/* This file is part of MAUS: http://micewww.pp.rl.ac.uk/projects/maus
 *
 * MAUS 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.
 *
 * MAUS 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 MAUS.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef _SRC_COMMON_CPP_UTILS_PYOBJECTWRAPPER_INL_HH
#define _SRC_COMMON_CPP_UTILS_PYOBJECTWRAPPER_INL_HH

#include <string>

#include "TPython.h" // root
#include "json/json.h"
#include "src/common_cpp/DataStructure/Data.hh"
#include "src/common_cpp/Converter/ConverterFactory.hh"

#include "src/common_cpp/Utils/PyObjectWrapper.hh"

namespace MAUS {
template <typename TEMP>
TEMP* PyObjectWrapper::unwrap(PyObject *args) {
  // Input should be a single PyStringObject
  std::string** string_ret = new std::string*(NULL);
  Json::Value** json_ret = new Json::Value*(NULL);
  Data** data_ret = new Data*(NULL);
  ImageData** image_ret = new ImageData*(NULL);
  JobHeaderData** jh_ret = new JobHeaderData*(NULL);
  JobFooterData** jf_ret = new JobFooterData*(NULL);
  RunHeaderData** rh_ret = new RunHeaderData*(NULL);
  RunFooterData** rf_ret = new RunFooterData*(NULL);
  PyObject** py_ret = new PyObject*(NULL);
  lazy_unwrap(args, py_ret, string_ret, json_ret,
              data_ret, jh_ret, jf_ret, rh_ret, rf_ret, image_ret);
  TEMP* cpp_ret = NULL;
  if (*py_ret != NULL) {
      cpp_ret = ConverterFactory().convert<PyObject, TEMP>(*py_ret);
      Py_DECREF(*py_ret);
  } else if (*string_ret != NULL) {
      cpp_ret = ConverterFactory().convert<std::string, TEMP>(*string_ret);
      delete *string_ret;
  } else if (*json_ret != NULL) {
      cpp_ret = ConverterFactory().convert<Json::Value, TEMP>(*json_ret);
      delete *json_ret;
  } else if (*data_ret != NULL) {
      cpp_ret = ConverterFactory().convert<Data, TEMP>(*data_ret);
      delete *data_ret;
  } else if (*jh_ret != NULL) {
      cpp_ret = ConverterFactory().convert<JobHeaderData, TEMP>(*jh_ret);
      delete *jh_ret;
  } else if (*jf_ret != NULL) {
      cpp_ret = ConverterFactory().convert<JobFooterData, TEMP>(*jf_ret);
      delete *jf_ret;
  } else if (*rh_ret != NULL) {
      cpp_ret = ConverterFactory().convert<RunHeaderData, TEMP>(*rh_ret);
      delete *rh_ret;
  } else if (*rf_ret != NULL) {
      cpp_ret = ConverterFactory().convert<RunFooterData, TEMP>(*rf_ret);
      delete *rf_ret;
  } else if (*image_ret != NULL) {
      cpp_ret = ConverterFactory().convert<ImageData, TEMP>(*image_ret);
      Py_DECREF(*py_ret);
  } else {
    throw Exception(Exception::recoverable,
                    "Failed to do the lazy conversion",
                    "PyObjectWrapper::unwrap_pyobject");
  }
  // note here we delete the pointer, not the allocated memory it points to
  delete image_ret;
  delete py_ret;
  delete rf_ret;
  delete rh_ret;
  delete jf_ret;
  delete jh_ret;
  delete data_ret;
  delete json_ret;
  delete string_ret;
  return cpp_ret;
}

PyObject* PyObjectWrapper::wrap(MAUS::Data* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::Data");
}

PyObject* PyObjectWrapper::wrap(MAUS::JobHeaderData* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::JobHeaderData");
}

PyObject* PyObjectWrapper::wrap(MAUS::JobFooterData* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::JobFooterData");
}

PyObject* PyObjectWrapper::wrap(MAUS::RunHeaderData* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::RunHeaderData");
}

PyObject* PyObjectWrapper::wrap(MAUS::RunFooterData* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::RunFooterData");
}

PyObject* PyObjectWrapper::wrap(MAUS::ImageData* cpp_data) {
  return wrap_root_object_proxy(cpp_data, "MAUS::ImageData");
}


PyObject* PyObjectWrapper::wrap(Json::Value* json_value) {
  // Confirm the object exists.
  if (!json_value) {
      throw Exception(Exception::recoverable,
                      "Json::Value was NULL",
                      "PyObjectWrapper::wrap_pyobject<Json::Value>");
  }

  // Place the Json::Value* inside a PyCapsule
  void* vptr = static_cast<void*>(json_value);
  PyObject *py_cap = PyCapsule_New(vptr, "JsonCpp", delete_jsoncpp_pycapsule);
  return py_cap;
}

PyObject* PyObjectWrapper::wrap(std::string* str) {
  // Export the std::string as a Python string.
  if (!str) {
      throw Exception(Exception::recoverable,
                      "str was NULL",
                      "PyObjectWrapper::wrap_pyobject<string>");
  }
  PyObject* py_string = PyString_FromString(str->c_str());
  delete str;
  return py_string;
}

PyObject* PyObjectWrapper::wrap(PyObject* py_object) {
  // We just do an incref (nothing else to do here)
  if (!py_object) {
      throw Exception(Exception::recoverable,
                      "py_object was NULL",
                      "PyObjectWrapper::wrap_pyobject<py_object>");
  }
  return py_object;
}

void PyObjectWrapper::lazy_unwrap(PyObject* py_cpp,
                            PyObject** py_ret,
                            std::string** string_ret,
                            Json::Value** json_ret,
                            MAUS::Data** data_ret,
                            JobHeaderData** jh_ret,
                            JobFooterData** jf_ret,
                            RunHeaderData** rh_ret,
                            RunFooterData** rf_ret,
                            ImageData** image_ret) {
    if (*string_ret != NULL ||
        *json_ret != NULL ||
        *data_ret != NULL ||
        *py_ret != NULL ||
        *jh_ret != NULL ||
        *jf_ret != NULL ||
        *rh_ret != NULL ||
        *rf_ret != NULL ||
        *image_ret != NULL) {
      throw Exception(Exception::recoverable,
                      "return values not initialised to NULL",
                      "PyObjectWrapper::lazy_unwrap");
    }

    if (!py_cpp) {
      throw Exception(Exception::recoverable,
                      "py_cpp was NULL",
                      "PyObjectWrapper::lazy_unwrap");
    }
    if (TPython::ObjectProxy_Check(py_cpp)) {
        try {
            unwrap_root_object_proxy(py_cpp, data_ret, "MAUS::Data");
            if (*data_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {}
        try {
            unwrap_root_object_proxy(py_cpp, jh_ret, "MAUS::JobHeaderData");
            if (*jh_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {}
        try {
            unwrap_root_object_proxy(py_cpp, jf_ret, "MAUS::JobFooterData");
            if (*jf_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {}
        try {
            unwrap_root_object_proxy(py_cpp, rh_ret, "MAUS::RunHeaderData");
            if (*rh_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {}
        try {
            unwrap_root_object_proxy(py_cpp, rf_ret, "MAUS::RunFooterData");
            if (*rf_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {}
        try {
            unwrap_root_object_proxy(py_cpp, image_ret, "MAUS::ImageData");
            if (*image_ret != NULL)
                return;
        } catch (MAUS::Exception &exc) {
        }
    } else if (PyCapsule_IsValid(py_cpp, "JsonCpp")) {
        void* vptr = PyCapsule_GetPointer(py_cpp, "JsonCpp");
        Json::Value *json_ptr = static_cast<Json::Value*>(vptr);
        if (!json_ptr) {
            throw Exception(Exception::recoverable,
                            "Could not parse JsonCpp capsule to Json::Value",
                            "PyObjectWrapper::lazy_unwrap");
        }
        *json_ret = new Json::Value(*json_ptr);
    } else if (PyString_Check(py_cpp)) {
        *string_ret = new std::string(PyString_AsString(py_cpp));
    } else if (PyDict_Check(py_cpp)) {
        *py_ret = PyDict_Copy(py_cpp); // shallow or deep? unclear...
    } else {
        throw Exception(Exception::recoverable,
                        "Could not parse PyObject as a valid data type",
                        "PyObjectWrapper::lazy_unwrap");
    }
}

template <class TEMP>
void PyObjectWrapper::unwrap_root_object_proxy(PyObject* py_cpp,
                                              TEMP** data_ret,
                                              std::string class_name) {
    PyObject* name = PyObject_CallMethod(py_cpp,
                                         const_cast<char*>("Class_Name"),
                                         NULL);
    if (!name) {
        throw Exception(Exception::recoverable,
                        "Class_Name method could not be called on ObjectProxy",
                        "PyObjectWrapper::lazy_unwrap");
    }
    char* c_string = NULL;
    if (!PyArg_Parse(name, "s", &c_string)) {
        throw Exception(Exception::recoverable,
                        "Class_Name method did not return a string",
                        "PyObjectWrapper::lazy_unwrap");
    }
    if (strcmp(c_string, class_name.c_str()) == 0) {
        Py_INCREF(py_cpp);  // TPyReturn decrefs py_cpp; we want to keep it
        void * vptr = static_cast<void*>(TPyReturn(py_cpp));
        TEMP* data = static_cast<TEMP*>(vptr); // caller owns this memory
        *data_ret = new TEMP(*data); // we own this memory
        if (!data_ret) {
            throw Exception(Exception::recoverable,
                        "Failed to cast py_cpp as a "+class_name,
                        "PyObjectWrapper::lazy_unwrap");
        }
    } else {
        return;
/*
        throw Exception(Exception::recoverable,
                    "Did not recognise ObjectProxy type "+\
                    std::string(c_string),
                    "PyObjectWrapper::lazy_unwrap");
*/
    }
}

void PyObjectWrapper::delete_jsoncpp_pycapsule(PyObject* py_capsule) {
    void* void_json = PyCapsule_GetPointer(py_capsule, "JsonCpp");
    Json::Value* json = static_cast<Json::Value*>(void_json);
    if (!void_json || !json) {
        PyErr_Clear();
        throw Exception(Exception::recoverable,
                    "Attempting to delete a JsonCpp capsule but none was found",
                    "PyObjectWrapper::delete_jsoncpp_pycapsule");
    }
    delete json;
}

template <class TEMP>
PyObject* PyObjectWrapper::wrap_root_object_proxy(TEMP* cpp_data,
                                                  std::string name) {
  // Confirm the object exists.
  if (!cpp_data) {
      throw Exception(Exception::recoverable,
                      "Cpp data was NULL",
                      "PyObjectWrapper::wrap_root_object_proxy<"+name+">");
  }
  // Require root_module to be imported for this to work (don't ask me why)
  static PyObject* root_module = PyImport_ImportModule("ROOT");
  if (!root_module)
      throw Exception(Exception::recoverable,
                      "Failed to import ROOT",
                      "PyObjectWrapper::wrap_root_object_proxy<"+name+">");

  // Place the MAUS::MAUSEvent* inside a ROOT Object Proxy
  void* void_data = static_cast<void*>(cpp_data);
  // cpp_data is now owned by python
  PyObject* py_data = TPython::ObjectProxy_FromVoidPtr(void_data,
                                                       name.c_str(),
                                                       true);
  if (!py_data) {
      throw Exception(Exception::recoverable,
                      "Could not convert "+name+" to PyRoot",
                      "PyObjectWrapper::wrap_root_object_proxy<"+name+">");
  }
  return py_data;
}
}  // namespace MAUS

#endif  // _SRC_COMMON_CPP_UTILS_PYOBJECTWRAPPER_INL_HH