/* microprotocols.c - minimalist and non-validating protocols implementation

 *

 * Copyright (C) 2003-2004 Federico Di Gregorio <fog@debian.org>

 *

 * This file is part of psycopg and was adapted for pysqlite. Federico Di

 * Gregorio gave the permission to use it within pysqlite under the following

 * license:

 *

 * This software is provided 'as-is', without any express or implied

 * warranty.  In no event will the authors be held liable for any damages

 * arising from the use of this software.

 *

 * Permission is granted to anyone to use this software for any purpose,

 * including commercial applications, and to alter it and redistribute it

 * freely, subject to the following restrictions:

 *

 * 1. The origin of this software must not be misrepresented; you must not

 *    claim that you wrote the original software. If you use this software

 *    in a product, an acknowledgment in the product documentation would be

 *    appreciated but is not required.

 * 2. Altered source versions must be plainly marked as such, and must not be

 *    misrepresented as being the original software.

 * 3. This notice may not be removed or altered from any source distribution.

 */

#include <Python.h>

#include <structmember.h>

#include "cursor.h"

#include "microprotocols.h"

#include "prepare_protocol.h"

/** the adapters registry **/

PyObject *psyco_adapters;

/* pysqlite_microprotocols_init - initialize the adapters dictionary */

int

pysqlite_microprotocols_init(PyObject *dict)

{

    /* create adapters dictionary and put it in module namespace */

    if ((psyco_adapters = PyDict_New()) == NULL) {

        return -1;

    }

    return PyDict_SetItemString(dict, "adapters", psyco_adapters);

}

/* pysqlite_microprotocols_add - add a reverse type-caster to the dictionary */

int

pysqlite_microprotocols_add(PyTypeObject *type, PyObject *proto, PyObject *cast)

{

    PyObject* key;

    int rc;

    if (proto == NULL) proto = (PyObject*)&pysqlite_PrepareProtocolType;

    key = Py_BuildValue("(OO)", (PyObject*)type, proto);

    if (!key) {

        return -1;

    }

    rc = PyDict_SetItem(psyco_adapters, key, cast);

    Py_DECREF(key);

    return rc;

}

/* pysqlite_microprotocols_adapt - adapt an object to the built-in protocol */

PyObject *

pysqlite_microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt)

{

    PyObject *adapter, *key;

    /* we don't check for exact type conformance as specified in PEP 246

       because the pysqlite_PrepareProtocolType type is abstract and there is no

       way to get a quotable object to be its instance */

    /* look for an adapter in the registry */

    key = Py_BuildValue("(OO)", (PyObject*)obj->ob_type, proto);

    if (!key) {

        return NULL;

    }

    adapter = PyDict_GetItem(psyco_adapters, key);

    Py_DECREF(key);

    if (adapter) {

        PyObject *adapted = PyObject_CallFunctionObjArgs(adapter, obj, NULL);

        return adapted;

    }

    /* try to have the protocol adapt this object*/

    if (PyObject_HasAttrString(proto, "__adapt__")) {

        PyObject *adapted = PyObject_CallMethod(proto, "__adapt__", "O", obj);

        if (adapted) {

            if (adapted != Py_None) {

                return adapted;

            } else {

                Py_DECREF(adapted);

            }

        }

        if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError))

            return NULL;

    }

    /* and finally try to have the object adapt itself */

    if (PyObject_HasAttrString(obj, "__conform__")) {

        PyObject *adapted = PyObject_CallMethod(obj, "__conform__","O", proto);

        if (adapted) {

            if (adapted != Py_None) {

                return adapted;

            } else {

                Py_DECREF(adapted);

            }

        }

        if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError)) {

            return NULL;

        }

    }

    /* else set the right exception and return NULL */

    PyErr_SetString(pysqlite_ProgrammingError, "can't adapt");

    return NULL;

}

/** module-level functions **/

PyObject *

pysqlite_adapt(pysqlite_Cursor *self, PyObject *args)

{

    PyObject *obj, *alt = NULL;

    PyObject *proto = (PyObject*)&pysqlite_PrepareProtocolType;

    if (!PyArg_ParseTuple(args, "O|OO", &obj, &proto, &alt)) return NULL;

    return pysqlite_microprotocols_adapt(obj, proto, alt);

}