/*
linphone
Copyright (C) 2010  Simon MORLAT (simon.morlat@free.fr)

This program 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.

This program 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "sal.h"
#include "offeranswer.h"


static PayloadType * find_payload_type_best_match(const MSList *l, const PayloadType *refpt){
	PayloadType *pt;
	char value[10];
	const MSList *elem;
	PayloadType *candidate=NULL;

	for (elem=l;elem!=NULL;elem=elem->next){
		pt=(PayloadType*)elem->data;
		if (strcasecmp(pt->mime_type,refpt->mime_type)==0 && pt->clock_rate==refpt->clock_rate){
			candidate=pt;
			/*good candidate, check fmtp for H264 */
			if (strcasecmp(pt->mime_type,"H264")==0){
				if (pt->recv_fmtp!=NULL && refpt->recv_fmtp!=NULL){
					int mode1=0,mode2=0;
					if (fmtp_get_value(pt->recv_fmtp,"packetization-mode",value,sizeof(value))){
						mode1=atoi(value);
					}
					if (fmtp_get_value(refpt->recv_fmtp,"packetization-mode",value,sizeof(value))){
						mode2=atoi(value);
					}
					if (mode1==mode2)
					    break; /*exact match */
				}
			}else break;
		}
	}
	return candidate;
}

static MSList *match_payloads(const MSList *local, const MSList *remote){
	const MSList *e2;
	MSList *res=NULL;
	PayloadType *matched;
	for(e2=remote;e2!=NULL;e2=e2->next){
		PayloadType *p2=(PayloadType*)e2->data;
		matched=find_payload_type_best_match(local,p2);
		if (matched){
			matched=payload_type_clone(matched);
			if (p2->recv_fmtp)
				payload_type_set_send_fmtp(matched,p2->recv_fmtp);
			res=ms_list_append(res,matched);
			payload_type_set_number(matched,payload_type_get_number(p2));
		}else{
			ms_message("No match for %s/%i",p2->mime_type,p2->clock_rate);
		}
	}
	return res;
}

static bool_t only_telephone_event(const MSList *l){
	for(;l!=NULL;l=l->next){
		PayloadType *p=(PayloadType*)l->data;
		if (strcasecmp(p->mime_type,"telephone-event")!=0){
			return FALSE;
		}
	}
	return TRUE;
}

static void initiate_outgoing(const SalStreamDescription *local_offer,
    					const SalStreamDescription *remote_answer,
    					SalStreamDescription *result){
	result->payloads=match_payloads(local_offer->payloads,remote_answer->payloads);
	if (result->payloads && !only_telephone_event(result->payloads)){
		result->port=remote_answer->port;
		result->bandwidth=remote_answer->bandwidth;
		result->ptime=remote_answer->ptime;
	}else{
		result->port=0;
	}
}


static void initiate_incoming(const SalStreamDescription *local_cap,
    					const SalStreamDescription *remote_offer,
    					SalStreamDescription *result){
	result->payloads=match_payloads(local_cap->payloads,remote_offer->payloads);
	if (result->payloads && !only_telephone_event(result->payloads)){
		result->port=local_cap->port;
		result->bandwidth=local_cap->bandwidth;
		result->ptime=local_cap->ptime;
	}else{
		result->port=0;
	}
}

/**
 * Returns a media description to run the streams with, based on a local offer
 * and the returned response (remote).
**/
int offer_answer_initiate_outgoing(const SalMediaDescription *local_offer,
									const SalMediaDescription *remote_answer,
    							SalMediaDescription *result){
    int i;
    for(i=0;i<local_offer->nstreams;++i){
    	initiate_outgoing(&local_offer->streams[i],&remote_answer->streams[i],&result->streams[i]);
    }
	result->nstreams=local_offer->nstreams;
	strcpy(result->addr,remote_answer->addr);
	return 0;
}

/**
 * Returns a media description to run the streams with, based on the local capabilities and
 * and the received offer.
 * The returned media description is an answer and should be sent to the offerer.
**/
int offer_answer_initiate_incoming(const SalMediaDescription *local_capabilities,
						const SalMediaDescription *remote_offer,
    					SalMediaDescription *result){
    int i;
    for(i=0;i<local_capabilities->nstreams;++i){
    	initiate_incoming(&local_capabilities->streams[i],&remote_offer->streams[i],&result->streams[i]);
    }
	result->nstreams=local_capabilities->nstreams;
	strcpy(result->addr,local_capabilities->addr);
	return 0;
}