/**
 * Copyright (C) 2013 Daniel-Constantin Mierla (asipto.com)
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * This file 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 file 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 "../../core/mem/shm_mem.h"
#include "../../core/mem/mem.h"
#include "../../core/dprint.h"
#include "../../core/hashes.h"
#include "../../core/ut.h"

#include "../../core/utils/sruid.h"
#include "../../core/rpc.h"
#include "../../core/rpc_lookup.h"
#include "../../core/sr_module.h"

#include "msrp_netio.h"
#include "msrp_env.h"
#include "msrp_cmap.h"

static msrp_cmap_t *_msrp_cmap_head = NULL;

static sruid_t _msrp_sruid;

extern int msrp_auth_min_expires;
extern int msrp_auth_max_expires;
extern int msrp_tls_module_loaded;
extern str msrp_use_path_addr;

/**
 *
 */
int msrp_sruid_init(void)
{
	return sruid_init(&_msrp_sruid, '-', "msrp", SRUID_INC);
}

/**
 *
 */
int msrp_citem_free(msrp_citem_t *it)
{
	if(it == NULL)
		return -1;
	shm_free(it);
	return 0;
}

/**
 *
 */
int msrp_cmap_init(int msize)
{
	int i;

	_msrp_cmap_head = (msrp_cmap_t *)shm_malloc(sizeof(msrp_cmap_t));
	if(_msrp_cmap_head == NULL) {
		SHM_MEM_ERROR;
		return -1;
	}
	memset(_msrp_cmap_head, 0, sizeof(msrp_cmap_t));
	_msrp_cmap_head->mapsize = msize;

	_msrp_cmap_head->cslots = (msrp_centry_t *)shm_malloc(
			_msrp_cmap_head->mapsize * sizeof(msrp_centry_t));
	if(_msrp_cmap_head->cslots == NULL) {
		SHM_MEM_ERROR;
		shm_free(_msrp_cmap_head);
		_msrp_cmap_head = NULL;
		return -1;
	}
	memset(_msrp_cmap_head->cslots, 0,
			_msrp_cmap_head->mapsize * sizeof(msrp_centry_t));

	for(i = 0; i < _msrp_cmap_head->mapsize; i++) {
		if(lock_init(&_msrp_cmap_head->cslots[i].lock) == 0) {
			LM_ERR("cannot initialize lock[%d]\n", i);
			i--;
			while(i >= 0) {
				lock_destroy(&_msrp_cmap_head->cslots[i].lock);
				i--;
			}
			shm_free(_msrp_cmap_head->cslots);
			shm_free(_msrp_cmap_head);
			_msrp_cmap_head = NULL;
			return -1;
		}
	}

	return 0;
}

/**
 *
 */
int msrp_cmap_destroy(void)
{
	int i;
	msrp_citem_t *ita, *itb;

	if(_msrp_cmap_head == NULL)
		return -1;

	for(i = 0; i < _msrp_cmap_head->mapsize; i++) {
		/* free entries */
		ita = _msrp_cmap_head->cslots[i].first;
		while(ita) {
			itb = ita;
			ita = ita->next;
			msrp_citem_free(itb);
		}
		/* free locks */
		lock_destroy(&_msrp_cmap_head->cslots[i].lock);
	}
	shm_free(_msrp_cmap_head->cslots);
	shm_free(_msrp_cmap_head);
	_msrp_cmap_head = NULL;
	return 0;
}

#define msrp_get_hashid(_s) core_case_hash(_s, 0, 0)
#define msrp_get_slot(_h, _size) (_h) & ((_size)-1)


static str msrp_reply_200_code = {"200", 3};
static str msrp_reply_200_text = {"OK", 2};
static str msrp_reply_423_code = {"423", 3};
static str msrp_reply_423_text = {"Interval Out Of Bounds", 22};

/**
 *
 */
int msrp_cmap_save(msrp_frame_t *mf)
{
	unsigned int idx;
	unsigned int hid;
	str fpeer;
#define MSRP_SBUF_SIZE 256
	char sbuf[MSRP_SBUF_SIZE];
	str srcaddr;
	str srcsock;
	int msize;
	int expires;
	msrp_citem_t *it;
	msrp_citem_t *itb;

	if(_msrp_cmap_head == NULL || mf == NULL)
		return -1;
	if(mf->fline.rtypeid != MSRP_REQ_AUTH) {
		LM_DBG("save can be used only for AUTH\n");
		return -2;
	}

	if(msrp_frame_get_expires(mf, &expires) < 0)
		expires = msrp_auth_max_expires;
	if(expires < msrp_auth_min_expires) {
		LM_DBG("expires is lower than min value\n");
		srcaddr.len = snprintf(sbuf, MSRP_SBUF_SIZE, "Min-Expires: %d\r\n",
				msrp_auth_min_expires);
		msrp_reply(mf, &msrp_reply_423_code, &msrp_reply_423_text, &srcaddr);
		return -3;
	}
	if(expires > msrp_auth_max_expires) {
		LM_DBG("expires is greater than max value\n");
		srcaddr.len = snprintf(sbuf, MSRP_SBUF_SIZE, "Max-Expires: %d\r\n",
				msrp_auth_max_expires);
		msrp_reply(mf, &msrp_reply_423_code, &msrp_reply_423_text, &srcaddr);
		return -4;
	}
	if(msrp_frame_get_first_from_path(mf, &fpeer) < 0) {
		LM_ERR("cannot get first path uri\n");
		return -1;
	}

	if(sruid_next(&_msrp_sruid) < 0) {
		LM_ERR("cannot get next msrp uid\n");
		return -1;
	}
	hid = msrp_get_hashid(&_msrp_sruid.uid);
	idx = msrp_get_slot(hid, _msrp_cmap_head->mapsize);

	srcaddr.len = snprintf(sbuf, MSRP_SBUF_SIZE, "msrp%s://%s:%d",
			(msrp_tls_module_loaded) ? "s" : "",
			ip_addr2a(&mf->tcpinfo->rcv->src_ip),
			(int)mf->tcpinfo->rcv->src_port);
	if(srcaddr.len < 0 || srcaddr.len >= MSRP_SBUF_SIZE) {
		LM_ERR("failure or address length too big (%d)\n", srcaddr.len);
		return -1;
	}
	srcaddr.s = sbuf;

	srcsock = mf->tcpinfo->rcv->bind_address->sock_str;
	LM_DBG("saving connection info for [%.*s] [%.*s] (%u/%u)\n", fpeer.len,
			fpeer.s, _msrp_sruid.uid.len, _msrp_sruid.uid.s, idx, hid);
	LM_DBG("frame received from [%.*s] via [%.*s]\n", srcaddr.len, srcaddr.s,
			srcsock.len, srcsock.s);

	msize = sizeof(msrp_citem_t)
			+ (_msrp_sruid.uid.len + fpeer.len + srcaddr.len + srcsock.len + 4)
					  * sizeof(char);

	/* build the item */
	it = (msrp_citem_t *)shm_malloc(msize);
	if(it == NULL) {
		SHM_MEM_ERROR;
		return -1;
	}
	memset(it, 0, msize);
	it->citemid = hid;

	it->sessionid.s = (char *)it + +sizeof(msrp_citem_t);
	it->sessionid.len = _msrp_sruid.uid.len;
	memcpy(it->sessionid.s, _msrp_sruid.uid.s, _msrp_sruid.uid.len);
	it->sessionid.s[it->sessionid.len] = '\0';

	it->peer.s = it->sessionid.s + it->sessionid.len + 1;
	it->peer.len = fpeer.len;
	memcpy(it->peer.s, fpeer.s, fpeer.len);
	it->peer.s[it->peer.len] = '\0';

	it->addr.s = it->peer.s + it->peer.len + 1;
	it->addr.len = srcaddr.len;
	memcpy(it->addr.s, srcaddr.s, srcaddr.len);
	it->addr.s[it->addr.len] = '\0';

	it->sock.s = it->addr.s + it->addr.len + 1;
	it->sock.len = srcsock.len;
	memcpy(it->sock.s, srcsock.s, srcsock.len);
	it->sock.s[it->sock.len] = '\0';

	it->expires = time(NULL) + expires;
	it->conid = mf->tcpinfo->con->id;

	/* insert item in cmap */
	lock_get(&_msrp_cmap_head->cslots[idx].lock);
	if(_msrp_cmap_head->cslots[idx].first == NULL) {
		_msrp_cmap_head->cslots[idx].first = it;
	} else {
		for(itb = _msrp_cmap_head->cslots[idx].first; itb; itb = itb->next) {
			if(itb->citemid > it->citemid) {
				/* insert before current item */
				it->next = itb;
				if(itb->prev == NULL) {
					_msrp_cmap_head->cslots[idx].first = it;
				} else {
					itb->prev->next = it;
				}
				it->prev = itb->prev;
				itb->prev = it;
				break;
			} else if(itb->next == NULL) {
				/* insert after last item */
				itb->next = it;
				it->prev = itb;
				break;
			}
		}
	}
	_msrp_cmap_head->cslots[idx].lsize++;
	lock_release(&_msrp_cmap_head->cslots[idx].lock);

	if(mf->tcpinfo->rcv->proto == PROTO_TLS
			|| mf->tcpinfo->rcv->proto == PROTO_WSS) {
		srcaddr.len = snprintf(sbuf, MSRP_SBUF_SIZE,
				"Use-Path: msrps://%.*s/%.*s;tcp\r\nExpires: %d\r\n",
				(msrp_use_path_addr.s) ? msrp_use_path_addr.len
									   : (srcsock.len - 4),
				(msrp_use_path_addr.s) ? msrp_use_path_addr.s : (srcsock.s + 4),
				_msrp_sruid.uid.len, _msrp_sruid.uid.s, expires);
	} else {
		srcaddr.len = snprintf(sbuf, MSRP_SBUF_SIZE,
				"Use-Path: msrp://%.*s/%.*s;tcp\r\nExpires: %d\r\n",
				(msrp_use_path_addr.s) ? msrp_use_path_addr.len
									   : (srcsock.len - 4),
				(msrp_use_path_addr.s) ? msrp_use_path_addr.s : (srcsock.s + 4),
				_msrp_sruid.uid.len, _msrp_sruid.uid.s, expires);
	}
	srcaddr.s = sbuf;

	if(msrp_reply(mf, &msrp_reply_200_code, &msrp_reply_200_text, &srcaddr) < 0)
		return -5;
	return 0;
}

/**
 *
 */
int msrp_cmap_lookup(msrp_frame_t *mf)
{
	unsigned int idx;
	unsigned int hid;
	str sesid;
	msrp_citem_t *itb;
	int ret;

	if(_msrp_cmap_head == NULL || mf == NULL)
		return -1;
	if(mf->fline.rtypeid == MSRP_REQ_AUTH) {
		LM_DBG("save cannot be used for AUTH\n");
		return -2;
	}
	if(msrp_frame_get_sessionid(mf, &sesid) < 0) {
		LM_ERR("cannot get session id\n");
		return -3;
	}

	LM_DBG("searching for session [%.*s]\n", sesid.len, sesid.s);

	hid = msrp_get_hashid(&sesid);
	idx = msrp_get_slot(hid, _msrp_cmap_head->mapsize);

	ret = 0;
	lock_get(&_msrp_cmap_head->cslots[idx].lock);
	for(itb = _msrp_cmap_head->cslots[idx].first; itb; itb = itb->next) {
		if(itb->citemid > hid) {
			break;
		} else {
			if(itb->sessionid.len == sesid.len
					&& memcmp(itb->sessionid.s, sesid.s, sesid.len) == 0) {
				LM_DBG("found session [%.*s]\n", sesid.len, sesid.s);
				ret = msrp_env_set_dstinfo(mf, &itb->addr, &itb->sock, 0);
				break;
			}
		}
	}
	lock_release(&_msrp_cmap_head->cslots[idx].lock);
	if(itb == NULL)
		return -4;
	return (ret < 0) ? -5 : 0;
}

/**
 *
 */
int msrp_cmap_clean(void)
{
	time_t tnow;
	msrp_citem_t *ita;
	msrp_citem_t *itb;
	int i;

	if(_msrp_cmap_head == NULL)
		return -1;
	tnow = time(NULL);
	for(i = 0; i < _msrp_cmap_head->mapsize; i++) {
		lock_get(&_msrp_cmap_head->cslots[i].lock);
		ita = _msrp_cmap_head->cslots[i].first;
		while(ita) {
			itb = ita;
			ita = ita->next;
			if(itb->expires < tnow) {
				if(itb->prev == NULL) {
					_msrp_cmap_head->cslots[i].first = itb->next;
				} else {
					itb->prev->next = ita;
				}
				if(ita != NULL)
					ita->prev = itb->prev;
				msrp_citem_free(itb);
				_msrp_cmap_head->cslots[i].lsize--;
			}
		}
		lock_release(&_msrp_cmap_head->cslots[i].lock);
	}

	return 0;
}

static const char *msrp_cmap_rpc_list_doc[2] = {
		"Return the content of dispatcher sets", 0};


/*
 * RPC command to print connections map table
 */
static void msrp_cmap_rpc_list(rpc_t *rpc, void *ctx)
{
	void *th;
	void *ih;
	void *vh;
	msrp_citem_t *it;
	int i;
	int n;
	char t_buf[26] = {0};
	str edate;

	if(_msrp_cmap_head == NULL) {
		LM_ERR("no connections map table\n");
		rpc->fault(ctx, 500, "No Connections Map Table");
		return;
	}

	/* add entry node */
	if(rpc->add(ctx, "{", &th) < 0) {
		rpc->fault(ctx, 500, "Internal error root reply");
		return;
	}

	if(rpc->struct_add(
			   th, "d{", "MAP_SIZE", _msrp_cmap_head->mapsize, "CONLIST", &ih)
			< 0) {
		rpc->fault(ctx, 500, "Internal error set structure");
		return;
	}
	n = 0;
	for(i = 0; i < _msrp_cmap_head->mapsize; i++) {
		lock_get(&_msrp_cmap_head->cslots[i].lock);
		for(it = _msrp_cmap_head->cslots[i].first; it; it = it->next) {
			if(rpc->struct_add(ih, "{", "CONDATA", &vh) < 0) {
				rpc->fault(ctx, 500, "Internal error creating connection");
				lock_release(&_msrp_cmap_head->cslots[i].lock);
				return;
			}
			ctime_r(&it->expires, t_buf);
			edate.s = t_buf;
			edate.len = 24;
			if(rpc->struct_add(vh, "dSSSSSdd", "CITEMID", it->citemid,
					   "SESSIONID", &it->sessionid, "PEER", &it->peer, "ADDR",
					   &it->addr, "SOCK", &it->sock, "EXPIRES", &edate, "CONID",
					   it->conid, "FLAGS", it->cflags)
					< 0) {
				rpc->fault(ctx, 500, "Internal error creating dest struct");
				lock_release(&_msrp_cmap_head->cslots[i].lock);
				return;
			}
			n++;
		}
		lock_release(&_msrp_cmap_head->cslots[i].lock);
	}
	if(rpc->struct_add(th, "d", "CONCOUNT", n) < 0) {
		rpc->fault(ctx, 500, "Internal error connection counter");
		return;
	}
	return;
}

rpc_export_t msrp_cmap_rpc_cmds[] = {
		{"msrp.cmaplist", msrp_cmap_rpc_list, msrp_cmap_rpc_list_doc, 0},
		{0, 0, 0, 0}};

/**
 *
 */
int msrp_cmap_init_rpc(void)
{
	if(rpc_register_array(msrp_cmap_rpc_cmds) != 0) {
		LM_ERR("failed to register RPC commands\n");
		return -1;
	}

	return 0;
}
