/* This file is part of
* ====================================================== 
* 
*           LyX, The Document Processor
*        
*           Copyright 1995 Matthias Ettrich
*           Copyright 1995-2000 the LyX Team.
*
* ====================================================== */

#include <config.h>

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

#include "Variables.h"
#include "support/LRegex.h"


void Variables::set(string const & var, string const & val)
{
  Vars::const_iterator cit = vars_.find(var);
  if (cit != vars_.end()) 
    vars_.erase(var);
  vars_[var] = val;;
}


string const Variables::get(string const & var) const
{
  Vars::const_iterator cit = vars_.find(var);
  if (cit != vars_.end()) 
    return (*cit).second;
  else 
    return string();
}


bool Variables::isset(string const & var) const
{
   Vars::const_iterator cit = vars_.find(var);
   return  (cit != vars_.end()); 
}


string const Variables::expand(string const & s) const
{
  string str(s);
  LRegex reg("\\$\\{\\(.*\\)\\}");

  if (!reg.exact_match(str))
    return str;

  LRegex::MatchPair match;
  string var;
  
  do {
    match = reg.first_match(str);
    var = str.substr(match.first,match.second);
    // we correct the match to take ${} in account.
    str.replace(match.first - 2, match.second + 3, get(var));
  } while (reg.exact_match(str));

  return str;
}

#ifdef TEST

#include <iostream>
using std::endl;
using std::cout;

int main() {
  Variables vars;
  vars.set("x", "hello");
  vars.set("y", "world");
  cout << vars.expand("${x}") << endl;
}

#endif