#ifndef _DATE_TIME_DATE_PARSING_HPP___

#define _DATE_TIME_DATE_PARSING_HPP___

/* Copyright (c) 2002,2003,2005 CrystalClear Software, Inc.

 *

 * Distributed under the Boost Software License, Version 1.0.

 *     (See accompanying file LICENSE_1_0.txt or copy at

 *           http://www.boost.org/LICENSE_1_0.txt)

 *

 * Author: Jeff Garland, Bart Garst

 * $Date: 2006/07/17 03:48:31 $

 */

#include "boost/tokenizer.hpp"

#include "boost/lexical_cast.hpp"

#include "boost/date_time/compiler_config.hpp"

#include "boost/date_time/parse_format_base.hpp"

#include <string>

#include <iterator>

#include <algorithm>

#if defined(BOOST_NO_STD_LOCALE)

#include <cctype> // ::tolower(int)

#else

#include <locale> // std::tolower(char, locale)

#endif

namespace boost {

namespace date_time {

  //! A function to replace the std::transform( , , ,tolower) construct

  /*! This function simply takes a string, and changes all the characters

   * in that string to lowercase (according to the default system locale).

   * In the event that a compiler does not support locales, the old 

   * C style tolower() is used.

   */

  inline

  std::string 

  convert_to_lower(const std::string& inp) {

    std::string tmp;

    unsigned i = 0;

#if defined(BOOST_NO_STD_LOCALE)

    while(i < inp.length()) {

      tmp += static_cast<char>(std::tolower(inp.at(i++)));

#else

      static const std::locale loc(std::locale::classic());

      while(i < inp.length()) {

        // tolower and others were brought in to std for borland >= v564

        // in compiler_config.hpp

        std::string::value_type c(inp.at(i++));

        tmp += std::tolower(c, loc);

#endif

      }

      return tmp;

    }

    //! Helper function for parse_date.

    /* Used by-value parameter because we change the string and may

     * want to preserve the original argument */

    template<class month_type>

    unsigned short 

    month_str_to_ushort(std::string s) {

      if((s.at(0) >= '0') && (s.at(0) <= '9')) {

        return boost::lexical_cast<unsigned short>(s);

      } 

      else {

        s = convert_to_lower(s);

        typename month_type::month_map_ptr_type ptr = month_type::get_month_map_ptr();

        typename month_type::month_map_type::iterator iter = ptr->find(s);

        if(iter != ptr->end()) { // required for STLport

          return iter->second;

        }

      }

      return 13; // intentionally out of range - name not found

    }

    //! Find index of a string in either of 2 arrays

    /*! find_match searches both arrays for a match to 's'. Indexing of the 

     * arrays is from 0 to 'limit'. The index of the match is returned.

     * Ex. "Jan" returns 0, "Dec" returns 11, "Tue" returns 2.

     * 'limit' can be sent in with: (greg_month::max)(), 

     * (greg_weekday::max)() or date_time::NumSpecialValues */

    template<class charT>

    short find_match(const charT* const* short_names, 

                     const charT* const* long_names, 

                     short limit,

                     const std::basic_string<charT>& s) {

      for(short i = 0; i <= limit; ++i){

        if(short_names[i] == s || long_names[i] == s){

          return i;

        }

      }

      return static_cast<short>(limit + 1); // not-found, return a value out of range

    }

    //! Generic function to parse a delimited date (eg: 2002-02-10)

    /*! Accepted formats are: "2003-02-10" or " 2003-Feb-10" or

     * "2003-Feburary-10" 

     * The order in which the Month, Day, & Year appear in the argument 

     * string can be accomodated by passing in the appropriate ymd_order_spec 

     */

    template<class date_type>

    date_type

    parse_date(const std::string& s, int order_spec = ymd_order_iso) {

      std::string spec_str("");

      if(order_spec == ymd_order_iso) {

        spec_str = "ymd";

      } 

      else if(order_spec == ymd_order_dmy) {

        spec_str = "dmy";

      } 

      else { // (order_spec == ymd_order_us)

        spec_str = "mdy";

      }

      typedef typename date_type::year_type year_type;

      typedef typename date_type::month_type month_type;

      unsigned pos = 0;

      unsigned short year(0), month(0), day(0);

      typedef typename std::basic_string<char>::traits_type traits_type;

      typedef boost::char_separator<char, traits_type> char_separator_type;

      typedef boost::tokenizer<char_separator_type,

                               std::basic_string<char>::const_iterator,

                               std::basic_string<char> > tokenizer;

      typedef boost::tokenizer<char_separator_type,

                               std::basic_string<char>::const_iterator,

                               std::basic_string<char> >::iterator tokenizer_iterator;

      // may need more delimiters, these work for the regression tests

      const char sep_char[] = {',','-','.',' ','/','\0'};

      char_separator_type sep(sep_char);

      tokenizer tok(s,sep);

      for(tokenizer_iterator beg=tok.begin(); 

          beg!=tok.end() && pos < spec_str.size(); 

          ++beg, ++pos) {

        switch(spec_str.at(pos)) {

          case 'y': 

          {

            year = boost::lexical_cast<unsigned short>(*beg);

            break;

          }

          case 'm': 

          {

            month = month_str_to_ushort<month_type>(*beg);

            break;

          }

          case 'd': 

          {

            day = boost::lexical_cast<unsigned short>(*beg);

            break;

          }

        } //switch

      }

      return date_type(year, month, day);

    }

    //! Generic function to parse undelimited date (eg: 20020201)

    template<class date_type>

    date_type

    parse_undelimited_date(const std::string& s) {

      int offsets[] = {4,2,2};

      int pos = 0;

      typedef typename date_type::year_type year_type;

      //typename date_type::ymd_type ymd((year_type::min)(),1,1);

      unsigned short y = 0, m = 0, d = 0;

      /* The two bool arguments state that parsing will not wrap 

       * (only the first 8 characters will be parsed) and partial 

       * strings will not be parsed. 

       * Ex:

       * "2005121" will parse 2005 & 12, but not the "1" */

      boost::offset_separator osf(offsets, offsets+3, false, false);

      typedef typename boost::tokenizer<boost::offset_separator, 

                                        std::basic_string<char>::const_iterator, 

                                        std::basic_string<char> > tokenizer_type;

      tokenizer_type tok(s, osf);

      for(typename tokenizer_type::iterator ti=tok.begin(); ti!=tok.end();++ti) {

        unsigned short i = boost::lexical_cast<unsigned short>(*ti);

        switch(pos) {

        case 0: y = i; break;

        case 1: m = i; break;

        case 2: d = i; break;

        }

        pos++;

      }

      return date_type(y,m,d);

    }

    //! Helper function for 'date gregorian::from_stream()'

    /*! Creates a string from the iterators that reference the

     * begining & end of a char[] or string. All elements are 

     * used in output string */

    template<class date_type, class iterator_type>

    inline 

    date_type

    from_stream_type(iterator_type& beg, 

                     iterator_type& end,

                     char) 

    {

      std::stringstream ss("");

      while(beg != end) {

        ss << *beg++;

      }

      return parse_date<date_type>(ss.str());

    }

    //! Helper function for 'date gregorian::from_stream()'

    /*! Returns the first string found in the stream referenced by the

     * begining & end iterators */

    template<class date_type, class iterator_type>

    inline 

    date_type

    from_stream_type(iterator_type& beg, 

                     iterator_type& end,

                     std::string) 

    {

      return parse_date<date_type>(*beg);

    }

    /* I believe the wchar stuff would be best elsewhere, perhaps in

     * parse_date<>()? In the mean time this gets us started... */

    //! Helper function for 'date gregorian::from_stream()'

    /*! Creates a string from the iterators that reference the

     * begining & end of a wstring. All elements are 

     * used in output string */

    template<class date_type, class iterator_type>

    inline 

    date_type from_stream_type(iterator_type& beg, 

                               iterator_type& end,

                               wchar_t) 

    {

      std::stringstream ss("");

      while(beg != end) {

#if !defined(BOOST_DATE_TIME_NO_LOCALE)

        ss << std::use_facet<std::ctype<wchar_t> >(std::locale()).narrow(*beg++, 'X'); // 'X' will cause exception to be thrown

#else

        ss << ss.narrow(*beg++, 'X');

#endif

      }

      return parse_date<date_type>(ss.str());

    }

#ifndef BOOST_NO_STD_WSTRING

    //! Helper function for 'date gregorian::from_stream()'

    /*! Creates a string from the first wstring found in the stream

     * referenced by the begining & end iterators */

    template<class date_type, class iterator_type>

    inline 

    date_type

    from_stream_type(iterator_type& beg, 

                     iterator_type& end,

                     std::wstring) {

      std::wstring ws = *beg;

      std::stringstream ss("");

      std::wstring::iterator wsb = ws.begin(), wse = ws.end();

      while(wsb != wse) {

#if !defined(BOOST_DATE_TIME_NO_LOCALE)

        ss << std::use_facet<std::ctype<wchar_t> >(std::locale()).narrow(*wsb++, 'X'); // 'X' will cause exception to be thrown

#else

        ss << ss.narrow(*wsb++, 'X'); // 'X' will cause exception to be thrown

#endif

      }

      return parse_date<date_type>(ss.str());

    }

#endif // BOOST_NO_STD_WSTRING

#if (defined(BOOST_MSVC) && (_MSC_VER < 1300))

    // This function cannot be compiled with MSVC 6.0 due to internal compiler shorcomings

#else

    //! function called by wrapper functions: date_period_from_(w)string()

    template<class date_type, class charT>

    period<date_type, typename date_type::duration_type> 

    from_simple_string_type(const std::basic_string<charT>& s){

      typedef typename std::basic_string<charT>::traits_type traits_type;

      typedef typename boost::char_separator<charT, traits_type> char_separator;

      typedef typename boost::tokenizer<char_separator, 

                                        typename std::basic_string<charT>::const_iterator, 

                                        std::basic_string<charT> > tokenizer;

      const charT sep_list[4] = {'[','/',']','\0'};

      char_separator sep(sep_list);

      tokenizer tokens(s, sep);

      typename tokenizer::iterator tok_it = tokens.begin(); 

      std::basic_string<charT> date_string = *tok_it;

      // get 2 string iterators and generate a date from them

      typename std::basic_string<charT>::iterator date_string_start = date_string.begin(), 

                                                  date_string_end = date_string.end(); 

      typedef typename std::iterator_traits<typename std::basic_string<charT>::iterator>::value_type value_type;

      date_type d1 = from_stream_type<date_type>(date_string_start, date_string_end, value_type());

      date_string = *(++tok_it); // next token

      date_string_start = date_string.begin(), date_string_end = date_string.end(); 

      date_type d2 = from_stream_type<date_type>(date_string_start, date_string_end, value_type());

      return period<date_type, typename date_type::duration_type>(d1, d2); 

    }

#endif

} } //namespace date_time

#endif