/* -*- mode: c; indent-tabs-mode: t; c-basic-offset: 8; -*- */
static gpointer
sv_to_callback (GIArgInfo * arg_info,
                GITypeInfo * type_info,
                SV * sv,
                GPerlI11nInvocationInfo * invocation_info)
{
        GIBaseInfo *callback_interface_info;
        GPerlI11nPerlCallbackInfo *callback_info;
        GIScopeType scope;
        /* the destroy notify func is handled by _handle_automatic_arg */
        dwarn ("pos = %d, name = %s\n",
               invocation_info->current_pos,
               g_base_info_get_name (arg_info));
        callback_interface_info = g_type_info_get_interface (type_info);
        callback_info = create_perl_callback_closure (callback_interface_info, sv);
        callback_info->data_pos = g_arg_info_get_closure (arg_info);
        callback_info->destroy_pos = g_arg_info_get_destroy (arg_info);
        callback_info->free_after_use = FALSE;
        g_base_info_unref (callback_interface_info);
        dwarn ("  data at %d, destroy at %d\n",
               callback_info->data_pos, callback_info->destroy_pos);
        scope = (!gperl_sv_is_defined (sv))
                ? GI_SCOPE_TYPE_CALL
                : g_arg_info_get_scope (arg_info);
        switch (scope) {
            case GI_SCOPE_TYPE_CALL:
                dwarn ("  scope = 'call'\n");
                free_after_call (invocation_info,
                                 release_perl_callback, callback_info);
                break;
            case GI_SCOPE_TYPE_NOTIFIED:
                dwarn ("  scope = 'notified'\n");
                /* This case is already taken care of by the notify
                 * stuff above */
                break;
            case GI_SCOPE_TYPE_ASYNC:
                dwarn ("  scope = 'async'\n");
                /* FIXME: callback_info->free_after_use = TRUE; */
                break;
            default:
                ccroak ("unhandled scope type %d encountered",
                       g_arg_info_get_scope (arg_info));
        }
        invocation_info->callback_infos =
                g_slist_prepend (invocation_info->callback_infos,
                                 callback_info);
        dwarn ("  -> closure %p from info %p\n",
               callback_info->closure, callback_info);
#if GI_CHECK_VERSION (1, 72, 0)
        if (callback_info->closure)
                return g_callable_info_get_closure_native_address (callback_interface_info,
                                                                   callback_info->closure);
        else
                return NULL;
#else
        return callback_info->closure;
#endif
}
static gpointer
sv_to_callback_data (SV * sv,
                     GPerlI11nInvocationInfo * invocation_info)
{
        GSList *l;
        if (!invocation_info)
                return NULL;
        for (l = invocation_info->callback_infos; l != NULL; l = l->next) {
                GPerlI11nPerlCallbackInfo *callback_info = l->data;
                if (callback_info->data_pos == ((gint) invocation_info->current_pos)) {
                        dwarn ("user data for Perl callback %p\n",
                               callback_info);
                        attach_perl_callback_data (callback_info, sv);
                        /* If the user did not specify any code and data and if
                         * there is no destroy notify function, then there is
                         * no need for us to pass on our callback info struct
                         * as C user data.  Some libraries (e.g., vte) even
                         * assert that the C user data be NULL if the C
                         * function pointer is NULL. */
                        if (!gperl_sv_is_defined (callback_info->code) &&
                            !gperl_sv_is_defined (callback_info->data) &&
                            -1 == callback_info->destroy_pos)
                        {
                                dwarn ("  -> handing over NULL");
                                return NULL;
                        }
                        return callback_info;
                }
        }
        if (invocation_info->is_callback) {
                GPerlI11nCCallbackInfo *wrapper = INT2PTR (GPerlI11nCCallbackInfo*, SvIV (sv));
                dwarn ("user data for C callback %p\n", wrapper);
                return wrapper->data;
        }
        return NULL;
}
static SV *
callback_to_sv (GICallableInfo *interface, gpointer func, GPerlI11nInvocationInfo *invocation_info)
{
        GIArgInfo arg_info;
        GPerlI11nCCallbackInfo *callback_info;
        HV *stash;
        SV *code_sv, *data_sv;
        GSList *l;
        for (l = invocation_info->callback_infos; l != NULL; l = l->next) {
                GPerlI11nCCallbackInfo *callback_info = l->data;
                if ((gint) invocation_info->current_pos == callback_info->destroy_pos) {
                        dwarn ("destroy notify for C callback %p\n",
                               callback_info);
                        callback_info->destroy = func;
                        /* release_c_callback is called from
                         * Glib::Object::Introspection::_FuncWrapper::DESTROY */
                        return NULL;
                }
        }
        g_callable_info_load_arg (invocation_info->interface,
                                  (gint) invocation_info->current_pos,
                                  &arg_info);
        dwarn ("C callback: pos = %d, name = %s\n",
               invocation_info->current_pos,
               g_base_info_get_name (&arg_info));
        callback_info = create_c_callback_closure (interface, func);
        callback_info->data_pos = g_arg_info_get_closure (&arg_info);
        callback_info->destroy_pos = g_arg_info_get_destroy (&arg_info);
        if (func) {
                data_sv = newSViv (PTR2IV (callback_info));
                stash = gv_stashpv ("Glib::Object::Introspection::_FuncWrapper", TRUE);
                code_sv = sv_bless (newRV_noinc (data_sv), stash);
        } else {
                data_sv = code_sv = &PL_sv_undef;
        }
        callback_info->data_sv = data_sv;
        dwarn ("  data at %d, destroy at %d\n",
               callback_info->data_pos, callback_info->destroy_pos);
        invocation_info->callback_infos =
                g_slist_prepend (invocation_info->callback_infos,
                                 callback_info);
        dwarn ("  -> SV %p from info %p\n",
               code_sv, callback_info);
        return code_sv;
}
static SV *
callback_data_to_sv (gpointer data,
                     GPerlI11nInvocationInfo * invocation_info)
{
        GSList *l;
        if (!invocation_info)
                return NULL;
        for (l = invocation_info->callback_infos; l != NULL; l = l->next) {
                GPerlI11nCCallbackInfo *callback_info = l->data;
                if (callback_info->data_pos == (gint) invocation_info->current_pos) {
                        dwarn ("user data for C callback %p\n",
                               callback_info);
                        attach_c_callback_data (callback_info, data);
                        return callback_info->data_sv;
                }
        }
        if (data && invocation_info->is_callback) {
                GPerlI11nPerlCallbackInfo *wrapper = data;
                dwarn ("user data for Perl callback %p\n", wrapper);
                return wrapper->data;
        }
        return NULL;
}