/* 
 * Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
 *
 * This program 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; version 2 of the
 * License.
 * 
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301  USA
 */

#include "python_context.h"
#include "grtpp.h"
#include "grtpp_util.h"
#include "grtpp_notifications.h"
#include "base/string_utilities.h"
#include "base/file_functions.h"
#include "base/util_functions.h"
#include "base/wb_memory.h"

// python internals
#include <node.h>
//#include <grammar.h>
//#include <parsetok.h>
#include <errcode.h>
#include <token.h>

#include "python_grtobject.h"
#include "python_grtlist.h"
#include "python_grtdict.h"

#include "base/log.h"

DEFAULT_LOG_DOMAIN("python context")

using namespace grt;
using namespace base;

// used to identify a proper GRT context object as a PyCObject
static const char *GRTTypeSignature= "GRTCONTEXT";
// used to identify a GRT value as a PyCObject
static const char *GRTValueSignature= "GRTVALUE";


static std::string flatten_class_name(std::string name)
{
  std::string::size_type p;
  while ((p= name.find('.')) != std::string::npos)
    name[p]= '_';
  return name;
}

//--------------------------------------------------------------------------------------------------

PythonContextHelper::PythonContextHelper(const std::string &module_path)
{
  static const char *argv[2] = { "/dev/null", NULL };

  if (getenv("PYTHON_DEBUG"))
    Py_VerboseFlag = 5;

#ifdef _WIN32
  // Hack needed in Windows because Python lib uses C:\Python26 as default pythonhome
  // That will cause conflicts if there is some other Python installed in there (bug #52949)

  // Program.cs also does this, but somehow, they don't seem to get reflected here
  char *path = getenv("PATH");
  if (path)
  {
    // strip away everything with Python in it
    std::vector<std::string> parts = base::split(path, ";");
    std::string npath;
    for (std::vector<std::string>::const_iterator p = parts.begin(); p != parts.end(); ++p)
    {
      if (!strstr(base::tolower(*p).c_str(), "python"))
      {
        if (!npath.empty())
          npath.append(";");
        npath.append(*p);
      }
    }
    putenv(g_strdup_printf("PATH=%s", npath.c_str()));
  }

  putenv(g_strdup_printf("PYTHONHOME=%s\\Python", module_path.c_str()));
  putenv(g_strdup_printf("PYTHONPATH=%s\\Python;%s\\Python\\DLLs;%s\\Python\\Lib;%s\\Python\\mysql_libs.zip;",
    module_path.c_str(), module_path.c_str(), module_path.c_str(), module_path.c_str()));
  //putenv("PYTHONHOME=C:\\nowhere");
#endif
  Py_InitializeEx(0); // skips signal handler init

  // Stores the main thread state
  _main_thread_state = PyThreadState_Get();

  PySys_SetArgv(1, (char**)argv);

  PyEval_InitThreads();
}

//--------------------------------------------------------------------------------------------------

PythonContextHelper::~PythonContextHelper()
{
  PyEval_RestoreThread(_main_thread_state);
  _main_thread_state = NULL;
#ifdef _DEBUG
  Py_Finalize();
#endif
}

//--------------------------------------------------------------------------------------------------

PythonContext::PythonContext(GRT *grt, const std::string &module_path)
: PythonContextHelper(module_path)
{
  _grt = grt;
  _grt_list_class= 0;
  _grt_dict_class= 0;
  _grt_object_class= 0;
  _grt_method_class= 0;
  
  register_grt_module();
  
  PyObject *main = PyImport_AddModule("__main__");
  PyDict_SetItemString(PyModule_GetDict(main),
                       "grt", PyImport_ImportModule("grt"));

  PySys_SetObject((char*)"real_stdout", PySys_GetObject((char*)"stdout"));
  PySys_SetObject((char*)"real_stderr", PySys_GetObject((char*)"stderr"));
  PySys_SetObject((char*)"real_stdin", PySys_GetObject((char*)"stdin"));

  // make sys.stdout and sys.stderr send stuff to GRT
  PySys_SetObject((char*)"stdout", get_grt_module());
  PySys_SetObject((char*)"stderr", get_grt_module());
  
  // set stdin to the GRT shell console
  PySys_SetObject((char*)"stdin", get_grt_module());

  run_post_init_script();
  
  {
    PyObject *path = from_grt(grt::StringRef(base::Logger::log_filename()));
    PyDict_SetItemString(PyModule_GetDict(PyImport_AddModule("grt")), "logpath", path);
    Py_XDECREF(path);
  }

  PyEval_SaveThread();
  
  // listen to all notifications so it can be forwarded to python
  GRTNotificationCenter::get()->add_grt_observer(this);
  NotificationCenter::get()->add_observer(this);
}


PythonContext::~PythonContext()
{
  GRTNotificationCenter::get()->remove_grt_observer(this);
  NotificationCenter::get()->remove_observer(this);
}


void PythonContext::add_module_path(const std::string &modpath, bool prepend)
{
  // add the path to the search path so that it can be imported
  PyObject *path_list;
  PyObject *path= PyString_FromString(modpath.c_str());

  WillEnterPython lock;
  
  path_list= PySys_GetObject((char *) "path"); // cast to (char *) required for gcc 4.3 to avoid warning about deprecated conversion
                                               // from string constant to 'char*'.
  Py_ssize_t i;
  
 // check if the path is already in it
  for (i= PyList_Size(path_list)-1; i >= 0; --i)
  {
    if (PyObject_Compare(PyList_GetItem(path_list, i), path) == 0)
      break;
  }
  
  if (i < 0) // not found
  {
    if (prepend)
      PyList_Insert(path_list, 0, path);
    else
      PyList_Append(path_list, path);
  }
  Py_DECREF(path);
}


void PythonContext::set_user_interrupted(const grt::user_cancelled &exc)
{
  PyErr_SetString(PythonContext::get()->_grt_user_interrupt_error, exc.what());
}

void PythonContext::set_db_access_denied(const grt::db_access_denied &exc)
{
  PyErr_SetString(PythonContext::get()->_grt_db_access_denied_error, exc.what());
}

void PythonContext::set_db_login_error(const grt::db_login_error &exc)
{
  PyErr_SetString(PythonContext::get()->_grt_db_login_error, exc.what());
}

void PythonContext::set_db_error(const grt::db_error &exc)
{
  PyObject *arg = Py_BuildValue("(si)", exc.what(), exc.error());
  PyErr_SetObject(PythonContext::get()->_grt_db_error, arg);
  Py_DECREF(arg);
}

void PythonContext::set_db_not_conected(const grt::db_not_connected &exc)
{
  PyErr_SetString(PythonContext::get()->_grt_db_not_connected, exc.what());
}

void PythonContext::set_python_error(const grt::type_error &exc, const std::string &location)
{
  PyErr_SetString(PyExc_TypeError, (location.empty() ? exc.what() : location + ": " + exc.what()).c_str());
}


void PythonContext::set_python_error(const grt::bad_item &exc, const std::string &location)
{
  PyErr_SetString(PyExc_IndexError, (location.empty() ? exc.what() : location + ": " + exc.what()).c_str());
}


void PythonContext::set_python_error(const std::exception &exc, const std::string &location)
{
  PyErr_SetString(PyExc_SystemError, (location.empty() ? exc.what() : location + ": " + exc.what()).c_str());
}



/** Gets the PythonContext from the Python interpreter.
 */
PythonContext *PythonContext::get()
{
  PyObject *ctx;
  PyObject *module;
  PyObject *dict;

  module= PyDict_GetItemString(PyImport_GetModuleDict(), "grt");
  if (!module)
    throw std::runtime_error("GRT module not found in Python runtime");
  
  dict= PyModule_GetDict(module);
  if (!dict)
    throw std::runtime_error("GRT module is invalid in Python runtime");
  
  ctx= PyDict_GetItemString(dict, "__GRT__");
  if (!ctx)
    throw std::runtime_error("GRT context not found in Python runtime");

  if (PyCObject_GetDesc(ctx) == &GRTTypeSignature)
    return static_cast<PythonContext*>(PyCObject_AsVoidPtr(ctx));

  throw std::runtime_error("Invalid GRT context in Python runtime");
}


PythonContext *PythonContext::get_and_check()
{
  try
  {
    return PythonContext::get();
  }
  catch (std::exception &exc)
  {
    PyErr_SetString(PyExc_SystemError, strfmt("Could not get GRT context: %s", exc.what()).c_str());
  }
  return NULL;
}


void PythonContext::set_grt_observer_callable(PyObject *obj)
{
  _grt_notification_observer = obj;
}


void PythonContext::handle_grt_notification(const std::string &name, ObjectRef sender, DictRef info)
{
  if (_grt_notification_observer)
  {
    WillEnterPython lock;
    
    PyObject *psender = from_grt(sender);
    PyObject *pinfo = from_grt(info);
    PyObject *args = Py_BuildValue("sOO", name.c_str(), psender, pinfo);
    PyObject *res;
  
    if (!(res = PyObject_CallObject(_grt_notification_observer, args)))
    {
      log_python_error("Error forwarding GRT notification to Python");
    }
    if (res)
    {
      Py_DECREF(res);
    }
    Py_DECREF(psender);
    Py_XDECREF(pinfo);
    Py_DECREF(args);
  }
}


void PythonContext::handle_notification(const std::string &name, void *sender, base::NotificationInfo &info)
{
  if (_grt_notification_observer)
  {
    WillEnterPython lock;

    PyObject *infodict = PyDict_New();
    PyObject *res;
    
    for (base::NotificationInfo::iterator i = info.begin(); i != info.end(); ++i)
    {
      PyObject *str = PyString_FromString(i->second.c_str());
      PyDict_SetItemString(infodict, i->first.c_str(), str);
      Py_DECREF(str);
    }
    PyObject *args = Py_BuildValue("sOO", name.c_str(), Py_None, infodict);
    
    if (!(res = PyObject_CallObject(_grt_notification_observer, args)))
    {
      log_python_error("Error forwarding notification to Python");
    }
    if (res)
    {
      Py_DECREF(res);
    }
    Py_DECREF(args);
    
    // apply back changes made to the info dict from python code
    {
      PyObject *key, *value;
      Py_ssize_t pos = 0;
      
      while (PyDict_Next(infodict, &pos, &key, &value)) 
      {
        std::string s;
        grt::ValueRef v;
        v = from_pyobject(value);
        if (!pystring_to_string(key, s) || !v.is_valid())
        {
          log_error("Error in Python notification handler: info dictionary contains an invalid item");
          continue;
        }
        info[s]= v.repr();
      }
    }
    Py_DECREF(infodict);
  }  
}


static PyObject *grt_print(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
    
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;

  PyObject *o;
  if (!PyArg_ParseTuple(args, "O", &o))
  {
    if (PyTuple_Size(args) == 1 && PyTuple_GetItem(args, 0) == Py_None)
    {
      PyErr_Clear();
      text = "None";
    }
    else
      return NULL;
  }  
  else
    if (!ctx->pystring_to_string(o, text, true))
      return NULL;
  
#ifdef _WIN32
  OutputDebugStringA(text.c_str());
#else
  g_print("%s", text.c_str()); // g_print is not routed to g_log
#endif
  ctx->get_grt()->send_output(text);
  
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *pylog(base::Logger::LogLevel level, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
  
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  char *domain;
  PyObject *o;
  if (!PyArg_ParseTuple(args, "sO", &domain, &o))
    return NULL;
  
  if (!ctx->pystring_to_string(o, text, true))
    return NULL;
  
  base::Logger::log(level, domain, "%s", text.c_str());

  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_log_error(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogError, args);
}

static PyObject *grt_log_warning(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogWarning, args);
}

static PyObject *grt_log_info(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogInfo, args);
}

static PyObject *grt_log_debug(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogDebug, args);
}

static PyObject *grt_log_debug2(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogDebug2, args);
}

static PyObject *grt_log_debug3(PyObject *self, PyObject *args)
{
  return pylog(base::Logger::LogDebug3, args);
}

static PyObject *grt_send_output(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
    
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o;
  if (!PyArg_ParseTuple(args, "O", &o))
  {
    if (PyTuple_Size(args) == 1 && PyTuple_GetItem(args, 0) == Py_None)
    {
      PyErr_Clear();
      text = "None";
    }
    else
      return NULL;
  }  
  else
    if (!ctx->pystring_to_string(o, text, true))
      return NULL;

  ctx->get_grt()->send_output(text);
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_send_warning(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
  std::string detail;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o, *d = NULL;
  if (!PyArg_ParseTuple(args, "O|O", &o, &d))
  {
    if (PyTuple_Size(args) == 1 && PyTuple_GetItem(args, 0) == Py_None)
    {
      PyErr_Clear();
      text = "None";
    }
    else
      return NULL;
  }  
  else
  {
    if (!ctx->pystring_to_string(o, text, true))
      return NULL;
    if (d && !ctx->pystring_to_string(d, detail, true))
      return NULL;
  }
  
  ctx->get_grt()->send_warning(text, detail);
  
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *grt_send_info(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
  std::string detail;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o, *d = NULL;
  if (!PyArg_ParseTuple(args, "O|O", &o, &d))
  {
    if (PyTuple_Size(args) == 1 && PyTuple_GetItem(args, 0) == Py_None)
    {
      PyErr_Clear();
      text = "None";
    }
    else
      return NULL;
  }  
  else
  {
    if (!ctx->pystring_to_string(o, text, true))
      return NULL;
    if (d && !ctx->pystring_to_string(d, detail, true))
      return NULL;
  }

  ctx->get_grt()->send_info(text, detail);
//  log_debug2("grt.python", "%s: (%s)", text.c_str(), detail.c_str());

  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *grt_send_error(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  std::string text;
  std::string detail;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o, *d = NULL;
  if (!PyArg_ParseTuple(args, "O|O", &o, &d))
  {
    if (PyTuple_Size(args) == 1 && PyTuple_GetItem(args, 0) == Py_None)
    {
      PyErr_Clear();
      text = "None";
    }
    else
      return NULL;
  }  
  else
  {
    if (!ctx->pystring_to_string(o, text, true))
      return NULL;
    if (d && !ctx->pystring_to_string(d, detail, true))
      return NULL;
  }
  
  ctx->get_grt()->send_error(text, detail);
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_send_progress(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  float pct;
  PyObject *texto, *detailo= NULL;
  if (!PyArg_ParseTuple(args, "fO|O", &pct, &texto, &detailo))
    return NULL;
  
  std::string text, detail;
  if (!ctx->pystring_to_string(texto, text, true))
    return NULL;
  if (detailo && !ctx->pystring_to_string(detailo, detail, true))
    return NULL;
  ctx->get_grt()->send_progress(pct, text, detail, NULL);
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *grt_begin_progress_step(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  float pct1, pct2;
  if (!PyArg_ParseTuple(args, "ff", &pct1, &pct2))
    return NULL;
  
  ctx->get_grt()->begin_progress_step(pct1, pct2);

  Py_RETURN_NONE;
}

static PyObject *grt_end_progress_step(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  
  ctx->get_grt()->end_progress_step();
  
  Py_RETURN_NONE;
}

static PyObject *grt_reset_progress_steps(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  
  ctx->get_grt()->reset_progress_steps();
  
  Py_RETURN_NONE;
}

static PyObject *grt_get_by_path(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  const char *path= "";
  PyObject *object;
  grt::ValueRef value;
  
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  if (!PyArg_ParseTuple(args, "s|O", &path, &object))
    return NULL;

  if (object)
  {
    try
    {
      value= ctx->from_pyobject(object);
    }
    catch (grt::type_error &exc)
    {
      PyErr_SetString(PyExc_TypeError, exc.what());
      return NULL;
    }
    catch (std::exception &exc)
    {
      PythonContext::set_python_error(exc);
      return NULL;
    }
  }
  else
    value= ctx->get_grt()->root();
  
  if (!path)
    path= "";

  try
  {
    value= get_value_by_path(value, path);
  }
  catch (std::exception &exc)
  {
    PythonContext::set_python_error(exc);
    return NULL;
  }

  return ctx->from_grt(value);
}


static PyObject *grt_readline(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  
  if (ctx->stdin_readline_slot)
  {
    std::string line = ctx->stdin_readline_slot();
    return Py_BuildValue("s", line.c_str());
  }
  PyErr_SetString(PyExc_NotImplementedError, "input()/stdin reading not available");
  return NULL;
}

void decrement_int(int *i)
{
  (*i)--;
}

static bool call_handle_message(const grt::Message &msg, void *sender, AutoPyObject callable)
{
  WillEnterPython lock;
  PyObject *ret;
  const char *type = NULL;
  static int handling_message = 0;
  
  if (handling_message > 10)
  {
    log_warning("Force-breaking apparent recursion of GRT message handlers\n");
    return false;
  }
  handling_message++;
  base::scope_ptr<int, decrement_int> guard(&handling_message);
  
  std::string text = msg.text;
  switch (msg.type)
  {
    case grt::ErrorMsg: type = "ERROR"; break;
    case grt::WarningMsg: type = "WARNING"; break;
    case grt::InfoMsg: type = "INFO"; break;
    case grt::OutputMsg: type = "OUTPUT"; break;
    case grt::VerboseMsg: type = "VERBOSE"; break;
    case grt::ProgressMsg: type = "PROGRESS"; text = strfmt("%f:%s", msg.progress, msg.text.c_str()); break;
    default:
      type = "???"; 
      break;
  }
  
  PyObject *args = Py_BuildValue("(sss)", type, text.c_str(), msg.detail.c_str());
  if (!(ret = PyObject_Call(callable, args, NULL)))
  {
    Py_DECREF(args);
    PythonContext::log_python_error("Error calling Python output handler:");
    PyErr_Clear();
    return false;
  }
  Py_DECREF(args);

  if (ret == Py_None || ret == Py_False || PyInt_AsLong(ret) == 0)
  {
    Py_DECREF(ret);
    return false;
  }
  Py_DECREF(ret);
  return true;
}


static PyObject *grt_push_message_handler(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o;
  if (!PyArg_ParseTuple(args, "O", &o))
    return NULL;
  
  if (!PyCallable_Check(o))
    return NULL;
  
  ctx->get_grt()->push_message_handler(boost::bind(&call_handle_message, _1, _2, AutoPyObject(o)));

  return Py_BuildValue("i", ctx->get_grt()->message_handler_count());
}


static PyObject *grt_pop_message_handler(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  ctx->get_grt()->pop_message_handler();
  
  return Py_BuildValue("i", ctx->get_grt()->message_handler_count());
}

//

static bool call_status_query(AutoPyObject callable)
{
  WillEnterPython lock;

  PyObject *ret;
  PyObject *args = Py_BuildValue("()");
  if (!(ret = PyObject_Call(callable, args, NULL)))
  {
    Py_DECREF(args);
    PythonContext::log_python_error("Error calling Python status handler:");
    PyErr_Clear();
    return false;
  }
  Py_DECREF(args);
  
  if (ret == Py_None || ret == Py_False || PyInt_AsLong(ret) == 0)
  {
    Py_DECREF(ret);
    return false;
  }
  Py_DECREF(ret);  
  return true;
}


static PyObject *grt_push_status_query_handler(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *o;
  if (!PyArg_ParseTuple(args, "O", &o))
    return NULL;
  
  if (!PyCallable_Check(o))
    return NULL;
  
  ctx->get_grt()->push_status_query_handler(boost::bind(&call_status_query, AutoPyObject(o)));
  
  Py_RETURN_NONE;
}


static PyObject *grt_pop_status_query_handler(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  ctx->get_grt()->pop_status_query_handler();
  
  Py_RETURN_NONE;
}

static PyObject *grt_query_status(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  if (args && !PyArg_ParseTuple(args, ""))
    return NULL;
  
  if (ctx->get_grt()->query_status())
    Py_RETURN_TRUE;
  else
    Py_RETURN_FALSE;
}

//

static PyObject *grt_serialize(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  PyObject *object;
  char *path = NULL;
  
  if (!PyArg_ParseTuple(args, "Os", &object, &path))
    return NULL;
  
  grt::ValueRef value(ctx->from_pyobject(object));
  if (!value.is_valid())
  {
    PyErr_SetString(PyExc_TypeError, "First argument must be a GRT object");
    return NULL;
  }
  
  if (!path)
  {
    PyErr_SetString(PyExc_ValueError, "File path expected for argument #2");
    return NULL;
  }
  
  try
  {
    ctx->get_grt()->serialize(value, path);
  }
  catch (const std::exception &exc)
  {
    PythonContext::set_python_error(exc, "serializing object");
    return NULL;
  }
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_unserialize(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  char *path = NULL;
  if (!PyArg_ParseTuple(args, "s", &path))
    return NULL;
  if (!path)
  {
    PyErr_SetString(PyExc_ValueError, "File path expected");
    return NULL;
  }
  
  try
  {
    grt::ValueRef value = ctx->get_grt()->unserialize(path);
    return ctx->from_grt(value);
  }
  catch (const std::exception &exc)
  {
    PythonContext::set_python_error(exc, base::strfmt("unserializing file %s", path));
    return NULL;
  }
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_set_notification_observer(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;

  PyObject *object;
  
  if (!PyArg_ParseTuple(args, "O", &object))
    return NULL;
  
  if (!PyCallable_Check(object))
  {
    PyErr_SetString(PyExc_ValueError, "notification observer argument must be a callable");
    return NULL;
  }
  
  ctx->set_grt_observer_callable(object);
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *grt_send_notification(PyObject *self, PyObject *args)
{
  PythonContext *ctx;
  if (!(ctx= PythonContext::get_and_check()))
    return NULL;
  
  char *name;
  PyObject *object;
  PyObject *info;
  
  if (!PyArg_ParseTuple(args, "sOO", &name, &object, &info))
    return NULL;
  
  ValueRef infodict = ctx->from_pyobject(info);
  if (infodict.is_valid() && !DictRef::can_wrap(infodict))
  {
    PyErr_SetString(PyExc_ValueError, "notification info must be a dict or None");
    return NULL;
  }
  ValueRef sender = ctx->from_pyobject(object);
  if (sender.is_valid() && !ObjectRef::can_wrap(sender))
  {
    PyErr_SetString(PyExc_ValueError, "notification sender info must be a GRT object");
    return NULL;
  }

  try
  {
    GRTNotificationCenter::get()->send_grt(name, ObjectRef::cast_from(sender), DictRef::cast_from(infodict));
  }
  catch (std::exception &exc)
  {
    ctx->set_python_error(exc, "Error sending notification");
    return NULL;
  }
  
  Py_INCREF(Py_None);
  return Py_None;
}


static PyObject *(*wrap_pyobject_func)(PyObject *, PyObject*) = NULL;
static PyObject *(*unwrap_pyobject_func)(PyObject *, PyObject*) = NULL;

static PyObject *grt_wrap_pyobject(PyObject *self, PyObject *args)
{
  // since the GRT objects are defined in an outer level, we forward this
  // to a callback which must be registered beforehand with PythonContext::set_wrap_callback
   if (wrap_pyobject_func)
    return wrap_pyobject_func(self, args);
    
  PyErr_SetString(PyExc_SystemError, "GRT python support not initialized correctly");
  return NULL;
}


static PyObject *grt_unwrap_pyobject(PyObject *self, PyObject *args)
{
  if (unwrap_pyobject_func)
    return unwrap_pyobject_func(self, args);
    
  PyErr_SetString(PyExc_SystemError, "GRT python support not initialized correctly");
  return NULL;
}


void PythonContext::set_wrap_pyobject_func(PyObject *(*func)(PyObject *, PyObject*))
{
  wrap_pyobject_func = func;
}


void PythonContext::set_unwrap_pyobject_func(PyObject *(*func)(PyObject *, PyObject*))
{
  unwrap_pyobject_func = func;
}

/** Register grt related functionality as a module

 Stuff made available in the module include:
 <li>__GRT__ variable holding a CObject pointer back to PythonContext
 <li>GRTList, GRTDict and GRTObject types
 <li>send_output, send_error, send_info etc
 <li>etc
 */
static PyMethodDef GrtModuleMethods[] = {
{"send_output",  grt_send_output, METH_VARARGS,
"Write a string in the GRT shell."},
{"write",  grt_print, METH_VARARGS,
"Write a string in the GRT shell (alias to send_output)."},
{"send_error",  grt_send_error, METH_VARARGS,
"Write an error message to the GRT shell."},
{"send_warning",  grt_send_warning, METH_VARARGS,
"Write a warning message to the GRT shell."},
{"send_info",  grt_send_info, METH_VARARGS,
"Write a info message to the GRT shell."},
{"send_progress",  grt_send_progress, METH_VARARGS,
"Write a progress message."},
{"begin_progress_step",  grt_begin_progress_step, METH_VARARGS,
  "Starts a new step in a larger task where progress is being tracked."},
{"end_progress_step",  grt_end_progress_step, METH_VARARGS,
  "Ends a step."},
{"reset_progress_steps", grt_reset_progress_steps, METH_VARARGS,
  "Clear the progress steps stack."},

{"log_error", grt_log_error, METH_VARARGS,
"Logs an error to the log file, in the specified context ex: log_error('myplugin', 'cannot open file')"},
{"log_warning", grt_log_warning, METH_VARARGS,
"Logs a warning to the log file, in the specified context ex: log_warning('myplugin', 'cannot open file very well')"},
{"log_debug", grt_log_debug, METH_VARARGS,
"Logs a debug message to the log file, in the specified context ex: log_debug('myplugin', 'trying to open file with ')"},
{"log_debug2", grt_log_debug2, METH_VARARGS,
 "Logs a verbose debug message to the log file, in the specified context ex: log_debug2('myplugin', 'reading from file')"},
{"log_debug3", grt_log_debug3, METH_VARARGS,
 "Logs a very verbose debug message to the log file, in the specified context ex: log_debug3('myplugin', 'processing file')"},
{"log_info", grt_log_info, METH_VARARGS,
"Logs an informational message to the log file, in the specified context ex: log_info('myplugin', 'file opened')"},

{"push_message_handler", grt_push_message_handler, METH_VARARGS,
  "Pushes a callback of the form function((type, text, detail)) to be called when a plugin outputs text. Return value must be True if the message was handled, False if it should be handled by a previously installed handler."},
{"pop_message_handler", grt_pop_message_handler, METH_NOARGS,
  "Pops previously pushed handler."},
  
{"push_status_query_handler", grt_push_status_query_handler, METH_VARARGS,
  "Pushes a callback that returns a boolean value. True should be returned for aborting running tasks that call grt.query_status()"},
{"pop_status_query_handler", grt_pop_status_query_handler, METH_NOARGS,
  "Pops status_query callback from the stack."},
{"query_status", grt_query_status, METH_NOARGS,
  "Queries the current status query handler whether currently running task should be cancelled. If True is returned, the task should be cancelled."},
  
{"readline", grt_readline, METH_VARARGS,
"Waits for a line of text to be input to the scripting shell prompt."},

{"get", grt_get_by_path, METH_VARARGS,
"Gets a value from a GRT dict or object (or from the global tree) by path."},

{"serialize", grt_serialize, METH_VARARGS,
  "Serializes a GRT object into a XML file. serialize(object, path)"},
{"unserialize", grt_unserialize, METH_VARARGS,
  "Unserializes a GRT object from a XML file created by serialize. unserialize(path) -> object"},

{"_set_grt_notification_observer", grt_set_notification_observer, METH_VARARGS,
  "Sets the GRT notification observer. Internal use."},

{"send_grt_notification", grt_send_notification, METH_VARARGS,
  "Sends a GRT notification to the application. ex: send_grt_notification('GNMyPluginStarted', sender, infodict)"},

{"fromgrt", grt_unwrap_pyobject, METH_VARARGS,
  "Extracts the Python object wrapped in a grt_PyObject GRT object (suitable for use with GRT object values)"},

{"togrt", grt_wrap_pyobject, METH_VARARGS,
  "Wraps a Python object in a grt_PyObject GRT object, which you can then use to reference from GRT objects (such as GRT dicts and lists)"},

{NULL, NULL, 0, NULL}        /* Sentinel */
};


void PythonContext::register_grt_module()
{
  PyObject *module = Py_InitModule("grt", GrtModuleMethods);
  if (module == NULL)
    throw std::runtime_error("Error initializing GRT module in Python support");
  
  _grt_module= module;
  
  // add the context ptr
  PyObject* context_object= PyCObject_FromVoidPtrAndDesc(this, &GRTTypeSignature, NULL);
  if (context_object != NULL)
    PyModule_AddObject(module, "__GRT__", context_object);
  
  PyModule_AddStringConstant(module, "INT", (char*)type_to_str(IntegerType).c_str());
  PyModule_AddStringConstant(module, "DOUBLE", (char*)type_to_str(DoubleType).c_str());
  PyModule_AddStringConstant(module, "STRING", (char*)type_to_str(StringType).c_str());
  PyModule_AddStringConstant(module, "LIST", (char*)type_to_str(ListType).c_str());
  PyModule_AddStringConstant(module, "DICT", (char*)type_to_str(DictType).c_str());
  PyModule_AddStringConstant(module, "OBJECT", (char*)type_to_str(ObjectType).c_str());
  
  init_grt_module_type();
  init_grt_list_type();
  init_grt_dict_type();
  init_grt_object_type();

  {
    _grt_user_interrupt_error = PyErr_NewException((char*)"grt.UserInterrupt", NULL, NULL);
    PyModule_AddObject(_grt_module, "UserInterrupt", _grt_user_interrupt_error);
  }
  {
    _grt_db_error = PyErr_NewException((char*)"grt.DBError", NULL, NULL);
    PyModule_AddObject(_grt_module, "DBError", _grt_db_error);
  }
  {
    _grt_db_access_denied_error = PyErr_NewException((char*)"grt.DBAccessDenied", NULL, NULL);
    PyModule_AddObject(_grt_module, "DBAccessDenied", _grt_db_access_denied_error);
  }
  {
    _grt_db_login_error = PyErr_NewException((char*)"grt.DBLoginError", NULL, NULL);
    PyModule_AddObject(_grt_module, "DBLoginError", _grt_db_login_error);
  }
  {
    _grt_db_not_connected = PyErr_NewException((char*)"grt.DBNotConnected", NULL, NULL);
    PyModule_AddObject(_grt_module, "DBNotConnected", _grt_db_not_connected);
  }

  _grt_modules_module = Py_InitModule("grt.modules", NULL);
  if (!_grt_modules_module)
    throw std::runtime_error("Error initializing grt.modules module in Python support");
  
  // AutoPyObject need to keep a reference but PyModule_AddObject steals it
  // so it is needed to increase it to avoid problems on destruction
  Py_INCREF(_grt_modules_module);
  PyModule_AddObject(_grt_module, "modules", _grt_modules_module);
  
  _grt_classes_module = Py_InitModule("grt.classes", NULL);
  if (!_grt_classes_module)
    throw std::runtime_error("Error initializing grt.classes module in Python support");
  
  Py_INCREF(_grt_classes_module);
  PyModule_AddObject(_grt_module, "classes", _grt_classes_module);
  
  PyModule_AddObject(_grt_classes_module, "grt", _grt_module);
}




PyObject *PythonContext::get_grt_module()
{
  return _grt_module;
}


bool PythonContext::import_module(const std::string &name)
{
  PyObject *main= PyImport_AddModule("__main__");
  PyObject *module = PyImport_ImportModule((char*)name.c_str());
  if (!main || !module)
  {
    PythonContext::log_python_error(base::strfmt("Error importing %s", name.c_str()).c_str());
    return false;
  }
  PyDict_SetItemString(PyModule_GetDict(main), name.c_str(), module);
  
  return true;
}


PyObject *PythonContext::eval_string(const std::string &expression)
{
//  LockPython lock(this);
  
  PyObject *mainmod= PyImport_AddModule("__main__");
  if (!mainmod)
  {
    PyErr_Clear();
    return NULL;
  }
  PyObject *globals= PyModule_GetDict(mainmod);
  if (globals)
  {
    PyObject *result= PyRun_String(expression.c_str(), Py_eval_input, globals, globals);
    if (!result)
      PythonContext::log_python_error(base::strfmt("Error running expr: %s", expression.c_str()).c_str());
    return result;
  }
  PyErr_Clear();
  return NULL;
}


PyObject *PythonContext::get_global(const std::string &value)
{
  /*
  PyObject *mainmod= PyImport_AddModule("__main__");
  if (!mainmod)
  {
    PyErr_Clear();
    return NULL;
  }
  PyObject *globals= PyModule_GetDict(mainmod);
  if (globals)
    return PyDict_GetItemString(globals, value.c_str());
   */
  return eval_string(value);
}


bool PythonContext::set_global(const std::string &name, PyObject *value)
{
  PyObject *mainmod= PyImport_AddModule("__main__");
  if (!mainmod)
  {
    PythonContext::log_python_error("Error getting __main__");
    PyErr_Clear();
    return false;
  }
  PyObject *globals= PyModule_GetDict(mainmod);
  if (!globals)
  {
    PythonContext::log_python_error("Error getting __main__ dict");
    PyErr_Clear();
    return false;
  }

  PyDict_SetItemString(globals, name.c_str(), value); 
  return true;
}


static void release_value(void *value, void *desc)
{
  internal::Value *v= reinterpret_cast<internal::Value*>(value);
  
  v->release();
}

/** Wraps a grt value in a PyCObject.
 
 PyCObjects are used internally to initialize a grt.List/Dict or Object from an existing grt value.
 */
PyObject *PythonContext::internal_cobject_from_value(const ValueRef &value)
{
  internal::Value *v= value.valueptr();
  v->retain();
  return PyCObject_FromVoidPtrAndDesc(v, &GRTValueSignature, release_value);
}


ValueRef PythonContext::value_from_internal_cobject(PyObject *value)
{
  if (PyCObject_GetDesc(value) == &GRTValueSignature)
    return ValueRef(reinterpret_cast<internal::Value*>(PyCObject_AsVoidPtr(value)));
  
  throw std::runtime_error("attempt to extract GRT value from invalid Python object");
}


/** Convert a GRT value to a Python object/value. 
 *
 * For objects, it will also wrap in the appropriate object subclass from grt.classes
 */
PyObject *PythonContext::from_grt(const ValueRef &value)
{
  if (value.is_valid())
  {
    switch (value.type())
    {
      case IntegerType:
      {
        /*
        long l = *IntegerRef::cast_from(value);
        if ((long)(int)l == l)
          return PyInt_FromLong(l);
        else
          return PyLong_FromLong(l);
          */
        return PyInt_FromSsize_t(*IntegerRef::cast_from(value));
      }

      case DoubleType:
        return PyFloat_FromDouble(*DoubleRef::cast_from(value));
        
      case StringType:
      {
        // maybe this should start returning unicode data, but before that all python code
        // should be tested if it can handle the unicode type. For now we just return utf8 strings.
        std::string data= *StringRef::cast_from(value);
        //return PyUnicode_DecodeUTF8(data.data(), data.size(), NULL);
        return PyString_FromStringAndSize(data.data(), data.size());
      }
      case ListType:
      {
        PyObject *content= PythonContext::internal_cobject_from_value(value);
        PyObject *args = Py_BuildValue("(ssO)", "", "", content);
        PyObject *r= PyObject_Call(_grt_list_class, args, NULL);
        Py_XDECREF(args);
        Py_XDECREF(content);
        return r;
      }
      case DictType:
      {
        PyObject *content= PythonContext::internal_cobject_from_value(value);
        PyObject *args = Py_BuildValue("(ssO)", "", "", content);
        PyObject *r= PyObject_Call(_grt_dict_class, args, NULL);
        Py_XDECREF(args);
        Py_XDECREF(content);
        return r;
      }
      case ObjectType:
      {
        std::string class_name= grt::ObjectRef::cast_from(value).class_name();
        PyObject *content= PythonContext::internal_cobject_from_value(value);
        PyObject *theclass= _grt_class_wrappers[class_name];
        PyObject *args = Py_BuildValue("(sO)", "", content);
        PyObject *r= PyObject_Call(theclass ? theclass : (PyObject*)_grt_object_class, args, NULL);
        Py_XDECREF(args);
        Py_XDECREF(content);
        
        return r;
      }
      default:
        return NULL;
    }
  }
  Py_INCREF(Py_None);
  return Py_None;
}

bool PythonContext::pystring_to_string(PyObject *strobject, std::string &ret_string, bool convert)
{
  if (PyUnicode_Check(strobject))
  {
    PyObject *ref = PyUnicode_AsUTF8String(strobject);
    if (ref)
    {
      char *s;
      Py_ssize_t len;
      PyString_AsStringAndSize(ref, &s, &len);
      if (s)
        ret_string= std::string(s, len);
      else
        ret_string= "";
      Py_DECREF(ref);
      return true;
    }
    return false;
  }
  
  if (PyString_Check(strobject))
  {
    char *s;
    Py_ssize_t len;
    PyString_AsStringAndSize(strobject, &s, &len);
    if (s)
      ret_string = std::string(s, len);
    else
      ret_string = "";
    return true;
  }
  
  if (convert)
  {
    PyObject *str = PyObject_Str(strobject);
    if (str)
    {
      bool ret = pystring_to_string(str, ret_string, false);
      Py_DECREF(str);
      return ret;
    }
  }
  
  return false;
}

ValueRef PythonContext::from_pyobject(PyObject *object)
{
  if (!object || object == Py_None)
    return ValueRef();

  if (PyInt_Check(object))
    return IntegerRef(PyInt_AsLong(object));

  if (PyLong_Check(object))
    return IntegerRef(PyLong_AsLong(object));

  if (PyFloat_Check(object))
    return DoubleRef(PyFloat_AsDouble(object));

  if (PyUnicode_Check(object) || PyString_Check(object))
  {
    std::string tmp;
    if (pystring_to_string(object, tmp))
      return StringRef(tmp);
    return ValueRef();
  }

  if (PyTuple_Check(object))
  {
    grt::BaseListRef list(_grt);
    
    for (Py_ssize_t c= PyTuple_Size(object), i= 0; i < c; i++)
    {
      PyObject *item= PyTuple_GetItem(object, i);
      list.ginsert(from_pyobject(item));
    }
    return list;
  }
  
  if (PyList_Check(object))
  {
    grt::BaseListRef list(_grt);
  
    for (Py_ssize_t c= PyList_Size(object), i= 0; i < c; i++)
    {
      PyObject *item= PyList_GetItem(object, i);
      list.ginsert(from_pyobject(item));
    }
    return list;
  }
  else if (PyObject_IsInstance(object, _grt_list_class))
    return *((PyGRTListObject*)object)->list;
  
  if (PyDict_Check(object))
  {
    grt::DictRef dict(_grt);
    PyObject *key, *value;
    Py_ssize_t pos = 0;
    
    while (PyDict_Next(object, &pos, &key, &value))
    {
      dict.set(PyString_AsString(key), from_pyobject(value));
    }
    
    return dict;
  }
  else if (PyObject_IsInstance(object, _grt_dict_class))
    return *((PyGRTDictObject*)object)->dict;
  
  if (PyObject_IsInstance(object, _grt_object_class))
    return *((PyGRTObjectObject*)object)->object;

  return ValueRef();
}


ValueRef PythonContext::simple_type_from_pyobject(PyObject *object, const grt::SimpleTypeSpec &type)
{
  switch (type.type)
  {
    case IntegerType:
    {
      if (PyFloat_Check(object))
        return IntegerRef((long)PyFloat_AsDouble(object));
      else
        PyErr_Clear();

      if (PyInt_Check(object))
        return IntegerRef(PyInt_AsLong(object));
      else
        PyErr_Clear();

      if (!PyLong_Check(object))
        return IntegerRef(PyLong_AsLong(object));
      else
        PyErr_Clear();
      
      throw grt::type_error("expected integer type x");
    }
    case DoubleType:
    {
      if (PyInt_Check(object))
        return DoubleRef(PyInt_AsLong(object));
      else
        PyErr_Clear();
      if (!PyFloat_Check(object))
        throw grt::type_error("expected double type");
      return DoubleRef(PyFloat_AsDouble(object));
    }
    case StringType:
    {
      std::string tmp;
      if (pystring_to_string(object, tmp))
        return StringRef(tmp);
      else
        throw grt::type_error("expected string type");
    }
    case ObjectType:
    {
      if (!PyObject_IsInstance(object, _grt_object_class))
        throw grt::type_error("expected GRT object");

      grt::ObjectRef grtobject(*((PyGRTObjectObject*)object)->object);

      if (!type.object_class.empty() && !grtobject->is_instance(type.object_class))
        throw grt::type_error(strfmt("expected GRT object of class %s", type.object_class.c_str()));

      return grtobject;
    }
    default:
      return ValueRef();
  }
}


ValueRef PythonContext::from_pyobject(PyObject *object, const grt::TypeSpec &expected_type)
{
  if (object == Py_None)
    return ValueRef();

  switch (expected_type.base.type)
  {
    case ObjectType:
    case IntegerType:
    case DoubleType:
    case StringType:
      return simple_type_from_pyobject(object, expected_type.base);
      
    case ListType:
    {
      if (PyList_Check(object))
      {
        grt::BaseListRef list(_grt, expected_type.content.type);
        
        for (Py_ssize_t c= PyList_Size(object), i= 0; i < c; i++)
        {
          PyObject *item= PyList_GetItem(object, i);
          switch (expected_type.content.type)
          {
            case ObjectType:
            case IntegerType:
            case DoubleType:
            case StringType:
              list.ginsert(simple_type_from_pyobject(item, expected_type.content));
              break;
            case AnyType:
              list.ginsert(from_pyobject(item));
              break;
            default:
              log_warning("invalid type spec requested\n");
              break;
          }
        }
        return list;
      }
      else if (PyObject_IsInstance(object, _grt_list_class))
      {
        return *((PyGRTListObject*)object)->list;
      }
      else
        throw grt::type_error("expected list");
    }
    case DictType:
    {
      if (PyDict_Check(object))
      {
        grt::DictRef dict(_grt);
        PyObject *key, *value;
        Py_ssize_t pos = 0;
        
        while (PyDict_Next(object, &pos, &key, &value))
        {
          switch (expected_type.content.type)
          {
            case ObjectType:
            case IntegerType:
            case DoubleType:
            case StringType:
              dict.set(PyString_AsString(key), simple_type_from_pyobject(value, expected_type.content));
              break;
            case AnyType:
              dict.set(PyString_AsString(key), from_pyobject(value));
              break;
            default:
              log_warning("invalid type spec requested\n");
              break;
          }
        }
        
        return dict;
      }
      else if (PyObject_IsInstance(object, _grt_dict_class))
      {
        return *((PyGRTDictObject*)object)->dict;
      }
      else
        throw grt::type_error("expected dict");
    }
    default:
      return from_pyobject(object);
  }
  
  return ValueRef();
}


int PythonContext::run_file(const std::string &file, bool interactive)
{
  PyObject *f = PyFile_FromString((char*)base::string_to_path_for_open(file).c_str(), (char*)"r");
  if (!f)
  {
    PythonContext::log_python_error(base::strfmt("Could not open file %s\n", file.c_str()).c_str());
    return -1;
  }

  log_debug2("About to pyrun '%s'\n", file.c_str());
  if (PyRun_SimpleFile(PyFile_AsFile(f), file.c_str()) != 0)
  {
    Py_DECREF(f);
    PythonContext::log_python_error(base::strfmt("Error running file %s\n", file.c_str()).c_str());
    return -1;
  }
  Py_DECREF(f);
  
  return 0;
}


/** Execute a string as Python code.
 
 If line_buffer is not null, it will be used as a buffer for multiple-line statements.
 It is used by interactive shell, to construct these from single-line components.
 
 If line_buffer is null, the passed buffer will be expected to contain complete code.
 */
int PythonContext::run_buffer(const std::string &buffer, std::string *line_buffer)
{
  node *n;
  PyObject *result;
  PyObject *mainmod;
  PyObject *globals;
  

  std::string old_buff;
  if (line_buffer)
    old_buff.append(*line_buffer);

  if (line_buffer)
  {
    //if previous buff is empty and new command is plain enter key, do nothing
    if (line_buffer->empty() && buffer[0] == '\n')
      return 0;

    line_buffer->append(buffer);
  }

  WillEnterPython lock;
  
  n= PyParser_SimpleParseStringFlags(line_buffer ? line_buffer->c_str() : buffer.c_str(),
                                     line_buffer ? Py_single_input : Py_file_input,
                                     0);
  
  if (n && (!buffer.empty() && (buffer[0] ==' ' || buffer[0] == '\t')) && line_buffer)
  {
    return 0; // continued line
  }
  if (!n && PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SyntaxError))
  {
    PyObject *excep;
    PyObject *value;
    PyObject *message;
    PyObject *trace;
    PyErr_Fetch(&excep, &value, &trace);
    message= PyTuple_GetItem(value, 0);
    if (strstr(PyString_AsString(message), "expected an indented block") ||
        strstr(PyString_AsString(message), "unexpected EOF") ||
        strncmp(PyString_AsString(message), "EOF", 3)==0)
    {
      Py_DECREF(excep);
      Py_DECREF(value);
      if (trace)
      {
        Py_DECREF(trace);
      }
      PyErr_Clear();
      return 0; // continued line
    }
    PyErr_Restore(excep, value, trace);
  }
  
  if (!n)
  {
    PythonContext::log_python_error("Error running buffer");
    
    if (line_buffer)
      line_buffer->clear();
    
    PyErr_Clear();
    return -1;
  }

  PyNode_Free(n);
  PyErr_Clear();
  
  // command is supposedly complete, try to execute it
  
  mainmod= PyImport_AddModule("__main__");
  if (!mainmod)
  {
    return -1;
  }
  globals= PyModule_GetDict(mainmod);
  
  if (line_buffer)
  {
    result= PyRun_String(line_buffer->c_str(), Py_single_input, globals, globals);
    
    line_buffer->clear();
  }
  else
    result= PyRun_String(buffer.c_str(), Py_file_input, globals, globals);
  
  if (!result)
  {
    if (PyErr_Occurred())
      PythonContext::log_python_error("Error running buffer");
    
    return -1;
  }
  else
  {    
    Py_DECREF(result);
  }
  
  return 0;  
}


// template of a python function to create a wrapper class for a GRT class
static const char *create_class_template=
"class %s(grt.Object):\n"
"  __grtclassname__ = \"%s\"\n"
"  def __init__(self, classname = None, wrapobj = None):\n"
"    grt.Object.__init__(self, classname, wrapobj)";

static const char *create_class_template_sub=
"class %s(%s):\n"
"  __grtclassname__ = \"%s\"\n"
"  def __init__(self, classname = '%s', wrapobj = None):\n"
"    %s.__init__(self, classname, wrapobj)";



/** Create a Python subclass of our grt.Object class, that will wrap around the given GRT class
 */
static void create_class_wrapper(grt::MetaClass *meta, PyObject *locals)
{
  std::string script;
  grt::MetaClass *parent;

  if ((parent= meta->parent()) && parent->parent() != 0)
  {
    std::string parname= flatten_class_name(parent->name());
    script= strfmt(create_class_template_sub, 
                   flatten_class_name(meta->name()).c_str(), parname.c_str(), 
                   meta->name().c_str(),
                   meta->name().c_str(),
                   parname.c_str());
  }
  else
  {
    script= strfmt(create_class_template, 
                   flatten_class_name(meta->name()).c_str(),
                   meta->name().c_str());
  }

  if (!PyRun_String(script.c_str(), Py_single_input, locals, locals))
    PythonContext::log_python_error(NULL);
}

/** Refresh Python environment with GRT information.
 */
int PythonContext::refresh()
{
  WillEnterPython lock;
  
  PyModule_AddObject(get_grt_module(), "root", from_grt(_grt->root()));
  
  PyObject *classes_dict= PyModule_GetDict(_grt_classes_module);

  Py_INCREF(classes_dict);

  // Generate Python class hierarchy to wrap GRT classes
  const std::list<grt::MetaClass*> &classes(_grt->get_metaclasses());
  for (std::list<grt::MetaClass*>::const_iterator iter= classes.begin(); iter != classes.end(); ++iter)
  {
    create_class_wrapper(*iter, classes_dict);

    _grt_class_wrappers[(*iter)->name()]= PyDict_GetItemString(classes_dict, flatten_class_name((*iter)->name()).c_str());
  }

  Py_DECREF(classes_dict);
  
  // Generate module wrappers
  const std::vector<grt::Module*> &modules(_grt->get_modules());
  for (std::vector<grt::Module*>::const_iterator iter= modules.begin(); iter != modules.end(); ++iter)
  {
    PyObject *arg = Py_BuildValue("(s)", (*iter)->name().c_str());
    PyObject *r= PyObject_Call(_grt_module_class, arg, NULL);
    Py_DECREF(arg);

    if (!r)
      PythonContext::log_python_error("Error refreshing grt modules");
    else
      if (PyModule_AddObject(_grt_modules_module, (char*)(*iter)->name().c_str(), r) < 0)
        PythonContext::log_python_error("Error refreshing grt modules");
  }

  return 0;
}


void PythonContext::log_python_error(const char *message)
{
  PythonContext *ctx = PythonContext::get();
  if (ctx)
  {
    if (message)
      base::Logger::log(base::Logger::LogError, "python", "%s", message);
    PyObject *grt_dict = PyModule_GetDict(ctx->get_grt_module());
    PyObject *_stderr = PyDict_GetItemString(grt_dict, "_log_stderr"); 
    PyObject *old_stderr = PySys_GetObject((char*)"stderr");
    Py_INCREF(old_stderr);
    if (_stderr)
      PySys_SetObject((char*)"stderr", _stderr);
    PyErr_Print();
    
    if (_stderr)
      PySys_SetObject((char*)"stderr", old_stderr);
    Py_DECREF(old_stderr);
  }
}



// script to be executed once GRT is initialized
// executed in the grt module namespace
static const char *post_init_script = 
"import grt\n"
"class _grtFileRedirector:\n"
"    def __init__(self, logger):\n"
"        self.logger = logger\n"
"    def write(self, text):\n"
"        if type(text) not in (str, unicode):\n"
"            text = str(text)\n"
"        grt.send_output(text)\n"
"        self.logger(grt._log_domain, text)\n"
"grt._log_domain = 'python'\n"
"grt._log_stdout = _grtFileRedirector(grt.log_info)\n"
"grt._log_stderr = _grtFileRedirector(grt.log_error)\n";

void PythonContext::run_post_init_script()
{
  WillEnterPython lock;

  if (PyRun_SimpleString((char*)post_init_script) < 0)
    PythonContext::log_python_error("Error running post-init script:");
}
