/////////////////////////////////////////////////////////////////////////////
// Name:        strconv.cpp
// Purpose:     Unicode conversion classes
// Author:      Ove Kaaven, Robert Roebling, Vadim Zeitlin
// Modified by:
// Created:     29/01/98
// RCS-ID:      $Id$
// Copyright:   (c) 1999 Ove Kaaven, Robert Roebling, Vadim Zeitlin
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

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

#ifdef __GNUG__
  #pragma implementation "strconv.h"
#endif

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

#ifdef __BORLANDC__
  #pragma hdrstop
#endif

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

#ifdef __SALFORDC__
  #include <clib.h>
#endif

#include "wx/debug.h"
#include "wx/strconv.h"

// ----------------------------------------------------------------------------
// globals
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv *) wxConvCurrent = &wxConvLibc;

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

#if wxUSE_WCHAR_T

// ----------------------------------------------------------------------------
// wxMBConv
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv) wxConvLibc;

size_t wxMBConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
    return wxMB2WC(buf, psz, n);
}

size_t wxMBConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
    return wxWC2MB(buf, psz, n);
}

const wxWCharBuffer wxMBConv::cMB2WC(const char *psz) const
{
    if (psz)
    {
        size_t nLen = MB2WC((wchar_t *) NULL, psz, 0);
        if (nLen == (size_t)-1)
            return wxWCharBuffer((wchar_t *) NULL);
        wxWCharBuffer buf(nLen);
        MB2WC((wchar_t *)(const wchar_t *) buf, psz, nLen);
        return buf;
    }
    else
        return wxWCharBuffer((wchar_t *) NULL);
}

const wxCharBuffer wxMBConv::cWC2MB(const wchar_t *psz) const
{
    if (psz)
    {
        size_t nLen = WC2MB((char *) NULL, psz, 0);
        if (nLen == (size_t)-1)
            return wxCharBuffer((char *) NULL);
        wxCharBuffer buf(nLen);
        WC2MB((char *)(const char *) buf, psz, nLen);
        return buf;
    }
    else
        return wxCharBuffer((char *) NULL);
}

// ----------------------------------------------------------------------------
// standard file conversion
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvFile) wxConvFile;

// just use the libc conversion for now
size_t wxMBConvFile::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
    return wxMB2WC(buf, psz, n);
}

size_t wxMBConvFile::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
    return wxWC2MB(buf, psz, n);
}

// ----------------------------------------------------------------------------
// standard gdk conversion
// ----------------------------------------------------------------------------

#ifdef __WXGTK12__

WXDLLEXPORT_DATA(wxMBConvGdk) wxConvGdk;

#include <gdk/gdk.h>

size_t wxMBConvGdk::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
  if (buf) {
    return gdk_mbstowcs((GdkWChar *)buf, psz, n);
  } else {
    GdkWChar *nbuf = new GdkWChar[n=strlen(psz)];
    size_t len = gdk_mbstowcs(nbuf, psz, n);
    delete [] nbuf;
    return len;
  }
}

size_t wxMBConvGdk::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
  char *mbstr = gdk_wcstombs((GdkWChar *)psz);
  size_t len = mbstr ? strlen(mbstr) : 0;
  if (buf) {
    if (len > n) len = n;
    memcpy(buf, psz, len);
    if (len < n) buf[len] = 0;
  }
  return len;
}

#endif // GTK > 1.0

// ----------------------------------------------------------------------------
// UTF-7
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvUTF7) wxConvUTF7;

#if 0
static char utf7_setD[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                        "abcdefghijklmnopqrstuvwxyz"
                        "0123456789'(),-./:?";
static char utf7_setO[]="!\"#$%&*;<=>@[]^_`{|}";
static char utf7_setB[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                        "abcdefghijklmnopqrstuvwxyz"
                        "0123456789+/";
#endif

// TODO: write actual implementations of UTF-7 here
size_t wxMBConvUTF7::MB2WC(wchar_t * WXUNUSED(buf),
                           const char * WXUNUSED(psz),
                           size_t WXUNUSED(n)) const
{
  return 0;
}

size_t wxMBConvUTF7::WC2MB(char * WXUNUSED(buf),
                           const wchar_t * WXUNUSED(psz),
                           size_t WXUNUSED(n)) const
{
  return 0;
}

// ----------------------------------------------------------------------------
// UTF-8
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConvUTF8) wxConvUTF8;

static unsigned long utf8_max[]={0x7f,0x7ff,0xffff,0x1fffff,0x3ffffff,0x7fffffff,0xffffffff};

size_t wxMBConvUTF8::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
  size_t len = 0;

  while (*psz && ((!buf) || (len<n))) {
    unsigned char cc=*psz++, fc=cc;
    unsigned cnt;
    for (cnt=0; fc&0x80; cnt++) fc<<=1;
    if (!cnt) {
      // plain ASCII char
      if (buf) *buf++=cc;
      len++;
    } else {
      cnt--;
      if (!cnt) {
        // invalid UTF-8 sequence
        return (size_t)-1;
      } else {
        unsigned ocnt=cnt-1;
        unsigned long res=cc&(0x3f>>cnt);
        while (cnt--) {
          cc = *psz++;
          if ((cc&0xC0)!=0x80) {
            // invalid UTF-8 sequence
            return (size_t)-1;
          }
          res=(res<<6)|(cc&0x3f);
        }
        if (res<=utf8_max[ocnt]) {
          // illegal UTF-8 encoding
          return (size_t)-1;
        }
        if (buf) *buf++=res;
        len++;
      }
    }
  }
  if (buf && (len<n)) *buf = 0;
  return len;
}

size_t wxMBConvUTF8::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
  size_t len = 0;

  while (*psz && ((!buf) || (len<n))) {
    unsigned long cc=(*psz++)&0x7fffffff;
    unsigned cnt;
    for (cnt=0; cc>utf8_max[cnt]; cnt++);
    if (!cnt) {
      // plain ASCII char
      if (buf) *buf++=cc;
      len++;
    } else {
      len+=cnt+1;
      if (buf) {
        *buf++=(-128>>cnt)|((cc>>(cnt*6))&(0x3f>>cnt));
        while (cnt--)
          *buf++=0x80|((cc>>(cnt*6))&0x3f);
      }
    }
  }
  if (buf && (len<n)) *buf = 0;
  return len;
}

// ----------------------------------------------------------------------------
// specified character set
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxCSConv) wxConvLocal((const wxChar *)NULL);

#include "wx/encconv.h"
#include "wx/fontmap.h"

class wxCharacterSet
{
public:
  // temporarily just use wxEncodingConverter stuff,
  // so that it works while a better implementation is built
  wxFontEncoding enc;
  wxEncodingConverter m2w, w2m;
  wxCharacterSet(wxFontEncoding e) : enc(e)
  {
    m2w.Init(enc, wxFONTENCODING_UNICODE);
    w2m.Init(wxFONTENCODING_UNICODE, enc);
  }
};

static wxCharacterSet *wxGetCharacterSet(const wxChar *name)
{
  wxFontEncoding enc = name ? wxTheFontMapper->CharsetToEncoding(name, FALSE)
                            : wxFONTENCODING_SYSTEM;
  wxCharacterSet *cset = (enc != wxFONTENCODING_SYSTEM) ? new wxCharacterSet(enc)
                                                        : (wxCharacterSet *)NULL;
  return cset;
}

wxCSConv::wxCSConv(const wxChar *charset)
{
  m_name = (wxChar *) NULL;
  m_cset = (wxCharacterSet *) NULL;
  m_deferred = TRUE;
  SetName(charset);
}

wxCSConv::~wxCSConv()
{
  if (m_name) free(m_name);
  if (m_cset) delete m_cset;
}

void wxCSConv::SetName(const wxChar *charset)
{
  if (charset) {
    m_name = wxStrdup(charset);
    m_deferred = TRUE;
  }
}

void wxCSConv::LoadNow()
{
//  wxPrintf(wxT("Conversion request\n"));
  if (m_deferred) {
    if (!m_name) {
#ifdef __UNIX__
      wxChar *lang = wxGetenv(wxT("LC_ALL"));
      if (!lang) lang = wxGetenv(wxT("LANG"));
      wxChar *dot = lang ? wxStrchr(lang, wxT('.')) : (wxChar *)NULL;
      if (dot) SetName(dot+1);
#endif
    }
    m_cset = wxGetCharacterSet(m_name);
    m_deferred = FALSE;
  }
}

size_t wxCSConv::MB2WC(wchar_t *buf, const char *psz, size_t n) const
{
  ((wxCSConv *)this)->LoadNow(); // discard constness
  if (buf) {
    if (m_cset) {
      m_cset->m2w.Convert(psz, buf);
    } else {
      // latin-1 (direct)
      for (size_t c=0; c<n; c++)
        buf[c] = (unsigned char)(psz[c]);
    }
    return n;
  }
  return strlen(psz);
}

size_t wxCSConv::WC2MB(char *buf, const wchar_t *psz, size_t n) const
{
  ((wxCSConv *)this)->LoadNow(); // discard constness
  if (buf) {
    if (m_cset) {
      m_cset->w2m.Convert(psz, buf);
    } else {
      // latin-1 (direct)
      for (size_t c=0; c<n; c++)
        buf[c] = (psz[c]>0xff) ? '?' : psz[c];
    }
    return n;
  }
#if defined(__BORLANDC__) && (__BORLANDC__ > 0x530)
  return std::wcslen(psz);
#else
  return ::wcslen(psz);
#endif
}

#else // !wxUSE_WCHAR_T

// ----------------------------------------------------------------------------
// stand-ins in absence of wchar_t
// ----------------------------------------------------------------------------

WXDLLEXPORT_DATA(wxMBConv) wxConvLibc, wxConvFile;

#endif // wxUSE_WCHAR_T