#include "kj/async.h"
#include "Python.h"

extern "C" {
   PyObject * wrap_kj_exception(kj::Exception &);
}

PyObject * wrapPyFunc(PyObject * func, PyObject * arg) {
    PyObject * result = PyObject_CallFunctionObjArgs(func, arg, NULL);
    Py_DECREF(func);
    return result;
}

::kj::Promise<PyObject *> evalLater(kj::EventLoop & loop, PyObject * func) {
  return loop.evalLater([func]() { return wrapPyFunc(func, NULL); } );
}

::kj::Promise<PyObject *> there(kj::EventLoop & loop, kj::Promise<PyObject *> & promise, PyObject * func, PyObject * error_func) {
  if(error_func == Py_None)
    return loop.there(kj::mv(promise), [func](PyObject * arg) { return wrapPyFunc(func, arg); } );
  else
    return loop.there(kj::mv(promise), [func](PyObject * arg) { return wrapPyFunc(func, arg); } 
                                     , [error_func](kj::Exception arg) { return wrapPyFunc(error_func, wrap_kj_exception(arg)); } );
}