/*
 * utils Module
 *
 * Copyright (C) 2008 Juha Heinanen
 * Copyright (C) 2009 1&1 Internet AG
 * Copyright (C) 2013 Carsten Bock, ng-voice GmbH
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * 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
 *
 */

/*! \file
 * \brief Kamailio utils :: Module core
 * \ingroup utils
 */

/*! \defgroup utils Kamailio :: Various utilities
 * @{
 */


#include <curl/curl.h>

#include "../../core/mod_fix.h"
#include "../../core/sr_module.h"
#include "../../core/ut.h"
#include "../../core/forward.h"
#include "../../core/resolve.h"
#include "../../core/locking.h"
#include "../../core/script_cb.h"
#include "../../core/kemi.h"
#include "../../core/mem/shm_mem.h"
#include "../../lib/srdb1/db.h"

#include "conf.h"
#include "xcap_auth.h"


MODULE_VERSION

#define XCAP_TABLE_VERSION 4

/* Module parameter variables */
static int forward_active = 0;
static int mp_max_id = 0;
static char *mp_switch = "";
static char *mp_filter = "";
static char *mp_proxy = "";
str xcap_table = str_init("xcap");
str pres_db_url = {0, 0};

/* lock for configuration access */
static gen_lock_t *conf_lock = NULL;

/* Database connection */
db1_con_t *pres_dbh = NULL;
db_func_t pres_dbf;

/* Module management function prototypes */
static int mod_init(void);
static int child_init(int);
static void destroy(void);

/* forward function */
int utils_forward(struct sip_msg *msg, int id, int proto);

/* Exported functions */
static cmd_export_t cmds[] = {
		{"xcap_auth_status", (cmd_function)w_xcap_auth_status, 2,
				fixup_spve_spve, fixup_free_spve_spve, REQUEST_ROUTE},
		{0, 0, 0, 0, 0, 0}};


/* Exported parameters */
static param_export_t params[] = {{"pres_db_url", PARAM_STR, &pres_db_url},
		{"xcap_table", PARAM_STR, &xcap_table},
		{"forward_active", PARAM_INT, &forward_active}, {0, 0, 0}};

/* Module interface */
struct module_exports exports = {
		"utils",		 /* module name */
		DEFAULT_DLFLAGS, /* dlopen flags */
		cmds,			 /* exported functions */
		params,			 /* exported parameters */
		0,				 /* exported rpc functions */
		0,				 /* exported pseudo-variables */
		0,				 /* response handling function*/
		mod_init,		 /* module init function */
		child_init,		 /* per-child init function */
		destroy			 /* destroy function */
};


static int init_shmlock(void)
{
	conf_lock = lock_alloc();
	if(conf_lock == NULL) {
		LM_CRIT("cannot allocate memory for lock.\n");
		return -1;
	}
	if(lock_init(conf_lock) == 0) {
		LM_CRIT("cannot initialize lock.\n");
		return -1;
	}

	return 0;
}


static int pre_script_filter(
		struct sip_msg *msg, unsigned int flags, void *unused)
{
	/* use id 0 for pre script callback */
	utils_forward(msg, 0, PROTO_UDP);

	/* always return 1 so that routing skript is called for msg */
	return 1;
}


static void destroy_shmlock(void)
{
	if(conf_lock) {
		lock_destroy(conf_lock);
		lock_dealloc((void *)conf_lock);
		conf_lock = NULL;
	}
}


static void pres_db_close(void)
{
	if(pres_dbh) {
		pres_dbf.close(pres_dbh);
		pres_dbh = NULL;
	}
}

static int pres_db_init(void)
{
	if(!pres_db_url.s || !pres_db_url.len) {
		LM_INFO("xcap_auth_status function is disabled\n");
		return 0;
	}
	if(db_bind_mod(&pres_db_url, &pres_dbf) < 0) {
		LM_ERR("can't bind database module\n");
		return -1;
	}
	if((pres_dbh = pres_dbf.init(&pres_db_url)) == NULL) {
		LM_ERR("can't connect to database\n");
		return -1;
	}
	if(db_check_table_version(
			   &pres_dbf, pres_dbh, &xcap_table, XCAP_TABLE_VERSION)
			< 0) {
		DB_TABLE_VERSION_ERROR(xcap_table);
		pres_db_close();
		return -1;
	}
	pres_db_close();
	return 0;
}

static int pres_db_open(void)
{
	if(!pres_db_url.s || !pres_db_url.len) {
		return 0;
	}
	if(pres_dbh) {
		pres_dbf.close(pres_dbh);
	}
	if((pres_dbh = pres_dbf.init(&pres_db_url)) == NULL) {
		LM_ERR("can't connect to database\n");
		return -1;
	}
	if(pres_dbf.use_table(pres_dbh, &xcap_table) < 0) {
		LM_ERR("in use_table: %.*s\n", xcap_table.len, xcap_table.s);
		return -1;
	}
	return 0;
}


/* Module initialization function */
static int mod_init(void)
{
	if(init_shmlock() != 0) {
		LM_CRIT("cannot initialize shmlock.\n");
		return -1;
	}

	if(conf_init(mp_max_id) < 0) {
		LM_CRIT("cannot initialize configuration.\n");
		return -1;
	}

	/* read module parameters and update configuration structure */
	if(conf_parse_proxy(mp_proxy) < 0) {
		LM_CRIT("cannot parse proxy module parameter.\n");
		return -1;
	}
	if(conf_parse_filter(mp_filter) < 0) {
		LM_CRIT("cannot parse filter module parameter.\n");
		return -1;
	}
	if(conf_parse_switch(mp_switch) < 0) {
		LM_CRIT("cannot parse switch module parameter.\n");
		return -1;
	}

	if(forward_active == 1) {
		/* register callback for id 0 */
		if(register_script_cb(pre_script_filter, PRE_SCRIPT_CB | ONREPLY_CB, 0)
				< 0) {
			LM_CRIT("cannot register script callback for requests.\n");
			return -1;
		}
		if(register_script_cb(pre_script_filter, PRE_SCRIPT_CB | ONREPLY_CB, 0)
				< 0) {
			LM_CRIT("cannot register script callback for replies.\n");
			return -1;
		}
	} else {
		LM_INFO("forward functionality disabled");
	}

	/* presence database */
	LM_DBG("pres_db_url=%s/%d/%p\n", ZSW(pres_db_url.s), pres_db_url.len,
			pres_db_url.s);

	if(pres_db_init() < 0) {
		return -1;
	}

	return 0;
}


/* Child initialization function */
static int child_init(int rank)
{
	if(rank == PROC_INIT || rank == PROC_MAIN || rank == PROC_TCP_MAIN)
		return 0; /* do nothing for the main process */

	return pres_db_open();
}

static void destroy(void)
{
	/* Cleanup forward */
	conf_destroy();
	destroy_shmlock();
	/* Close pres db */
	pres_db_close();
}


/*!
 * \brief checks precondition, switch, filter and forwards msg if necessary
 * \param msg the message to be forwarded
 * \param id use configuration with this ID when checking switch, filter, proxy.
 * \param proto protocol to be used. Should be PROTO_UDP.
 *  \return 0 on success, -1 otherwise
 */
int utils_forward(struct sip_msg *msg, int id, int proto)
{
	int ret = -1;
	struct dest_info dst;

	init_dest_info(&dst);
	dst.proto = proto;

	// critical section start:
	// avoids dirty reads when updating configuration.
	lock_get(conf_lock);

	struct proxy_l *proxy = conf_needs_forward(msg, id);

	if(proxy != NULL) {
		proxy2su(&dst.to, proxy);
		if(forward_request(msg, NULL, 0, &dst) < 0) {
			LM_ERR("could not forward message\n");
		}
		ret = 0;
	}

	// critical section end
	lock_release(conf_lock);

	return ret;
}

/**
 *
 */
/* clang-format off */
static sr_kemi_t sr_kemi_utils_exports[] = {
	{ str_init("utils"), str_init("xcap_auth_status"),
		SR_KEMIP_INT, ki_xcap_auth_status,
		{ SR_KEMIP_STR, SR_KEMIP_STR, SR_KEMIP_NONE,
			SR_KEMIP_NONE, SR_KEMIP_NONE, SR_KEMIP_NONE }
	},

	{ {0, 0}, {0, 0}, 0, NULL, { 0, 0, 0, 0, 0, 0 } }
};
/* clang-format on */

/**
 *
 */
int mod_register(char *path, int *dlflags, void *p1, void *p2)
{
	sr_kemi_modules_add(sr_kemi_utils_exports);
	return 0;
}

/** @} */
