// This contains the implementation of pyqtClassInfo.
//
// Copyright (c) 2025 Riverbank Computing Limited <info@riverbankcomputing.com>
// 
// This file is part of PyQt6.
// 
// This file may be used under the terms of the GNU General Public License
// version 3.0 as published by the Free Software Foundation and appearing in
// the file LICENSE included in the packaging of this file.  Please review the
// following information to ensure the GNU General Public License version 3.0
// requirements will be met: http://www.gnu.org/copyleft/gpl.html.
// 
// If you do not wish to use this file under the terms of the GPL version 3.0
// then you may purchase a commercial license.  For more information contact
// info@riverbankcomputing.com.
// 
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.


#include <Python.h>

#include <QByteArray>
#include <QMultiHash>

#include "qpycore_api.h"
#include "qpycore_classinfo.h"
#include "qpycore_misc.h"

#include "sipAPIQtCore.h"


// Forward declarations.
extern "C" {static PyObject *decorator(PyObject *self, PyObject *cls);}


// The class info name/values keyed by the class type object.
static QMultiHash<PyObject *, ClassInfo> class_info_hash;


// Implement the pyqtClassInfo class decorator.
PyObject *qpycore_pyqtClassInfo(PyObject *args, PyObject *kwds)
{
    // Check there are no positional arguments.
    if (PyTuple_Size(args) != 2)
    {
        PyErr_SetString(PyExc_TypeError,
                "PyQt6.QObject.pyqtClassInfo() requires two positional arguments");
        return 0;
    }

    // Check there are no keyword arguments.
    if (kwds)
    {
        PyErr_SetString(PyExc_TypeError,
                "PyQt6.QObject.pyqtClassInfo() does not support keyword arguments");
        return 0;
    }

    // Create the decorator function itself.  We stash the arguments in "self".
    // This may be an abuse, but it seems to be Ok.
    static PyMethodDef deco_method = {
        "_deco", decorator, METH_O, 0
    };

    return PyCFunction_New(&deco_method, args);
}


// Return the list on the heap of class info name/values for a class.
QList<ClassInfo> qpycore_pop_class_info_list(PyObject *cls)
{
    QList<ClassInfo> all;

    for (;;)
    {
        ClassInfo class_info = class_info_hash.take(cls);
        if (class_info.first.isNull())
            break;

        all.append(class_info);
        Py_DECREF(cls);
    }

    return all;
}


// This is the decorator function that saves the class info for later
// retrieval.
static PyObject *decorator(PyObject *self, PyObject *cls)
{
    // Convert the name.
    QByteArray name = qpycore_convert_ASCII(PyTuple_GetItem(self, 0));
    if (name.isNull())
        return 0;

    // Convert the value.
    QByteArray value = qpycore_convert_ASCII(PyTuple_GetItem(self, 1));
    if (value.isNull())
        return 0;

    Py_INCREF(cls);
    class_info_hash.insert(cls, ClassInfo(name, value));

    // Return the class.
    Py_INCREF(cls);
    return cls;
}
