/*
 * Copyright (C) 2009 Sippy Software, Inc., http://www.sippysoft.com
 *
 * This file is part of opensips, a free SIP server.
 *
 * opensips 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 2 of the License, or
 * (at your option) any later version
 *
 * opensips 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
*/

#include <Python.h>
#include "python_compat.h"

#include "../../str.h"
#include "../../sr_module.h"

#include "python_exec.h"
#include "python_iface.h"
#include "python_msgobj.h"
#include "python_support.h"

#include <libgen.h>

static int mod_init(void);
static int child_init(int rank);
static void mod_destroy(void);

static str script_name = str_init("/usr/local/etc/opensips/handler.py");
static str mod_init_fname = str_init("mod_init");
static str child_init_mname = str_init("child_init");
PyObject *handler_obj;
PyObject *format_exc_obj;

PyThreadState *myThreadState;

/** module parameters */
static param_export_t params[]={
 {"script_name", STR_PARAM, &script_name.s },
 {"mod_init_function", STR_PARAM, &mod_init_fname.s },
 {"child_init_method", STR_PARAM, &child_init_mname.s },
 {0,0,0}
};

/*
 * Exported functions
 */
static cmd_export_t cmds[] = {
 {"python_exec", (cmd_function)python_exec, {
 {CMD_PARAM_STR,0,0},
 {CMD_PARAM_STR|CMD_PARAM_OPT,0,0}, {0,0,0}},
 REQUEST_ROUTE|FAILURE_ROUTE|ONREPLY_ROUTE|BRANCH_ROUTE},
 {0,0,{{0,0,0}},0}
};

/** module exports */
struct module_exports exports = {
 "python", /* module name */
 MOD_TYPE_DEFAULT,/* class of this module */
 MODULE_VERSION,
 RTLD_NOW | RTLD_GLOBAL, /* dlopen flags */
 0, /* load function */
 NULL, /* OpenSIPS module dependencies */
 cmds, /* exported functions */
 0, /* exported async functions */
 params, /* exported parameters */
 0, /* exported statistics */
 0, /* exported MI functions */
 0, /* exported pseudo-variables */
 0, /* exported transformations */
 0, /* extra processes */
 0, /* module pre-initialization function */
 mod_init, /* module initialization function */
 (response_function) NULL, /* response handling function */
 (destroy_function) mod_destroy, /* destroy function */
 child_init, /* per-child init function */
 0 /* reload confirm function */
};

static int
mod_init(void)
{
 char *dname, *bname;
 int i;
 PyObject *sys_path, *pDir, *pModule, *pFunc, *pArgs;
 PyThreadState *mainThreadState;

 script_name.len = strlen(script_name.s);
 mod_init_fname.len = strlen(mod_init_fname.s);
 child_init_mname.len = strlen(child_init_mname.s);

 bname = basename(script_name.s);
 i = strlen(bname);
 if (bname[i - 1] == 'c' || bname[i - 1] == 'o')
 i -= 1;
 if (bname[i - 3] == '.' && bname[i - 2] == 'p' && bname[i - 1] == 'y') {
 bname[i - 3] = '0円';
 } else {
 LM_ERR("%s: script_name doesn't look like a python script\n",
 script_name.s);
 return -1;
 }
 dname = dirname(script_name.s);
 if (strlen(dname) == 0)
 dname = ".";

 if (PyImport_AppendInittab("OpenSIPS", &PyInit_OpenSIPS) < 0) {
 LM_ERR("could not append init tab for OpenSIPS!\n");
 return -1;
 }

 Py_Initialize();
#if PY_VERSION_HEX < 0x03070000
 PyEval_InitThreads();
#endif
 mainThreadState = PyThreadState_Get();

 if (python_msgobj_init() != 0) {
 LM_ERR("python_msgobj_init() has failed\n");
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 sys_path = PySys_GetObject("path");
 /* PySys_GetObject doesn't pass reference! No need to DEREF */
 if (sys_path == NULL) {
 PyErr_Print();
 LM_ERR("cannot import sys.path\n");
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 pDir = PyUnicode_FromString(dname);
 if (pDir == NULL) {
 PyErr_Print();
 LM_ERR("PyUnicode_FromString() has filed\n");
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }
 PyList_Insert(sys_path, 0, pDir);
 Py_DECREF(pDir);

 pModule = PyImport_ImportModule(bname);
 if (pModule == NULL) {
 PyErr_Print();
 LM_ERR("cannot import %s\n", bname);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 pFunc = PyObject_GetAttrString(pModule, mod_init_fname.s);
 Py_DECREF(pModule);
 /* pFunc is a new reference */
 if (pFunc == NULL || !PyCallable_Check(pFunc)) {
 PyErr_Print();
 LM_ERR("cannot locate %s function in %s module\n",
 mod_init_fname.s, script_name.s);
 Py_XDECREF(pFunc);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 pModule = PyImport_ImportModule("traceback");
 if (pModule == NULL) {
 PyErr_Print();
 LM_ERR("cannot import traceback module\n");
 Py_DECREF(pFunc);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 format_exc_obj = PyObject_GetAttrString(pModule, "format_exception");
 Py_DECREF(pModule);
 if (format_exc_obj == NULL || !PyCallable_Check(format_exc_obj)) {
 PyErr_Print();
 LM_ERR("cannot locate format_exception function in" \
 " traceback module\n");
 Py_XDECREF(format_exc_obj);
 Py_DECREF(pFunc);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 pArgs = PyTuple_New(0);
 if (pArgs == NULL) {
 PyErr_Print();
 LM_ERR("PyTuple_New() has failed\n");
 Py_DECREF(pFunc);
 Py_DECREF(format_exc_obj);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 handler_obj = PyObject_CallObject(pFunc, pArgs);
 Py_DECREF(pFunc);
 Py_DECREF(pArgs);

 if (PyErr_Occurred()) {
 PyErr_Print();
 python_handle_exception("mod_init", NULL);
 Py_XDECREF(handler_obj);
 Py_DECREF(format_exc_obj);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 if (handler_obj == NULL) {
 PyErr_Print();
 LM_ERR("%s function has not returned object\n",
 mod_init_fname.s);
 Py_DECREF(format_exc_obj);
 PyEval_ReleaseThread(mainThreadState);
 return -1;
 }

 myThreadState = PyThreadState_New(mainThreadState->interp);
 PyEval_ReleaseThread(mainThreadState);

 return 0;
}

static int
child_init(int rank)
{
 PyObject *pFunc, *pArgs, *pValue, *pResult;
 int rval;

 PyEval_AcquireThread(myThreadState);

 pFunc = PyObject_GetAttrString(handler_obj, child_init_mname.s);
 if (pFunc == NULL || !PyCallable_Check(pFunc)) {
 PyErr_Print();
 LM_ERR("cannot locate %s function\n", child_init_mname.s);
 if (pFunc != NULL) {
 Py_DECREF(pFunc);
 }
 PyEval_ReleaseThread(myThreadState);
 return -1;
 }

 pArgs = PyTuple_New(1);
 if (pArgs == NULL) {
 PyErr_Print();
 LM_ERR("PyTuple_New() has failed\n");
 Py_DECREF(pFunc);
 PyEval_ReleaseThread(myThreadState);
 return -1;
 }

 pValue = PyLong_FromLong(rank);
 if (pValue == NULL) {
 PyErr_Print();
 LM_ERR("PyLong_FromLong() has failed\n");
 Py_DECREF(pArgs);
 Py_DECREF(pFunc);
 PyEval_ReleaseThread(myThreadState);
 return -1;
 }
 PyTuple_SetItem(pArgs, 0, pValue);
 /* pValue has been stolen */

 pResult = PyObject_CallObject(pFunc, pArgs);
 Py_DECREF(pFunc);
 Py_DECREF(pArgs);

 if (PyErr_Occurred()) {
 char srank[16];
 snprintf(srank, sizeof(srank), "%d", rank);
 python_handle_exception("child_init", srank);
 Py_XDECREF(pResult);
 PyEval_ReleaseThread(myThreadState);
 return -1;
 }

 if (pResult == NULL) {
 PyErr_Print();
 LM_ERR("PyObject_CallObject() returned NULL but no exception!\n");
 PyEval_ReleaseThread(myThreadState);
 return -1;
 }

 rval = PyLong_AsLong(pResult);
 Py_DECREF(pResult);
 PyEval_ReleaseThread(myThreadState);
 return rval;
}

static void
mod_destroy(void)
{

 return;
}

#if PY_MAJOR_VERSION >= 3
PyMODINIT_FUNC PyInit_OpenSIPS(void)
{
 PyObject *m;
 static struct PyModuleDef moduledef = {
 PyModuleDef_HEAD_INIT,
 "OpenSIPS", /* m_name */
 NULL, /* m_doc */
 -1, /* m_size */
 OpenSIPSMethods, /* m_methods */
 NULL, /* m_reload */
 NULL, /* m_traverse */
 NULL, /* m_clear */
 NULL, /* m_free */
 };
 m = PyModule_Create(&moduledef);
 if (!m) {
 LM_ERR("could not create OpenSIPS module!\n");
 return NULL;
 }
 return m;
}
#else
void initOpenSIPS(void)
{
 Py_InitModule("OpenSIPS", OpenSIPSMethods);
}
#endif