/*
 * Copyright (C) 2020 Weber Yann
 * 
 * This file is part of pyrpn.
 * 
 * pyrpn is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 * 
 * pyrpn 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with pyrpn.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "python_pyrpn.h"

/**@file python_pyrpn.c
 * @brief Python module & type definition
 * @ingroup python_ext
 *
 * This file contains pyrpn Python module definition
 */

PyMethodDef rpnmodule_methods[] = {
	{"get_ops", (PyCFunction)pyrpn_ops, METH_NOARGS,
		"Returns a valid operands dict"},
	{"random_expr", (PyCFunction)pyrpn_random, METH_VARARGS | METH_KEYWORDS,
		"Return a random RPN expression"},
	{NULL} // Sentinel
};

PyModuleDef rpnmodule = {
	PyModuleDef_HEAD_INIT,
	"pyrpn",
	"Python librarie for RPN evaluation",
	-1,	// module size
	rpnmodule_methods,
	NULL,	// m_slots
	NULL,	// m_traverse
	NULL,	// m_clear
	NULL	// m_free
};

PyMODINIT_FUNC
PyInit_pyrpn(void)
{

	PyObject *mod;
	// init module & globals
	mod = PyModule_Create(&rpnmodule);
	if(mod == NULL) { return NULL; }
	
	// Init RPNExpr type
	if(PyType_Ready(&RPNExprType) < 0)
	{
		return NULL;
	}

	// Add type to module
	Py_INCREF(&RPNExprType);
	if(PyModule_AddObject(mod, "RPNExpr", (PyObject*)&RPNExprType) < 0)
	{
		Py_DECREF(&RPNExprType);
		Py_DECREF(mod);
		return NULL;
	}

	return mod;
}

PyObject* pyrpn_ops(PyObject* mod, PyObject* noargs)
{
	PyObject *ret, *value;
	const rpn_op_t *op;
	size_t i;

	ret = PyDict_New();
	if(!ret)
	{
		return ret;
	}

	foreach_rpn_ops(i)
	{
		op = &rpn_ops[i];
		value = Py_BuildValue("C", op->chr);
		if(PyDict_SetItemString(ret, op->str, value))
		{
			Py_DECREF(value);
			Py_DECREF(ret);
			return NULL;
		}
		Py_DECREF(value);
	}
	
	return ret;
}

PyObject* pyrpn_random(PyObject *mod, PyObject *args, PyObject *kwds)
{
	long long int args_count, expr_sz;
	char *expr, err_str[128];
	PyObject *res;
	char *names[] = {"args_count", "token_count", NULL};

	expr_sz = 10;
	if(!PyArg_ParseTupleAndKeywords(args, kwds, "L|L:pyrpn.random_expr", names,
		&args_count, &expr_sz))
	{
		return NULL;
	}
	
	expr = rpn_random(expr_sz, args_count);
	if(!expr)
	{
		snprintf(err_str, 128,
			"Error generating random expression : %s",
			strerror(errno));
		PyErr_SetString(PyExc_RuntimeError, err_str);
		return NULL;
	}
	res = Py_BuildValue("s", expr);
	//free(expr);
	return res;
}