#define PY_SSIZE_T_CLEAN
#include <Python.h>

typedef struct {
    PyObject_VAR_HEAD
} ManagedDictObject;

int ManagedDict_traverse(PyObject *self, visitproc visit, void *arg) {
    PyObject_VisitManagedDict(self, visit, arg);
    Py_VISIT(Py_TYPE(self));
    return 0;
}

int ManagedDict_clear(PyObject *self) {
    PyObject_ClearManagedDict(self);
    return 0;
}

static PyGetSetDef ManagedDict_getset[] = {
    {"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict, NULL, NULL},
    {NULL, NULL, NULL, NULL, NULL},
};

static PyType_Slot ManagedDict_slots[] = {
    {Py_tp_new, (void *)PyType_GenericNew},
    {Py_tp_getset, (void *)ManagedDict_getset},
    {Py_tp_traverse, (void *)ManagedDict_traverse},
    {Py_tp_clear, (void *)ManagedDict_clear},
    {0}
};

static PyType_Spec ManagedDict_spec = {
    "manageddictbug.ManagedDict",
    sizeof(ManagedDictObject),
    0, // itemsize
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_MANAGED_DICT | Py_TPFLAGS_HEAPTYPE | Py_TPFLAGS_HAVE_GC,
    ManagedDict_slots
};

static PyModuleDef manageddictbugmodule = {
    PyModuleDef_HEAD_INIT,
    "manageddictbug",
    NULL,
    -1,
    NULL,
};

PyMODINIT_FUNC
PyInit_manageddictbug(void) {
    PyObject *m = PyModule_Create(&manageddictbugmodule);
    if (m == NULL)
        return NULL;

    PyObject *ManagedDictType = PyType_FromSpec(&ManagedDict_spec);
    if (ManagedDictType == NULL) {
        Py_DECREF(m);
        return NULL;
    }

    if (PyModule_AddObject(m, "ManagedDict", ManagedDictType) < 0) {
        Py_DECREF(ManagedDictType);
        Py_DECREF(m);
        return NULL;
    }

    return m;
}