/**
 * $Id$
 *
 * Copyright (C) 2010 Elena-Ramona Modroiu (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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#include "../../dprint.h"
#include "../../mem/mem.h"
#include "../../mem/shm_mem.h"
#include "../../parser/parse_param.h"
#include "../../ut.h"
#include "../../shm_init.h"

#include "mqueue_api.h"

/**
 *
 */
typedef struct _mq_item
{
	str key;
	str val;
	struct _mq_item *prev;
	struct _mq_item *next;
} mq_item_t;

/**
 *
 */
typedef struct _mq_head
{
	str name;
	int msize;
	int csize;
	gen_lock_t lock;
	mq_item_t *ifirst;
	mq_item_t *ilast;
	struct _mq_head *next;
} mq_head_t;

/**
 *
 */
typedef struct _mq_pv
{
	str *name;
	mq_item_t *item;
	struct _mq_pv *next;
} mq_pv_t;

/**
 *
 */
static mq_head_t *_mq_head_list = NULL;

/**
 *
 */
static mq_pv_t *_mq_pv_list = NULL;

/**
 *
 */
int mq_head_defined(void)
{
	if(_mq_head_list!=NULL)
		return 1;
	return 0;
}

/**
 *
 */
void mq_destroy(void)
{
	mq_head_t *mh = NULL;
	mq_pv_t *mp = NULL;
	mq_item_t *mi = NULL;
	mq_head_t *mh1 = NULL;
	mq_pv_t *mp1 = NULL;
	mq_item_t *mi1 = NULL;
	
	mh = _mq_head_list;
	while(mh!=NULL)
	{
		mi = mh->ifirst;
		while(mi!=NULL)
		{
			mi1 = mi;
			mi = mi->next;
			shm_free(mi1);
		}
		mh1 = mh;
		mh = mh->next;
		lock_destroy(&mh1->lock);
		shm_free(mh1);
	}
	_mq_head_list = 0;
	mp = _mq_pv_list;
	while(mp!=NULL)
	{
		mp1 = mp;
		mp = mp->next;
		pkg_free(mp1);
	}
}

/**
 *
 */
int mq_head_add(str *name, int msize)
{
	mq_head_t *mh = NULL;
	mq_pv_t *mp = NULL;
	int len;

	if(!shm_initialized())
	{
		LM_ERR("shm not intialized - cannot define mqueue now\n");
		return 0;
	}

	mh = _mq_head_list;
	while(mh!=NULL)
	{
		if(name->len == mh->name.len
				&& strncmp(mh->name.s, name->s, name->len)==0)
		{
			LM_ERR("mqueue redefined: %.*s\n", name->len, name->s);
			return -1;
		}
		mh = mh->next;
	}

	mp = (mq_pv_t*)pkg_malloc(sizeof(mq_pv_t));
	if(mp==NULL)
	{
		LM_ERR("no more pkg for: %.*s\n", name->len, name->s);
		return -1;
	}
	memset(mp, 0, sizeof(mq_pv_t));

	len = sizeof(mq_head_t) + name->len + 1;
	mh = (mq_head_t*)shm_malloc(len);
	if(mh==NULL)
	{
		LM_ERR("no more shm for: %.*s\n", name->len, name->s);
		pkg_free(mp);
		return -1;
	}
	memset(mh, 0, len);
	if (lock_init(&mh->lock)==0 )
	{
		LM_CRIT("failed to init lock\n");
		pkg_free(mp);
		shm_free(mh);
		return -1;
	}

	mh->name.s = (char*)mh + sizeof(mq_head_t);
	memcpy(mh->name.s, name->s, name->len);
	mh->name.len = name->len;
	mh->name.s[name->len] = '\0';
	mh->msize = msize;
	mh->next = _mq_head_list;
	_mq_head_list = mh;

	mp->name = &mh->name;
	mp->next = _mq_pv_list;
	_mq_pv_list = mp;

	return 0;
}

/**
 *
 */
mq_head_t *mq_head_get(str *name)
{
	mq_head_t *mh = NULL;

	mh = _mq_head_list;
	while(mh!=NULL)
	{
		if(name->len == mh->name.len
				&& strncmp(mh->name.s, name->s, name->len)==0)
		{
			return mh;
		}
		mh = mh->next;
	}
	return NULL;
}

/**
 *
 */
mq_pv_t *mq_pv_get(str *name)
{
	mq_pv_t *mp = NULL;

	mp = _mq_pv_list;
	while(mp!=NULL)
	{
		if(mp->name->len==name->len
				&& strncmp(mp->name->s, name->s, name->len)==0)
			return mp;
		mp = mp->next;
	}
	return NULL;
}

/**
 *
 */
int mq_head_fetch(str *name)
{
	mq_head_t *mh = NULL;
	mq_pv_t *mp = NULL;

	mp = mq_pv_get(name);
	if(mp==NULL)
		return -1;
	if(mp->item!=NULL)
	{
		shm_free(mp->item);
		mp->item = NULL;
	}
	mh = mq_head_get(name);
	if(mh==NULL)
		return -1;
	lock_get(&mh->lock);

	if(mh->ifirst==NULL)
	{
		/* empty queue */
		lock_release(&mh->lock);
		return -2;
	}

	mp->item = mh->ifirst;
	mh->ifirst = mh->ifirst->next;
	if(mh->ifirst==NULL) {
		mh->ilast = NULL;
	} else {
		mh->ifirst->prev = NULL;
	}
	mh->csize--;

	lock_release(&mh->lock);
	return 0;
}

/**
 *
 */
void mq_pv_free(str *name)
{
	mq_pv_t *mp = NULL;

	mp = mq_pv_get(name);
	if(mp==NULL)
		return;
	if(mp->item!=NULL)
	{
		shm_free(mp->item);
		mp->item = NULL;
	}
}

/**
 *
 */
int mq_item_add(str *qname, str *key, str *val)
{
	mq_head_t *mh = NULL;
	mq_item_t *mi = NULL;
	int len;

	mh = mq_head_get(qname);
	if(mh==NULL)
	{
		LM_ERR("mqueue not found: %.*s\n", qname->len, qname->s);
		return -1;
	}
	len = sizeof(mq_item_t) + key->len + val->len + 2;
	mi = (mq_item_t*)shm_malloc(len);
	if(mi==NULL)
	{
		LM_ERR("no more shm to add to: %.*s\n", qname->len, qname->s);
		return -1;
	}
	memset(mi, 0, len);
	mi->key.s = (char*)mi + sizeof(mq_item_t);
	memcpy(mi->key.s, key->s, key->len);
	mi->key.len = key->len;
	mi->key.s[key->len] = '\0';
	
	mi->val.s = mi->key.s + mi->key.len + 1;
	memcpy(mi->val.s, val->s, val->len);
	mi->val.len = val->len;
	mi->val.s[val->len] = '\0';
	
	lock_get(&mh->lock);
	if(mh->ifirst==NULL)
	{
		mh->ifirst = mi;
		mh->ilast = mi;
	} else {
		mh->ilast->next = mi;
		mi->prev = mh->ilast;
		mh->ilast = mi;
	}
	mh->csize++;
	if(mh->msize>0 && mh->csize>mh->msize)
	{
		mi = mh->ifirst;
		mh->ifirst = mh->ifirst->next;
		if(mh->ifirst==NULL)
			mh->ilast = NULL;
		else
			mh->ifirst->prev = NULL;
		mh->csize--;
		shm_free(mi);
	}
	lock_release(&mh->lock);
	return 0;
}

/**
 *
 */
int pv_parse_mqk_name(pv_spec_t *sp, str *in)
{
	mq_head_t *mh = NULL;
	mh = mq_head_get(in);
	if(mh==NULL)
	{
		LM_ERR("mqueue not found: %.*s\n", in->len, in->s);
		return -1;
	}
	sp->pvp.pvn.u.isname.name.s = *in;
	sp->pvp.pvn.type = PV_NAME_INTSTR;
	sp->pvp.pvn.u.isname.type = 1;
	return 0;
}

/**
 *
 */
int pv_get_mqk(struct sip_msg *msg, pv_param_t *param,
		pv_value_t *res)
{
	mq_pv_t *mp = NULL;
	mp = mq_pv_get(&param->pvn.u.isname.name.s);
	if(mp==NULL || mp->item==NULL || mp->item->key.len<=0)
		return pv_get_null(msg, param, res);
	return pv_get_strval(msg, param, res, &mp->item->key);
}

/**
 *
 */
int pv_parse_mqv_name(pv_spec_t *sp, str *in)
{
	mq_head_t *mh = NULL;
	mh = mq_head_get(in);
	if(mh==NULL)
	{
		LM_ERR("mqueue not found: %.*s\n", in->len, in->s);
		return -1;
	}
	sp->pvp.pvn.u.isname.name.s = *in;
	sp->pvp.pvn.type = PV_NAME_INTSTR;
	sp->pvp.pvn.u.isname.type = 1;
	return 0;
}

/**
 *
 */
int pv_get_mqv(struct sip_msg *msg, pv_param_t *param,
		pv_value_t *res)
{
	mq_pv_t *mp = NULL;
	mp = mq_pv_get(&param->pvn.u.isname.name.s);
	if(mp==NULL || mp->item==NULL || mp->item->val.len<=0)
		return pv_get_null(msg, param, res);
	return pv_get_strval(msg, param, res, &mp->item->val);
}