// TortoiseSVN - a Windows shell extension for easy version control

// Copyright (C) 2005-2006, 2009-2010, 2014, 2021 - TortoiseSVN

// 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.
#include "stdafx.h"
#include "DirFileEnum.h"

CSimpleFileFind::CSimpleFileFind(const CString& sPath, LPCWSTR pPattern)
    : m_dError(ERROR_SUCCESS)
    , m_bFirst(TRUE)
    , m_sPathPrefix(sPath)
{
    // Add a trailing \ to m_sPathPrefix if it is missing.
    // Do not add one to "C:" since "C:" and "C:\" are different.
    int len = m_sPathPrefix.GetLength();
    if (len != 0)
    {
        wchar_t ch = sPath[len - 1];
        if (ch != '\\' && (ch != ':' || len != 2))
        {
            m_sPathPrefix += "\\";
        }
    }
    if ((len >= 248) && (m_sPathPrefix.Left(4).Compare(L"\\\\?\\")))
        m_hFindFile = ::FindFirstFile(static_cast<LPCWSTR>(L"\\\\?\\" + m_sPathPrefix + pPattern), &m_findFileData);
    else
        m_hFindFile = ::FindFirstFile(static_cast<LPCWSTR>(m_sPathPrefix + pPattern), &m_findFileData);
    if (m_hFindFile == INVALID_HANDLE_VALUE)
    {
        m_dError = ::GetLastError();
    }
}

CSimpleFileFind::~CSimpleFileFind()
{
    if (m_hFindFile != INVALID_HANDLE_VALUE)
    {
        ::FindClose(m_hFindFile);
    }
}

BOOL CSimpleFileFind::FindNextFile()
{
    if (m_dError)
    {
        return FALSE;
    }

    if (m_bFirst)
    {
        m_bFirst = FALSE;
        return TRUE;
    }

    if (!::FindNextFile(m_hFindFile, &m_findFileData))
    {
        m_dError = ::GetLastError();
        return FALSE;
    }

    return TRUE;
}

BOOL CSimpleFileFind::FindNextFileNoDots()
{
    BOOL result;
    do
    {
        result = FindNextFile();
    } while (result && IsDots());

    return result;
}

BOOL CSimpleFileFind::FindNextFileNoDirectories()
{
    BOOL result;
    do
    {
        result = FindNextFile();
    } while (result && IsDirectory());

    return result;
}

/*
 * Implementation notes:
 *
 * This is a depth-first traversal.  Directories are visited before
 * their contents.
 *
 * We keep a stack of directories.  The deepest directory is at the top
 * of the stack, the originally-requested directory is at the bottom.
 * If we come across a directory, we first return it to the user, then
 * recurse into it.  The finder at the bottom of the stack always points
 * to the file or directory last returned to the user (except immediately
 * after creation, when the finder points to the first valid thing we need
 * to return, but we haven't actually returned anything yet - hence the
 * m_bIsNew variable).
 *
 * Errors reading a directory are assumed to be end-of-directory, and
 * are otherwise ignored.
 *
 * The "." and ".." psedo-directories are ignored for obvious reasons.
 */

CDirFileEnum::CDirStackEntry::CDirStackEntry(CDirStackEntry* seNext,
                                             const CString&  sDirName)
    : CSimpleFileFind(sDirName)
    , m_seNext(seNext)
{
}

CDirFileEnum::CDirStackEntry::~CDirStackEntry()
{
}

inline void CDirFileEnum::PopStack()
{
    CDirStackEntry* seToDelete = m_seStack;
    m_seStack                  = seToDelete->m_seNext;
    delete seToDelete;
}

inline void CDirFileEnum::PushStack(const CString& sDirName)
{
    m_seStack = new CDirStackEntry(m_seStack, sDirName);
}

CDirFileEnum::CDirFileEnum(const CString& sDirName)
    : m_seStack(nullptr)
    , m_bIsNew(TRUE)
{
    PushStack(sDirName);
}

CDirFileEnum::~CDirFileEnum()
{
    while (m_seStack != nullptr)
    {
        PopStack();
    }
}

BOOL CDirFileEnum::NextFile(CString& sResult, bool* pbIsDirectory, bool bRecurse /* = true */)
{
    if (m_bIsNew)
    {
        // Special-case first time - haven't found anything yet,
        // so don't do recurse-into-directory check.
        m_bIsNew = FALSE;
    }
    else if (m_seStack && m_seStack->IsDirectory() && bRecurse)
    {
        PushStack(m_seStack->GetFilePath());
    }

    while (m_seStack && !m_seStack->FindNextFileNoDots())
    {
        // No more files in this directory, try parent.
        PopStack();
    }

    if (m_seStack)
    {
        sResult = m_seStack->GetFilePath();
        if (pbIsDirectory != nullptr)
        {
            *pbIsDirectory = m_seStack->IsDirectory();
        }
        return TRUE;
    }
    else
    {
        return FALSE;
    }
}