/*
 * txqueue.c
 *
 * Herein lies all the mangement routines for the transmit (Tx) queue.
 *
 */

#define FAIM_INTERNAL
#include <aim.h>

#ifndef _WIN32
#include <sys/socket.h>
#else
#include "win32dep.h"
#endif

/*
 * Allocate a new tx frame.
 *
 * This is more for looks than anything else.
 *
 * Right now, that is.  If/when we implement a pool of transmit
 * frames, this will become the request-an-unused-frame part.
 *
 * framing = AIM_FRAMETYPE_OFT/FLAP
 * chan = channel for FLAP, hdrtype for OFT
 *
 */
faim_internal aim_frame_t *aim_tx_new(aim_session_t *sess, aim_conn_t *conn, fu8_t framing, fu16_t chan, int datalen)
{
  aim_frame_t *fr;
  
  if (!conn) {
    faimdprintf(sess, 0, "aim_tx_new: ERROR: no connection specified\n");
    return NULL;
  }
  
  /* For sanity... */
  if ((conn->type == AIM_CONN_TYPE_RENDEZVOUS) || (conn->type == AIM_CONN_TYPE_LISTENER)) {
    if (framing != AIM_FRAMETYPE_OFT) {
      faimdprintf(sess, 0, "aim_tx_new: attempted to allocate inappropriate frame type for rendezvous connection\n");
      return NULL;
    }
  } else {
    if (framing != AIM_FRAMETYPE_FLAP) {
      faimdprintf(sess, 0, "aim_tx_new: attempted to allocate inappropriate frame type for FLAP connection\n");
      return NULL;
    }
  }
  
  if (!(fr = (aim_frame_t *)malloc(sizeof(aim_frame_t)))) return NULL;
  memset(fr, 0, sizeof(aim_frame_t));
  
  fr->conn = conn; 
  fr->hdrtype = framing;
  if (fr->hdrtype == AIM_FRAMETYPE_FLAP) {
    fr->hdr.flap.type = chan;
  } else if (fr->hdrtype == AIM_FRAMETYPE_OFT) {
    fr->hdr.rend.type = chan;
  } else {
    faimdprintf(sess, 0, "tx_new: unknown framing\n");
  }
  
  if (datalen > 0) {
    fu8_t *data;
    if (!(data = (unsigned char *)malloc(datalen))) {
      aim_frame_destroy(fr);
      return NULL;
    }
    aim_bstream_init(&fr->data, data, datalen);
  }
  
  return fr;
}

/*
 * aim_tx_enqeue__queuebased()
 *
 * The overall purpose here is to enqueue the passed in command struct
 * into the outgoing (tx) queue.  Basically...
 *   1) Make a scope-irrelevent copy of the struct
 *   3) Mark as not-sent-yet
 *   4) Enqueue the struct into the list
 *   6) Return
 *
 * Note that this is only used when doing queue-based transmitting;
 * that is, when sess->tx_enqueue is set to &aim_tx_enqueue__queuebased.
 *
 */
static int aim_tx_enqueue__queuebased(aim_session_t *sess, aim_frame_t *fr)
{
  
  if (!fr->conn) {
    faimdprintf(sess, 1, "aim_tx_enqueue: WARNING: enqueueing packet with no connecetion\n");
    fr->conn = aim_getconn_type(sess, AIM_CONN_TYPE_BOS);
  }
  
  if (fr->hdrtype == AIM_FRAMETYPE_FLAP) {
    /* assign seqnum -- XXX should really not assign until hardxmit */
    fr->hdr.flap.seqnum = aim_get_next_txseqnum(fr->conn);
  }
  
  fr->handled = 0; /* not sent yet */
  
  /* see overhead note in aim_rxqueue counterpart */
  if (!sess->queue_outgoing)
    sess->queue_outgoing = fr;
  else {
    aim_frame_t *cur;
    
    for (cur = sess->queue_outgoing; cur->next; cur = cur->next)
      ;
    cur->next = fr;
  }
  
  return 0;
}

/*
 * aim_tx_enqueue__immediate()
 *
 * Parallel to aim_tx_enqueue__queuebased, however, this bypasses
 * the whole queue mess when you want immediate writes to happen.
 *
 * Basically the same as its __queuebased couterpart, however
 * instead of doing a list append, it just calls aim_tx_sendframe()
 * right here. 
 * 
 */
static int aim_tx_enqueue__immediate(aim_session_t *sess, aim_frame_t *fr)
{

  if (!fr->conn) {
    faimdprintf(sess, 1, "aim_tx_enqueue: ERROR: packet has no connection\n");
    aim_frame_destroy(fr);
    return 0;
  }
  
  if (fr->hdrtype == AIM_FRAMETYPE_FLAP) fr->hdr.flap.seqnum = aim_get_next_txseqnum(fr->conn);
  fr->handled = 0; /* not sent yet */
  aim_tx_sendframe(sess, fr);
  aim_frame_destroy(fr);
  
  return 0;
}

faim_export int aim_tx_setenqueue(aim_session_t *sess, int what, int (*func)(aim_session_t *, aim_frame_t *))
{
  if (what == AIM_TX_QUEUED) {
    sess->tx_enqueue = &aim_tx_enqueue__queuebased;
  } else if (what == AIM_TX_IMMEDIATE) {
    sess->tx_enqueue = &aim_tx_enqueue__immediate;
  } else if (what == AIM_TX_USER) {
    if (!func) return -EINVAL;
    sess->tx_enqueue = func;
  } else {
    return -EINVAL; /* unknown action */
  }
  
  return 0;
}

faim_internal int aim_tx_enqueue(aim_session_t *sess, aim_frame_t *fr)
{
  
  /*
   * If we want to send a connection thats inprogress, we have to force
   * them to use the queue based version. Otherwise, use whatever they
   * want.
   */
  if (fr && fr->conn && 
      (fr->conn->status & AIM_CONN_STATUS_INPROGRESS)) {
    return aim_tx_enqueue__queuebased(sess, fr);
  }
  
  return (*sess->tx_enqueue)(sess, fr);
}

/* 
 *  aim_get_next_txseqnum()
 *
 *   This increments the tx command count, and returns the seqnum
 *   that should be stamped on the next FLAP packet sent.  This is
 *   normally called during the final step of packet preparation
 *   before enqueuement (in aim_tx_enqueue()).
 *
 */
faim_internal flap_seqnum_t aim_get_next_txseqnum(aim_conn_t *conn)
{
  flap_seqnum_t ret;
  ret = ++conn->seqnum;
  return ret;
}

static int aim_send(int fd, const void *buf, size_t count)
{
  int left, cur;
  
  for (cur = 0, left = count; left; ) {
    int ret;
    
    ret = send(fd, ((unsigned char *)buf)+cur, left, 0);
    if (ret == -1) {
      return -1;
    } else if (ret == 0) {
      return cur;
    }
    
    cur += ret;
    left -= ret;
  }
  
  return cur;
}

static int aim_bstream_send(aim_bstream_t *bs, aim_conn_t *conn, size_t count)
{
  int wrote = 0;
  if (!bs || !conn || (count < 0))
    return -EINVAL;
  
  if (count > aim_bstream_empty(bs))
    count = aim_bstream_empty(bs); /* truncate to remaining space */
  
  if (count) {
    if ((conn->type == AIM_CONN_TYPE_RENDEZVOUS) && 
	(conn->subtype == AIM_CONN_SUBTYPE_OFT_DIRECTIM)) {
      /* I strongly suspect that this is a horrible thing to do
       * and I feel really guilty doing it. */
      const char *sn = aim_odc_getsn(conn);
      aim_rxcallback_t userfunc;
      while (count - wrote > 1024) {
	wrote = wrote + aim_send(conn->fd, bs->data + bs->offset + wrote, 1024);
	if ((userfunc=aim_callhandler(conn->sessv, conn, 
				      AIM_CB_FAM_SPECIAL, 
				      AIM_CB_SPECIAL_IMAGETRANSFER)))
	  userfunc(conn->sessv, NULL, sn, 
		   count-wrote>1024 ? ((double)wrote / count) : 1);
      }
    }
    if (count - wrote) {
      wrote = wrote + aim_send(conn->fd, bs->data + bs->offset + wrote, count - wrote);
    }
    
  }
  
  if (((aim_session_t *)conn->sessv)->debug >= 2) {
    int i;
    aim_session_t *sess = (aim_session_t *)conn->sessv;
    
    faimdprintf(sess, 2, "\nOutgoing data: (%d bytes)", wrote);
    for (i = 0; i < wrote; i++) {
      if (!(i % 8)) 
	faimdprintf(sess, 2, "\n\t");
      faimdprintf(sess, 2, "0x%02x ", *(bs->data + bs->offset + i));
    }
    faimdprintf(sess, 2, "\n");
  }
  
  bs->offset += wrote;
  
  return wrote;
}

static int sendframe_flap(aim_session_t *sess, aim_frame_t *fr)
{
  aim_bstream_t obs;
  fu8_t *obs_raw;
  int payloadlen, err = 0, obslen;
  
  payloadlen = aim_bstream_curpos(&fr->data);
  
  if (!(obs_raw = malloc(6 + payloadlen)))
    return -ENOMEM;
  
  aim_bstream_init(&obs, obs_raw, 6 + payloadlen);
  
  /* FLAP header */
  aimbs_put8(&obs, 0x2a);
  aimbs_put8(&obs, fr->hdr.flap.type);
  aimbs_put16(&obs, fr->hdr.flap.seqnum);
  aimbs_put16(&obs, payloadlen);
  
  /* payload */
  aim_bstream_rewind(&fr->data);
  aimbs_putbs(&obs, &fr->data, payloadlen);
  
  obslen = aim_bstream_curpos(&obs);
  aim_bstream_rewind(&obs);
  if (aim_bstream_send(&obs, fr->conn, obslen) != obslen)
    err = -errno;
  
  free(obs_raw); /* XXX aim_bstream_free */
  
  fr->handled = 1;
  fr->conn->lastactivity = time(NULL);
  
  return err;
}

static int sendframe_rendezvous(aim_session_t *sess, aim_frame_t *fr)
{
	aim_bstream_t bs;
	fu8_t *bs_raw;
	int err = 0;
	int totlen = 8 + aim_bstream_curpos(&fr->data);

	if (!(bs_raw = malloc(totlen)))
		return -1;

	aim_bstream_init(&bs, bs_raw, totlen);

	aimbs_putraw(&bs, fr->hdr.rend.magic, 4);
	aimbs_put16(&bs, 8 + fr->hdr.rend.hdrlen);
	aimbs_put16(&bs, fr->hdr.rend.type);

	/* payload */
	aim_bstream_rewind(&fr->data);
	aimbs_putbs(&bs, &fr->data, totlen - 8);

	aim_bstream_rewind(&bs);

	if (aim_bstream_send(&bs, fr->conn, totlen) != totlen)
		err = -errno;

	free(bs_raw); /* XXX aim_bstream_free */

	fr->handled = 1;
	fr->conn->lastactivity = time(NULL);

	return err;
}

faim_internal int aim_tx_sendframe(aim_session_t *sess, aim_frame_t *fr)
{
	if (fr->hdrtype == AIM_FRAMETYPE_FLAP)
		return sendframe_flap(sess, fr);
	else if (fr->hdrtype == AIM_FRAMETYPE_OFT)
		return sendframe_rendezvous(sess, fr);
	return -1;
}

faim_export int aim_tx_flushqueue(aim_session_t *sess)
{
	aim_frame_t *cur;

	for (cur = sess->queue_outgoing; cur; cur = cur->next) {

		if (cur->handled)
	       		continue; /* already been sent */

		if (cur->conn && (cur->conn->status & AIM_CONN_STATUS_INPROGRESS))
			continue;

		/*
		 * And now for the meager attempt to force transmit
		 * latency and avoid missed messages.
		 */
		if ((cur->conn->lastactivity + cur->conn->forcedlatency) >= time(NULL)) {
			/* 
			 * XXX should be a break! we dont want to block the 
			 * upper layers
			 *
			 * XXX or better, just do this right.
			 *
			 */
			sleep((cur->conn->lastactivity + cur->conn->forcedlatency) - time(NULL));
		}

		/* XXX this should call the custom "queuing" function!! */
		aim_tx_sendframe(sess, cur);
	}

	/* purge sent commands from queue */
	aim_tx_purgequeue(sess);

	return 0;
}

/*
 *  aim_tx_purgequeue()
 *  
 *  This is responsable for removing sent commands from the transmit 
 *  queue. This is not a required operation, but it of course helps
 *  reduce memory footprint at run time!  
 *
 */
faim_export void aim_tx_purgequeue(aim_session_t *sess)
{
	aim_frame_t *cur, **prev;

	for (prev = &sess->queue_outgoing; (cur = *prev); ) {

		if (cur->handled) {
			*prev = cur->next;

			aim_frame_destroy(cur);

		} else
			prev = &cur->next;
	}

	return;
}

/**
 * aim_tx_cleanqueue - get rid of packets waiting for tx on a dying conn
 * @sess: session
 * @conn: connection that's dying
 *
 * for now this simply marks all packets as sent and lets them
 * disappear without warning.
 *
 */
faim_internal void aim_tx_cleanqueue(aim_session_t *sess, aim_conn_t *conn)
{
	aim_frame_t *cur;

	for (cur = sess->queue_outgoing; cur; cur = cur->next) {
		if (cur->conn == conn)
			cur->handled = 1;
	}

	return;
}