// namespace object implementation

#include "Python.h"
#include "structmember.h"


typedef struct {
 PyObject_HEAD
 PyObject *ns_dict;
} _PyNamespaceObject;


static PyMemberDef namespace_members[] = {
 {"__dict__", T_OBJECT, offsetof(_PyNamespaceObject, ns_dict), READONLY},
 {NULL}
};


// Methods

static PyObject *
namespace_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
 PyObject *self;

 assert(type != NULL && type->tp_alloc != NULL);
 self = type->tp_alloc(type, 0);
 if (self != NULL) {
 _PyNamespaceObject *ns = (_PyNamespaceObject *)self;
 ns->ns_dict = PyDict_New();
 if (ns->ns_dict == NULL) {
 Py_DECREF(ns);
 return NULL;
 }
 }
 return self;
}


static int
namespace_init(_PyNamespaceObject *ns, PyObject *args, PyObject *kwds)
{
 if (PyTuple_GET_SIZE(args) != 0) {
 PyErr_Format(PyExc_TypeError, "no positional arguments expected");
 return -1;
 }
 if (kwds == NULL) {
 return 0;
 }
 if (!PyArg_ValidateKeywordArguments(kwds)) {
 return -1;
 }
 return PyDict_Update(ns->ns_dict, kwds);
}


static void
namespace_dealloc(_PyNamespaceObject *ns)
{
 PyObject_GC_UnTrack(ns);
 Py_CLEAR(ns->ns_dict);
 Py_TYPE(ns)->tp_free((PyObject *)ns);
}


static PyObject *
namespace_repr(PyObject *ns)
{
 int i, loop_error = 0;
 PyObject *pairs = NULL, *d = NULL, *keys = NULL, *keys_iter = NULL;
 PyObject *key;
 PyObject *separator, *pairsrepr, *repr = NULL;
 const char * name;

 name = (Py_TYPE(ns) == &_PyNamespace_Type) ? "namespace"
 : ns->ob_type->tp_name;

 i = Py_ReprEnter(ns);
 if (i != 0) {
 return i > 0 ? PyUnicode_FromFormat("%s(...)", name) : NULL;
 }

 pairs = PyList_New(0);
 if (pairs == NULL)
 goto error;

 d = ((_PyNamespaceObject *)ns)->ns_dict;
 assert(d != NULL);
 Py_INCREF(d);

 keys = PyDict_Keys(d);
 if (keys == NULL)
 goto error;
 if (PyList_Sort(keys) != 0)
 goto error;

 keys_iter = PyObject_GetIter(keys);
 if (keys_iter == NULL)
 goto error;

 while ((key = PyIter_Next(keys_iter)) != NULL) {
 if (PyUnicode_Check(key) && PyUnicode_GET_LENGTH(key) > 0) {
 PyObject *value, *item;

 value = PyDict_GetItemWithError(d, key);
 if (value != NULL) {
 item = PyUnicode_FromFormat("%U=%R", key, value);
 if (item == NULL) {
 loop_error = 1;
 }
 else {
 loop_error = PyList_Append(pairs, item);
 Py_DECREF(item);
 }
 }
 else if (PyErr_Occurred()) {
 loop_error = 1;
 }
 }

 Py_DECREF(key);
 if (loop_error)
 goto error;
 }

 separator = PyUnicode_FromString(", ");
 if (separator == NULL)
 goto error;

 pairsrepr = PyUnicode_Join(separator, pairs);
 Py_DECREF(separator);
 if (pairsrepr == NULL)
 goto error;

 repr = PyUnicode_FromFormat("%s(%S)", name, pairsrepr);
 Py_DECREF(pairsrepr);

error:
 Py_XDECREF(pairs);
 Py_XDECREF(d);
 Py_XDECREF(keys);
 Py_XDECREF(keys_iter);
 Py_ReprLeave(ns);

 return repr;
}


static int
namespace_traverse(_PyNamespaceObject *ns, visitproc visit, void *arg)
{
 Py_VISIT(ns->ns_dict);
 return 0;
}


static int
namespace_clear(_PyNamespaceObject *ns)
{
 Py_CLEAR(ns->ns_dict);
 return 0;
}


static PyObject *
namespace_richcompare(PyObject *self, PyObject *other, int op)
{
 if (PyObject_TypeCheck(self, &_PyNamespace_Type) &&
 PyObject_TypeCheck(other, &_PyNamespace_Type))
 return PyObject_RichCompare(((_PyNamespaceObject *)self)->ns_dict,
 ((_PyNamespaceObject *)other)->ns_dict, op);
 Py_RETURN_NOTIMPLEMENTED;
}


PyDoc_STRVAR(namespace_reduce__doc__, "Return state information for pickling");

static PyObject *
namespace_reduce(_PyNamespaceObject *ns, PyObject *Py_UNUSED(ignored))
{
 PyObject *result, *args = PyTuple_New(0);

 if (!args)
 return NULL;

 result = PyTuple_Pack(3, (PyObject *)Py_TYPE(ns), args, ns->ns_dict);
 Py_DECREF(args);
 return result;
}


static PyMethodDef namespace_methods[] = {
 {"__reduce__", (PyCFunction)namespace_reduce, METH_NOARGS,
 namespace_reduce__doc__},
 {NULL, NULL} // sentinel
};


PyDoc_STRVAR(namespace_doc,
"A simple attribute-based namespace.\n\
\n\
SimpleNamespace(**kwargs)");

PyTypeObject _PyNamespace_Type = {
 PyVarObject_HEAD_INIT(&PyType_Type, 0)
 "types.SimpleNamespace", /* tp_name */
 sizeof(_PyNamespaceObject), /* tp_basicsize */
 0, /* tp_itemsize */
 (destructor)namespace_dealloc, /* tp_dealloc */
 0, /* tp_vectorcall_offset */
 0, /* tp_getattr */
 0, /* tp_setattr */
 0, /* tp_as_async */
 (reprfunc)namespace_repr, /* tp_repr */
 0, /* tp_as_number */
 0, /* tp_as_sequence */
 0, /* tp_as_mapping */
 0, /* tp_hash */
 0, /* tp_call */
 0, /* tp_str */
 PyObject_GenericGetAttr, /* tp_getattro */
 PyObject_GenericSetAttr, /* tp_setattro */
 0, /* tp_as_buffer */
 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
 Py_TPFLAGS_BASETYPE, /* tp_flags */
 namespace_doc, /* tp_doc */
 (traverseproc)namespace_traverse, /* tp_traverse */
 (inquiry)namespace_clear, /* tp_clear */
 namespace_richcompare, /* tp_richcompare */
 0, /* tp_weaklistoffset */
 0, /* tp_iter */
 0, /* tp_iternext */
 namespace_methods, /* tp_methods */
 namespace_members, /* tp_members */
 0, /* tp_getset */
 0, /* tp_base */
 0, /* tp_dict */
 0, /* tp_descr_get */
 0, /* tp_descr_set */
 offsetof(_PyNamespaceObject, ns_dict), /* tp_dictoffset */
 (initproc)namespace_init, /* tp_init */
 PyType_GenericAlloc, /* tp_alloc */
 (newfunc)namespace_new, /* tp_new */
 PyObject_GC_Del, /* tp_free */
};


PyObject *
_PyNamespace_New(PyObject *kwds)
{
 PyObject *ns = namespace_new(&_PyNamespace_Type, NULL, NULL);
 if (ns == NULL)
 return NULL;

 if (kwds == NULL)
 return ns;
 if (PyDict_Update(((_PyNamespaceObject *)ns)->ns_dict, kwds) != 0) {
 Py_DECREF(ns);
 return NULL;
 }

 return (PyObject *)ns;
}