////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1993-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// 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
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_token_h)
#define octave_token_h 1

#include "octave-config.h"

#include <string>

#include "filepos.h"
#include "symrec.h"

namespace octave
{
  class token
  {
  public:

    enum token_type
    {
      generic_token,
      keyword_token,
      string_token,
      double_token,
      ettype_token,
      sym_rec_token,
      scls_name_token,
    };

    enum end_tok_type
    {
      simple_end,
      classdef_end,
      enumeration_end,
      events_end,
      for_end,
      function_end,
      if_end,
      methods_end,
      parfor_end,
      properties_end,
      switch_end,
      try_catch_end,
      unwind_protect_end,
      while_end,
    };

    token (int tv, const filepos& beg_pos, const filepos& end_pos);

    token (int tv, bool is_keyword, const filepos& beg_pos
           , const filepos& end_pos);

    token (int tv, const char *s, const filepos& beg_pos,
           const filepos& end_pos);

    token (int tv, const std::string& s, const filepos& beg_pos,
           const filepos& end_pos);

    token (int tv, double d, const std::string& s, const filepos& beg_pos,
           const filepos& end_pos);

    token (int tv, end_tok_type t, const filepos& beg_pos,
           const filepos& end_pos);

    token (int tv, const symbol_record& s, const filepos& beg_pos,
           const filepos& end_pos);

    token (int tv, const std::string& mth, const std::string& cls,
           const filepos& beg_pos, const filepos& end_pos);

    // No copying!

    token (const token&) = delete;

    token& operator = (const token&) = delete;

    ~token (void);

    void mark_may_be_command (void) { m_maybe_cmd = true; }
    bool may_be_command (void) const { return m_maybe_cmd; }

    void mark_trailing_space (void) { m_tspc = true; }
    bool space_follows_token (void) const { return m_tspc; }

    int token_value (void) const { return m_tok_val; }
    bool token_value_is (int tv) const { return tv == m_tok_val; }

    filepos beg_pos (void) const { return m_beg_pos; }
    filepos end_pos (void) const { return m_end_pos; }

    void beg_pos (const filepos& pos) { m_beg_pos = pos; }
    void end_pos (const filepos& pos) { m_end_pos = pos; }

    // These will probably be removed.
    int line (void) const { return m_beg_pos.line (); }
    int column (void) const { return m_beg_pos.column (); }

    bool iskeyword (void) const
    {
      return m_type_tag == keyword_token || m_type_tag == ettype_token;
    }

    OCTAVE_DEPRECATED (5, "use 'octave::iskeyword' instead")
    bool is_keyword (void) const
    {
      return iskeyword ();
    }

    bool is_symbol (void) const
    {
      return m_type_tag == sym_rec_token;
    }

    std::string text (void) const;
    std::string symbol_name (void) const;
    double number (void) const;
    token_type ttype (void) const;
    end_tok_type ettype (void) const;
    symbol_record sym_rec (void) const;

    std::string superclass_method_name (void) const;
    std::string superclass_class_name (void) const;

    std::string text_rep (void) const;

  private:

    bool m_maybe_cmd;

    bool m_tspc;

    filepos m_beg_pos;
    filepos m_end_pos;

    int m_tok_val;

    token_type m_type_tag;

    union tok_info
    {
      tok_info (void) { }

      tok_info (const char *s) : m_str (new std::string (s)) { }

      tok_info (const std::string& str) : m_str (new std::string (str)) { }

      tok_info (double num) : m_num (num) { }

      tok_info (end_tok_type et) : m_et (et) { }

      tok_info (const symbol_record& sr)
        : m_sr (new symbol_record (sr))
      { }

      tok_info (const std::string& meth, const std::string& cls)
        : m_superclass_info (new superclass_info (meth, cls))
      { }

      tok_info (const tok_info&) = delete;

      tok_info& operator = (const tok_info&) = delete;

      ~tok_info (void) { }

      std::string *m_str;

      double m_num;

      end_tok_type m_et;

      symbol_record *m_sr;

      struct superclass_info
      {
        superclass_info (void) = delete;

        superclass_info (const std::string& meth,
                         const std::string& cls)
          : m_method_name (meth), m_class_name (cls)
        { }

        superclass_info (const superclass_info&) = delete;

        superclass_info& operator = (const superclass_info&) = delete;

        ~superclass_info (void) = default;

        // The name of the method to call.  This is the text before the
        // "@" and may be of the form "object.method".
        std::string m_method_name;

        // The name of the superclass.  This is the text after the "@"
        // and may be of the form "object.method".
        std::string m_class_name;
      };

      superclass_info *m_superclass_info;
    };

    tok_info m_tok_info;

    std::string m_orig_text;
  };
}

#endif