/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id$

#include <mapnik/unicode.hpp>

#ifdef USE_FRIBIDI
#include <fribidi/fribidi.h>
#endif

#include <string>

#ifdef MAPNIK_DEBUG
#include <iostream>
#endif 

namespace mapnik {
    
/*
** Use FRIBIDI to encode the string.
** The return value must be freed by the caller.
*/

#ifdef USE_FRIBIDI
    inline wchar_t* bidi_string(const wchar_t *logical)
    {
        FriBidiCharType base = FRIBIDI_TYPE_ON;
        size_t len;

        len = wcslen(logical);

        FriBidiChar *visual;

        FriBidiStrIndex *ltov, *vtol;
        FriBidiLevel *levels;
        FriBidiStrIndex new_len;
        fribidi_boolean log2vis;
        
        visual = (FriBidiChar *) calloc (sizeof (FriBidiChar), len + 1);
        ltov = 0;
        vtol = 0;
        levels = 0;

        /* Create a bidi string. */
        log2vis = fribidi_log2vis ((FriBidiChar *)logical, len, &base,
                /* output */
                visual, ltov, vtol, levels);

        if (!log2vis) {
            return 0;
        }

        new_len = len;

        return (wchar_t *)visual;
    }
#endif


    inline std::wstring to_unicode(std::string const& text)
    {
        std::wstring out;
        unsigned long code = 0;
        int expect = 0;
        std::string::const_iterator itr=text.begin();
        std::string::const_iterator end=text.end();
        while ( itr != end)
        {
            unsigned p = (*itr++) & 0xff;
            if ( p >= 0xc0)
            {
                if ( p < 0xe0)      // U+0080 - U+07ff
                {
                    expect = 1;
                    code = p & 0x1f;
                }
                else if ( p < 0xf0)  // U+0800 - U+ffff
                {
                    expect = 2;
                    code = p & 0x0f;
                }
                else if ( p  < 0xf8) // U+1000 - U+10ffff
                {
                    expect = 3;
                    code = p & 0x07;
                }
                continue;
            }
            else if (p >= 0x80)
            {
                --expect;
                if (expect >= 0)
                {
                    code <<= 6;
                    code += p & 0x3f;
                }
                if (expect > 0)
                    continue;
                expect = 0;
            }
            else 
            {
                code = p;            // U+0000 - U+007f (ascii)
            }
            out.push_back(wchar_t(code));
        }
#ifdef USE_FRIBIDI
        wchar_t *bidi_text = bidi_string(out.c_str());
        out = bidi_text;
        free(bidi_text);
#endif
        
        return out;
    }
   
   inline std::wstring latin1_to_unicode(std::string const& text)
   {
      std::wstring out;
      std::string::const_iterator itr=text.begin();
      std::string::const_iterator end=text.end();
      while ( itr != end)
      {
         unsigned p = (*itr++) & 0xff;     
         out.push_back(wchar_t(p));
      }      
      return out;
   }

   inline std::string latin1_to_unicode2(std::string const& text)
   {
      std::string out;
      std::string::const_iterator itr=text.begin();
      std::string::const_iterator end=text.end();
      while ( itr != end)
      {
         out.push_back(0x00);
         out.push_back(*itr++);  
      }      
      return out;
   }
   

   transcoder::transcoder (std::string const& encoding)
   {
#ifdef MAPNIK_DEBUG
      std::cerr << "ENCODING = " << encoding << "\n"; 
#endif
      
#ifndef WORDS_BIGENDIAN
      desc_ = iconv_open("UCS-4LE",encoding.c_str());
#else
      desc_ = iconv_open("UCS-4BE",encoding.c_str());
#endif
   }
   
   std::wstring transcoder::transcode(std::string const& input) const
   {
      if (desc_ == iconv_t(-1)) return to_unicode(input); 
      size_t inleft = input.size();
      std::wstring output(inleft,0);
      size_t outleft = inleft * sizeof(wchar_t);
#ifdef DARWIN
      const char * in = input.c_str();
#else
      char * in = const_cast<char*>(input.data());
#endif
      char * out = const_cast<char*>(reinterpret_cast<const char*>(output.data()));			
      iconv(desc_,&in,&inleft,&out,&outleft);
      output = output.substr(0,output.size()-(outleft/sizeof(wchar_t)));
#ifdef USE_FRIBIDI
      if (output.length() > 0)
      {
         wchar_t *bidi_text = bidi_string(output.c_str());
         output = bidi_text;
         free(bidi_text);
      }
#endif
      return output;
   }
   
   transcoder::~transcoder()
   {
      if (desc_ != iconv_t(-1)) iconv_close(desc_);
   }   
}