///////////////////////////////////////////////////////////////////////////////
// Name:        src/common/fileconf.cpp
// Purpose:     implementation of wxFileConfig derivation of wxConfig
// Author:      Vadim Zeitlin
// Modified by:
// Created:     07.04.98 (adapted from appconf.cpp)
// RCS-ID:      $Id: fileconf.cpp 48776 2007-09-19 00:41:55Z VZ $
// Copyright:   (c) 1997 Karsten Ballüder   &  Vadim Zeitlin
//                       Ballueder@usa.net     <zeitlin@dptmaths.ens-cachan.fr>
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include  "wx/wxprec.h"

#ifdef    __BORLANDC__
    #pragma hdrstop
#endif  //__BORLANDC__

#if wxUSE_CONFIG && wxUSE_FILECONFIG

#ifndef   WX_PRECOMP
    #include  "wx/dynarray.h"
    #include  "wx/string.h"
    #include  "wx/intl.h"
    #include  "wx/log.h"
    #include  "wx/app.h"
    #include  "wx/utils.h"    // for wxGetHomeDir
    #if wxUSE_STREAMS
        #include  "wx/stream.h"
    #endif // wxUSE_STREAMS
#endif  //WX_PRECOMP

#include  "wx/file.h"
#include  "wx/textfile.h"
#include  "wx/memtext.h"
#include  "wx/config.h"
#include  "wx/fileconf.h"
#include  "wx/filefn.h"

#if defined(__WXMAC__)
    #include  "wx/mac/private.h"  // includes mac headers
    #include  "wx/filename.h"     // for MacSetTypeAndCreator
#endif

#if defined(__WXMSW__)
    #include "wx/msw/private.h"
#endif  //windows.h
#if defined(__WXPM__)
    #define INCL_DOS
    #include <os2.h>
#endif

#include  <stdlib.h>
#include  <ctype.h>

// ----------------------------------------------------------------------------
// macros
// ----------------------------------------------------------------------------
#define CONST_CAST ((wxFileConfig *)this)->

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

#ifndef MAX_PATH
    #define MAX_PATH 512
#endif

#define FILECONF_TRACE_MASK _T("fileconf")

// ----------------------------------------------------------------------------
// global functions declarations
// ----------------------------------------------------------------------------

// compare functions for sorting the arrays
static int LINKAGEMODE CompareEntries(wxFileConfigEntry *p1, wxFileConfigEntry *p2);
static int LINKAGEMODE CompareGroups(wxFileConfigGroup *p1, wxFileConfigGroup *p2);

// filter strings
static wxString FilterInValue(const wxString& str);
static wxString FilterOutValue(const wxString& str);

static wxString FilterInEntryName(const wxString& str);
static wxString FilterOutEntryName(const wxString& str);

// get the name to use in wxFileConfig ctor
static wxString GetAppName(const wxString& appname);

// ============================================================================
// private classes
// ============================================================================

// ----------------------------------------------------------------------------
// "template" array types
// ----------------------------------------------------------------------------

#ifdef WXMAKINGDLL_BASE
    WX_DEFINE_SORTED_USER_EXPORTED_ARRAY(wxFileConfigEntry *, ArrayEntries,
                                         WXDLLIMPEXP_BASE);
    WX_DEFINE_SORTED_USER_EXPORTED_ARRAY(wxFileConfigGroup *, ArrayGroups,
                                         WXDLLIMPEXP_BASE);
#else
    WX_DEFINE_SORTED_ARRAY(wxFileConfigEntry *, ArrayEntries);
    WX_DEFINE_SORTED_ARRAY(wxFileConfigGroup *, ArrayGroups);
#endif

// ----------------------------------------------------------------------------
// wxFileConfigLineList
// ----------------------------------------------------------------------------

// we store all lines of the local config file as a linked list in memory
class wxFileConfigLineList
{
public:
  void SetNext(wxFileConfigLineList *pNext)  { m_pNext = pNext; }
  void SetPrev(wxFileConfigLineList *pPrev)  { m_pPrev = pPrev; }

  // ctor
  wxFileConfigLineList(const wxString& str,
                       wxFileConfigLineList *pNext = NULL) : m_strLine(str)
    { SetNext(pNext); SetPrev(NULL); }

  // next/prev nodes in the linked list
  wxFileConfigLineList *Next() const { return m_pNext;  }
  wxFileConfigLineList *Prev() const { return m_pPrev;  }

  // get/change lines text
  void SetText(const wxString& str) { m_strLine = str;  }
  const wxString& Text() const { return m_strLine; }

private:
  wxString  m_strLine;                  // line contents
  wxFileConfigLineList *m_pNext,        // next node
                       *m_pPrev;        // previous one

    DECLARE_NO_COPY_CLASS(wxFileConfigLineList)
};

// ----------------------------------------------------------------------------
// wxFileConfigEntry: a name/value pair
// ----------------------------------------------------------------------------

class wxFileConfigEntry
{
private:
  wxFileConfigGroup *m_pParent; // group that contains us

  wxString      m_strName,      // entry name
                m_strValue;     //       value
  bool          m_bImmutable:1, // can be overriden locally?
                m_bHasValue:1;  // set after first call to SetValue()

  int           m_nLine;        // used if m_pLine == NULL only

  // pointer to our line in the linked list or NULL if it was found in global
  // file (which we don't modify)
  wxFileConfigLineList *m_pLine;

public:
  wxFileConfigEntry(wxFileConfigGroup *pParent,
                    const wxString& strName, int nLine);

  // simple accessors
  const wxString& Name()        const { return m_strName;    }
  const wxString& Value()       const { return m_strValue;   }
  wxFileConfigGroup *Group()    const { return m_pParent;    }
  bool            IsImmutable() const { return m_bImmutable; }
  bool            IsLocal()     const { return m_pLine != 0; }
  int             Line()        const { return m_nLine;      }
  wxFileConfigLineList *
                  GetLine()     const { return m_pLine;      }

  // modify entry attributes
  void SetValue(const wxString& strValue, bool bUser = true);
  void SetLine(wxFileConfigLineList *pLine);

    DECLARE_NO_COPY_CLASS(wxFileConfigEntry)
};

// ----------------------------------------------------------------------------
// wxFileConfigGroup: container of entries and other groups
// ----------------------------------------------------------------------------

class wxFileConfigGroup
{
private:
  wxFileConfig *m_pConfig;          // config object we belong to
  wxFileConfigGroup  *m_pParent;    // parent group (NULL for root group)
  ArrayEntries  m_aEntries;         // entries in this group
  ArrayGroups   m_aSubgroups;       // subgroups
  wxString      m_strName;          // group's name
  wxFileConfigLineList *m_pLine;    // pointer to our line in the linked list
  wxFileConfigEntry *m_pLastEntry;  // last entry/subgroup of this group in the
  wxFileConfigGroup *m_pLastGroup;  // local file (we insert new ones after it)

  // DeleteSubgroupByName helper
  bool DeleteSubgroup(wxFileConfigGroup *pGroup);

  // used by Rename()
  void UpdateGroupAndSubgroupsLines();

public:
  // ctor
  wxFileConfigGroup(wxFileConfigGroup *pParent, const wxString& strName, wxFileConfig *);

  // dtor deletes all entries and subgroups also
  ~wxFileConfigGroup();

  // simple accessors
  const wxString& Name()    const { return m_strName; }
  wxFileConfigGroup    *Parent()  const { return m_pParent; }
  wxFileConfig   *Config()  const { return m_pConfig; }

  const ArrayEntries& Entries() const { return m_aEntries;   }
  const ArrayGroups&  Groups()  const { return m_aSubgroups; }
  bool  IsEmpty() const { return Entries().IsEmpty() && Groups().IsEmpty(); }

  // find entry/subgroup (NULL if not found)
  wxFileConfigGroup *FindSubgroup(const wxChar *szName) const;
  wxFileConfigEntry *FindEntry   (const wxChar *szName) const;

  // delete entry/subgroup, return false if doesn't exist
  bool DeleteSubgroupByName(const wxChar *szName);
  bool DeleteEntry(const wxChar *szName);

  // create new entry/subgroup returning pointer to newly created element
  wxFileConfigGroup *AddSubgroup(const wxString& strName);
  wxFileConfigEntry *AddEntry   (const wxString& strName, int nLine = wxNOT_FOUND);

  void SetLine(wxFileConfigLineList *pLine);

  // rename: no checks are done to ensure that the name is unique!
  void Rename(const wxString& newName);

  //
  wxString GetFullName() const;

  // get the last line belonging to an entry/subgroup of this group
  wxFileConfigLineList *GetGroupLine();     // line which contains [group]
  wxFileConfigLineList *GetLastEntryLine(); // after which our subgroups start
  wxFileConfigLineList *GetLastGroupLine(); // after which the next group starts

  // called by entries/subgroups when they're created/deleted
  void SetLastEntry(wxFileConfigEntry *pEntry);
  void SetLastGroup(wxFileConfigGroup *pGroup)
    { m_pLastGroup = pGroup; }

  DECLARE_NO_COPY_CLASS(wxFileConfigGroup)
};

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// static functions
// ----------------------------------------------------------------------------
wxString wxFileConfig::GetGlobalDir()
{
  wxString strDir;

#ifdef __VMS__ // Note if __VMS is defined __UNIX is also defined
    strDir = wxT("sys$manager:");
#elif defined(__WXMAC__)
    strDir = wxMacFindFolder(  (short) kOnSystemDisk, kPreferencesFolderType, kDontCreateFolder ) ;
#elif defined( __UNIX__ )
    strDir = wxT("/etc/");
#elif defined(__OS2__)
    ULONG aulSysInfo[QSV_MAX] = {0};
    UINT drive;
    APIRET rc;

    rc = DosQuerySysInfo( 1L, QSV_MAX, (PVOID)aulSysInfo, sizeof(ULONG)*QSV_MAX);
    if (rc == 0)
    {
        drive = aulSysInfo[QSV_BOOT_DRIVE - 1];
        strDir.Printf(wxT("%c:\\OS2\\"), 'A'+drive-1);
    }
#elif defined(__WXSTUBS__)
    wxFAIL_MSG( wxT("TODO") );
#elif defined(__DOS__)
    // There's no such thing as global cfg dir in MS-DOS, let's return
    // current directory (FIXME_MGL?)
    strDir = wxT(".\\");
#elif defined(__WXWINCE__)
    strDir = wxT("\\Windows\\");
#else // Windows

    wxChar szWinDir[MAX_PATH];
    ::GetWindowsDirectory(szWinDir, MAX_PATH);

    strDir = szWinDir;
    strDir << wxT('\\');
#endif // Unix/Windows

    return strDir;
}

wxString wxFileConfig::GetLocalDir()
{
    wxString strDir;

#if defined(__WXMAC__) || defined(__DOS__)
    // no local dir concept on Mac OS 9 or MS-DOS
    strDir << GetGlobalDir() ;
#else
    wxGetHomeDir(&strDir);

    #ifdef  __UNIX__
        if (
            (strDir.Last() != wxT('/'))
        #ifdef __VMS
            && (strDir.Last() != wxT(']'))
        #endif
            )
            strDir << wxT('/');
    #else
        if (strDir.Last() != wxT('\\'))
            strDir << wxT('\\');
    #endif
#endif

    return strDir;
}

wxString wxFileConfig::GetGlobalFileName(const wxChar *szFile)
{
    wxString str = GetGlobalDir();
    str << szFile;

    if ( wxStrchr(szFile, wxT('.')) == NULL )
#if defined( __WXMAC__ )
        str << wxT(" Preferences") ;
#elif defined( __UNIX__ )
        str << wxT(".conf");
#else   // Windows
        str << wxT(".ini");
#endif  // UNIX/Win

    return str;
}

wxString wxFileConfig::GetLocalFileName(const wxChar *szFile)
{
#ifdef __VMS__
    // On VMS I saw the problem that the home directory was appended
    // twice for the configuration file. Does that also happen for
    // other platforms?
    wxString str = wxT( '.' );
#else
    wxString str = GetLocalDir();
#endif

#if defined( __UNIX__ ) && !defined( __VMS ) && !defined( __WXMAC__ )
    str << wxT('.');
#endif

    str << szFile;

#if defined(__WINDOWS__) || defined(__DOS__)
    if ( wxStrchr(szFile, wxT('.')) == NULL )
        str << wxT(".ini");
#endif

#ifdef __WXMAC__
    str << wxT(" Preferences") ;
#endif

    return str;
}

// ----------------------------------------------------------------------------
// ctor
// ----------------------------------------------------------------------------

void wxFileConfig::Init()
{
    m_pCurrentGroup =
    m_pRootGroup    = new wxFileConfigGroup(NULL, wxEmptyString, this);

    m_linesHead =
    m_linesTail = NULL;

    // It's not an error if (one of the) file(s) doesn't exist.

    // parse the global file
    if ( !m_strGlobalFile.empty() && wxFile::Exists(m_strGlobalFile) )
    {
        wxTextFile fileGlobal(m_strGlobalFile);

        if ( fileGlobal.Open(*m_conv/*ignored in ANSI build*/) )
        {
            Parse(fileGlobal, false /* global */);
            SetRootPath();
        }
        else
        {
            wxLogWarning(_("can't open global configuration file '%s'."), m_strGlobalFile.c_str());
        }
    }

    // parse the local file
    if ( !m_strLocalFile.empty() && wxFile::Exists(m_strLocalFile) )
    {
        wxTextFile fileLocal(m_strLocalFile);
        if ( fileLocal.Open(*m_conv/*ignored in ANSI build*/) )
        {
            Parse(fileLocal, true /* local */);
            SetRootPath();
        }
        else
        {
            wxLogWarning(_("can't open user configuration file '%s'."),  m_strLocalFile.c_str() );
        }
    }

    m_isDirty = false;
}

// constructor supports creation of wxFileConfig objects of any type
wxFileConfig::wxFileConfig(const wxString& appName, const wxString& vendorName,
                           const wxString& strLocal, const wxString& strGlobal,
                           long style,
                           const wxMBConv& conv)
            : wxConfigBase(::GetAppName(appName), vendorName,
                           strLocal, strGlobal,
                           style),
              m_strLocalFile(strLocal), m_strGlobalFile(strGlobal),
              m_conv(conv.Clone())
{
    // Make up names for files if empty
    if ( m_strLocalFile.empty() && (style & wxCONFIG_USE_LOCAL_FILE) )
    {
        m_strLocalFile = GetLocalFileName(GetAppName());
#if defined(__UNIX__) && !defined(__VMS)
        if ( style & wxCONFIG_USE_SUBDIR )
            m_strLocalFile << wxFILE_SEP_PATH << GetAppName() << _T(".conf");
#endif
    }

    if ( m_strGlobalFile.empty() && (style & wxCONFIG_USE_GLOBAL_FILE) )
        m_strGlobalFile = GetGlobalFileName(GetAppName());

    // Check if styles are not supplied, but filenames are, in which case
    // add the correct styles.
    if ( !m_strLocalFile.empty() )
        SetStyle(GetStyle() | wxCONFIG_USE_LOCAL_FILE);

    if ( !m_strGlobalFile.empty() )
        SetStyle(GetStyle() | wxCONFIG_USE_GLOBAL_FILE);

    // if the path is not absolute, prepend the standard directory to it
    // UNLESS wxCONFIG_USE_RELATIVE_PATH style is set
    if ( !(style & wxCONFIG_USE_RELATIVE_PATH) )
    {
        if ( !m_strLocalFile.empty() && !wxIsAbsolutePath(m_strLocalFile) )
        {
            const wxString strLocalOrig = m_strLocalFile;
            m_strLocalFile = GetLocalDir();
            m_strLocalFile << strLocalOrig;
        }

        if ( !m_strGlobalFile.empty() && !wxIsAbsolutePath(m_strGlobalFile) )
        {
            const wxString strGlobalOrig = m_strGlobalFile;
            m_strGlobalFile = GetGlobalDir();
            m_strGlobalFile << strGlobalOrig;
        }
    }

    SetUmask(-1);

    Init();
}

#if wxUSE_STREAMS

wxFileConfig::wxFileConfig(wxInputStream &inStream, const wxMBConv& conv)
            : m_conv(conv.Clone())
{
    // always local_file when this constructor is called (?)
    SetStyle(GetStyle() | wxCONFIG_USE_LOCAL_FILE);

    m_pCurrentGroup =
    m_pRootGroup    = new wxFileConfigGroup(NULL, wxEmptyString, this);

    m_linesHead =
    m_linesTail = NULL;

    // read the entire stream contents in memory
    wxString str;
    {
        static const size_t chunkLen = 1024;

        wxMemoryBuffer buf(chunkLen);
        do
        {
            inStream.Read(buf.GetAppendBuf(chunkLen), chunkLen);
            buf.UngetAppendBuf(inStream.LastRead());

            const wxStreamError err = inStream.GetLastError();

            if ( err != wxSTREAM_NO_ERROR && err != wxSTREAM_EOF )
            {
                wxLogError(_("Error reading config options."));
                break;
            }
        }
        while ( !inStream.Eof() );

#if wxUSE_UNICODE
        size_t len;
        str = conv.cMB2WC((char *)buf.GetData(), buf.GetDataLen(), &len);
        if ( !len && buf.GetDataLen() )
        {
            wxLogError(_("Failed to read config options."));
        }
#else // !wxUSE_UNICODE
        // no need for conversion
        str.assign((char *)buf.GetData(), buf.GetDataLen());
#endif // wxUSE_UNICODE/!wxUSE_UNICODE
    }


    // translate everything to the current (platform-dependent) line
    // termination character
    str = wxTextBuffer::Translate(str);

    wxMemoryText memText;

    // Now we can add the text to the memory text. To do this we extract line
    // by line from the translated string, until we've reached the end.
    //
    // VZ: all this is horribly inefficient, we should do the translation on
    //     the fly in one pass saving both memory and time (TODO)

    const wxChar *pEOL = wxTextBuffer::GetEOL(wxTextBuffer::typeDefault);
    const size_t EOLLen = wxStrlen(pEOL);

    int posLineStart = str.Find(pEOL);
    while ( posLineStart != -1 )
    {
        wxString line(str.Left(posLineStart));

        memText.AddLine(line);

        str = str.Mid(posLineStart + EOLLen);

        posLineStart = str.Find(pEOL);
    }

    // also add whatever we have left in the translated string.
    if ( !str.empty() )
        memText.AddLine(str);

    // Finally we can parse it all.
    Parse(memText, true /* local */);

    SetRootPath();
    ResetDirty();
}

#endif // wxUSE_STREAMS

void wxFileConfig::CleanUp()
{
    delete m_pRootGroup;

    wxFileConfigLineList *pCur = m_linesHead;
    while ( pCur != NULL ) {
        wxFileConfigLineList *pNext = pCur->Next();
        delete pCur;
        pCur = pNext;
    }
}

wxFileConfig::~wxFileConfig()
{
    Flush();

    CleanUp();

    delete m_conv;
}

// ----------------------------------------------------------------------------
// parse a config file
// ----------------------------------------------------------------------------

void wxFileConfig::Parse(const wxTextBuffer& buffer, bool bLocal)
{
  const wxChar *pStart;
  const wxChar *pEnd;
  wxString strLine;

  size_t nLineCount = buffer.GetLineCount();

  for ( size_t n = 0; n < nLineCount; n++ )
  {
    strLine = buffer[n];

    // add the line to linked list
    if ( bLocal )
    {
      LineListAppend(strLine);

      // let the root group have its start line as well
      if ( !n )
      {
        m_pCurrentGroup->SetLine(m_linesTail);
      }
    }


    // skip leading spaces
    for ( pStart = strLine; wxIsspace(*pStart); pStart++ )
      ;

    // skip blank/comment lines
    if ( *pStart == wxT('\0')|| *pStart == wxT(';') || *pStart == wxT('#') )
      continue;

    if ( *pStart == wxT('[') ) {          // a new group
      pEnd = pStart;

      while ( *++pEnd != wxT(']') ) {
        if ( *pEnd == wxT('\\') ) {
            // the next char is escaped, so skip it even if it is ']'
            pEnd++;
        }

        if ( *pEnd == wxT('\n') || *pEnd == wxT('\0') ) {
            // we reached the end of line, break out of the loop
            break;
        }
      }

      if ( *pEnd != wxT(']') ) {
        wxLogError(_("file '%s': unexpected character %c at line %d."),
                   buffer.GetName(), *pEnd, n + 1);
        continue; // skip this line
      }

      // group name here is always considered as abs path
      wxString strGroup;
      pStart++;
      strGroup << wxCONFIG_PATH_SEPARATOR
               << FilterInEntryName(wxString(pStart, pEnd - pStart));

      // will create it if doesn't yet exist
      SetPath(strGroup);

      if ( bLocal )
      {
        if ( m_pCurrentGroup->Parent() )
          m_pCurrentGroup->Parent()->SetLastGroup(m_pCurrentGroup);
        m_pCurrentGroup->SetLine(m_linesTail);
      }

      // check that there is nothing except comments left on this line
      bool bCont = true;
      while ( *++pEnd != wxT('\0') && bCont ) {
        switch ( *pEnd ) {
          case wxT('#'):
          case wxT(';'):
            bCont = false;
            break;

          case wxT(' '):
          case wxT('\t'):
            // ignore whitespace ('\n' impossible here)
            break;

          default:
            wxLogWarning(_("file '%s', line %d: '%s' ignored after group header."),
                         buffer.GetName(), n + 1, pEnd);
            bCont = false;
        }
      }
    }
    else {                        // a key
      pEnd = pStart;
      while ( *pEnd && *pEnd != wxT('=') /* && !wxIsspace(*pEnd)*/ ) {
        if ( *pEnd == wxT('\\') ) {
          // next character may be space or not - still take it because it's
          // quoted (unless there is nothing)
          pEnd++;
          if ( !*pEnd ) {
            // the error message will be given below anyhow
            break;
          }
        }

        pEnd++;
      }

      wxString strKey(FilterInEntryName(wxString(pStart, pEnd).Trim()));

      // skip whitespace
      while ( wxIsspace(*pEnd) )
        pEnd++;

      if ( *pEnd++ != wxT('=') ) {
        wxLogError(_("file '%s', line %d: '=' expected."),
                   buffer.GetName(), n + 1);
      }
      else {
        wxFileConfigEntry *pEntry = m_pCurrentGroup->FindEntry(strKey);

        if ( pEntry == NULL ) {
          // new entry
          pEntry = m_pCurrentGroup->AddEntry(strKey, n);
        }
        else {
          if ( bLocal && pEntry->IsImmutable() ) {
            // immutable keys can't be changed by user
            wxLogWarning(_("file '%s', line %d: value for immutable key '%s' ignored."),
                         buffer.GetName(), n + 1, strKey.c_str());
            continue;
          }
          // the condition below catches the cases (a) and (b) but not (c):
          //  (a) global key found second time in global file
          //  (b) key found second (or more) time in local file
          //  (c) key from global file now found in local one
          // which is exactly what we want.
          else if ( !bLocal || pEntry->IsLocal() ) {
            wxLogWarning(_("file '%s', line %d: key '%s' was first found at line %d."),
                         buffer.GetName(), n + 1, strKey.c_str(), pEntry->Line());

          }
        }

        if ( bLocal )
          pEntry->SetLine(m_linesTail);

        // skip whitespace
        while ( wxIsspace(*pEnd) )
          pEnd++;

        wxString value = pEnd;
        if ( !(GetStyle() & wxCONFIG_USE_NO_ESCAPE_CHARACTERS) )
            value = FilterInValue(value);

        pEntry->SetValue(value, false);
      }
    }
  }
}

// ----------------------------------------------------------------------------
// set/retrieve path
// ----------------------------------------------------------------------------

void wxFileConfig::SetRootPath()
{
    m_strPath.Empty();
    m_pCurrentGroup = m_pRootGroup;
}

bool
wxFileConfig::DoSetPath(const wxString& strPath, bool createMissingComponents)
{
    wxArrayString aParts;

    if ( strPath.empty() ) {
        SetRootPath();
        return true;
    }

    if ( strPath[0] == wxCONFIG_PATH_SEPARATOR ) {
        // absolute path
        wxSplitPath(aParts, strPath);
    }
    else {
        // relative path, combine with current one
        wxString strFullPath = m_strPath;
        strFullPath << wxCONFIG_PATH_SEPARATOR << strPath;
        wxSplitPath(aParts, strFullPath);
    }

    // change current group
    size_t n;
    m_pCurrentGroup = m_pRootGroup;
    for ( n = 0; n < aParts.Count(); n++ ) {
        wxFileConfigGroup *pNextGroup = m_pCurrentGroup->FindSubgroup(aParts[n]);
        if ( pNextGroup == NULL )
        {
            if ( !createMissingComponents )
                return false;

            pNextGroup = m_pCurrentGroup->AddSubgroup(aParts[n]);
        }

        m_pCurrentGroup = pNextGroup;
    }

    // recombine path parts in one variable
    m_strPath.Empty();
    for ( n = 0; n < aParts.Count(); n++ ) {
        m_strPath << wxCONFIG_PATH_SEPARATOR << aParts[n];
    }

    return true;
}

void wxFileConfig::SetPath(const wxString& strPath)
{
    DoSetPath(strPath, true /* create missing path components */);
}

// ----------------------------------------------------------------------------
// enumeration
// ----------------------------------------------------------------------------

bool wxFileConfig::GetFirstGroup(wxString& str, long& lIndex) const
{
    lIndex = 0;
    return GetNextGroup(str, lIndex);
}

bool wxFileConfig::GetNextGroup (wxString& str, long& lIndex) const
{
    if ( size_t(lIndex) < m_pCurrentGroup->Groups().Count() ) {
        str = m_pCurrentGroup->Groups()[(size_t)lIndex++]->Name();
        return true;
    }
    else
        return false;
}

bool wxFileConfig::GetFirstEntry(wxString& str, long& lIndex) const
{
    lIndex = 0;
    return GetNextEntry(str, lIndex);
}

bool wxFileConfig::GetNextEntry (wxString& str, long& lIndex) const
{
    if ( size_t(lIndex) < m_pCurrentGroup->Entries().Count() ) {
        str = m_pCurrentGroup->Entries()[(size_t)lIndex++]->Name();
        return true;
    }
    else
        return false;
}

size_t wxFileConfig::GetNumberOfEntries(bool bRecursive) const
{
    size_t n = m_pCurrentGroup->Entries().Count();
    if ( bRecursive ) {
        wxFileConfigGroup *pOldCurrentGroup = m_pCurrentGroup;
        size_t nSubgroups = m_pCurrentGroup->Groups().Count();
        for ( size_t nGroup = 0; nGroup < nSubgroups; nGroup++ ) {
            CONST_CAST m_pCurrentGroup = m_pCurrentGroup->Groups()[nGroup];
            n += GetNumberOfEntries(true);
            CONST_CAST m_pCurrentGroup = pOldCurrentGroup;
        }
    }

    return n;
}

size_t wxFileConfig::GetNumberOfGroups(bool bRecursive) const
{
    size_t n = m_pCurrentGroup->Groups().Count();
    if ( bRecursive ) {
        wxFileConfigGroup *pOldCurrentGroup = m_pCurrentGroup;
        size_t nSubgroups = m_pCurrentGroup->Groups().Count();
        for ( size_t nGroup = 0; nGroup < nSubgroups; nGroup++ ) {
            CONST_CAST m_pCurrentGroup = m_pCurrentGroup->Groups()[nGroup];
            n += GetNumberOfGroups(true);
            CONST_CAST m_pCurrentGroup = pOldCurrentGroup;
        }
    }

    return n;
}

// ----------------------------------------------------------------------------
// tests for existence
// ----------------------------------------------------------------------------

bool wxFileConfig::HasGroup(const wxString& strName) const
{
    // special case: DoSetPath("") does work as it's equivalent to DoSetPath("/")
    // but there is no group with empty name so treat this separately
    if ( strName.empty() )
        return false;

    const wxString pathOld = GetPath();

    wxFileConfig *self = wx_const_cast(wxFileConfig *, this);
    const bool
        rc = self->DoSetPath(strName, false /* don't create missing components */);

    self->SetPath(pathOld);

    return rc;
}

bool wxFileConfig::HasEntry(const wxString& entry) const
{
    // path is the part before the last "/"
    wxString path = entry.BeforeLast(wxCONFIG_PATH_SEPARATOR);

    // except in the special case of "/keyname" when there is nothing before "/"
    if ( path.empty() && *entry.c_str() == wxCONFIG_PATH_SEPARATOR )
    {
        path = wxCONFIG_PATH_SEPARATOR;
    }

    // change to the path of the entry if necessary and remember the old path
    // to restore it later
    wxString pathOld;
    wxFileConfig * const self = wx_const_cast(wxFileConfig *, this);
    if ( !path.empty() )
    {
        pathOld = GetPath();
        if ( pathOld.empty() )
            pathOld = wxCONFIG_PATH_SEPARATOR;

        if ( !self->DoSetPath(path, false /* don't create if doesn't exist */) )
        {
            return false;
        }
    }

    // check if the entry exists in this group
    const bool exists = m_pCurrentGroup->FindEntry(
                            entry.AfterLast(wxCONFIG_PATH_SEPARATOR)) != NULL;

    // restore the old path if we changed it above
    if ( !pathOld.empty() )
    {
        self->SetPath(pathOld);
    }

    return exists;
}

// ----------------------------------------------------------------------------
// read/write values
// ----------------------------------------------------------------------------

bool wxFileConfig::DoReadString(const wxString& key, wxString* pStr) const
{
    wxConfigPathChanger path(this, key);

    wxFileConfigEntry *pEntry = m_pCurrentGroup->FindEntry(path.Name());
    if (pEntry == NULL) {
        return false;
    }

    *pStr = pEntry->Value();

    return true;
}

bool wxFileConfig::DoReadLong(const wxString& key, long *pl) const
{
    wxString str;
    if ( !Read(key, &str) )
        return false;

    // extra spaces shouldn't prevent us from reading numeric values
    str.Trim();

    return str.ToLong(pl);
}

bool wxFileConfig::DoWriteString(const wxString& key, const wxString& szValue)
{
    wxConfigPathChanger     path(this, key);
    wxString                strName = path.Name();

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("  Writing String '%s' = '%s' to Group '%s'"),
                strName.c_str(),
                szValue.c_str(),
                GetPath().c_str() );

    if ( strName.empty() )
    {
            // setting the value of a group is an error

        wxASSERT_MSG( szValue.empty(), wxT("can't set value of a group!") );

            // ... except if it's empty in which case it's a way to force it's creation

        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("  Creating group %s"),
                    m_pCurrentGroup->Name().c_str() );

        SetDirty();

            // this will add a line for this group if it didn't have it before

        (void)m_pCurrentGroup->GetGroupLine();
    }
    else
    {
        // writing an entry check that the name is reasonable
        if ( strName[0u] == wxCONFIG_IMMUTABLE_PREFIX )
        {
            wxLogError( _("Config entry name cannot start with '%c'."),
                        wxCONFIG_IMMUTABLE_PREFIX);
            return false;
        }

        wxFileConfigEntry   *pEntry = m_pCurrentGroup->FindEntry(strName);

        if ( pEntry == 0 )
        {
            wxLogTrace( FILECONF_TRACE_MASK,
                        _T("  Adding Entry %s"),
                        strName.c_str() );
            pEntry = m_pCurrentGroup->AddEntry(strName);
        }

        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("  Setting value %s"),
                    szValue.c_str() );
        pEntry->SetValue(szValue);

        SetDirty();
    }

    return true;
}

bool wxFileConfig::DoWriteLong(const wxString& key, long lValue)
{
  return Write(key, wxString::Format(_T("%ld"), lValue));
}

bool wxFileConfig::Flush(bool /* bCurrentOnly */)
{
  if ( !IsDirty() || !m_strLocalFile )
    return true;

  // set the umask if needed
  wxCHANGE_UMASK(m_umask);

  wxTempFile file(m_strLocalFile);

  if ( !file.IsOpened() )
  {
    wxLogError(_("can't open user configuration file."));
    return false;
  }

  // write all strings to file
  wxString filetext;
  filetext.reserve(4096);
  for ( wxFileConfigLineList *p = m_linesHead; p != NULL; p = p->Next() )
  {
    filetext << p->Text() << wxTextFile::GetEOL();
  }

  if ( !file.Write(filetext, *m_conv) )
  {
    wxLogError(_("can't write user configuration file."));
    return false;
  }

  if ( !file.Commit() )
  {
      wxLogError(_("Failed to update user configuration file."));

      return false;
  }

  ResetDirty();

#if defined(__WXMAC__)
  wxFileName(m_strLocalFile).MacSetTypeAndCreator('TEXT', 'ttxt');
#endif // __WXMAC__

  return true;
}

#if wxUSE_STREAMS

bool wxFileConfig::Save(wxOutputStream& os, const wxMBConv& conv)
{
    // save unconditionally, even if not dirty
    for ( wxFileConfigLineList *p = m_linesHead; p != NULL; p = p->Next() )
    {
        wxString line = p->Text();
        line += wxTextFile::GetEOL();

        wxCharBuffer buf(line.mb_str(conv));
        if ( !os.Write(buf, strlen(buf)) )
        {
            wxLogError(_("Error saving user configuration data."));

            return false;
        }
    }

    ResetDirty();

    return true;
}

#endif // wxUSE_STREAMS

// ----------------------------------------------------------------------------
// renaming groups/entries
// ----------------------------------------------------------------------------

bool wxFileConfig::RenameEntry(const wxString& oldName,
                               const wxString& newName)
{
    wxASSERT_MSG( !wxStrchr(oldName, wxCONFIG_PATH_SEPARATOR),
                   _T("RenameEntry(): paths are not supported") );

    // check that the entry exists
    wxFileConfigEntry *oldEntry = m_pCurrentGroup->FindEntry(oldName);
    if ( !oldEntry )
        return false;

    // check that the new entry doesn't already exist
    if ( m_pCurrentGroup->FindEntry(newName) )
        return false;

    // delete the old entry, create the new one
    wxString value = oldEntry->Value();
    if ( !m_pCurrentGroup->DeleteEntry(oldName) )
        return false;

    SetDirty();

    wxFileConfigEntry *newEntry = m_pCurrentGroup->AddEntry(newName);
    newEntry->SetValue(value);

    return true;
}

bool wxFileConfig::RenameGroup(const wxString& oldName,
                               const wxString& newName)
{
    // check that the group exists
    wxFileConfigGroup *group = m_pCurrentGroup->FindSubgroup(oldName);
    if ( !group )
        return false;

    // check that the new group doesn't already exist
    if ( m_pCurrentGroup->FindSubgroup(newName) )
        return false;

    group->Rename(newName);

    SetDirty();

    return true;
}

// ----------------------------------------------------------------------------
// delete groups/entries
// ----------------------------------------------------------------------------

bool wxFileConfig::DeleteEntry(const wxString& key, bool bGroupIfEmptyAlso)
{
  wxConfigPathChanger path(this, key);

  if ( !m_pCurrentGroup->DeleteEntry(path.Name()) )
    return false;

  SetDirty();

  if ( bGroupIfEmptyAlso && m_pCurrentGroup->IsEmpty() ) {
    if ( m_pCurrentGroup != m_pRootGroup ) {
      wxFileConfigGroup *pGroup = m_pCurrentGroup;
      SetPath(wxT(".."));  // changes m_pCurrentGroup!
      m_pCurrentGroup->DeleteSubgroupByName(pGroup->Name());
    }
    //else: never delete the root group
  }

  return true;
}

bool wxFileConfig::DeleteGroup(const wxString& key)
{
  wxConfigPathChanger path(this, RemoveTrailingSeparator(key));

  if ( !m_pCurrentGroup->DeleteSubgroupByName(path.Name()) )
      return false;

  path.UpdateIfDeleted();

  SetDirty();

  return true;
}

bool wxFileConfig::DeleteAll()
{
  CleanUp();

  if ( !m_strLocalFile.empty() )
  {
      if ( wxFile::Exists(m_strLocalFile) && wxRemove(m_strLocalFile) == -1 )
      {
          wxLogSysError(_("can't delete user configuration file '%s'"),
                        m_strLocalFile.c_str());
          return false;
      }
  }

  Init();

  return true;
}

// ----------------------------------------------------------------------------
// linked list functions
// ----------------------------------------------------------------------------

    // append a new line to the end of the list

wxFileConfigLineList *wxFileConfig::LineListAppend(const wxString& str)
{
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("    ** Adding Line '%s'"),
                str.c_str() );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    wxFileConfigLineList *pLine = new wxFileConfigLineList(str);

    if ( m_linesTail == NULL )
    {
        // list is empty
        m_linesHead = pLine;
    }
    else
    {
        // adjust pointers
        m_linesTail->SetNext(pLine);
        pLine->SetPrev(m_linesTail);
    }

    m_linesTail = pLine;

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    return m_linesTail;
}

// insert a new line after the given one or in the very beginning if !pLine
wxFileConfigLineList *wxFileConfig::LineListInsert(const wxString& str,
                                                   wxFileConfigLineList *pLine)
{
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("    ** Inserting Line '%s' after '%s'"),
                str.c_str(),
                ((pLine) ? pLine->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    if ( pLine == m_linesTail )
        return LineListAppend(str);

    wxFileConfigLineList *pNewLine = new wxFileConfigLineList(str);
    if ( pLine == NULL )
    {
        // prepend to the list
        pNewLine->SetNext(m_linesHead);
        m_linesHead->SetPrev(pNewLine);
        m_linesHead = pNewLine;
    }
    else
    {
        // insert before pLine
        wxFileConfigLineList *pNext = pLine->Next();
        pNewLine->SetNext(pNext);
        pNewLine->SetPrev(pLine);
        pNext->SetPrev(pNewLine);
        pLine->SetNext(pNewLine);
    }

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    return pNewLine;
}

void wxFileConfig::LineListRemove(wxFileConfigLineList *pLine)
{
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("    ** Removing Line '%s'"),
                pLine->Text().c_str() );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    wxFileConfigLineList    *pPrev = pLine->Prev(),
                            *pNext = pLine->Next();

        // first entry?

    if ( pPrev == NULL )
        m_linesHead = pNext;
    else
        pPrev->SetNext(pNext);

        // last entry?

    if ( pNext == NULL )
        m_linesTail = pPrev;
    else
        pNext->SetPrev(pPrev);

    if ( m_pRootGroup->GetGroupLine() == pLine )
        m_pRootGroup->SetLine(m_linesHead);

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        head: %s"),
                ((m_linesHead) ? m_linesHead->Text().c_str() : wxEmptyString) );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("        tail: %s"),
                ((m_linesTail) ? m_linesTail->Text().c_str() : wxEmptyString) );

    delete pLine;
}

bool wxFileConfig::LineListIsEmpty()
{
    return m_linesHead == NULL;
}

// ============================================================================
// wxFileConfig::wxFileConfigGroup
// ============================================================================

// ----------------------------------------------------------------------------
// ctor/dtor
// ----------------------------------------------------------------------------

// ctor
wxFileConfigGroup::wxFileConfigGroup(wxFileConfigGroup *pParent,
                                       const wxString& strName,
                                       wxFileConfig *pConfig)
                         : m_aEntries(CompareEntries),
                           m_aSubgroups(CompareGroups),
                           m_strName(strName)
{
  m_pConfig = pConfig;
  m_pParent = pParent;
  m_pLine   = NULL;

  m_pLastEntry = NULL;
  m_pLastGroup = NULL;
}

// dtor deletes all children
wxFileConfigGroup::~wxFileConfigGroup()
{
  // entries
  size_t n, nCount = m_aEntries.Count();
  for ( n = 0; n < nCount; n++ )
    delete m_aEntries[n];

  // subgroups
  nCount = m_aSubgroups.Count();
  for ( n = 0; n < nCount; n++ )
    delete m_aSubgroups[n];
}

// ----------------------------------------------------------------------------
// line
// ----------------------------------------------------------------------------

void wxFileConfigGroup::SetLine(wxFileConfigLineList *pLine)
{
    // for a normal (i.e. not root) group this method shouldn't be called twice
    // unless we are resetting the line
    wxASSERT_MSG( !m_pParent || !m_pLine || !pLine,
                   _T("changing line for a non-root group?") );

    m_pLine = pLine;
}

/*
  This is a bit complicated, so let me explain it in details. All lines that
  were read from the local file (the only one we will ever modify) are stored
  in a (doubly) linked list. Our problem is to know at which position in this
  list should we insert the new entries/subgroups. To solve it we keep three
  variables for each group: m_pLine, m_pLastEntry and m_pLastGroup.

  m_pLine points to the line containing "[group_name]"
  m_pLastEntry points to the last entry of this group in the local file.
  m_pLastGroup                   subgroup

  Initially, they're NULL all three. When the group (an entry/subgroup) is read
  from the local file, the corresponding variable is set. However, if the group
  was read from the global file and then modified or created by the application
  these variables are still NULL and we need to create the corresponding lines.
  See the following functions (and comments preceding them) for the details of
  how we do it.

  Also, when our last entry/group are deleted we need to find the new last
  element - the code in DeleteEntry/Subgroup does this by backtracking the list
  of lines until it either founds an entry/subgroup (and this is the new last
  element) or the m_pLine of the group, in which case there are no more entries
  (or subgroups) left and m_pLast<element> becomes NULL.

  NB: This last problem could be avoided for entries if we added new entries
      immediately after m_pLine, but in this case the entries would appear
      backwards in the config file (OTOH, it's not that important) and as we
      would still need to do it for the subgroups the code wouldn't have been
      significantly less complicated.
*/

// Return the line which contains "[our name]". If we're still not in the list,
// add our line to it immediately after the last line of our parent group if we
// have it or in the very beginning if we're the root group.
wxFileConfigLineList *wxFileConfigGroup::GetGroupLine()
{
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("  GetGroupLine() for Group '%s'"),
                Name().c_str() );

    if ( !m_pLine )
    {
        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("    Getting Line item pointer") );

        wxFileConfigGroup   *pParent = Parent();

        // this group wasn't present in local config file, add it now
        if ( pParent )
        {
            wxLogTrace( FILECONF_TRACE_MASK,
                        _T("    checking parent '%s'"),
                        pParent->Name().c_str() );

            wxString    strFullName;

            // add 1 to the name because we don't want to start with '/'
            strFullName << wxT("[")
                        << FilterOutEntryName(GetFullName().c_str() + 1)
                        << wxT("]");
            m_pLine = m_pConfig->LineListInsert(strFullName,
                                                pParent->GetLastGroupLine());
            pParent->SetLastGroup(this);  // we're surely after all the others
        }
        //else: this is the root group and so we return NULL because we don't
        //      have any group line
    }

    return m_pLine;
}

// Return the last line belonging to the subgroups of this group (after which
// we can add a new subgroup), if we don't have any subgroups or entries our
// last line is the group line (m_pLine) itself.
wxFileConfigLineList *wxFileConfigGroup::GetLastGroupLine()
{
    // if we have any subgroups, our last line is the last line of the last
    // subgroup
    if ( m_pLastGroup )
    {
        wxFileConfigLineList *pLine = m_pLastGroup->GetLastGroupLine();

        wxASSERT_MSG( pLine, _T("last group must have !NULL associated line") );

        return pLine;
    }

    // no subgroups, so the last line is the line of thelast entry (if any)
    return GetLastEntryLine();
}

// return the last line belonging to the entries of this group (after which
// we can add a new entry), if we don't have any entries we will add the new
// one immediately after the group line itself.
wxFileConfigLineList *wxFileConfigGroup::GetLastEntryLine()
{
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("  GetLastEntryLine() for Group '%s'"),
                Name().c_str() );

    if ( m_pLastEntry )
    {
        wxFileConfigLineList    *pLine = m_pLastEntry->GetLine();

        wxASSERT_MSG( pLine, _T("last entry must have !NULL associated line") );

        return pLine;
    }

    // no entries: insert after the group header, if any
    return GetGroupLine();
}

void wxFileConfigGroup::SetLastEntry(wxFileConfigEntry *pEntry)
{
    m_pLastEntry = pEntry;

    if ( !m_pLine )
    {
        // the only situation in which a group without its own line can have
        // an entry is when the first entry is added to the initially empty
        // root pseudo-group
        wxASSERT_MSG( !m_pParent, _T("unexpected for non root group") );

        // let the group know that it does have a line in the file now
        m_pLine = pEntry->GetLine();
    }
}

// ----------------------------------------------------------------------------
// group name
// ----------------------------------------------------------------------------

void wxFileConfigGroup::UpdateGroupAndSubgroupsLines()
{
    // update the line of this group
    wxFileConfigLineList *line = GetGroupLine();
    wxCHECK_RET( line, _T("a non root group must have a corresponding line!") );

    // +1: skip the leading '/'
    line->SetText(wxString::Format(_T("[%s]"), GetFullName().c_str() + 1));


    // also update all subgroups as they have this groups name in their lines
    const size_t nCount = m_aSubgroups.Count();
    for ( size_t n = 0; n < nCount; n++ )
    {
        m_aSubgroups[n]->UpdateGroupAndSubgroupsLines();
    }
}

void wxFileConfigGroup::Rename(const wxString& newName)
{
    wxCHECK_RET( m_pParent, _T("the root group can't be renamed") );

    if ( newName == m_strName )
        return;

    // we need to remove the group from the parent and it back under the new
    // name to keep the parents array of subgroups alphabetically sorted
    m_pParent->m_aSubgroups.Remove(this);

    m_strName = newName;

    m_pParent->m_aSubgroups.Add(this);

    // update the group lines recursively
    UpdateGroupAndSubgroupsLines();
}

wxString wxFileConfigGroup::GetFullName() const
{
    wxString fullname;
    if ( Parent() )
        fullname = Parent()->GetFullName() + wxCONFIG_PATH_SEPARATOR + Name();

    return fullname;
}

// ----------------------------------------------------------------------------
// find an item
// ----------------------------------------------------------------------------

// use binary search because the array is sorted
wxFileConfigEntry *
wxFileConfigGroup::FindEntry(const wxChar *szName) const
{
  size_t i,
       lo = 0,
       hi = m_aEntries.Count();
  int res;
  wxFileConfigEntry *pEntry;

  while ( lo < hi ) {
    i = (lo + hi)/2;
    pEntry = m_aEntries[i];

    #if wxCONFIG_CASE_SENSITIVE
      res = wxStrcmp(pEntry->Name(), szName);
    #else
      res = wxStricmp(pEntry->Name(), szName);
    #endif

    if ( res > 0 )
      hi = i;
    else if ( res < 0 )
      lo = i + 1;
    else
      return pEntry;
  }

  return NULL;
}

wxFileConfigGroup *
wxFileConfigGroup::FindSubgroup(const wxChar *szName) const
{
  size_t i,
       lo = 0,
       hi = m_aSubgroups.Count();
  int res;
  wxFileConfigGroup *pGroup;

  while ( lo < hi ) {
    i = (lo + hi)/2;
    pGroup = m_aSubgroups[i];

    #if wxCONFIG_CASE_SENSITIVE
      res = wxStrcmp(pGroup->Name(), szName);
    #else
      res = wxStricmp(pGroup->Name(), szName);
    #endif

    if ( res > 0 )
      hi = i;
    else if ( res < 0 )
      lo = i + 1;
    else
      return pGroup;
  }

  return NULL;
}

// ----------------------------------------------------------------------------
// create a new item
// ----------------------------------------------------------------------------

// create a new entry and add it to the current group
wxFileConfigEntry *wxFileConfigGroup::AddEntry(const wxString& strName, int nLine)
{
    wxASSERT( FindEntry(strName) == 0 );

    wxFileConfigEntry   *pEntry = new wxFileConfigEntry(this, strName, nLine);

    m_aEntries.Add(pEntry);
    return pEntry;
}

// create a new group and add it to the current group
wxFileConfigGroup *wxFileConfigGroup::AddSubgroup(const wxString& strName)
{
    wxASSERT( FindSubgroup(strName) == 0 );

    wxFileConfigGroup   *pGroup = new wxFileConfigGroup(this, strName, m_pConfig);

    m_aSubgroups.Add(pGroup);
    return pGroup;
}

// ----------------------------------------------------------------------------
// delete an item
// ----------------------------------------------------------------------------

/*
  The delete operations are _very_ slow if we delete the last item of this
  group (see comments before GetXXXLineXXX functions for more details),
  so it's much better to start with the first entry/group if we want to
  delete several of them.
 */

bool wxFileConfigGroup::DeleteSubgroupByName(const wxChar *szName)
{
    wxFileConfigGroup * const pGroup = FindSubgroup(szName);

    return pGroup ? DeleteSubgroup(pGroup) : false;
}

// Delete the subgroup and remove all references to it from
// other data structures.
bool wxFileConfigGroup::DeleteSubgroup(wxFileConfigGroup *pGroup)
{
    wxCHECK_MSG( pGroup, false, _T("deleting non existing group?") );

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("Deleting group '%s' from '%s'"),
                pGroup->Name().c_str(),
                Name().c_str() );

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("  (m_pLine) = prev: %p, this %p, next %p"),
                m_pLine ? wx_static_cast(void*, m_pLine->Prev()) : 0,
                wx_static_cast(void*, m_pLine),
                m_pLine ? wx_static_cast(void*, m_pLine->Next()) : 0 );
    wxLogTrace( FILECONF_TRACE_MASK,
                _T("  text: '%s'"),
                m_pLine ? m_pLine->Text().c_str() : wxEmptyString );

    // delete all entries...
    size_t nCount = pGroup->m_aEntries.Count();

    wxLogTrace(FILECONF_TRACE_MASK,
               _T("Removing %lu entries"), (unsigned long)nCount );

    for ( size_t nEntry = 0; nEntry < nCount; nEntry++ )
    {
        wxFileConfigLineList *pLine = pGroup->m_aEntries[nEntry]->GetLine();

        if ( pLine )
        {
            wxLogTrace( FILECONF_TRACE_MASK,
                        _T("    '%s'"),
                        pLine->Text().c_str() );
            m_pConfig->LineListRemove(pLine);
        }
    }

    // ...and subgroups of this subgroup
    nCount = pGroup->m_aSubgroups.Count();

    wxLogTrace( FILECONF_TRACE_MASK,
                _T("Removing %lu subgroups"), (unsigned long)nCount );

    for ( size_t nGroup = 0; nGroup < nCount; nGroup++ )
    {
        pGroup->DeleteSubgroup(pGroup->m_aSubgroups[0]);
    }

    // and then finally the group itself
    wxFileConfigLineList *pLine = pGroup->m_pLine;
    if ( pLine )
    {
        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("  Removing line for group '%s' : '%s'"),
                    pGroup->Name().c_str(),
                    pLine->Text().c_str() );
        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("  Removing from group '%s' : '%s'"),
                    Name().c_str(),
                    ((m_pLine) ? m_pLine->Text().c_str() : wxEmptyString) );

        // notice that we may do this test inside the previous "if"
        // because the last entry's line is surely !NULL
        if ( pGroup == m_pLastGroup )
        {
            wxLogTrace( FILECONF_TRACE_MASK,
                        _T("  Removing last group") );

            // our last entry is being deleted, so find the last one which
            // stays by going back until we find a subgroup or reach the
            // group line
            const size_t nSubgroups = m_aSubgroups.Count();

            m_pLastGroup = NULL;
            for ( wxFileConfigLineList *pl = pLine->Prev();
                  pl && !m_pLastGroup;
                  pl = pl->Prev() )
            {
                // does this line belong to our subgroup?
                for ( size_t n = 0; n < nSubgroups; n++ )
                {
                    // do _not_ call GetGroupLine! we don't want to add it to
                    // the local file if it's not already there
                    if ( m_aSubgroups[n]->m_pLine == pl )
                    {
                        m_pLastGroup = m_aSubgroups[n];
                        break;
                    }
                }

                if ( pl == m_pLine )
                    break;
            }
        }

        m_pConfig->LineListRemove(pLine);
    }
    else
    {
        wxLogTrace( FILECONF_TRACE_MASK,
                    _T("  No line entry for Group '%s'?"),
                    pGroup->Name().c_str() );
    }

    m_aSubgroups.Remove(pGroup);
    delete pGroup;

    return true;
}

bool wxFileConfigGroup::DeleteEntry(const wxChar *szName)
{
  wxFileConfigEntry *pEntry = FindEntry(szName);
  if ( !pEntry )
  {
      // entry doesn't exist, nothing to do
      return false;
  }

  wxFileConfigLineList *pLine = pEntry->GetLine();
  if ( pLine != NULL ) {
    // notice that we may do this test inside the previous "if" because the
    // last entry's line is surely !NULL
    if ( pEntry == m_pLastEntry ) {
      // our last entry is being deleted - find the last one which stays
      wxASSERT( m_pLine != NULL );  // if we have an entry with !NULL pLine...

      // find the previous entry (if any)
      wxFileConfigEntry *pNewLast = NULL;
      const wxFileConfigLineList * const
        pNewLastLine = m_pLastEntry->GetLine()->Prev();
      const size_t nEntries = m_aEntries.GetCount();
      for ( size_t n = 0; n < nEntries; n++ ) {
        if ( m_aEntries[n]->GetLine() == pNewLastLine ) {
          pNewLast = m_aEntries[n];
          break;
        }
      }

      // pNewLast can be NULL here -- it's ok and can happen if we have no
      // entries left
      m_pLastEntry = pNewLast;
    }

    m_pConfig->LineListRemove(pLine);
  }

  m_aEntries.Remove(pEntry);
  delete pEntry;

  return true;
}

// ============================================================================
// wxFileConfig::wxFileConfigEntry
// ============================================================================

// ----------------------------------------------------------------------------
// ctor
// ----------------------------------------------------------------------------
wxFileConfigEntry::wxFileConfigEntry(wxFileConfigGroup *pParent,
                                       const wxString& strName,
                                       int nLine)
                         : m_strName(strName)
{
  wxASSERT( !strName.empty() );

  m_pParent = pParent;
  m_nLine   = nLine;
  m_pLine   = NULL;

  m_bHasValue = false;

  m_bImmutable = strName[0] == wxCONFIG_IMMUTABLE_PREFIX;
  if ( m_bImmutable )
    m_strName.erase(0, 1);  // remove first character
}

// ----------------------------------------------------------------------------
// set value
// ----------------------------------------------------------------------------

void wxFileConfigEntry::SetLine(wxFileConfigLineList *pLine)
{
  if ( m_pLine != NULL ) {
    wxLogWarning(_("entry '%s' appears more than once in group '%s'"),
                 Name().c_str(), m_pParent->GetFullName().c_str());
  }

  m_pLine = pLine;
  Group()->SetLastEntry(this);
}

// second parameter is false if we read the value from file and prevents the
// entry from being marked as 'dirty'
void wxFileConfigEntry::SetValue(const wxString& strValue, bool bUser)
{
    if ( bUser && IsImmutable() )
    {
        wxLogWarning( _("attempt to change immutable key '%s' ignored."),
                      Name().c_str());
        return;
    }

    // do nothing if it's the same value: but don't test for it if m_bHasValue
    // hadn't been set yet or we'd never write empty values to the file
    if ( m_bHasValue && strValue == m_strValue )
        return;

    m_bHasValue = true;
    m_strValue = strValue;

    if ( bUser )
    {
        wxString strValFiltered;

        if ( Group()->Config()->GetStyle() & wxCONFIG_USE_NO_ESCAPE_CHARACTERS )
        {
            strValFiltered = strValue;
        }
        else {
            strValFiltered = FilterOutValue(strValue);
        }

        wxString    strLine;
        strLine << FilterOutEntryName(m_strName) << wxT('=') << strValFiltered;

        if ( m_pLine )
        {
            // entry was read from the local config file, just modify the line
            m_pLine->SetText(strLine);
        }
        else // this entry didn't exist in the local file
        {
            // add a new line to the file: note that line returned by
            // GetLastEntryLine() may be NULL if we're in the root group and it
            // doesn't have any entries yet, but this is ok as passing NULL
            // line to LineListInsert() means to prepend new line to the list
            wxFileConfigLineList *line = Group()->GetLastEntryLine();
            m_pLine = Group()->Config()->LineListInsert(strLine, line);

            Group()->SetLastEntry(this);
        }
    }
}

// ============================================================================
// global functions
// ============================================================================

// ----------------------------------------------------------------------------
// compare functions for array sorting
// ----------------------------------------------------------------------------

int CompareEntries(wxFileConfigEntry *p1, wxFileConfigEntry *p2)
{
#if wxCONFIG_CASE_SENSITIVE
    return wxStrcmp(p1->Name(), p2->Name());
#else
    return wxStricmp(p1->Name(), p2->Name());
#endif
}

int CompareGroups(wxFileConfigGroup *p1, wxFileConfigGroup *p2)
{
#if wxCONFIG_CASE_SENSITIVE
    return wxStrcmp(p1->Name(), p2->Name());
#else
    return wxStricmp(p1->Name(), p2->Name());
#endif
}

// ----------------------------------------------------------------------------
// filter functions
// ----------------------------------------------------------------------------

// undo FilterOutValue
static wxString FilterInValue(const wxString& str)
{
  wxString strResult;
  strResult.Alloc(str.Len());

  bool bQuoted = !str.empty() && str[0] == '"';

  for ( size_t n = bQuoted ? 1 : 0; n < str.Len(); n++ ) {
    if ( str[n] == wxT('\\') ) {
      switch ( str[++n] ) {
        case wxT('n'):
          strResult += wxT('\n');
          break;

        case wxT('r'):
          strResult += wxT('\r');
          break;

        case wxT('t'):
          strResult += wxT('\t');
          break;

        case wxT('\\'):
          strResult += wxT('\\');
          break;

        case wxT('"'):
          strResult += wxT('"');
          break;
      }
    }
    else {
      if ( str[n] != wxT('"') || !bQuoted )
        strResult += str[n];
      else if ( n != str.Len() - 1 ) {
        wxLogWarning(_("unexpected \" at position %d in '%s'."),
                     n, str.c_str());
      }
      //else: it's the last quote of a quoted string, ok
    }
  }

  return strResult;
}

// quote the string before writing it to file
static wxString FilterOutValue(const wxString& str)
{
   if ( !str )
      return str;

  wxString strResult;
  strResult.Alloc(str.Len());

  // quoting is necessary to preserve spaces in the beginning of the string
  bool bQuote = wxIsspace(str[0]) || str[0] == wxT('"');

  if ( bQuote )
    strResult += wxT('"');

  wxChar c;
  for ( size_t n = 0; n < str.Len(); n++ ) {
    switch ( str[n] ) {
      case wxT('\n'):
        c = wxT('n');
        break;

      case wxT('\r'):
        c = wxT('r');
        break;

      case wxT('\t'):
        c = wxT('t');
        break;

      case wxT('\\'):
        c = wxT('\\');
        break;

      case wxT('"'):
        if ( bQuote ) {
          c = wxT('"');
          break;
        }
        //else: fall through

      default:
        strResult += str[n];
        continue;   // nothing special to do
    }

    // we get here only for special characters
    strResult << wxT('\\') << c;
  }

  if ( bQuote )
    strResult += wxT('"');

  return strResult;
}

// undo FilterOutEntryName
static wxString FilterInEntryName(const wxString& str)
{
  wxString strResult;
  strResult.Alloc(str.Len());

  for ( const wxChar *pc = str.c_str(); *pc != '\0'; pc++ ) {
    if ( *pc == wxT('\\') ) {
      // we need to test it here or we'd skip past the NUL in the loop line
      if ( *++pc == _T('\0') )
        break;
    }

    strResult += *pc;
  }

  return strResult;
}

// sanitize entry or group name: insert '\\' before any special characters
static wxString FilterOutEntryName(const wxString& str)
{
  wxString strResult;
  strResult.Alloc(str.Len());

  for ( const wxChar *pc = str.c_str(); *pc != wxT('\0'); pc++ ) {
    const wxChar c = *pc;

    // we explicitly allow some of "safe" chars and 8bit ASCII characters
    // which will probably never have special meaning and with which we can't
    // use isalnum() anyhow (in ASCII built, in Unicode it's just fine)
    //
    // NB: note that wxCONFIG_IMMUTABLE_PREFIX and wxCONFIG_PATH_SEPARATOR
    //     should *not* be quoted
    if (
#if !wxUSE_UNICODE
            ((unsigned char)c < 127) &&
#endif // ANSI
         !wxIsalnum(c) && !wxStrchr(wxT("@_/-!.*%"), c) )
    {
      strResult += wxT('\\');
    }

    strResult += c;
  }

  return strResult;
}

// we can't put ?: in the ctor initializer list because it confuses some
// broken compilers (Borland C++)
static wxString GetAppName(const wxString& appName)
{
    if ( !appName && wxTheApp )
        return wxTheApp->GetAppName();
    else
        return appName;
}

#endif // wxUSE_CONFIG
