/*
 * Copyright (C) 2009 Sippy Software, Inc., http://www.sippysoft.com
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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 <libgen.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 "python_mod.h"

#include "mod_Router.h"
#include "mod_Core.h"
#include "mod_Ranks.h"
#include "mod_Logger.h"

MODULE_VERSION


static str script_name = str_init("/usr/local/etc/" NAME "/handler.py");
static str mod_init_fname = str_init("mod_init");
static str child_init_mname = str_init("child_init");

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

PyObject *handler_obj;

char *dname = NULL, *bname = NULL;

PyThreadState *myThreadState;

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

/*
 * Exported functions
 */
static cmd_export_t cmds[] = {
	{ "python_exec", (cmd_function)python_exec1, 1,  NULL, 0,	ANY_ROUTE },
	{ "python_exec", (cmd_function)python_exec2, 2,  NULL, 0,	ANY_ROUTE },
	{ 0, 0, 0, 0, 0, 0 }
};

/** module exports */
struct module_exports exports = {
	"app_python",                   /* module name */
	RTLD_NOW | RTLD_GLOBAL,         /* dlopen flags */
	cmds,                           /* exported functions */
	params,                         /* exported parameters */
	0,                              /* exported statistics */
	0,                              /* exported MI functions */
	0,                              /* exported pseudo-variables */
	0,                              /* extra processes */
	mod_init,                       /* module initialization function */
	(response_function) NULL,       /* response handling function */
	(destroy_function) mod_destroy, /* destroy function */
	child_init                      /* per-child init function */
};

static int mod_init(void)
{
	char *dname_src, *bname_src;

	int i;
	PyObject *sys_path, *pDir, *pModule, *pFunc, *pArgs;
	PyThreadState *mainThreadState;

	dname_src = as_asciiz(&script_name);
	bname_src = as_asciiz(&script_name);

	if(dname_src==NULL || bname_src==NULL)
	{
		LM_ERR("no more pkg memory\n");
		return -1;
	}

	dname = strdup(dirname(dname_src));
	if(dname==NULL) {
		LM_ERR("no more system memory\n");
		return -1;
	}
	if (strlen(dname) == 0) {
		free(dname);
		dname = malloc(2);
		if(dname==NULL) {
			LM_ERR("no more system memory\n");
			return -1;
		}
		dname[0] = '.';
		dname[1] = '\0';
	}
	bname = strdup(basename(bname_src));
	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';
	} else {
		LM_ERR("%s: script_name doesn't look like a python script\n",
				script_name.s);
		return -1;
	}

	Py_Initialize();
	PyEval_InitThreads();
	mainThreadState = PyThreadState_Get();

	format_exc_obj = InitTracebackModule();

	if (format_exc_obj == NULL || !PyCallable_Check(format_exc_obj))
	{
		Py_XDECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	sys_path = PySys_GetObject("path");
	/* PySys_GetObject doesn't pass reference! No need to DEREF */
	if (sys_path == NULL) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "'module' object 'sys' has no attribute 'path'");
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	pDir = PyString_FromString(dname);
	if (pDir == NULL) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "PyString_FromString() has failed");
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	PyList_Insert(sys_path, 0, pDir);
	Py_DECREF(pDir);

	if (ap_init_modules() != 0) {
		if (!PyErr_Occurred())
			PyErr_SetString(PyExc_AttributeError, "init_modules() has failed");
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	if (python_msgobj_init() != 0) {
		if (!PyErr_Occurred())
			PyErr_SetString(PyExc_AttributeError, "python_msgobj_init() has failed");
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	pModule = PyImport_ImportModule(bname);
	if (pModule == NULL) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_ImportError, "No module named '%s'", bname);
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	pkg_free(dname_src);
	pkg_free(bname_src);

	pFunc = PyObject_GetAttrString(pModule, mod_init_fname.s);
	Py_DECREF(pModule);

	/* pFunc is a new reference */

	if (pFunc == NULL) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "'module' object '%s' has no attribute '%s'",  bname, mod_init_fname.s);
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		Py_XDECREF(pFunc);
		PyEval_ReleaseLock();
		return -1;
	}

	if (!PyCallable_Check(pFunc)) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "module object '%s' has is not callable attribute '%s'", bname, mod_init_fname.s);
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		Py_XDECREF(pFunc);
		PyEval_ReleaseLock();
		return -1;
	}


	pArgs = PyTuple_New(0);
	if (pArgs == NULL) {
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		Py_DECREF(pFunc);
		PyEval_ReleaseLock();
		return -1;
	}

	handler_obj = PyObject_CallObject(pFunc, pArgs);

	Py_XDECREF(pFunc);
	Py_XDECREF(pArgs);

	if (handler_obj == Py_None) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_TypeError, "Function '%s' of module '%s' has returned None. Should be a class instance.", mod_init_fname.s, bname);
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	if (PyErr_Occurred()) {
		python_handle_exception("mod_init");
		Py_XDECREF(handler_obj);
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

	if (handler_obj == NULL) {
		LM_ERR("PyObject_CallObject() returned NULL but no exception!\n");
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_TypeError, "Function '%s' of module '%s' has returned not returned object. Should be a class instance.", mod_init_fname.s, bname);
		python_handle_exception("mod_init");
		Py_DECREF(format_exc_obj);
		PyEval_ReleaseLock();
		return -1;
	}

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

	return 0;
}

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

	PyEval_AcquireLock();
	PyThreadState_Swap(myThreadState);

	// get instance class name
	classname = get_instance_class_name(handler_obj);
	if (classname == NULL)
	{
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "'module' instance has no class name");
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}

	pFunc = PyObject_GetAttrString(handler_obj, child_init_mname.s);

	if (pFunc == NULL) {
		python_handle_exception("child_init");
		Py_XDECREF(pFunc);
		Py_DECREF(format_exc_obj);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}

	if (!PyCallable_Check(pFunc)) {
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_AttributeError, "class object '%s' has is not callable attribute '%s'", !classname ? "None" : classname, mod_init_fname.s);
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		Py_XDECREF(pFunc);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}

	pArgs = PyTuple_New(1);
	if (pArgs == NULL) {
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		Py_DECREF(pFunc);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}

	pValue = PyInt_FromLong((long)rank);
	if (pValue == NULL) {
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		Py_DECREF(pArgs);
		Py_DECREF(pFunc);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		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()) {
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		Py_XDECREF(pResult);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}

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

	if (!PyInt_Check(pResult))
	{
		if (!PyErr_Occurred())
			PyErr_Format(PyExc_TypeError, "method '%s' of class '%s' should return 'int' type", child_init_mname.s, !classname ? "None" : classname);
		python_handle_exception("child_init");
		Py_DECREF(format_exc_obj);
		Py_XDECREF(pResult);
		PyThreadState_Swap(NULL);
		PyEval_ReleaseLock();
		return -1;
	}


	rval = PyInt_AsLong(pResult);
	Py_DECREF(pResult);
	PyThreadState_Swap(NULL);
	PyEval_ReleaseLock();

	return rval;
}

static void mod_destroy(void)
{
	if (dname)
		free(dname);	// dname was strdup'ed
	if (bname)
		free(bname);	// bname was strdup'ed

	destroy_mod_Core();
	destroy_mod_Ranks();
	destroy_mod_Logger();
	destroy_mod_Router();
}