/////////////////////////////////////////////////////////////////////////////

// Name:        wx/ffile.h

// Purpose:     wxFFile - encapsulates "FILE *" stream

// Author:      Vadim Zeitlin

// Created:     14.07.99

// Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>

// Licence:     wxWindows licence

/////////////////////////////////////////////////////////////////////////////

#ifndef   _WX_FFILE_H_

#define   _WX_FFILE_H_

#include "wx/defs.h"        // for wxUSE_FFILE

#if wxUSE_FFILE

#include  "wx/string.h"

#include  "wx/filefn.h"

#include  "wx/convauto.h"

#include <stdio.h>

// ----------------------------------------------------------------------------

// class wxFFile: standard C stream library IO

//

// NB: for space efficiency this class has no virtual functions, including

//     dtor which is _not_ virtual, so it shouldn't be used as a base class.

// ----------------------------------------------------------------------------

class WXDLLIMPEXP_BASE wxFFile

{

public:

  // ctors

  // -----

    // def ctor

  wxFFile() { m_fp = nullptr; }

    // open specified file (may fail, use IsOpened())

  wxFFile(const wxString& filename, const wxString& mode = wxT("r"));

    // attach to (already opened) file

  wxFFile(FILE *lfp) { m_fp = lfp; }

  // open/close

    // open a file (existing or not - the mode controls what happens)

  bool Open(const wxString& filename, const wxString& mode = wxT("r"));

    // closes the opened file (this is a NOP if not opened)

  bool Close();

  // assign an existing file descriptor and get it back from wxFFile object

  void Attach(FILE *lfp, const wxString& name = wxEmptyString)

    { Close(); m_fp = lfp; m_name = name; }

  FILE* Detach() { FILE* fpOld = m_fp; m_fp = nullptr; return fpOld; }

  FILE *fp() const { return m_fp; }

  // read/write (unbuffered)

    // read all data from the file into a string (useful for text files)

  bool ReadAll(wxString *str, const wxMBConv& conv = wxConvAuto());

    // returns number of bytes read - use Eof() and Error() to see if an error

    // occurred or not

  size_t Read(void *pBuf, size_t nCount);

    // returns the number of bytes written

  size_t Write(const void *pBuf, size_t nCount);

    // returns true on success

  bool Write(const wxString& s, const wxMBConv& conv = wxConvAuto());

    // flush data not yet written

  bool Flush();

  // file pointer operations (return ofsInvalid on failure)

    // move ptr ofs bytes related to start/current pos/end of file

  bool Seek(wxFileOffset ofs, wxSeekMode mode = wxFromStart);

    // move ptr to ofs bytes before the end

  bool SeekEnd(wxFileOffset ofs = 0) { return Seek(ofs, wxFromEnd); }

    // get current position in the file

  wxFileOffset Tell() const;

    // get current file length

  wxFileOffset Length() const;

  // simple accessors: note that Eof() and Error() may only be called if

  // IsOpened(). Otherwise they assert and return false.

    // is file opened?

  bool IsOpened() const { return m_fp != nullptr; }

    // is end of file reached?

  bool Eof() const;

    // has an error occurred?

  bool Error() const;

    // get the file name

  const wxString& GetName() const { return m_name; }

    // type such as disk or pipe

  wxFileKind GetKind() const { return wxGetFileKind(m_fp); }

  // dtor closes the file if opened

  ~wxFFile() { Close(); }

private:

  // copy ctor and assignment operator are private because it doesn't make

  // sense to copy files this way: attempt to do it will provoke a compile-time

  // error.

  wxFFile(const wxFFile&);

  wxFFile& operator=(const wxFFile&);

  FILE *m_fp;       // IO stream or nullptr if not opened

  wxString m_name;  // the name of the file (for diagnostic messages)

};

// ----------------------------------------------------------------------------

// class wxTempFFile: if you want to replace another file, create an instance

// of wxTempFFile passing the name of the file to be replaced to the ctor. Then

// you can write to wxTempFFile and call Commit() function to replace the old

// file (and close this one) or call Discard() to cancel the modification. If

// you call neither of them, dtor will call Discard().

// ----------------------------------------------------------------------------

class WXDLLIMPEXP_BASE wxTempFFile

{

public:

  // ctors

    // default

  wxTempFFile() = default;

    // associates the temp file with the file to be replaced and opens it

  explicit wxTempFFile(const wxString& strName);

  // open the temp file (strName is the name of file to be replaced)

  bool Open(const wxString& strName);

  // is the file opened?

  bool IsOpened() const { return m_file.IsOpened(); }

    // get current file length

  wxFileOffset Length() const { return m_file.Length(); }

    // move ptr ofs bytes related to start/current pos/end of file

  bool Seek(wxFileOffset ofs, wxSeekMode mode = wxFromStart)

    { return m_file.Seek(ofs, mode); }

    // get current position in the file

  wxFileOffset Tell() const { return m_file.Tell(); }

  // I/O (both functions return true on success, false on failure)

  bool Write(const void *p, size_t n) { return m_file.Write(p, n) == n; }

  bool Write(const wxString& str, const wxMBConv& conv = wxMBConvUTF8())

    { return m_file.Write(str, conv); }

  // flush data: can be called before closing file to ensure that data was

  // correctly written out

  bool Flush() { return m_file.Flush(); }

  // different ways to close the file

    // validate changes and delete the old file of name m_strName

  bool Commit();

    // discard changes

  void Discard();

  // dtor calls Discard() if file is still opened

 ~wxTempFFile();

private:

  // no copy ctor/assignment operator

  wxTempFFile(const wxTempFFile&);

  wxTempFFile& operator=(const wxTempFFile&);

  wxString  m_strName,  // name of the file to replace in Commit()

            m_strTemp;  // temporary file name

  wxFFile   m_file;     // the temporary file

};

#endif // wxUSE_FFILE

#endif // _WX_FFILE_H_