/*

Copyright (C) 2016 Mike Miller

This file is part of Pytave.

Pytave 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.

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

*/

#if defined (HAVE_CONFIG_H)
#  include <config.h>
#endif

#include <string>
#include <boost/python.hpp>
#include <octave/ov.h>
#include <octave/ovl.h>

#include "oct-py-eval.h"
#include "oct-py-util.h"
#include "octave_to_python.h"

namespace pytave
{

PyObject *
py_call_function (const std::string& func, const octave_value_list& args)
{
  PyObject *func_obj = py_find_function (func);
  PyObject *retval = py_call_function (func_obj, args);
  Py_DECREF (func_obj);
  return retval;
}

PyObject *
py_call_function (const std::string& func, PyObject *args, PyObject *kwargs)
{
  PyObject *func_obj = py_find_function (func);
  PyObject *retval = py_call_function (func_obj, args, kwargs);
  Py_DECREF (func_obj);
  return retval;
}

PyObject *
py_call_function (PyObject *callable, const octave_value_list& args)
{
  PyObject *kwargs = 0;
  PyObject *args_list = PyList_New (0);
  if (! args_list)
    octave_throw_bad_alloc ();

  for (int i = 0; i < args.length (); ++i)
    {
      boost::python::object arg;
      pytave::octvalue_to_pyobj (arg, args(i));
      PyObject *obj = arg.ptr ();

      if (pytave::is_py_kwargs_argument (obj))
        kwargs = pytave::update_py_dict (kwargs, obj);
      else
        {
          Py_INCREF (obj);
          PyList_Append (args_list, obj);
        }
    }

  PyObject *args_tuple = PyList_AsTuple (args_list);
  Py_DECREF (args_list);

  PyObject *retval =  py_call_function (callable, args_tuple, kwargs);
  Py_DECREF (args_tuple);
  Py_XDECREF (kwargs);

  return retval;
}

PyObject *
py_call_function (PyObject *callable, PyObject *args, PyObject *kwargs)
{
  PyObject *retval = PyEval_CallObjectWithKeywords (callable, args, kwargs);
  if (! retval)
    throw boost::python::error_already_set ();

  return retval;
}

PyObject *
py_run_string_safe (const std::string& expr, int start, PyObject *globals,
                    PyObject *locals)
{
  bool alloc = false;

  if (! globals || (globals == Py_None))
    {
      PyObject *main = py_import_module ("__main__");
      globals = PyModule_GetDict (main);
      Py_DECREF (main);
      if (! globals)
        {
          globals = PyDict_New ();
          alloc = true;
        }
    }

  if (! locals || (locals == Py_None))
    locals = globals;

  // Evaluate all expressions under "from __future__ import print_function"
  PyCompilerFlags flags { CO_FUTURE_PRINT_FUNCTION };

  PyObject *retval = PyRun_StringFlags (expr.c_str (), start, globals, locals,
                                        &flags);

  if (alloc)
    Py_DECREF (globals);

  if (! retval)
    throw boost::python::error_already_set ();

  return retval;
}

PyObject *
py_eval_string (const std::string& expr, PyObject *globals, PyObject *locals)
{
  return py_run_string_safe (expr, Py_eval_input, globals, locals);
}

PyObject *
py_exec_string (const std::string& expr, PyObject *globals, PyObject *locals)
{
  return py_run_string_safe (expr, Py_file_input, globals, locals);
}

}