/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 2003-2025 Free Software Foundation, Inc.

   GNU Mailutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GNU Mailutils 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */

#include <mh.h>
#include <mailutils/sys/msgset.h>

static char *
private_sequence_name (const char *name)
{
  char *p;
  char *mbox_dir = mh_expand_name (NULL, mh_current_folder (), NAME_ANY);
  mu_asprintf (&p, "atr-%s-%s", name, mbox_dir);
  free (mbox_dir);
  return p;
}

const char *
mh_seq_read (mu_mailbox_t mbox, const char *name, int flags)
{
  const char *value;

  if (flags & SEQ_PRIVATE)
    {
      char *p = private_sequence_name (name);
      value = mh_global_context_get (p, NULL);
      free (p);
    }
  else
    value = mh_global_sequences_get (mbox, name, NULL);
  return value;
}

static void
write_sequence (mu_mailbox_t mbox, const char *name, char *value, int private)
{
  if (value && value[0] == 0)
    value = NULL;
  if (private)
    {
      char *p = private_sequence_name (name);
      mh_global_context_set (p, value);
      free (p);
    }
  else
    mh_global_sequences_set (mbox, name, value);
}

static void
delete_sequence (mu_mailbox_t mbox, const char *name, int private)
{
  write_sequence (mbox, name, NULL, private);
}

static void
save_sequence (mu_mailbox_t mbox, const char *name, mu_msgset_t mset,
	       int flags)
{
  int rc;
  mu_stream_t mstr;
  mu_msgset_t outset;
  mu_transport_t trans[2];
      
  rc = mu_msgset_translate (&outset, mset,
			    MU_MSGSET_UID|MU_MSGSET_IGNORE_TRANSERR);
  if (rc)
    {
      mu_diag_funcall (MU_DIAG_ERROR, "mu_msgset_translate", NULL, rc);
      exit (1);
    }

  rc = mu_memory_stream_create (&mstr, MU_STREAM_RDWR);
  if (rc)
    {
      mu_diag_funcall (MU_DIAG_ERROR, "mu_memory_stream_create", NULL, rc);
      exit (1);
    }
  mu_stream_msgset_format (mstr, mu_msgset_fmt_mh, outset);
  mu_stream_write (mstr, "", 1, NULL);
  mu_stream_ioctl (mstr, MU_IOCTL_TRANSPORT, MU_IOCTL_OP_GET, trans);
  write_sequence (mbox, name, (char*)trans[0], flags & SEQ_PRIVATE);
  mu_stream_unref (mstr);
  mu_msgset_free (outset);
}

void
mh_seq_add (mu_mailbox_t mbox, const char *name, mu_msgset_t mset, int flags)
{
  const char *value = mh_seq_read (mbox, name, flags);
  
  delete_sequence (mbox, name, !(flags & SEQ_PRIVATE));
  if (value && !(flags & SEQ_ZERO))
    {
      mu_msgset_t oldset;
      mh_msgset_parse_string (&oldset, mbox, value, "cur");
      mu_msgset_add (oldset, mset);
      save_sequence (mbox, name, oldset, flags);
      mu_msgset_free (oldset);
    }
  else
    save_sequence (mbox, name, mset, flags);
}

int
mh_seq_delete (mu_mailbox_t mbox, const char *name,
	       mu_msgset_t mset, int flags)
{
  const char *value = mh_seq_read (mbox, name, flags);
  mu_msgset_t oldset;

  if (!value)
    return 0;
  mh_msgset_parse_string (&oldset, mbox, value, "cur");
  mu_msgset_sub (oldset, mset);
  save_sequence (mbox, name, oldset, flags);
  mu_msgset_free (oldset);
  return 0;
}

struct privseq_closure
{
  const char *mbox_dir;
  mu_mhprop_iterator_t fun;
  void *data;
  char *namebuf;
  size_t namelen;
};
  
static int
privseq_handler (const char *name, const char *value, void *data)
{
  struct privseq_closure *pclos = data;

  if (strncmp (name, "atr-", 4) == 0)
    {
      char *p = strchr (name + 4, '-');
      if (p && strcmp (p + 1, pclos->mbox_dir) == 0)
	{
	  size_t len = p - name - 4;
	  if (pclos->namelen < len + 1)
	    {
	      pclos->namelen = len + 1;
	      pclos->namebuf = mu_realloc (pclos->namebuf, pclos->namelen);
	    }
	  memcpy (pclos->namebuf, name + 4, len);
	  pclos->namebuf[len] = 0;
	}
	return pclos->fun (pclos->namebuf, value, pclos->data);
    }
  return 0;
}

int
mh_private_sequences_iterate (mu_mailbox_t mbox,
			      mu_mhprop_iterator_t fp, void *data)
{
  int rc;
  struct privseq_closure clos;
  mu_url_t url;

  rc = mu_mailbox_get_url (mbox, &url);
  if (rc)
    {
      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_url", NULL, rc);
      exit (1);
    }
  rc = mu_url_sget_path (url, &clos.mbox_dir);
  if (rc)
    {
      mu_diag_funcall (MU_DIAG_ERROR, "mu_url_sget_path",
		       mu_url_to_string (url), rc);
      exit (1);
    }
  
  clos.fun = fp;
  clos.data = data;
  clos.namebuf = NULL;
  clos.namelen = 0;
  rc = mu_mhprop_iterate (mu_mh_context, privseq_handler, &clos);
  free (clos.namebuf);
  return rc;
}
