/*

Copyright (C) 1996-2017 John W. Eaton

This file is part of Octave.

Octave 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 3 of the License, or
(at your option) any later version.

Octave 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 Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include "error.h"
#include "ovl.h"
#include "oct-lvalue.h"
#include "pager.h"
#include "parse.h"
#include "pt-bp.h"
#include "pt-const.h"
#include "pt-eval.h"
#include "pt-id.h"
#include "pt-walk.h"
#include "symtab.h"
#include "utils.h"
#include "variables.h"

namespace octave
{
  // Symbols from the symbol table.

  void
  tree_identifier::eval_undefined_error (void)
  {
    int l = line ();
    int c = column ();

    maybe_missing_function_hook (name ());

    if (l == -1 && c == -1)
      error_with_id ("Octave:undefined-function",
                     "'%s' undefined", name ().c_str ());
    else
      error_with_id ("Octave:undefined-function",
                     "'%s' undefined near line %d column %d",
                     name ().c_str (), l, c);
  }

  octave_value_list
  tree_identifier::rvalue (int nargout,
                           const std::list<octave_lvalue> *lvalue_list)
  {
    octave_value_list retval;

    octave_value val = sym->find ();

    if (val.is_defined ())
      {
        // GAGME -- this would be cleaner if we required
        // parens to indicate function calls.
        //
        // If this identifier refers to a function, we need to know
        // whether it is indexed so that we can do the same thing
        // for 'f' and 'f()'.  If the index is present and the function
        // object declares it can handle it, return the function object
        // and let tree_index_expression::rvalue handle indexing.
        // Otherwise, arrange to call the function here, so that we don't
        // return the function definition as a value.

        octave_function *fcn = 0;

        if (val.is_function ())
          fcn = val.function_value (true);

        if (fcn && ! (is_postfix_indexed ()
                      && fcn->is_postfix_index_handled (postfix_index ())))
          {
            octave_value_list tmp_args;

            retval = (lvalue_list
                      ? val.do_multi_index_op (nargout, tmp_args, lvalue_list)
                      : val.do_multi_index_op (nargout, tmp_args));
          }
        else
          {
            if (print_result () && nargout == 0
                && octave::tree_evaluator::statement_printing_enabled ())
              {
                octave_value_list args = ovl (val, name ());
                string_vector name_tags (2);
                name_tags(0) = name ();
                name_tags(1) = "name";
                args.stash_name_tags (name_tags);
                octave::feval ("display", args);
              }

            retval = val;
          }
      }
    else if (sym->is_added_static ())
      static_workspace_error ();
    else
      eval_undefined_error ();

    return retval;
  }

  octave_value
  tree_identifier::rvalue1 (int nargout)
  {
    octave_value retval;

    octave_value_list tmp = rvalue (nargout);

    if (! tmp.empty ())
      retval = tmp(0);

    return retval;
  }

  octave_lvalue
  tree_identifier::lvalue (void)
  {
    if (sym->is_added_static ())
      static_workspace_error ();

    return octave_lvalue (sym);
  }

  tree_identifier *
  tree_identifier::dup (symbol_table::scope_id sc,
                        symbol_table::context_id) const
  {
    // The new tree_identifier object contains a symbol_record
    // entry from the duplicated scope.

    // FIXME: is this the best way?
    symbol_table::symbol_record new_sym
      = symbol_table::find_symbol (name (), sc);

    tree_identifier *new_id
      = new tree_identifier (new_sym, line (), column ());

    new_id->copy_base (*this);

    return new_id;
  }

  void
  tree_identifier::accept (tree_walker& tw)
  {
    tw.visit_identifier (*this);
  }
}