////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002-2020 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 (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <cstring>

#include <ostream>
#include <sstream>
#include <new>

#include "quit.h"

sig_atomic_t octave_interrupt_state = 0;

// DEPRECATED in Octave 6.
// This variable should never have been public.
sig_atomic_t octave_exception_state = 0;
// Use this variable internally until the functions that use it can be
// removed.
static sig_atomic_t internal_exception_state;

volatile sig_atomic_t octave_signal_caught = 0;

void (*octave_signal_hook) (void) = nullptr;
void (*octave_interrupt_hook) (void) = nullptr;

// DEPRECATED in Octave 6.
void (*octave_bad_alloc_hook) (void) = nullptr;

// The octave_exception enum values were DEPRECATED in Octave 6.
// Use these values internally until the functions that use them can be
// removed.
enum octave_internal_exception
{
  octave_internal_no_exception = 0,
  octave_internal_exec_exception = 1,
  octave_internal_alloc_exception = 3,
  octave_internal_quit_exception = 4
};

namespace octave
{
  std::string execution_exception::stack_trace (void) const
  {
    size_t nframes = m_stack_info.size ();

    if (nframes == 0)
      return std::string ();

    std::ostringstream buf;

    buf << "error: called from\n";

    for (const auto& frm : m_stack_info)
      {
        buf << "    " << frm.fcn_name ();

        int line = frm.line ();

        if (line > 0)
          {
            buf << " at line " << line;

            int column = frm.column ();

            if (column > 0)
              buf << " column " << column;
          }

        buf << "\n";
      }

    return buf.str ();
  }

  void execution_exception::display (std::ostream& os) const
  {
    if (! m_message.empty ())
      {
        os << m_err_type << ": " << m_message;

        if (m_message.back () != '\n')
          {
            os << "\n";

            std::string st = stack_trace ();

            if (! st.empty ())
              os << st;
          }
      }
  }
}

void
octave_handle_signal (void)
{
  if (octave_signal_hook)
    octave_signal_hook ();

  if (octave_interrupt_state > 0)
    {
      octave_interrupt_state = -1;

      throw octave::interrupt_exception ();
    }
}

// DEPRECATED in Octave 6
void
octave_throw_interrupt_exception (void)
{
  if (octave_interrupt_hook)
    octave_interrupt_hook ();

  throw octave::interrupt_exception ();
}

// DEPRECATED in Octave 6
void
octave_throw_execution_exception (void)
{
  // FIXME: would a hook function be useful here?

  internal_exception_state = octave_internal_exec_exception;

  throw octave::execution_exception ();
}

// DEPRECATED in Octave 6
void
octave_throw_bad_alloc (void)
{
  internal_exception_state = octave_internal_alloc_exception;

  throw std::bad_alloc ();
}

// DEPRECATED in Octave 6
void
octave_rethrow_exception (void)
{
  if (octave_interrupt_state)
    {
      octave_interrupt_state = -1;

      throw octave::interrupt_exception ();
    }
  else
    {
      switch (internal_exception_state)
        {
        case octave_internal_exec_exception:
          throw octave::execution_exception ();
          break;

        case octave_internal_alloc_exception:
          throw std::bad_alloc ();
          break;

        default:
          break;
        }
    }
}