/*
 * Secure eXtended Message Passing framework
 * Secure eXtended Transport layer implementation (libsxt).
 *
 * socket wrapper
 *
 * (c) Alexander Vdolainen 2016 <avdolainen@zoho.com>
 *
 * libsxmp is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libsxmp 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.";
 *
 */

#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <string.h>
#include <poll.h>

#include <sxt/errno.h>
#include <sxt/socket.h>

sxtsocket_t *sxtsocket_new(void)
{
  sxtsocket_t *s = malloc(sizeof(sxtsocket_t));

  if(!s)  return NULL;

  s->state = SXTSOCKET_NIL;

  return s;
}

int sxtsocket_close(sxtsocket_t *s)
{
  if(!s) return SXT_EINVAL;

  if(s->state == SXTSOCKET_ACTIVE || s->state == SXTSOCKET_DEAD) {
    close(s->fd);
    s->state = SXTSOCKET_CLOSED;
  }
  /* in other cases ignore, already closed or never opened */
  return SXT_SUCCESS;
}

int sxtsocket_setnb(sxtsocket_t *s)
{
#ifndef WIN32
  int fdmode;
#endif

  if(!s || s->state != SXTSOCKET_ACTIVE) return SXT_EINVAL;

#ifndef WIN32
  fdmode = fcntl(s->fd, F_GETFL, 0);
  fdmode |= O_NDELAY;
  if(fcntl(s->fd, F_SETFL, fdmode)) return SXT_EIO;
#endif
  return SXT_SUCCESS;
}

ssize_t sxtsocket_read(sxtsocket_t *s, void *buf, size_t bufsize)
{
  ssize_t rcnt = -1;

  if(!s || s->state != SXTSOCKET_ACTIVE) goto __failed;

  rcnt = read(s->fd, buf, bufsize);

 __failed:
  return rcnt;
}

ssize_t sxtsocket_write(sxtsocket_t *s, void *buf, size_t bufsize)
{
  ssize_t wcnt = -1;

  if(!s || s->state != SXTSOCKET_ACTIVE) goto __failed;

  wcnt = write(s->fd, (const void *)buf, bufsize);

 __failed:
  return wcnt;
}

int sxtsocket_poll(sxtsocket_t **rsck, int rscksz, sxtsocket_t **wsck,
                   int wscksz, int tm_msec, int **ra, int **wa)
{
  int r = 0, i = 0, err = SXTSCT_ERR, c, ii;
  struct pollfd *fds = NULL;
  int *rr = NULL, *wr = NULL;

  if(!rsck || !wsck) return SXTSCT_ERR;
  if(!rscksz || !wscksz) return SXTSCT_ERR;

  if(!(fds = malloc(sizeof(struct pollfd)*(rscksz + wscksz)))) return SXTSCT_ERR;
  else memset(fds, 0, sizeof(struct pollfd)*(rscksz + wscksz));

  /* fill and check given values */
  for(i = 0; i < rscksz; i++) {
    if(rsck[i]->state != SXTSOCKET_ACTIVE) goto __failed;
    fds[i].fd = rsck[i]->fd;
    fds[i].events = POLLIN | POLLPRI;
  }
  for(; i < rscksz + wscksz; i++) {
    if(wsck[i - rscksz]->state != SXTSOCKET_ACTIVE) goto __failed;
    fds[i].fd = wsck[i - rscksz]->fd;
    fds[i].events = POLLOUT;
  }

  r = poll(fds, rscksz + wscksz, tm_msec);
  if(!r) {
    err = SXTSCT_TMO;
    goto __failed;
  } else if(r < 0) goto __failed;

  for(i = 0, c = 0; i < rscksz; i++) {
    if(fds[i].revents) {
      if((fds[i].revents & POLLHUP) || (fds[i].revents & POLLERR))
        rsck[i]->state = SXTSOCKET_DEAD;
      c++;
    }
  }
  if(c) {
    if(!(rr = malloc(sizeof(int)*(c + 1)))) {
      err = SXTSCT_ERR;
      goto __failed;
    }

    for(i = 0, ii = 0; i < rscksz; i++) {
      if(fds[i].revents) {
        rr[ii] = i;
        ii++;
      }
    }
    rr[ii] = -1;
    err = 0;
    err |= SXTSCK_RDR;
  }

  if((r - c) > 0) {
    r -= c;
    if(!(wr = malloc(sizeof(int)*(r + 1)))) {
      err = SXTSCT_ERR;
      goto __failed;
    }

    for(i = rscksz, ii = 0; i < (rscksz + wscksz); i++) {
      if(fds[i].revents) {
        if((fds[i].revents & POLLHUP) || (fds[i].revents & POLLERR))
          wsck[i - rscksz]->state = SXTSOCKET_DEAD;
        wr[ii] = i - rscksz;
        ii++;
      }
    }
    wr[ii] = -1;
    if(err == SXTSCT_ERR) err = 0;
    err |= SXTSCK_WRR;
  }
  r = 0;

 __failed:
  if(fds) free(fds);
  if(r > 0 && err == SXTSCT_ERR) {
    if(rr) free(rr);
    if(wr) free(wr);
  }
  return err;
}

void sxtsocket_free(sxtsocket_t *s)
{
  if(!s) return;
  else sxtsocket_close(s);

  free(s);

  return;
}