/* -*- Mode: C; c-basic-offset: 4 -*-
 * vim: tabstop=4 shiftwidth=4 expandtab
 *
 * Copyright (C) 2011 John (J5) Palmieri <johnp@redhat.com>
 * Copyright (C) 2014 Simon Feltman <sfeltman@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include <glib.h>
#include <pythoncapi_compat.h>

#include "pygi-fundamental.h"
#include "pygi-object.h"
#include "pygobject-object.h"

/*
 * GObject from Python
 */

typedef gboolean (*PyGIObjectMarshalFromPyFunc) (PyObject *py_arg,
                                                 GIArgument *arg,
                                                 GITransfer transfer);

/* pygi_marshal_from_py_object:
 * py_arg: (in):
 * arg: (out):
 */
gboolean
pygi_marshal_from_py_object (PyObject *py_arg, /*in*/
                             GIArgument *arg,  /*out*/
                             GITransfer transfer)
{
    GObject *gobj;

    if (Py_IsNone (py_arg)) {
        arg->v_pointer = NULL;
        return TRUE;
    }

    if (PyObject_TypeCheck (py_arg, &PyGIFundamental_Type)) {
        arg->v_pointer = pygi_fundamental_get (py_arg);
        if (transfer == GI_TRANSFER_EVERYTHING) {
            pygi_fundamental_ref ((PyGIFundamental *)py_arg);
        }
        return TRUE;
    }

    if (!pygobject_check (py_arg, &PyGObject_Type)) {
        PyObject *repr = PyObject_Repr (py_arg);
        PyErr_Format (PyExc_TypeError, "expected GObject but got %s",
                      PyUnicode_AsUTF8 (repr));
        Py_DECREF (repr);
        return FALSE;
    }

    gobj = pygobject_get (py_arg);
    if (gobj == NULL) {
        PyErr_Format (PyExc_RuntimeError,
                      "object at %p of type %s is not initialized", py_arg,
                      Py_TYPE (py_arg)->tp_name);
        return FALSE;
    }

    if (transfer == GI_TRANSFER_EVERYTHING) {
        /* For transfer everything, add a new ref that the callee will take ownership of.
         * Pythons existing ref to the GObject will be managed with the PyGObject wrapper.
         */
        g_object_ref (gobj);
    }

    arg->v_pointer = gobj;
    return TRUE;
}

/* pygi_arg_gobject_out_arg_from_py:
 * py_arg: (in):
 * arg: (out):
 *
 * A specialization for marshaling Python GObjects used for out/return values
 * from a Python implemented vfuncs, signals, or an assignment to a GObject property.
 */
gboolean
pygi_arg_gobject_out_arg_from_py (PyObject *py_arg, /* in */
                                  GIArgument *arg,  /* out */
                                  GITransfer transfer)
{
    GObject *gobj;
    if (!pygi_marshal_from_py_object (py_arg, arg, transfer)) {
        return FALSE;
    }

    /* HACK: At this point the basic marshaling of the GObject was successful
     * but we add some special case hacks for vfunc returns due to buggy APIs:
     * https://bugzilla.gnome.org/show_bug.cgi?id=693393
     */
    gobj = arg->v_pointer;
    // In Python 3.13 the py_arg refcount is 3, in 3.14 only 1
    if (Py_REFCNT (py_arg) == 1 && gobj->ref_count == 1) {
        /* If both object ref counts are only 1 at this point (the reference held
         * in a return tuple), we assume the GObject will be free'd before reaching
         * its target and become invalid. So instead of getting invalid object errors
         * we add a new GObject ref.
         */
        g_object_ref (gobj);

        if (((PyGObject *)py_arg)->private_flags.flags
            & PYGOBJECT_GOBJECT_WAS_FLOATING) {
            /*
             * We want to re-float instances that were floating and the Python
             * wrapper assumed ownership. With the additional caveat that there
             * are not any strong references beyond the return tuple.
             */
            g_object_force_floating (gobj);

        } else {
            // This may no longer be true, due to differences in refcounting
            PyObject *repr = PyObject_Repr (py_arg);
            gchar *msg = g_strdup_printf (
                "Expecting to marshal a borrowed reference for %s, "
                "but nothing in Python is holding a reference to this object. "
                "See: https://bugzilla.gnome.org/show_bug.cgi?id=687522",
                PyUnicode_AsUTF8 (repr));
            Py_DECREF (repr);
            if (PyErr_WarnEx (PyExc_RuntimeWarning, msg, 2)) {
                g_free (msg);
                return FALSE;
            }
            g_free (msg);
        }
    }

    return TRUE;
}

static gboolean
_pygi_marshal_from_py_interface_object (PyGIInvokeState *state,
                                        PyGICallableCache *callable_cache,
                                        PyGIArgCache *arg_cache,
                                        PyObject *py_arg, GIArgument *arg,
                                        gpointer *cleanup_data,
                                        PyGIObjectMarshalFromPyFunc func)
{
    PyGIInterfaceCache *iface_cache = (PyGIInterfaceCache *)arg_cache;

    if (Py_IsNone (py_arg)) {
        arg->v_pointer = NULL;
        return TRUE;
    }

    if (PyObject_IsInstance (py_arg, iface_cache->py_type)
        || (pygobject_check (py_arg, &PyGObject_Type)
            && g_type_is_a (G_OBJECT_TYPE (pygobject_get (py_arg)),
                            iface_cache->g_type))) {
        gboolean res;
        res = func (py_arg, arg, arg_cache->transfer);
        *cleanup_data = arg->v_pointer;
        return res;

    } else {
        PyObject *module = PyObject_GetAttrString (py_arg, "__module__");

        PyErr_Format (PyExc_TypeError,
                      "argument %s: Expected %s, but got %s%s%s",
                      arg_cache->arg_name ? arg_cache->arg_name : "self",
                      ((PyGIInterfaceCache *)arg_cache)->type_name,
                      module ? PyUnicode_AsUTF8 (module) : "",
                      module ? "." : "", Py_TYPE (py_arg)->tp_name);
        if (module) Py_DECREF (module);
        return FALSE;
    }
}

static gboolean
_pygi_marshal_from_py_called_from_c_interface_object (
    PyGIInvokeState *state, PyGICallableCache *callable_cache,
    PyGIArgCache *arg_cache, PyObject *py_arg, GIArgument *arg,
    gpointer *cleanup_data)
{
    return _pygi_marshal_from_py_interface_object (
        state, callable_cache, arg_cache, py_arg, arg, cleanup_data,
        pygi_arg_gobject_out_arg_from_py);
}

static gboolean
_pygi_marshal_from_py_called_from_py_interface_object (
    PyGIInvokeState *state, PyGICallableCache *callable_cache,
    PyGIArgCache *arg_cache, PyObject *py_arg, GIArgument *arg,
    gpointer *cleanup_data)
{
    return _pygi_marshal_from_py_interface_object (
        state, callable_cache, arg_cache, py_arg, arg, cleanup_data,
        pygi_marshal_from_py_object);
}

static void
_pygi_marshal_cleanup_from_py_interface_object (PyGIInvokeState *state,
                                                PyGIArgCache *arg_cache,
                                                PyObject *py_arg,
                                                gpointer data,
                                                gboolean was_processed)
{
    /* If we processed the parameter but fail before invoking the method,
       we need to remove the ref we added */
    if (was_processed && state->failed && data != NULL
        && arg_cache->transfer == GI_TRANSFER_EVERYTHING)
        g_object_unref (G_OBJECT (data));
}


/*
 * GObject to Python
 */

static PyObject *
pygi_arg_object_to_py (GIArgument *arg, GITransfer transfer)
{
    PyObject *pyobj;

    if (arg->v_pointer == NULL) {
        pyobj = Py_None;
        Py_INCREF (pyobj);
    } else if (G_IS_OBJECT (arg->v_pointer)) {
        pyobj =
            pygobject_new_full (arg->v_pointer,
                                /*steal=*/transfer == GI_TRANSFER_EVERYTHING,
                                /*type=*/NULL);
    } else {
        pyobj = pygi_fundamental_new (arg->v_pointer);
        if (pyobj && transfer == GI_TRANSFER_EVERYTHING)
            pygi_fundamental_unref ((PyGIFundamental *)pyobj);
    }

    return pyobj;
}

PyObject *
pygi_arg_object_to_py_called_from_c (GIArgument *arg, GITransfer transfer)
{
    PyObject *object;

    /* HACK:
     * The following hack is to work around GTK sending signals which
     * contain floating widgets in them. This assumes control of how
     * references are added by the PyGObject wrapper and avoids the sink
     * behavior by explicitly passing GI_TRANSFER_EVERYTHING as the transfer
     * mode and then re-forcing the object as floating afterwards.
     *
     * See: https://bugzilla.gnome.org/show_bug.cgi?id=693400
     */
    if (arg->v_pointer != NULL && transfer == GI_TRANSFER_NOTHING
        && G_IS_OBJECT (arg->v_pointer)
        && g_object_is_floating (arg->v_pointer)) {
        g_object_ref (arg->v_pointer);
        object = pygi_arg_object_to_py (arg, GI_TRANSFER_EVERYTHING);
        g_object_force_floating (arg->v_pointer);
    } else {
        object = pygi_arg_object_to_py (arg, transfer);
    }

    return object;
}

static PyObject *
_pygi_marshal_to_py_called_from_c_interface_object_cache_adapter (
    PyGIInvokeState *state, PyGICallableCache *callable_cache,
    PyGIArgCache *arg_cache, GIArgument *arg, gpointer *cleanup_data)
{
    return pygi_arg_object_to_py_called_from_c (arg, arg_cache->transfer);
}

static PyObject *
_pygi_marshal_to_py_called_from_py_interface_object_cache_adapter (
    PyGIInvokeState *state, PyGICallableCache *callable_cache,
    PyGIArgCache *arg_cache, GIArgument *arg, gpointer *cleanup_data)
{
    return pygi_arg_object_to_py (arg, arg_cache->transfer);
}

static void
_pygi_marshal_cleanup_to_py_interface_object (PyGIInvokeState *state,
                                              PyGIArgCache *arg_cache,
                                              gpointer cleanup_data,
                                              gpointer data,
                                              gboolean was_processed)
{
    if (was_processed && state->failed && data != NULL
        && arg_cache->transfer == GI_TRANSFER_EVERYTHING) {
        if (G_IS_OBJECT (data)) {
            g_object_unref (G_OBJECT (data));
        } else {
            PyGIInterfaceCache *iface_cache = (PyGIInterfaceCache *)arg_cache;
            GIObjectInfoUnrefFunction unref_func;

            unref_func = gi_object_info_get_unref_function_pointer (
                (GIObjectInfo *)iface_cache->interface_info);
            if (unref_func) unref_func (data);
        }
    }
}

static gboolean
pygi_arg_gobject_setup_from_info (PyGIArgCache *arg_cache,
                                  GITypeInfo *type_info, GIArgInfo *arg_info,
                                  GITransfer transfer, PyGIDirection direction,
                                  PyGICallableCache *callable_cache)
{
    /* NOTE: usage of pygi_arg_interface_new_from_info already calls
     * pygi_arg_interface_setup so no need to do it here.
     */

    if (direction & PYGI_DIRECTION_FROM_PYTHON) {
        if (callable_cache->calling_context
            == PYGI_CALLING_CONTEXT_IS_FROM_C) {
            arg_cache->from_py_marshaller =
                _pygi_marshal_from_py_called_from_c_interface_object;
        } else {
            arg_cache->from_py_marshaller =
                _pygi_marshal_from_py_called_from_py_interface_object;
        }

        arg_cache->from_py_cleanup =
            _pygi_marshal_cleanup_from_py_interface_object;
    }

    if (direction & PYGI_DIRECTION_TO_PYTHON) {
        if (callable_cache->calling_context
            == PYGI_CALLING_CONTEXT_IS_FROM_C) {
            arg_cache->to_py_marshaller =
                _pygi_marshal_to_py_called_from_c_interface_object_cache_adapter;
        } else {
            arg_cache->to_py_marshaller =
                _pygi_marshal_to_py_called_from_py_interface_object_cache_adapter;
        }

        arg_cache->to_py_cleanup =
            _pygi_marshal_cleanup_to_py_interface_object;
    }

    return TRUE;
}

PyGIArgCache *
pygi_arg_gobject_new_from_info (GITypeInfo *type_info, GIArgInfo *arg_info,
                                GITransfer transfer, PyGIDirection direction,
                                GIRegisteredTypeInfo *iface_info,
                                PyGICallableCache *callable_cache)
{
    gboolean res = FALSE;
    PyGIArgCache *cache = NULL;

    cache = pygi_arg_interface_new_from_info (type_info, arg_info, transfer,
                                              direction, iface_info);
    if (cache == NULL) return NULL;

    res = pygi_arg_gobject_setup_from_info (
        cache, type_info, arg_info, transfer, direction, callable_cache);
    if (res) {
        return cache;
    } else {
        pygi_arg_cache_free (cache);
        return NULL;
    }
}