/*
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * 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 "stdlib.h"
#include "../../core/dprint.h"
#include "../../core/error.h"
#include "../../core/mem/mem.h"
#include "../../core/usr_avp.h"
#include "../../core/atomic_ops.h" /* membar_write() */
#include "t_hooks.h"
#include "t_lookup.h"
#include "t_funcs.h"


struct tmcb_head_list* req_in_tmcb_hl = 0;
struct tmcb_head_list* local_req_in_tmcb_hl = 0;

struct tm_early_cb {
	unsigned int msgid;
	struct tmcb_head_list cb_list;
} tmcb_early_hl = { 0, {0, 0} };

struct tmcb_head_list* get_early_tmcb_list(struct sip_msg *msg)
{
	struct tm_callback *cbp, *cbp_tmp;
	if (msg->id!=tmcb_early_hl.msgid) {
		for( cbp=(struct tm_callback*)tmcb_early_hl.cb_list.first; cbp ; ) {
			cbp_tmp = cbp;
			cbp = cbp->next;
			if (cbp_tmp->param && cbp_tmp->release)
					cbp_tmp->release( cbp_tmp->param );
			shm_free( cbp_tmp );
		}
		memset(&tmcb_early_hl.cb_list, 0, sizeof(struct tmcb_head_list));
		tmcb_early_hl.msgid = msg->id;
	}
	return &tmcb_early_hl.cb_list;
}

void set_early_tmcb_list(struct sip_msg *msg, struct cell *t)
{
	if (msg->id==tmcb_early_hl.msgid) {
		t->tmcb_hl = tmcb_early_hl.cb_list;
		memset(&tmcb_early_hl.cb_list, 0, sizeof(struct tmcb_head_list));
		tmcb_early_hl.msgid = 0;
	}
}

int init_tmcb_lists()
{
	req_in_tmcb_hl = (struct tmcb_head_list*)shm_malloc
		( sizeof(struct tmcb_head_list) );
	local_req_in_tmcb_hl = (struct tmcb_head_list*)shm_malloc
		( sizeof(struct tmcb_head_list) );
	if ((req_in_tmcb_hl==0) || (local_req_in_tmcb_hl==0)) {
		LM_CRIT("no more shared mem\n");
		goto error;
	}
	req_in_tmcb_hl->first = 0;
	req_in_tmcb_hl->reg_types = 0;
	local_req_in_tmcb_hl->first = 0;
	local_req_in_tmcb_hl->reg_types = 0;
	return 1;
error:
	if (req_in_tmcb_hl){
		shm_free(req_in_tmcb_hl);
		req_in_tmcb_hl=0;
	}
	if(local_req_in_tmcb_hl){
		shm_free(local_req_in_tmcb_hl);
		local_req_in_tmcb_hl=0;
	}
	return -1;
}


void destroy_tmcb_lists()
{
	struct tm_callback *cbp, *cbp_tmp;

	if (req_in_tmcb_hl){
		for( cbp=(struct tm_callback*)req_in_tmcb_hl->first; cbp ; ) {
			cbp_tmp = cbp;
			cbp = cbp->next;
			if (cbp_tmp->param && cbp_tmp->release)
					cbp_tmp->release( cbp_tmp->param );
			shm_free( cbp_tmp );
		}
		shm_free(req_in_tmcb_hl);
		req_in_tmcb_hl=0;
	}
	if(local_req_in_tmcb_hl){
		for( cbp=(struct tm_callback*)local_req_in_tmcb_hl->first; cbp ; ) {
			cbp_tmp = cbp;
			cbp = cbp->next;
			if (cbp_tmp->param && cbp_tmp->release)
					cbp_tmp->release( cbp_tmp->param );
			shm_free( cbp_tmp );
		}
		shm_free(local_req_in_tmcb_hl);
		local_req_in_tmcb_hl=0;
	}
}



/* lockless insert: should be always safe */
int insert_tmcb(struct tmcb_head_list *cb_list, int types,
				transaction_cb f, void *param,
				release_tmcb_param rel_func)
{
	struct tm_callback *cbp;
	struct tm_callback *old;


	/* build a new callback structure */
	if (!(cbp=shm_malloc( sizeof( struct tm_callback)))) {
		LM_ERR("out of shm. mem\n");
		return E_OUT_OF_MEM;
	}

	atomic_or_int(&cb_list->reg_types, types);
	/* ... and fill it up */
	cbp->callback = f;
	cbp->param = param;
	cbp->release = rel_func;
	cbp->types = types;
	cbp->id=0;
	old=(struct tm_callback*)cb_list->first;
	/* link it into the proper place... */
	do{
		cbp->next = old;
		membar_write_atomic_op();
		old=(void*)atomic_cmpxchg_long((void*)&cb_list->first,
										(long)old, (long)cbp);
	}while(old!=cbp->next);

	return 1;
}



/* register a callback function 'f' for 'types' mask of events;
 * will be called back whenever one of the events occurs in transaction module
 * (global or per transaction, depending of event type)
 * It _must_ be always called either with the REPLY_LOCK held, or before the
 *  branches are created.
 *  Special cases: TMCB_REQUEST_IN & TMCB_LOCAL_REQUEST_IN - must be called
 *                 from mod_init (before forking!).
*/
int register_tmcb( struct sip_msg* p_msg, struct cell *t, int types,
				transaction_cb f, void *param,
				release_tmcb_param rel_func)
{
	//struct cell* t;
	struct tmcb_head_list *cb_list;

	/* are the callback types valid?... */
	if ( types<0 || types>TMCB_MAX ) {
		LM_CRIT("BUG: invalid callback types: mask=%d\n",
			types);
		return E_BUG;
	}
	/* we don't register null functions */
	if (f==0) {
		LM_CRIT("BUG: null callback function\n");
		return E_BUG;
	}

	if ((types!=TMCB_MAX) && (types&TMCB_REQUEST_IN)) {
		if (types!=TMCB_REQUEST_IN) {
			LM_CRIT("BUG: callback type TMCB_REQUEST_IN"
				" can't be register along with types\n");
			return E_BUG;
		}
		cb_list = req_in_tmcb_hl;
	}else if ((types!=TMCB_MAX) && (types & TMCB_LOCAL_REQUEST_IN)) {
		if (types!=TMCB_LOCAL_REQUEST_IN) {
			LM_CRIT("BUG: callback type"
					" TMCB_LOCAL_REQUEST_IN can't be register along with"
					" other types\n");
			return E_BUG;
		}
		cb_list = local_req_in_tmcb_hl;
	} else {
		if (!t) {
			if (!p_msg) {
				LM_CRIT("BUG: no sip_msg, nor transaction given\n");
				return E_BUG;
			}
			/* look for the transaction */
			t=get_t();
			if ( t!=0 && t!=T_UNDEFINED) {
				cb_list = &(t->tmcb_hl);
			} else {
				cb_list = get_early_tmcb_list(p_msg);
			}
		} else {
			cb_list = &(t->tmcb_hl);
		}
	}

	return insert_tmcb( cb_list, types, f, param, rel_func );
}


void run_trans_callbacks_internal(struct tmcb_head_list* cb_lst, int type,
									struct cell *trans,
									struct tmcb_params *params)
{
	struct tm_callback    *cbp;
	avp_list_t* backup_from, *backup_to, *backup_dom_from, *backup_dom_to, *backup_uri_from, *backup_uri_to;
	sr_xavp_t **backup_xavps;

	backup_uri_from = set_avp_list(AVP_CLASS_URI | AVP_TRACK_FROM,
			&trans->uri_avps_from );
	backup_uri_to = set_avp_list(AVP_CLASS_URI | AVP_TRACK_TO,
			&trans->uri_avps_to );
	backup_from = set_avp_list(AVP_CLASS_USER | AVP_TRACK_FROM,
			&trans->user_avps_from );
	backup_to = set_avp_list(AVP_CLASS_USER | AVP_TRACK_TO,
			&trans->user_avps_to );
	backup_dom_from = set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_FROM,
			&trans->domain_avps_from);
	backup_dom_to = set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_TO,
			&trans->domain_avps_to);
	backup_xavps = xavp_set_list(&trans->xavps_list);

	cbp=(struct tm_callback*)cb_lst->first;
	while(cbp){
		membar_depends(); /* make sure the cache has the correct cbp contents */
		if ( (cbp->types)&type ) {
			DBG("DBG: trans=%p, callback type %d, id %d entered\n",
				trans, type, cbp->id );
			params->param = &(cbp->param);
			cbp->callback( trans, type, params );
		}
		cbp=cbp->next;
	}
	set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_TO, backup_dom_to );
	set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_FROM, backup_dom_from );
	set_avp_list(AVP_CLASS_USER | AVP_TRACK_TO, backup_to );
	set_avp_list(AVP_CLASS_USER | AVP_TRACK_FROM, backup_from );
	set_avp_list(AVP_CLASS_URI | AVP_TRACK_TO, backup_uri_to );
	set_avp_list(AVP_CLASS_URI | AVP_TRACK_FROM, backup_uri_from );
	xavp_set_list(backup_xavps);
}



void run_trans_callbacks( int type , struct cell *trans,
						struct sip_msg *req, struct sip_msg *rpl, int code )
{
	struct tmcb_params params;
	if (trans->tmcb_hl.first==0 || ((trans->tmcb_hl.reg_types)&type)==0 )
		return;
	memset (&params, 0, sizeof(params));
	params.req = req;
	params.rpl = rpl;
	params.code = code;
	run_trans_callbacks_internal(&trans->tmcb_hl, type, trans, &params);
}



void run_trans_callbacks_with_buf(int type, struct retr_buf* rbuf,
		struct sip_msg* req, struct sip_msg* repl, short flags)
{
	struct tmcb_params params;
	struct cell * trans;

	trans=rbuf->my_T;
	if ( trans==0 || trans->tmcb_hl.first==0 ||
			((trans->tmcb_hl.reg_types)&type)==0 )
		return;
	INIT_TMCB_ONSEND_PARAMS(params, req, repl, rbuf, &rbuf->dst, rbuf->buffer,
					rbuf->buffer_len, flags, rbuf->branch, rbuf->rbtype);
	/* req, rpl */
	run_trans_callbacks_internal(&trans->tmcb_hl, type, trans, &params);
}


void run_trans_callbacks_off_params(int type, struct cell* trans,
		struct tmcb_params* p)
{

	if (p->t_rbuf==0) return;
	if ( trans==0 || trans->tmcb_hl.first==0 ||
			((trans->tmcb_hl.reg_types)&type)==0 )
		return;
	run_trans_callbacks_internal(&trans->tmcb_hl, type, p->t_rbuf->my_T, p);
}


static void run_reqin_callbacks_internal(struct tmcb_head_list* hl,
							struct cell *trans, struct tmcb_params* params)
{
	struct tm_callback    *cbp;
	avp_list_t* backup_from, *backup_to, *backup_dom_from, *backup_dom_to,
				*backup_uri_from, *backup_uri_to;
	sr_xavp_t **backup_xavps;

	if (hl==0 || hl->first==0) return;
	backup_uri_from = set_avp_list(AVP_CLASS_URI | AVP_TRACK_FROM,
			&trans->uri_avps_from );
	backup_uri_to = set_avp_list(AVP_CLASS_URI | AVP_TRACK_TO,
			&trans->uri_avps_to );
	backup_from = set_avp_list(AVP_CLASS_USER | AVP_TRACK_FROM,
			&trans->user_avps_from );
	backup_to = set_avp_list(AVP_CLASS_USER | AVP_TRACK_TO,
			&trans->user_avps_to );
	backup_dom_from = set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_FROM,
			&trans->domain_avps_from);
	backup_dom_to = set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_TO,
			&trans->domain_avps_to);
	backup_xavps = xavp_set_list(&trans->xavps_list);
	for (cbp=(struct tm_callback*)hl->first; cbp; cbp=cbp->next)  {
		LM_DBG("trans=%p, callback type %d, id %d entered\n",
			trans, cbp->types, cbp->id );
		params->param = &(cbp->param);
		cbp->callback( trans, cbp->types, params );
	}
	set_avp_list(AVP_CLASS_URI | AVP_TRACK_TO, backup_uri_to );
	set_avp_list(AVP_CLASS_URI | AVP_TRACK_FROM, backup_uri_from );
	set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_TO, backup_dom_to );
	set_avp_list(AVP_CLASS_DOMAIN | AVP_TRACK_FROM, backup_dom_from );
	set_avp_list(AVP_CLASS_USER | AVP_TRACK_TO, backup_to );
	set_avp_list(AVP_CLASS_USER | AVP_TRACK_FROM, backup_from );
	xavp_set_list(backup_xavps);
}



void run_reqin_callbacks( struct cell *trans, struct sip_msg *req, int code )
{
	static struct tmcb_params params;

	if (req_in_tmcb_hl->first==0)
		return;
	memset (&params, 0, sizeof(params));
	params.req = req;
	params.code = code;

	run_reqin_callbacks_internal(req_in_tmcb_hl, trans, &params);
}


void run_local_reqin_callbacks( struct cell *trans, struct sip_msg *req,
								int code )
{
	static struct tmcb_params params;

	if (local_req_in_tmcb_hl->first==0)
		return;
	memset (&params, 0, sizeof(params));
	params.req = req;
	params.code = code;

	run_reqin_callbacks_internal(local_req_in_tmcb_hl, trans, &params);
}
