/********************************************************************
**                Image Component Library (ICL)                    **
**                                                                 **
** Copyright (C) 2006-2013 CITEC, University of Bielefeld          **
**                         Neuroinformatics Group                  **
** Website: www.iclcv.org and                                      **
**          http://opensource.cit-ec.de/projects/icl               **
**                                                                 **
** File   : ICLUtils/src/ICLUtils/StrTok.cpp                       **
** Module : ICLUtils                                               **
** Authors: Christof Elbrechter                                    **
**                                                                 **
**                                                                 **
** GNU LESSER GENERAL PUBLIC LICENSE                               **
** This file may be used under the terms of the GNU Lesser General **
** Public License version 3.0 as published by the                  **
**                                                                 **
** Free Software Foundation and appearing in the file LICENSE.LGPL **
** included in the packaging of this file.  Please review the      **
** following information to ensure the license requirements will   **
** be met: http://www.gnu.org/licenses/lgpl-3.0.txt                **
**                                                                 **
** The development of this software was supported by the           **
** Excellence Cluster EXC 277 Cognitive Interaction Technology.    **
** The Excellence Cluster EXC 277 is a grant of the Deutsche       **
** Forschungsgemeinschaft (DFG) in the context of the German       **
** Excellence Initiative.                                          **
**                                                                 **
********************************************************************/

#include <ICLUtils/StrTok.h>
#include <ICLUtils/Macros.h>

namespace icl{
  namespace utils{
  
    using std::size_t;
  
  
  
    inline size_t find_str(const std::string &s, const std::string &pattern, size_t idx){
      return s.find(pattern,idx);
    }
  
    inline size_t find_chars(const std::string &s, const std::string &pattern, size_t idx){
      return s.find_first_of(pattern,idx);
    }
  
    typedef size_t (*str_find_func)(const std::string&,const std::string&,size_t);
  
    template<bool useEscapeChar,str_find_func find>
    inline size_t find_escape(const std::string &s, const std::string &delims, size_t idx, char escapeChar, std::vector<size_t> &escapeIndices){
      size_t p = find(s,delims,idx);
      if(p == std::string::npos) return p;
  
      if(useEscapeChar){
        if(!p) return p;
        while(s[p-1] == escapeChar){
          escapeIndices.push_back(p-1);
          p = find(s,delims,p+1);
          if(p == std::string::npos) return p;
        }
      }
      return p;
    }
  
    typedef size_t (*str_find_func_esc)(const std::string&,const std::string&,size_t,char,std::vector<size_t>&);
  
    StrTok::StrTok(const std::string &s, const std::string &delims, bool singleCharDelims, char escapeChar){
  
      if(!(s.length())){
        this->m_uiPos = 0;
        return;
      }
      str_find_func_esc find;
      if(singleCharDelims){
        find = escapeChar=='\0' ?
        (str_find_func_esc)find_escape<false,find_chars> :
        (str_find_func_esc)find_escape<true,find_chars>;
      }else{
        find = escapeChar=='\0' ?
        (str_find_func_esc)find_escape<false,find_str> :
        (str_find_func_esc)find_escape<true,find_str>;
      }
      size_t pos = 0;
      size_t lastPos = 0;
      std::vector<size_t> escapeIndices;
  
      while(pos != std::string::npos){
        escapeIndices.clear();
        pos = find(s,delims,lastPos,escapeChar,escapeIndices);
        if(pos == std::string::npos) pos = s.length();
        // we don't want empty tokens
        size_t e = escapeIndices.size();
        if (pos-lastPos > e){
          if(!e){
            m_oTokens.push_back(s.substr(lastPos,pos-lastPos));
          }else{
            std::string t(pos-(lastPos+e),' ');
            for(size_t i=lastPos,j=0,k=0;i<pos;++i){
              if(j<e && escapeIndices[j] == i) { j++; continue; }
              t[k++] = s[i];
            }
            m_oTokens.push_back(t);
          }
        }
        lastPos = pos + (singleCharDelims ? 1 : delims.length());
        if(pos == s.length()) pos = std::string::npos;
      }
      this->m_uiPos = 0;
    }
  
    bool StrTok::hasMoreTokens() const{
      return m_uiPos<m_oTokens.size();
    }
  
    const std::string &StrTok::nextToken(){
      return m_oTokens[m_uiPos++];
    }
  
    unsigned int StrTok::nTokens() const{
      return static_cast<unsigned int>(m_oTokens.size());
    }
  
    const std::vector<std::string> &StrTok::allTokens()const{
      return m_oTokens;
    }
  
  } // namespace utils
}