/* This file is part of the Project Athena Zephyr Notification System.
 * It contains source for the ZSubscribeTo, ZUnsubscribeTo, and
 * ZCancelSubscriptions functions.
 *
 *	Created by:	Robert French
 *
 *	$Id$
 *
 *	Copyright (c) 1987,1988 by the Massachusetts Institute of Technology.
 *	For copying and distribution information, see the file
 *	"mit-copyright.h". 
 */

#include <internal.h>

#ifndef lint
static const char rcsid_ZSubscriptions_c[] = "$Id$";
#endif

static Code_t Z_SendAndWaitForServer(ZNotice_t *notice, char *buf, int len,
				     int waitforack);

#ifdef CMU_ZCTL_PUNT
Code_t
ZPunt(ZSubscription_t *sublist,
      int nitems,
      unsigned int port)
{
    return (ZSubscriptions(sublist, nitems, port, "SUPPRESS",
			   Z_SendAndWaitForServer));
}
#endif

Code_t
ZSubscribeTo(ZSubscription_t *sublist,
	     int nitems,
	     unsigned int port)
{
    return (ZSubscriptions(sublist, nitems, port, CLIENT_SUBSCRIBE,
			   Z_SendAndWaitForServer));
}

Code_t
ZSubscribeToSansDefaults(ZSubscription_t *sublist,
			 int nitems,
			 unsigned int port)
{
    return (ZSubscriptions(sublist, nitems, port, CLIENT_SUBSCRIBE_NODEFS,
			   Z_SendAndWaitForServer));
}

Code_t
ZUnsubscribeTo(ZSubscription_t *sublist,
	       int nitems,
	       unsigned int port)
{
    return (ZSubscriptions(sublist, nitems, port, CLIENT_UNSUBSCRIBE,
			   Z_SendAndWaitForServer));
}

Code_t
ZCancelSubscriptions(unsigned int port)
{
    return (ZSubscriptions((ZSubscription_t *)0, 0, port, CLIENT_CANCELSUB,
			   Z_SendAndWaitForServer));
}

/*
 * This routine must do its own fragmentation.  Subscriptions must
 * not be broken across packet boundaries, or else the server will
 * mis-interpret them.
 */

Code_t
ZSubscriptions(register ZSubscription_t *sublist,
	       int nitems,
	       unsigned int port,
	       char *opcode,
	       Code_t (*send_routine)(ZNotice_t *, char *, int, int))
{
    register int i, j;
    int retval;
    ZNotice_t notice;
    char header[Z_MAXHEADERLEN];
    char **list;
    char *recip;
    int hdrlen;
    /* Space available for data, adjusted below. Take off Z_FRAGFUDGE twice.
       The first is to account for Z_SendFragmentedNotice's space. The second
       to account for hdrlen not being constant. Zcode escapes bytes 0x00 and
       0xFF, so some bytes are encoded as two bytes. */
    int size_avail = Z_MAXPKTLEN-Z_FRAGFUDGE-Z_FRAGFUDGE;
    int size, start, numok;
    Z_AuthProc cert_routine;

    /* nitems = 0 means cancel all subscriptions; still need to allocate a */
    /* array for one item so we can cancel, however. */
  
    list = (char **)malloc((unsigned)((nitems==0)?1:nitems)*3*sizeof(char *));
    if (!list)
        return (ENOMEM);

    (void) memset((char *)&notice, 0, sizeof(notice));
    notice.z_kind = ACKED;
    notice.z_port = port;
    notice.z_class = ZEPHYR_CTL_CLASS;
    notice.z_class_inst = ZEPHYR_CTL_CLIENT;
    notice.z_opcode = opcode;
    notice.z_sender = 0;
    notice.z_recipient = "";
    notice.z_default_format = "";
    notice.z_message_len = 0;

    /* format the header to figure out how long it is */
    retval = Z_FormatHeader(&notice, header, sizeof(header), &hdrlen, ZAUTH);
    if (retval != ZERR_NONE) {
	free((char *)list);
	return(retval);
    }

    /* if a subscription request, we save the key */
    if (strcmp(opcode, CLIENT_SUBSCRIBE) == 0 ||
	strcmp(opcode, CLIENT_SUBSCRIBE_NODEFS) == 0) {
	cert_routine = ZSUBAUTH;
    } else {
	cert_routine = ZAUTH;
    }

    /* compute amount of room left */
    size_avail -= hdrlen;
    size = size_avail;

    /* assemble subs into an array of pointers */
    for (i=0;i<nitems;i++) {
	list[i*3] = sublist[i].zsub_class;
	list[i*3+1] = sublist[i].zsub_classinst;
	recip = sublist[i].zsub_recipient;
	if (recip && *recip == '*')
	    recip++;
	if (!recip || (*recip != 0 && *recip != '@'))
	    recip = ZGetSender();
	list[i*3+2] = recip;
    }

    start = -1;
    i = 0;
    numok = 0;
    if (!nitems) {
	/* there aren't really any, but we need to xmit anyway */
	retval = ZSrvSendList(&notice, list, 0, cert_routine, send_routine);
	free((char *)list);
	return(retval);
    }
    while(i < nitems) {
	if (start == -1) {
	    size = size_avail;
	    start = i;
	    numok = 0;
	}
	if ((j = strlen(list[i*3])
	     + strlen(list[i*3+1])
	     + strlen(list[i*3+2]) + 3) <= size) {
	    /* it will fit in this packet */
	    size -= j;
	    numok++;
	    i++;
	    continue;
	}
	if (!numok) {			/* a single subscription won't
					   fit into one packet */
	    free((char *)list);
	    return(ZERR_FIELDLEN);
	}
	retval = ZSrvSendList(&notice, &list[start*3], numok * 3,
			      cert_routine, send_routine);
	if (retval) {
	    free((char *)list);
	    return(retval);
	}
	start = -1;
    }
    if (numok)
	retval = ZSrvSendList(&notice, &list[start*3], numok * 3,
			      cert_routine, send_routine);
    free((char *)list);
    return(retval);
}

static Code_t
Z_SendAndWaitForServer(ZNotice_t *notice,
		       char *buf, int len,
		       int waitforack)
{
    Code_t retval;
    ZNotice_t retnotice;

    retval = ZSendPacket(buf, len, waitforack);
    if (retval != ZERR_NONE)
	return (retval);
    /* Z_ReadWait drops non-initial SERVACKs and SERVNAKs on the floor. We
       should never see a non-initial one here, but be defensive about bugs in the
       sharding code above. */
    if (!ZCompareUID(&notice->z_multiuid, &notice->z_uid))
	return (retval);
    if ((retval = ZIfNotice(&retnotice, (struct sockaddr_in *)0, 
				ZCompareUIDPred, (char *)&notice->z_uid)) !=
	ZERR_NONE)
	return (retval);
    if (retnotice.z_kind == SERVNAK) {
	ZFreeNotice(&retnotice);
	return (ZERR_SERVNAK);
    }
    if (retnotice.z_kind != SERVACK) {
	ZFreeNotice(&retnotice);
	return (ZERR_INTERNAL);
    }
    ZFreeNotice(&retnotice);
    return (ZERR_NONE);
}

Code_t
ZFlushUserSubscriptions(char *recip)
{
    register Code_t retval;
    ZNotice_t notice, retnotice;

    (void)memset((char *)&notice, 0, sizeof(notice));
    notice.z_kind = ACKED;
    notice.z_class = ZEPHYR_CTL_CLASS;
    notice.z_class_inst = ZEPHYR_CTL_CLIENT;
    notice.z_opcode = CLIENT_FLUSHSUBS;
    notice.z_recipient = "";
    notice.z_default_format = "";
    if (recip) {
	notice.z_message = recip;
	notice.z_message_len = strlen(recip) + 1;
    } else {
	notice.z_message_len = 0;
    }

    if ((retval = ZSendNotice(&notice, ZAUTH)) != ZERR_NONE)
	return (retval);

    if ((retval = ZIfNotice(&retnotice, (struct sockaddr_in *)0,
			    ZCompareUIDPred, (char *)&notice.z_uid)) !=
	ZERR_NONE)
	return (retval);
    if (retnotice.z_kind == SERVNAK) {
	ZFreeNotice(&retnotice);
	return (ZERR_SERVNAK);
    }
    if (retnotice.z_kind != SERVACK) {
	ZFreeNotice(&retnotice);
	return (ZERR_INTERNAL);
    }
    ZFreeNotice(&retnotice);
    return (ZERR_NONE);
}