/*  Arg_parser - POSIX/GNU command line argument parser. (C++ version)
    Copyright (C) 2006-2014 Antonio Diaz Diaz.

    This library is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 2 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this library.  If not, see <http://www.gnu.org/licenses/>.

    As a special exception, you may use this file as part of a free
    software library without restriction.  Specifically, if other files
    instantiate templates or use macros or inline functions from this
    file, or you compile this file and link it with other files to
    produce an executable, this file does not by itself cause the
    resulting executable to be covered by the GNU General Public
    License.  This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General
    Public License.
*/

#include <cstring>
#include <string>
#include <vector>

#include "arg_parser.h"


bool Arg_parser::parse_long_option( const char * const opt, const char * const arg,
                                    const Option options[], int & argind )
  {
  unsigned len;
  int index = -1;
  bool exact = false, ambig = false;

  for( len = 0; opt[len+2] && opt[len+2] != '='; ++len ) ;

  // Test all long options for either exact match or abbreviated matches.
  for( int i = 0; options[i].code != 0; ++i )
    if( options[i].name && std::strncmp( options[i].name, &opt[2], len ) == 0 )
      {
      if( std::strlen( options[i].name ) == len )	// Exact match found
        { index = i; exact = true; break; }
      else if( index < 0 ) index = i;		// First nonexact match found
      else if( options[index].code != options[i].code ||
               options[index].has_arg != options[i].has_arg )
        ambig = true;			// Second or later nonexact match found
      }

  if( ambig && !exact )
    {
    error_ = "option '"; error_ += opt; error_ += "' is ambiguous";
    return false;
    }

  if( index < 0 )		// nothing found
    {
    error_ = "unrecognized option '"; error_ += opt; error_ += '\'';
    return false;
    }

  ++argind;
  data.push_back( Record( options[index].code ) );

  if( opt[len+2] )		// '--<long_option>=<argument>' syntax
    {
    if( options[index].has_arg == no )
      {
      error_ = "option '--"; error_ += options[index].name;
      error_ += "' doesn't allow an argument";
      return false;
      }
    if( options[index].has_arg == yes && !opt[len+3] )
      {
      error_ = "option '--"; error_ += options[index].name;
      error_ += "' requires an argument";
      return false;
      }
    data.back().argument = &opt[len+3];
    return true;
    }

  if( options[index].has_arg == yes )
    {
    if( !arg || !arg[0] )
      {
      error_ = "option '--"; error_ += options[index].name;
      error_ += "' requires an argument";
      return false;
      }
    ++argind; data.back().argument = arg;
    return true;
    }

  return true;
  }


bool Arg_parser::parse_short_option( const char * const opt, const char * const arg,
                                     const Option options[], int & argind )
  {
  int cind = 1;			// character index in opt

  while( cind > 0 )
    {
    int index = -1;
    const unsigned char c = opt[cind];

    if( c != 0 )
      for( int i = 0; options[i].code; ++i )
        if( c == options[i].code )
          { index = i; break; }

    if( index < 0 )
      {
      error_ = "invalid option -- '"; error_ += c; error_ += '\'';
      return false;
      }

    data.push_back( Record( c ) );
    if( opt[++cind] == 0 ) { ++argind; cind = 0; }	// opt finished

    if( options[index].has_arg != no && cind > 0 && opt[cind] )
      {
      data.back().argument = &opt[cind]; ++argind; cind = 0;
      }
    else if( options[index].has_arg == yes )
      {
      if( !arg || !arg[0] )
        {
        error_ = "option requires an argument -- '"; error_ += c;
        error_ += '\'';
        return false;
        }
      data.back().argument = arg; ++argind; cind = 0;
      }
    }
  return true;
  }


Arg_parser::Arg_parser( const int argc, const char * const argv[],
                        const Option options[], const bool in_order )
  {
  if( argc < 2 || !argv || !options ) return;

  std::vector< std::string > non_options;	// skipped non-options
  int argind = 1;				// index in argv

  while( argind < argc )
    {
    const unsigned char ch1 = argv[argind][0];
    const unsigned char ch2 = ch1 ? argv[argind][1] : 0;

    if( ch1 == '-' && ch2 )		// we found an option
      {
      const char * const opt = argv[argind];
      const char * const arg = ( argind + 1 < argc ) ? argv[argind+1] : 0;
      if( ch2 == '-' )
        {
        if( !argv[argind][2] ) { ++argind; break; }	// we found "--"
        else if( !parse_long_option( opt, arg, options, argind ) ) break;
        }
      else if( !parse_short_option( opt, arg, options, argind ) ) break;
      }
    else
      {
      if( !in_order ) non_options.push_back( argv[argind++] );
      else { data.push_back( Record() ); data.back().argument = argv[argind++]; }
      }
    }
  if( error_.size() ) data.clear();
  else
    {
    for( unsigned i = 0; i < non_options.size(); ++i )
      { data.push_back( Record() ); data.back().argument.swap( non_options[i] ); }
    while( argind < argc )
      { data.push_back( Record() ); data.back().argument = argv[argind++]; }
    }
  }


Arg_parser::Arg_parser( const char * const opt, const char * const arg,
                        const Option options[] )
  {
  if( !opt || !opt[0] || !options ) return;

  if( opt[0] == '-' && opt[1] )		// we found an option
    {
    int argind = 1;			// dummy
    if( opt[1] == '-' )
      { if( opt[2] ) parse_long_option( opt, arg, options, argind ); }
    else
      parse_short_option( opt, arg, options, argind );
    if( error_.size() ) data.clear();
    }
  else { data.push_back( Record() ); data.back().argument = opt; }
  }