/****************************************************************************
 * This file is part of the project AqHome.
 * AqHome (c) by 2025 Martin Preuss, all rights reserved.
 *
 * The license for this file can be found in the file COPYING which you
 * should have received along with this file.
 ****************************************************************************/

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include "./tcp_object.h"

#include <gwenhywfar/debug.h>

#include <unistd.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <errno.h>
#include <string.h>



/* ------------------------------------------------------------------------------------------------
 * forward declarations
 * ------------------------------------------------------------------------------------------------
 */

static int _socketSetBlocking(int sk, int fl);
static int _translateHError(int herr);
static int _setHostAddr(struct in_addr *inetAddr, const char *sAddr);
static int _setHostName(struct in_addr *inetAddr, const char *sAddr);



/* ------------------------------------------------------------------------------------------------
 * implementations
 * ------------------------------------------------------------------------------------------------
 */

int AQH_TcpObject_CreateConnectedSocket(const char *addr, int port)
{
  int sk;
  struct sockaddr_in inetAddr;
  int rv;

  memset(&inetAddr, 0, sizeof(inetAddr));
  inetAddr.sin_family=AF_INET;
  rv=_setHostAddr(&inetAddr.sin_addr, addr);   /* try tuple */
  if (rv<0) {
    rv=_setHostName(&inetAddr.sin_addr, addr); /* lookup name */
    if (rv<0) {
      DBG_INFO(AQH_LOGDOMAIN, "here (%d)", rv);
      return rv;
    }
  }
  inetAddr.sin_port=htons(port);

  sk=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (sk<0) {
    DBG_INFO(AQH_LOGDOMAIN, "socket(): %s", strerror(errno));
    return GWEN_ERROR_IO;
  }

  rv=connect(sk, (struct sockaddr*) &inetAddr, sizeof(inetAddr));
  if (rv<0) {
    DBG_INFO(AQH_LOGDOMAIN, "here (%d)", rv);
    close(sk);
    return rv;
  }

  rv=_socketSetBlocking(sk, 0);
  if (rv<0) {
    DBG_INFO(AQH_LOGDOMAIN, "here (%d)", rv);
    close(sk);
    return rv;
  }

  return sk;
}



int _setHostAddr(struct in_addr *inetAddr, const char *sAddr)
{
  inetAddr->s_addr=0;
  if (!inet_aton(sAddr, inetAddr)) {
    DBG_ERROR(AQH_LOGDOMAIN, "Invalid address \"%s\"", sAddr);
    return GWEN_ERROR_INVALID;
  }

  return 0;
}



int _setHostName(struct in_addr *inetAddr, const char *sAddr)
{
  struct hostent *he;

  he=gethostbyname(sAddr);
  if (!he) {
    DBG_ERROR(AQH_LOGDOMAIN, "gethostbyname(\"%s\"): %s", sAddr, hstrerror(h_errno));
    return _translateHError(h_errno);
  }
  /* name resolved, store address */
  memcpy(inetAddr, he->h_addr_list[0], sizeof(struct in_addr));
  return 0;
}



int _socketSetBlocking(int sk, int fl)
{
  int prevFlags;
  int newFlags;

  /* get current socket flags */
  prevFlags=fcntl(sk, F_GETFL);
  if (prevFlags==-1) {
    DBG_INFO(AQH_LOGDOMAIN, "fcntl(): %s", strerror(errno));
    return GWEN_ERROR_IO;
  }

  /* set nonblocking/blocking */
  if (fl)
    newFlags=prevFlags&(~O_NONBLOCK);
  else
    newFlags=prevFlags|O_NONBLOCK;

  if (-1==fcntl(sk, F_SETFL, newFlags)) {
    DBG_INFO(AQH_LOGDOMAIN, "fcntl(): %s", strerror(errno));
    return GWEN_ERROR_IO;
  }
  prevFlags=fcntl(sk, F_GETFL);
  if (prevFlags!=newFlags) {
    DBG_ERROR(AQH_LOGDOMAIN, "fcntl() did not set flags correctly (%08x!=%08x)", prevFlags, newFlags);
    return GWEN_ERROR_IO;
  }

  return 0;
}



int _translateHError(int herr)
{
  int rv;

  switch (herr) {
  case HOST_NOT_FOUND:
    rv=GWEN_ERROR_HOST_NOT_FOUND;
    break;
#ifdef NO_ADDRESS
  case NO_ADDRESS:
    rv=GWEN_ERROR_NO_ADDRESS;
    break;
#endif
  case NO_RECOVERY:
    rv=GWEN_ERROR_NO_RECOVERY;
    break;
  case TRY_AGAIN:
    rv=GWEN_ERROR_TRY_AGAIN;
    break;
  default:
    rv=GWEN_ERROR_UNKNOWN_DNS_ERROR;
    break;
  } /* switch */

  return rv;
}