/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999-2025 Free Software Foundation, Inc.

   This library 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.

   This library 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 library.  If not, see
   <http://www.gnu.org/licenses/>. */

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

#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <mailutils/sys/pop3.h>

int
mu_pop3_uidl (mu_pop3_t pop3, unsigned int msgno, char **uidl)
{
  int status;
  char *space;

  if (pop3 == NULL)
    return EINVAL;
  if (uidl == NULL)
    return MU_ERR_OUT_PTR_NULL;

  switch (pop3->state)
    {
    case MU_POP3_NO_STATE:
      status = mu_pop3_writeline (pop3, "UIDL %d\r\n", msgno);
      MU_POP3_CHECK_ERROR (pop3, status);
      MU_POP3_FCLR (pop3, MU_POP3_ACK);
      pop3->state = MU_POP3_UIDL;

    case MU_POP3_UIDL:
      status = mu_pop3_response (pop3, NULL);
      MU_POP3_CHECK_EAGAIN (pop3, status);
      MU_POP3_CHECK_OK (pop3);
      pop3->state = MU_POP3_NO_STATE;

      *uidl = NULL;

      /* Format:  +OK msgno uidlstring  */

      /* Pass the "+OK".  */
      space = strchr (pop3->ackbuf, ' ');
      if (space)
	{
	  /* Skip spaces.  */
	  while (*space == ' ') space++;
	  /* Pass the number.  */
	  space = strchr (space, ' ');
	  if (space)
	    {
	      size_t len;
	      /* Skip spaces between msgno and uidlstring  */
	      while (*space == ' ') space++;
	      len = strlen (space);
	      if (space[len - 1] == '\n')
		{
		  space[len - 1] = '\0';
		  len--;
		}
	      *uidl = calloc (len + 1, 1);
	      if (*uidl)
		memcpy (*uidl, space, len);
	    }
	}

      if (*uidl == NULL) /* What can we do?  */
	{
	  *uidl = malloc (1);
	  if (*uidl)
	    **uidl = '\0';
	  else
	    status = ENOMEM;
	}
      break;

      /* They must deal with the error first by reopening.  */
    case MU_POP3_ERROR:
      status = ECANCELED;
      break;

    default:
      status = EINPROGRESS;
    }

  return status;
}
