (fname)
            StrCopy(fname, path, MAX_FNAME);
        if (ext)
            *ext = 0;
    }
}

//===========================================================================
void PathMakePath (
    wchar *         path,
    unsigned        chars,
    const wchar     drive[],
    const wchar     dir[],
    const wchar     fname[],
    const wchar     ext[]
) {
    ASSERT(path);
    ASSERT(path != drive);
    ASSERT(path != dir);
    ASSERT(path != fname);
    ASSERT(path != ext);

    // save space for string terminator
    if (!chars--)
        return;

    // copy drive
    if (drive && *drive && chars) {
        do {
            *path++ = ConvertSlash(*drive++);
        } while (--chars && *drive);
        ASSERT(!IsSlash(path[-1]));
    }

    // copy directory
    if (dir && *dir && chars) {
        do {
            *path++ = ConvertSlash(*dir++);
        } while (--chars && *dir);

        // add trailing backslash
        if (chars && (path[-1] != '\\')) {
            *path++ = L'\\';
            chars--;
        }
    }

    // copy filename
    if (fname && *fname && chars) {
        // skip leading backslash
        if (IsSlash(*fname))
            ++fname;

        do {
            *path++ = ConvertSlash(*fname++);
        } while (--chars && *fname);
    }

    // copy extension
    if (ext && *ext && chars) {
        if (*ext != L'.') {
            *path++ = L'.';
            chars--;
        }
        while (chars-- && *ext)
            *path++ = ConvertSlash(*ext++);
    }

    // add string terminator
    *path = L'\0';
}

//===========================================================================
bool PathMakeRelative (
    wchar       *dst,
    unsigned    fromFlags,  // 0 or kPathFlagDirectory
    const wchar from[],
    unsigned    toFlags,    // 0 or kPathFlagDirectory
    const wchar to[],
    unsigned    dstChars
) {
    ASSERT(dst);
    ASSERT(from);
    ASSERT(to);
    ASSERT(dstChars);
    *dst = 0;

    unsigned prefixLength = CommonPrefixLength(from, to);
    if (!prefixLength)
        return false;

    wchar fromBuf[MAX_PATH];
    if (fromFlags & kPathFlagDirectory)
        StrCopy(fromBuf, from, arrsize(fromBuf));
    else
        PathRemoveFilename(fromBuf, from, arrsize(fromBuf));

    wchar toBuf[MAX_PATH];
    if (toFlags & kPathFlagDirectory)
        StrCopy(toBuf, to, arrsize(toBuf));
    else
        PathRemoveFilename(toBuf, to, arrsize(toBuf));

    const wchar * curr = fromBuf + prefixLength;
    if (*curr) {
        // build ..\.. part of the path
        if (IsSlash(*curr))
            curr++;              // skip slash

        while (*curr) {
            curr = PathSkipOverSeparator(const_cast<wchar *>(curr));
            StrPack(dst, *curr ? L"..\\" : L"..", dstChars);
        }
    }
    else {
        StrCopy(dst, L".", dstChars);
    }

    if (to[prefixLength]) {
        // deal with root case
        if (!IsSlash(to[prefixLength]))
            --prefixLength;

        ASSERT(IsSlash(to[prefixLength]));
        StrPack(dst, to + prefixLength, dstChars);
    }

    return true;
}

//===========================================================================
bool PathIsRelative (
    const wchar src[]
) {
    ASSERT(src);
    if (!src[0])
        return true;
    if (IsSlash(src[0]))
        return false;
    if (src[1] == L':')
        return false;
    return true;
}

//===========================================================================
const wchar * PathFindFilename (
    const wchar path[]
) {
    ASSERT(path);

    if (IsUncPath(path))
        path = SkipUncDrive(path);

    const wchar * last_slash = path;
    for (const wchar * p = path; *p; p++) {
        if ((*p == L'/') || (*p == L'\\') || (*p == L':'))
            last_slash = p + 1;
    }

    return last_slash;
}

//===========================================================================
const wchar * PathFindExtension (
    const wchar path[]
) {
    ASSERT(path);

    const wchar * last_dot = 0;
    const wchar * p = PathFindFilename(path);
    for ( ; *p; p++) {
        if (*p == L'.')
            last_dot = p;
    }

    return last_dot ? last_dot : p;
}

//===========================================================================
void PathGetCurrentDirectory (
    wchar *     dst,
    unsigned    dstChars
) {
    ASSERT(dst);
    ASSERT(dstChars);

    DWORD result = GetCurrentDirectoryW(dstChars, dst);
    if (!result || (result >= dstChars)) {
        ErrorAssert(__LINE__, __FILE__, "GetDir failed");
        *dst = 0;
    }
}

//===========================================================================
void PathGetTempDirectory (
    wchar *     dst,
    unsigned    dstChars
) {
    ASSERT(dst);
    ASSERT(dstChars);

    DWORD result = GetTempPathW(dstChars, dst);
    if (!result || (result >= dstChars))
        StrCopy(dst, L"C:\\temp\\", dstChars);
}

//============================================================================
void PathGetUserDirectory (
	wchar *		dst,
	unsigned	dstChars
) {
	ASSERT(dst);
	ASSERT(dstChars);

	wchar temp[MAX_PATH]; // GetSpecialFolder path requires a buffer of MAX_PATH size or larger
	if (SHGetSpecialFolderPathW(NULL, temp, CSIDL_PERSONAL, TRUE) == FALSE)
		StrCopy(temp, L"C:\\", arrsize(temp));

	// append the product name
	PathAddFilename(dst, temp, ProductLongName(), dstChars);

#if BUILD_TYPE != BUILD_TYPE_LIVE
	// non-live builds live in a subdir
	PathAddFilename(dst, dst, BuildTypeString(), dstChars);
#endif

	// ensure it exists
	if (!PathDoesDirectoryExist(dst))
		PathCreateDirectory(dst, kPathCreateDirFlagEntireTree);
}

//============================================================================
void PathGetLogDirectory (
	wchar *		dst,
	unsigned	dstChars
) {
	ASSERT(dst);
	ASSERT(dstChars);
	PathGetUserDirectory(dst, dstChars);
	PathAddFilename(dst, dst, L"Log", dstChars);
	if (!PathDoesDirectoryExist(dst))
		PathCreateDirectory(dst, kPathCreateDirFlagEntireTree);
}

//============================================================================
void PathGetInitDirectory (
	wchar *		dst,
	unsigned	dstChars
) {
	ASSERT(dst);
	ASSERT(dstChars);
	PathGetUserDirectory(dst, dstChars);
	PathAddFilename(dst, dst, L"Init", dstChars);
	if (!PathDoesDirectoryExist(dst))
		PathCreateDirectory(dst, kPathCreateDirFlagEntireTree);
}

//===========================================================================
bool PathSetCurrentDirectory (
    const wchar path[]
) {
    ASSERT(path);
    return SetCurrentDirectoryW(path) != 0;
}

//===========================================================================
void PathSetProgramDirectory () {
    wchar dir[MAX_PATH];
    PathGetProgramDirectory(dir, arrsize(dir));
    PathSetCurrentDirectory(dir);
}

//===========================================================================
void PathFindFiles (
    ARRAY(PathFind) *   paths,
    const wchar         fileSpec[],
    unsigned            pathFlags
) {
    ASSERT(paths);
    ASSERT(fileSpec);

    HANDLE find;
    WIN32_FIND_DATAW fd;
    wchar directory[MAX_PATH];
    PathRemoveFilename(directory, fileSpec, arrsize(directory));
    if (INVALID_HANDLE_VALUE == (find = FindFirstFileW(fileSpec, &fd))) {
        DWORD err = GetLastError();
        if ((err != ERROR_FILE_NOT_FOUND) && (err != ERROR_PATH_NOT_FOUND))
            ASSERTMSG(err, "PathFindFiles failed");
    }
    else {
        // find all the items in the current directory
        do {
            unsigned fileFlags = 0;
            if (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
                if (! (pathFlags & kPathFlagDirectory))
                    continue;

                // don't add "." and ".."
                if (fd.cFileName[0] == L'.') {
                    if (!fd.cFileName[1])
                        continue;
                    if (fd.cFileName[1] == L'.' && !fd.cFileName[2])
                        continue;
                }

                fileFlags = kPathFlagDirectory;
            }
            else {
                if (! (pathFlags & kPathFlagFile))
                    continue;
                fileFlags = kPathFlagFile;
            }
            if (fd.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN) {
                if (! (pathFlags & kPathFlagHidden))
                    continue;
                fileFlags |= kPathFlagHidden;
            }
            if (fd.dwFileAttributes & FILE_ATTRIBUTE_SYSTEM) {
                if (! (pathFlags & kPathFlagSystem))
                    continue;
                fileFlags |= kPathFlagSystem;
            }

            // add this one to the list of found files
            PathFind * pf       = paths->New();
            pf->flags           = fileFlags;
            pf->fileLength      = ((qword) fd.nFileSizeHigh << 32) | fd.nFileSizeLow;
            pf->lastWriteTime   = * (const qword *) &fd.ftLastWriteTime;
            PathAddFilename(pf->name, directory, fd.cFileName, arrsize(pf->name));
        } while (FindNextFileW(find, &fd));
        FindClose(find);
    }

    // check for directory recursing
    if ((pathFlags & kPathFlagRecurse) || StrStr(fileSpec, L"**")) {
        // recurse directories
    }
    else {
        return;
    }

    wchar dirSpec[MAX_PATH];
    PathAddFilename(dirSpec, directory, L"*", arrsize(dirSpec));
    if (INVALID_HANDLE_VALUE == (find = FindFirstFileW(dirSpec, &fd))) {
        DWORD err = GetLastError();
        if ((err != ERROR_FILE_NOT_FOUND) && (err != ERROR_PATH_NOT_FOUND))
            ErrorAssert(__LINE__, __FILE__, "PathFindFiles failed");
        return;
    }

    // find all the directories in the current directory
    const wchar * spec = PathFindFilename(fileSpec);
    do {
        if (! (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
            continue;
        }
        if (fd.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN) {
            if (! (pathFlags & kPathFlagHidden))
                continue;
        }
        if (fd.dwFileAttributes & FILE_ATTRIBUTE_SYSTEM) {
            if (! (pathFlags & kPathFlagSystem))
                continue;
        }

        // don't recurse "." and ".."
        if (fd.cFileName[0] == L'.') {
            if (!fd.cFileName[1])
                continue;
            if (fd.cFileName[1] == L'.' && !fd.cFileName[2])
                continue;
        }

        // recursively search subdirectory
        PathAddFilename(dirSpec, directory, fd.cFileName, arrsize(dirSpec));
        PathAddFilename(dirSpec, dirSpec, spec, arrsize(dirSpec));
        PathFindFiles(paths, dirSpec, pathFlags);

    } while (FindNextFileW(find, &fd));
    FindClose(find);
}

//===========================================================================
EPathCreateDirError PathCreateDirectory (const wchar path[], unsigned flags) {
    ASSERT(path);

    // convert from relative path to full path
    wchar dir[MAX_PATH];
    if (!PathFromString(dir, path, arrsize(dir))) {
        return kPathCreateDirErrInvalidPath;
    }

    // are we going to build the entire directory tree?
    wchar * dirEnd;
    if (flags & kPathCreateDirFlagEntireTree) {
        dirEnd = dir;

        // skip over leading slashes in UNC paths
        while (IsSlash(*dirEnd))
            ++dirEnd;

        // skip forward to first directory
        dirEnd = PathSkipOverSeparator(dirEnd);
    }
    // we're only creating the very last entry in the path
    else {
        dirEnd = dir + StrLen(dir);
    }

    bool result = true;
    for (wchar saveChar = L' '; saveChar; *dirEnd++ = saveChar) {
        // find the end of the current directory string and terminate it
        dirEnd = PathSkipOverSeparator(dirEnd);
        saveChar = *dirEnd;
        *dirEnd = 0;

        // create the directory and track the result from the last call
        result = CreateDirectoryW(dir, (LPSECURITY_ATTRIBUTES) nil);
    }

    // if we successfully created the directory then we're done
    if (result) {
        // Avoid check for kPathCreateDirFlagOsError
        COMPILER_ASSERT(kPathCreateDirSuccess == NO_ERROR);
        return kPathCreateDirSuccess;
    }

    unsigned error = GetLastError();
    switch (error) {
        case ERROR_ACCESS_DENIED:
        return kPathCreateDirErrAccessDenied;

        case ERROR_ALREADY_EXISTS: {
            DWORD attrib;
            if (0xffffffff == (attrib = GetFileAttributesW(dir)))
                return kPathCreateDirErrInvalidPath;

            if (! (attrib & FILE_ATTRIBUTE_DIRECTORY))
                return kPathCreateDirErrFileWithSameName;

            if (flags & kPathCreateDirFlagCreateNew)
                return kPathCreateDirErrDirExists;
        }
        return kPathCreateDirSuccess;

        default:
        return kPathCreateDirErrInvalidPath;
    }
}

//===========================================================================
void PathDeleteDirectory (const wchar path[], unsigned flags) {
    ASSERT(path);

    // convert from relative path to full path
    wchar dir[MAX_PATH];
    if (!PathFromString(dir, path, arrsize(dir)))
        return;

    for (;;) {
        // Important: in order to ensure that we don't delete NTFS
        // partition links, we must ensure that this is a directory!
        dword attributes = GetFileAttributesW(dir);
        if (attributes == (dword) -1)
            break;
        if ((attributes & FILE_ATTRIBUTE_DIRECTORY) == 0)
            break;
        if (attributes & FILE_ATTRIBUTE_REPARSE_POINT)
            break;

        if (!RemoveDirectoryW(dir))
            break;

        if ((flags & kPathCreateDirFlagEntireTree) == 0)
            break;

        wchar * filename = PathFindFilename(dir);
        if (!filename)
            break;

        // Move up one level in the directory hierarchy
        unsigned oldLength = StrLen(dir);
        while ((filename > dir) && IsSlash(filename[-1]))
            --filename;
        *filename = 0;
        if (oldLength == StrLen(dir))
            break;
    }
}

//===========================================================================
bool PathDoesFileExist (const wchar fileName[]) {
    dword attributes = GetFileAttributesW(fileName);
    if (attributes == (dword) -1)
        return false;
    if (attributes & FILE_ATTRIBUTE_DIRECTORY)
        return false;
    return true;
}

//============================================================================
bool PathDoesDirectoryExist (const wchar directory[]) {
	dword attributes = GetFileAttributesW(directory);
	if (attributes == (dword) -1)
		return false;
	if (attributes & FILE_ATTRIBUTE_DIRECTORY)
		return true;
	return false;
}

//===========================================================================
bool PathDeleteFile (
    const wchar file[]
) {
    return DeleteFileW(file) != 0;
}

//===========================================================================
bool PathMoveFile (
    const wchar src[],
    const wchar dst[]
) {
    return MoveFileW(src, dst) != 0;
}

//===========================================================================
bool PathCopyFile (
    const wchar src[],
    const wchar dst[]
) {
    return CopyFileW(src, dst, FALSE) != 0;    
}