/* -*- Mode: C; c-basic-offset: 4 -*-
 * pygtk- Python bindings for the GTK toolkit.
 * Copyright (C) 1998-2003  James Henstridge
 * Copyright (C) 2004       Johan Dahlin
 *
 *   pygenum.c: GEnum wrapper
 *
 * 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 <config.h>

#include "pygi-type.h"
#include "pygi-util.h"
#include "pygi-type.h"
#include "pygi-basictype.h"
#include "pygenum.h"
#include "pygboxed.h"

GQuark pygenum_class_key;

PYGI_DEFINE_TYPE("gobject.GEnum", PyGEnum_Type, PyGEnum);

static PyObject *
pyg_enum_val_new(PyObject* subclass, GType gtype, PyObject *intval)
{
    PyObject *args, *item;
    args = Py_BuildValue("(O)", intval);
    item =  (&PyLong_Type)->tp_new((PyTypeObject*)subclass, args, NULL);
    Py_DECREF(args);
    if (!item)
	return NULL;
    ((PyGEnum*)item)->gtype = gtype;

    return item;
}

static PyObject *
pyg_enum_richcompare(PyGEnum *self, PyObject *other, int op)
{
    static char warning[256];

    if (!PyLong_Check (other)) {
	Py_INCREF(Py_NotImplemented);
	return Py_NotImplemented;
    }

    if (PyObject_TypeCheck(other, &PyGEnum_Type) && ((PyGEnum*)other)->gtype != self->gtype) {
	g_snprintf(warning, sizeof(warning), "comparing different enum types: %s and %s",
		   g_type_name(self->gtype), g_type_name(((PyGEnum*)other)->gtype));
	if (PyErr_Warn(PyExc_Warning, warning))
	    return NULL;
    }

    return pyg_integer_richcompare((PyObject *)self, other, op);
}

static PyObject *
pyg_enum_repr(PyGEnum *self)
{
    PyObject *module;
    GEnumClass *enum_class;
    const char *value;
    guint index;
    char *namespace, *module_str;
    static char tmp[256];
    long l;

    module = PyObject_GetAttrString ((PyObject *)self, "__module__");
    if (module == NULL)
        return NULL;

    if (!PyUnicode_Check (module)) {
        Py_DECREF (module);
        return NULL;
    }

    enum_class = g_type_class_ref(self->gtype);
    g_assert(G_IS_ENUM_CLASS(enum_class));

    l = PyLong_AS_LONG ((PyObject*)self);
    for (index = 0; index < enum_class->n_values; index++)
        if (l == enum_class->values[index].value)
            break;

    module_str = PyUnicode_AsUTF8 (module);
    namespace = g_strrstr (module_str, ".");
    if (namespace == NULL) {
        namespace = module_str;
    } else {
        namespace += 1;
    }

    value = enum_class->values[index].value_name;
    if (value)
        sprintf(tmp, "<enum %s of type %s.%s>", value,
                namespace, Py_TYPE (self)->tp_name);
    else
        sprintf(tmp, "<enum %ld of type %s.%s>", PyLong_AS_LONG ((PyObject*)self),
                namespace, Py_TYPE (self)->tp_name);
    Py_DECREF (module);
    g_type_class_unref(enum_class);

    return PyUnicode_FromString (tmp);
}

static PyObject *
pyg_enum_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
{
    static char *kwlist[] = { "value", NULL };
    long value;
    PyObject *pytc, *values, *ret, *intvalue;
    GType gtype;
    GEnumClass *eclass;

    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "l", kwlist, &value))
	return NULL;

    pytc = PyObject_GetAttrString((PyObject *)type, "__gtype__");
    if (!pytc)
	return NULL;

    if (!PyObject_TypeCheck(pytc, &PyGTypeWrapper_Type)) {
	Py_DECREF(pytc);
	PyErr_SetString(PyExc_TypeError,
			"__gtype__ attribute not a typecode");
	return NULL;
    }

    gtype = pyg_type_from_object(pytc);
    Py_DECREF(pytc);

    eclass = G_ENUM_CLASS(g_type_class_ref(gtype));

    /* A check that 0 < value < eclass->n_values was here but got
     * removed: enumeration values do not need to be consequitive,
     * e.g. GtkPathPriorityType values are not.
     */

    values = PyObject_GetAttrString((PyObject *)type, "__enum_values__");
    if (!values) {
	g_type_class_unref(eclass);
	return NULL;
    }

    /* Note that size of __enum_values__ dictionary can easily be less
     * than 'n_values'.  This happens if some values of the enum are
     * numerically equal, e.g. gtk.ANCHOR_N == gtk.ANCHOR_NORTH.
     * Johan said that "In retrospect, using a dictionary to store the
     * values might not have been that good", but we need to keep
     * backward compatibility.
     */
    if (!PyDict_Check(values) || (gsize)PyDict_Size(values) > eclass->n_values) {
	PyErr_SetString(PyExc_TypeError, "__enum_values__ badly formed");
	Py_DECREF(values);
	g_type_class_unref(eclass);
	return NULL;
    }

    g_type_class_unref(eclass);

    intvalue = PyLong_FromLong(value);
    ret = PyDict_GetItem(values, intvalue);
    Py_DECREF(intvalue);
    Py_DECREF(values);
    if (ret)
        Py_INCREF(ret);
    else
	PyErr_Format(PyExc_ValueError, "invalid enum value: %ld", value);

    return ret;
}

PyObject*
pyg_enum_from_gtype (GType gtype, int value)
{
    PyObject *pyclass, *values, *retval, *intvalue;

    g_return_val_if_fail(gtype != G_TYPE_INVALID, NULL);

    /* Get a wrapper class by:
     * 1. check for one attached to the gtype
     * 2. lookup one in a typelib
     * 3. creating a new one
     */
    pyclass = (PyObject*)g_type_get_qdata(gtype, pygenum_class_key);
    if (!pyclass)
        pyclass = pygi_type_import_by_g_type(gtype);
    if (!pyclass)
        pyclass = pyg_enum_add(NULL, g_type_name(gtype), NULL, gtype);
    if (!pyclass)
	return PyLong_FromLong(value);

    values = PyDict_GetItemString(((PyTypeObject *)pyclass)->tp_dict,
				  "__enum_values__");
    intvalue = PyLong_FromLong(value);
    retval = PyDict_GetItem(values, intvalue);
    if (retval) {
	Py_INCREF(retval);
    }
    else {
	PyErr_Clear();
	retval = pyg_enum_val_new(pyclass, gtype, intvalue);
    }
    Py_DECREF(intvalue);

    return retval;
}

/*
 * pyg_enum_add
 * Dynamically create a class derived from PyGEnum based on the given GType.
 */
PyObject *
pyg_enum_add (PyObject *   module,
	      const char * typename,
	      const char * strip_prefix,
	      GType        gtype)
{
    PyGILState_STATE state;
    PyObject *instance_dict, *stub, *values, *o;
    GEnumClass *eclass;
    guint i;

    g_return_val_if_fail(typename != NULL, NULL);
    if (!g_type_is_a (gtype, G_TYPE_ENUM)) {
        PyErr_Format (PyExc_TypeError, "Trying to register gtype '%s' as enum when in fact it is of type '%s'",
                      g_type_name (gtype), g_type_name (G_TYPE_FUNDAMENTAL (gtype)));
        return NULL;
    }

    state = PyGILState_Ensure();

    /* Create a new type derived from GEnum. This is the same as:
     * >>> stub = type(typename, (GEnum,), {})
     */
    instance_dict = PyDict_New();
    stub = PyObject_CallFunction((PyObject *)&PyType_Type, "s(O)O",
                                 typename, (PyObject *)&PyGEnum_Type,
                                 instance_dict);
    Py_DECREF(instance_dict);
    if (!stub) {
	PyErr_SetString(PyExc_RuntimeError, "can't create const");
	PyGILState_Release(state);
	return NULL;
    }

    ((PyTypeObject *)stub)->tp_flags &= ~Py_TPFLAGS_BASETYPE;

    if (module)
	PyDict_SetItemString(((PyTypeObject *)stub)->tp_dict,
			     "__module__",
			     PyUnicode_FromString (PyModule_GetName(module)));

    g_type_set_qdata(gtype, pygenum_class_key, stub);

    o = pyg_type_wrapper_new(gtype);
    PyDict_SetItemString(((PyTypeObject *)stub)->tp_dict, "__gtype__", o);
    Py_DECREF(o);

    if (module) {
	/* Add it to the module name space */
	PyModule_AddObject(module, (char*)typename, stub);
	Py_INCREF(stub);
    }

    /* Register enum values */
    eclass = G_ENUM_CLASS(g_type_class_ref(gtype));

    values = PyDict_New();
    for (i = 0; i < eclass->n_values; i++) {
	PyObject *item, *intval;
      
        intval = PyLong_FromLong(eclass->values[i].value);
	item = pyg_enum_val_new(stub, gtype, intval);
	PyDict_SetItem(values, intval, item);
        Py_DECREF(intval);

	if (module) {
	    char *prefix;

	    prefix = g_strdup(pyg_constant_strip_prefix(eclass->values[i].value_name, strip_prefix));
	    PyModule_AddObject(module, prefix, item);
	    g_free(prefix);

	    Py_INCREF(item);
	}
    }

    PyDict_SetItemString(((PyTypeObject *)stub)->tp_dict,
			 "__enum_values__", values);
    Py_DECREF(values);

    g_type_class_unref(eclass);

    PyGILState_Release(state);
    return stub;
}

static PyObject *
pyg_enum_reduce(PyObject *self, PyObject *args)
{
    if (!PyArg_ParseTuple(args, ":GEnum.__reduce__"))
        return NULL;

    return Py_BuildValue("(O(i)O)", Py_TYPE(self), PyLong_AsLong (self),
                         PyObject_GetAttrString(self, "__dict__"));
}

static PyObject *
pyg_enum_get_value_name(PyGEnum *self, void *closure)
{
  GEnumClass *enum_class;
  GEnumValue *enum_value;
  PyObject *retval;
  gint intvalue;

  if (!pygi_gint_from_py ((PyObject*) self, &intvalue))
    return NULL;

  enum_class = g_type_class_ref(self->gtype);
  g_assert(G_IS_ENUM_CLASS(enum_class));

  enum_value = g_enum_get_value(enum_class, intvalue);

  retval = pygi_utf8_to_py (enum_value->value_name);
  g_type_class_unref(enum_class);

  return retval;
}

static PyObject *
pyg_enum_get_value_nick(PyGEnum *self, void *closure)
{
  GEnumClass *enum_class;
  GEnumValue *enum_value;
  PyObject *retval;
  gint intvalue;

  if (!pygi_gint_from_py ((PyObject*) self, &intvalue))
    return NULL;

  enum_class = g_type_class_ref(self->gtype);
  g_assert(G_IS_ENUM_CLASS(enum_class));

  enum_value = g_enum_get_value(enum_class, intvalue);

  retval = pygi_utf8_to_py (enum_value->value_nick);

  g_type_class_unref(enum_class);

  return retval;
}


static PyMethodDef pyg_enum_methods[] = {
    { "__reduce__", (PyCFunction)pyg_enum_reduce, METH_VARARGS },
    { NULL, NULL, 0 }
};

static PyGetSetDef pyg_enum_getsets[] = {
    { "value_name", (getter)pyg_enum_get_value_name, (setter)0 },
    { "value_nick", (getter)pyg_enum_get_value_nick, (setter)0 },
    { NULL, 0, 0 }
};

/**
 * Returns 0 on success, or -1 and sets an exception.
 */
int
pygi_enum_register_types(PyObject *d)
{
    PyObject *pygtype;

    pygenum_class_key        = g_quark_from_static_string("PyGEnum::class");

    PyGEnum_Type.tp_base = &PyLong_Type;
    PyGEnum_Type.tp_new = pyg_enum_new;
    PyGEnum_Type.tp_hash = PyLong_Type.tp_hash;
    PyGEnum_Type.tp_repr = (reprfunc)pyg_enum_repr;
    PyGEnum_Type.tp_str = (reprfunc)pyg_enum_repr;
    PyGEnum_Type.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
    PyGEnum_Type.tp_richcompare = (richcmpfunc)pyg_enum_richcompare;
    PyGEnum_Type.tp_methods = pyg_enum_methods;
    PyGEnum_Type.tp_getset = pyg_enum_getsets;
    PyGEnum_Type.tp_alloc = PyType_GenericAlloc;
    if (PyType_Ready(&PyGEnum_Type))
        return -1;

    pygtype = pyg_type_wrapper_new (G_TYPE_ENUM);
    PyDict_SetItemString (PyGEnum_Type.tp_dict, "__gtype__", pygtype);
    Py_DECREF (pygtype);

    PyDict_SetItemString(d, "GEnum", (PyObject *)&PyGEnum_Type);

    return 0;
}