/*
 * Copyright (C) 2012 Smile Communications, jason.penton@smilecoms.com
 * Copyright (C) 2012 Smile Communications, richard.good@smilecoms.com
 *
 * The initial version of this code was written by Dragos Vingarzan
 * (dragos(dot)vingarzan(at)fokus(dot)fraunhofer(dot)de and the
 * Fraunhofer FOKUS Institute. It was and still is maintained in a separate
 * branch of the original SER. We are therefore migrating it to
 * Kamailio/SR and look forward to maintaining it from here on out.
 * 2011/2012 Smile Communications, Pty. Ltd.
 * ported/maintained/improved by
 * Jason Penton (jason(dot)penton(at)smilecoms.com and
 * Richard Good (richard(dot)good(at)smilecoms.com) as part of an
 * effort to add full IMS support to Kamailio/SR using a new and
 * improved architecture
 *
 * NB: A lot of this code was originally part of OpenIMSCore,
 * FhG Fokus.
 * Copyright (C) 2004-2006 FhG Fokus
 * Thanks for great work! This is an effort to
 * break apart the various CSCF functions into logically separate
 * components. We hope this will drive wider use. We also feel
 * that in this way the architecture is more complete and thereby easier
 * to manage in the Kamailio/SR environment
 *
 * 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
 *
 */

#include "transaction.h"

#include "timer.h"
#include "globals.h"
#include "cdp_stats.h"

extern struct cdp_counters_h cdp_cnts_h;
cdp_trans_list_t *trans_list = 0; /**< list of transactions */

/**
 * Initializes the transaction structure.
 * Also adds a timer callback for checking the transaction statuses
 * @returns 1 if success or 0 on error
 */
int cdp_trans_init()
{
	trans_list = shm_malloc(sizeof(cdp_trans_list_t));
	if(!trans_list) {
		LOG_NO_MEM("shm", sizeof(cdp_trans_list_t));
		return 0;
	}
	trans_list->head = 0;
	trans_list->tail = 0;
	trans_list->lock = lock_alloc();
	trans_list->lock = lock_init(trans_list->lock);

	add_timer(1, 0, cdp_trans_timer, 0);
	return 1;
}

int cdp_trans_destroy()
{
	cdp_trans_t *t = 0;
	if(trans_list) {
		lock_get(trans_list->lock);
		while(trans_list->head) {
			t = trans_list->head;
			trans_list->head = t->next;
			cdp_free_trans(t);
		}
		lock_destroy(trans_list->lock);
		lock_dealloc((void *)trans_list->lock);
		shm_free(trans_list);
		trans_list = 0;
	}

	return 1;
}
/**
 * Create and add a transaction to the transaction list.
 * @param msg - the message that this related to
 * @param cb - callback to be called on response or time-out
 * @param ptr - generic pointer to pass to the callback on call
 * @param timeout - timeout time in seconds
 * @param auto_drop - whether to auto drop the transaction on event, or let the application do it later
 * @returns the created cdp_trans_t* or NULL on error
 */
cdp_trans_t *cdp_add_trans(AAAMessage *msg, AAATransactionCallback_f *cb,
		void *ptr, int timeout, int auto_drop)
{
	cdp_trans_t *x;
	x = shm_malloc(sizeof(cdp_trans_t));
	if(!x) {
		LOG_NO_MEM("shm", sizeof(cdp_trans_t));
		return 0;
	}
	x->ptr = shm_malloc(sizeof(void *));
	if(!x->ptr) {
		LOG_NO_MEM("shm", sizeof(void *));
		shm_free(x);
		return 0;
	}

	gettimeofday(&x->started, NULL);
	x->endtoendid = msg->endtoendId;
	x->hopbyhopid = msg->hopbyhopId;
	x->cb = cb;
	*(x->ptr) = ptr;
	x->expires = timeout + time(0);
	x->auto_drop = auto_drop;
	x->next = 0;

	lock_get(trans_list->lock);
	x->prev = trans_list->tail;
	if(trans_list->tail)
		trans_list->tail->next = x;
	trans_list->tail = x;
	if(!trans_list->head)
		trans_list->head = x;
	lock_release(trans_list->lock);
	return x;
}

/**
 * Remove from the list and deallocate a transaction.
 * @param msg - the message that relates to that particular transaction
 */
void del_trans(AAAMessage *msg)
{
	cdp_trans_t *x;
	lock_get(trans_list->lock);
	x = trans_list->head;
	while(x && x->endtoendid != msg->endtoendId
			&& x->hopbyhopid != msg->hopbyhopId)
		x = x->next;
	if(x) {
		if(x->prev)
			x->prev->next = x->next;
		else
			trans_list->head = x->next;
		if(x->next)
			x->next->prev = x->prev;
		else
			trans_list->tail = x->prev;
		cdp_free_trans(x);
	}
	lock_release(trans_list->lock);
}

/**
 * Return and remove the transaction from the transaction list.
 * @param msg - the message that this transaction relates to
 * @returns the cdp_trans_t* if found or NULL if not
 */
cdp_trans_t *cdp_take_trans(AAAMessage *msg)
{
	cdp_trans_t *x;
	lock_get(trans_list->lock);
	x = trans_list->head;
	while(x && x->endtoendid != msg->endtoendId
			&& x->hopbyhopid != msg->hopbyhopId)
		x = x->next;
	if(x) {
		if(x->prev)
			x->prev->next = x->next;
		else
			trans_list->head = x->next;
		if(x->next)
			x->next->prev = x->prev;
		else
			trans_list->tail = x->prev;
	}
	lock_release(trans_list->lock);
	return x;
}

/**
 * Deallocate the memory taken by a transaction.
 * @param x - the transaction to deallocate
 */
void cdp_free_trans(cdp_trans_t *x)
{
	if(x->ptr)
		shm_free(x->ptr);
	shm_free(x);
}

/**
 * Timer callback for checking the transaction status.
 * @param now - time of call
 * @param ptr - generic pointer, passed to the transactional callbacks
 */
int cdp_trans_timer(time_t now, void *ptr)
{
	cdp_trans_t *x, *n;
	cdp_trans_list_t *cb_queue = 0;
	cb_queue = pkg_malloc(sizeof(cdp_trans_list_t));
	if(!cb_queue) {
		LOG_NO_MEM("pkg", sizeof(cdp_trans_list_t));
		return 0;
	}
	cb_queue->head = 0;
	cb_queue->tail = 0;

	lock_get(trans_list->lock);
	x = trans_list->head;
	while(x) {
		if(now > x->expires) {
			counter_inc(
					cdp_cnts_h
							.timeout); //Transaction has timed out waiting for response

			x->ans = 0;
			n = x->next;

			if(x->prev)
				x->prev->next = x->next;
			else
				trans_list->head = x->next;
			if(x->next)
				x->next->prev = x->prev;
			else
				trans_list->tail = x->prev;

			if(x->cb) {
				/* queue cb to be done after list unlock */
				x->next = 0;
				x->prev = cb_queue->tail;
				if(cb_queue->tail)
					cb_queue->tail->next = x;
				cb_queue->tail = x;
				if(!cb_queue->head)
					cb_queue->head = x;
			} else if(x->auto_drop) /* if no callback, auto drop here */
				cdp_free_trans(x);

			x = n;
		} else
			x = x->next;
	}
	lock_release(trans_list->lock);

	/* do all queued callbacks */
	x = cb_queue->head;
	while(x) {
		n = x->next;
		(x->cb)(1, *(x->ptr), 0, (now - x->expires));
		if(x->auto_drop)
			cdp_free_trans(x);
		x = n;
	}
	pkg_free(cb_queue);

	return 1;
}


/* TRANSACTIONS */

/**
 * Create an AAATransaction for the given request.
 * @param app_id - id of the request's application
 * @param cmd_code - request's code
 * @returns the AAATransaction*
 */
AAATransaction *AAACreateTransaction(
		AAAApplicationId app_id, AAACommandCode cmd_code)
{
	AAATransaction *t;
	t = shm_malloc(sizeof(AAATransaction));
	if(!t)
		return 0;
	memset(t, 0, sizeof(AAATransaction));
	t->application_id = app_id;
	t->command_code = cmd_code;
	return t;
}

/**
 * Free the memory allocated for the AAATransaction.
 * @param trans - the AAATransaction to be deallocated
 * @returns 1 on success, 0 on failure
 */
int AAADropTransaction(AAATransaction *trans)
{
	if(!trans)
		return 0;
	shm_free(trans);
	return 1;
}
