DirFileEnum.h

// sktoolslib - common files for SK tools

// Copyright (C) 2012, 2017-2018, 2020-2021 - Stefan Kueng

// 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 2
// 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, write to the Free Software Foundation,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//

#pragma once

#include <string>

/**
 * Enumerates over a directory tree, non-recursively.
 * Advantages over CFileFind:
 * 1) Return values are not broken.  An error return from
 *    CFileFind::FindNext() indicates that the *next*
 *    call to CFileFind::FindNext() will fail.
 *    A failure from CSimpleFileFind means *that* call
 *    failed, which is what I'd expect.
 * 2) Error handling.  If you use CFileFind, you are
 *    required to call ::GetLastError() yourself, there
 *    is no abstraction.
 * 3) Support for ignoring the "." and ".." directories
 *    automatically.
 * 4) No dynamic memory allocation.
 */
class CSimpleFileFind
{
private:
    /**
     * Windows FindFirstFile() handle.
     */
    HANDLE m_hFindFile;

    /**
     * Windows error code - if all is well, ERROR_SUCCESS.
     * At end of directory, ERROR_NO_MORE_FILES.
     */
    DWORD m_dError;

    /**
     * Flag indicating that FindNextFile() has not yet been
     * called.
     */
    BOOL m_bFirst;

    /**
     * Flag indicating whether CSimpleFileFind was started for a file
     */
    BOOL m_bFile;

protected:
    /**
     * The prefix for files in this directory.
     * Ends with a "\", unless it's a drive letter only
     * ("C:" is different from "C:\", and "C:filename" is
     * legal anyway.)
     */
    std::wstring m_sPathPrefix;

    /**
     * The file data returned by FindFirstFile()/FindNextFile().
     */
    WIN32_FIND_DATA m_findFileData;

public:
    /**
     * Constructor.
     *
     * \param sPath    The path to search in.
     * \param sPattern The filename pattern - default all files.
     */
    CSimpleFileFind(const std::wstring& sPath, LPCWSTR pPattern = L"*.*", FINDEX_INFO_LEVELS infoLevel = FindExInfoBasic);
    ~CSimpleFileFind();

    /**
     * Advance to the next file.
     * Note that the state of this object is undefined until
     * this method is called the first time.
     *
     * \return TRUE if a file was found, FALSE on error or
     * end-of-directory (use IsError() and IsPastEnd() to
     * disambiguate).
     */
    bool FindNextFile();

    /**
     * Advance to the next file, ignoring the "." and ".."
     * pseudo-directories (if seen).
     *
     * Behaves like FindNextFile(), apart from ignoring "."
     * and "..".
     *
     * \return TRUE if a file was found, FALSE on error or
     * end-of-directory.
     */
    bool FindNextFileNoDots(DWORD attrToIgnore);

    /**
     * Advance to the next file, ignoring all directories.
     *
     * Behaves like FindNextFile(), apart from ignoring
     * directories.
     *
     * \return TRUE if a file was found, FALSE on error or
     * end-of-directory.
     */
    bool FindNextFileNoDirectories();

    /**
     * Get the Windows error code.
     * Only useful when IsError() returns true.
     *
     * \return Windows error code.
     */
    inline DWORD GetError() const
    {
        return m_dError;
    }

    /**
     * Get the file/directory attributes.
     *
     * \return item attributes.
     */
    inline DWORD GetAttributes() const
    {
        return m_findFileData.dwFileAttributes;
    }

    /**
     * Check if the current file data is valid.
     * (I.e. there has not been an error and we are not past
     * the end of the directory).
     *
     * \return TRUE iff the current file data is valid.
     */
    inline bool IsValid() const
    {
        return (m_dError == ERROR_SUCCESS);
    }

    /**
     * Check if we have passed the end of the directory.
     *
     * \return TRUE iff we have passed the end of the directory.
     */
    inline BOOL IsPastEnd() const
    {
        return (m_dError == ERROR_NO_MORE_FILES);
    }

    /**
     * Check if there has been an unexpected error - i.e.
     * any error other than passing the end of the directory.
     *
     * \return TRUE iff there has been an unexpected error.
     */
    inline bool IsError() const
    {
        return (m_dError != ERROR_SUCCESS) && (m_dError != ERROR_NO_MORE_FILES);
    }

    /**
     * Check if the current file is a directory.
     *
     * \return TRUE iff the current file is a directory.
     */
    inline bool IsDirectory() const
    {
        return !!(m_findFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
    }

    /**
     * Get the current file name (excluding the path).
     *
     * \return the current file name.
     */
    inline std::wstring GetFileName() const
    {
        return m_findFileData.cFileName;
    }

    const WIN32_FIND_DATA* GetFileFindData() const { return &m_findFileData; }

    /*
     * Get the current file name, including the path.
     *
     * \return the current file path.
     */
    inline std::wstring GetFilePath() const
    {
        if (m_bFile)
            return m_sPathPrefix;
        return m_sPathPrefix + m_findFileData.cFileName;
    }

    /**
    * Get the last write time of the file
    *
    * \return the last write time
    */
    FILETIME GetLastWriteTime() const
    {
        return m_findFileData.ftLastWriteTime;
    }

    /**
    * Get the creation time of the file
    *
    * \return the creation time
    */
    FILETIME GetCreateTime() const
    {
        return m_findFileData.ftCreationTime;
    }

    /**
     * Check if the current file is the "." or ".."
     * pseudo-directory.
     *
     * \return TRUE iff the current file is the "." or ".."
     * pseudo-directory.
     */
    inline bool IsDots() const
    {
        return IsDirectory() && m_findFileData.cFileName[0] == L'.' && ((m_findFileData.cFileName[1] == 0) || (m_findFileData.cFileName[1] == L'.' && m_findFileData.cFileName[2] == 0));
    }
};

/**
 * Enumerates over a directory tree, recursively.
 */
class CDirFileEnum
{
private:
    class CDirStackEntry : public CSimpleFileFind
    {
    public:
        CDirStackEntry(CDirStackEntry* seNext, const std::wstring& sDirName);
        ~CDirStackEntry();

        CDirStackEntry* m_seNext;
    };

    CDirStackEntry* m_seStack;
    bool            m_bIsNew;
    DWORD           m_attrToIgnore;

    inline void PopStack();
    inline void PushStack(const std::wstring& sDirName);

public:
    /**
     * Iterate through the specified directory and all subdirectories.
     * It does not matter whether or not the specified directory ends
     * with a slash.  Both relative and absolute paths are allowed,
     * the results of this iterator will be consistent with the style
     * passed to this constructor.
     *
     * @param dirName The directory to search in.
     */
    CDirFileEnum(const std::wstring& dirName);

    /**
     * Destructor.  Frees all resources.
     */
    ~CDirFileEnum();

    /**
     * Get the next file from this iterator.
     *
     * \param  result On successful return, holds the full path to the found
     *                file. (If this function returns FALSE, the value of
     *                result is unspecified).
     * \param  pbIsDirectory Pointer to a bool variable which will hold
     *                TRUE if the \c result path is a directory, FALSE
     *                if it's a file. Pass nullptr if you don't need that information.
     * \param  recurse true if recursing into subdirectories is requested.
     * \return TRUE iff a file was found, false at end of the iteration.
     */
    bool NextFile(std::wstring& result, bool* pbIsDirectory, bool recurse = true);

    /**
     * Get the file info structure.
     *
     * \return The WIN32_FIND_DATA structure of the file or directory
     */
    const WIN32_FIND_DATA* GetFileInfo() const { return m_seStack->GetFileFindData(); }

    /**
     * Set a mask of file attributes to ignore. Files or directories that
     * have any one of those attributes set won't be returned.
     * Useful if you want to ignore e.g. all system or hidden files: pass
     * FILE_ATTRIBUTE_SYSTEM | FILE_ATTRIBUTE_HIDDEN in that case.
     *
     * \param attr the file attribute mask
     */
    void SetAttributesToIgnore(DWORD attr) { m_attrToIgnore = attr; }

    /**
    * Get the last write time of the file
    *
    * \return the last write time
    */
    FILETIME GetLastWriteTime() const
    {
        if (m_seStack)
            return m_seStack->GetLastWriteTime();
        FILETIME ft = {0};
        return ft;
    }

    /**
    * Get the creation time of the file
    *
    * \return the creation time
    */
    FILETIME GetCreateTime() const
    {
        if (m_seStack)
            return m_seStack->GetCreateTime();
        FILETIME ft = {0};
        return ft;
    }

    DWORD GetError() const
    {
        if (m_seStack)
            return m_seStack->GetError();
        return 0;
    }
};