/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999-2021 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/>. */

#include "mu_scm.h"
#include <mailutils/iterator.h>

static scm_t_bits mailbox_tag;

/* NOTE: Maybe will have to add some more members. That's why it is a
   struct, not just a typedef mu_mailbox_t */
struct mu_mailbox
{
  mu_mailbox_t mbox;       /* Mailbox */
  mu_iterator_t itr;
  int noclose;
};

static size_t
mu_scm_mailbox_free (SCM mailbox_smob)
{
  struct mu_mailbox *mum = (struct mu_mailbox *) SCM_CDR (mailbox_smob);

  mu_iterator_destroy (&mum->itr);
  
  if (!mum->noclose)
    {
      mu_mailbox_close (mum->mbox);
      mu_mailbox_destroy (&mum->mbox);
    }
  return sizeof 0;
}

static int
mu_scm_mailbox_print (SCM mailbox_smob, SCM port, scm_print_state * pstate)
{
  struct mu_mailbox *mum = (struct mu_mailbox *) SCM_CDR (mailbox_smob);
  size_t count = 0;
  mu_url_t url = NULL;

  mu_mailbox_get_url (mum->mbox, &url);

  scm_puts ("#<mailbox ", port);

  if (mailbox_smob == SCM_BOOL_F)
    {
      /* mu_mailbox.* functions may return #f */
      scm_puts ("#f", port);
    }
  else
    {
      const char *p = mu_url_to_string (url);
      if (p)
	{
	  mu_mailbox_messages_count (mum->mbox, &count);
	  scm_puts (p, port);
	  scm_puts (" (", port);
	  scm_intprint (count, 10, port);
	  scm_putc (')', port);
	}
      else
	scm_puts ("uninitialized", port);
    }
  scm_puts (">", port);

  return 1;
}

/* Internal functions */

/* There are two C interfaces for creating mailboxes in Scheme.
   The first one, mu_scm_mailbox_create0, allows to set `noclose'
   bit, which disables closing and releasing the underlying mu_mailbox_t
   after the hosting SCM object is freed. Use this, if this mailbox
   is referenced elsewhere.

   Another one, mu_scm_mailbox_create, always create an object that
   will cause closing the mu_mailbox_t object and releasing its memory
   after the hosting SCM object is swept away by GC. This is the only
   official one.

   The mu_scm_mailbox_create0 function is a kludge, needed because
   mu_mailbox_t objects don't have reference counters. When it is fixed in
   the library, the interface will be removed. */

SCM
mu_scm_mailbox_create0 (mu_mailbox_t mbox, int noclose)
{
  struct mu_mailbox *mum;

  mum = scm_gc_malloc (sizeof (struct mu_mailbox), "mailbox");
  mum->mbox = mbox;
  mum->itr = NULL;
  mum->noclose = noclose;
  SCM_RETURN_NEWSMOB (mailbox_tag, mum);
}

SCM
mu_scm_mailbox_create (mu_mailbox_t mbox)
{
  return mu_scm_mailbox_create0 (mbox, 0);
}

int
mu_scm_is_mailbox (SCM scm)
{
  return SCM_NIMP (scm) && (long) SCM_CAR (scm) == mailbox_tag;
}

/* ************************************************************************* */
/* Guile primitives */

SCM_DEFINE_PUBLIC (scm_mu_mailbox_p, "mu-mailbox?", 1, 0, 0,
		   (SCM scm),
"Return @code{true} if @var{scm} is a Mailutils mailbox.\n")
#define FUNC_NAME s_scm_mu_mailbox_p
{
  return scm_from_bool (mu_scm_is_mailbox (scm));
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_user_mailbox_url, "mu-user-mailbox-url", 1, 0, 0, 
		   (SCM user),
		   "Return URL of the default mailbox for user @var{user}.")
#define FUNC_NAME s_scm_mu_user_mailbox_url
{
  int rc;
  char *p, *str;
  SCM ret;
  
  SCM_ASSERT (scm_is_string (user), user, SCM_ARG1, FUNC_NAME);
  str = scm_to_locale_string (user);
  rc = mu_construct_user_mailbox_url (&p, str);
  free (str);
  if (rc)
    mu_scm_error (FUNC_NAME, rc,
		  "Cannot construct mailbox URL for ~A",
		  scm_list_1 (user));
  ret = scm_from_locale_string (p);
  free (p);
  return ret;
}
#undef FUNC_NAME 

SCM_DEFINE_PUBLIC (scm_mu_folder_directory, "mu-folder-directory", 0, 1, 0,
		   (SCM url), 
"If @var{url} is given, sets it as a name of the user's folder directory.\n"
"Returns the current value of the folder directory.")
#define FUNC_NAME s_scm_mu_folder_directory
{
  if (!SCM_UNBNDP (url))
    {
      char *s;

      SCM_ASSERT (scm_is_string (url), url, SCM_ARG1, FUNC_NAME);
      s = scm_to_locale_string (url);
      mu_set_folder_directory (s);
      free (s);
    }
  return scm_from_locale_string (mu_folder_directory ());
}
#undef FUNC_NAME 

SCM_DEFINE_PUBLIC (scm_mu_mailbox_open, "mu-mailbox-open", 2, 0, 0,
	    (SCM url, SCM mode), 
"Opens the mailbox specified by @var{url}. The @var{mode} argument defines\n"
"access mode for the mailbox. It is a string, consisting of one or more of the\n"
"following characters:\n"
"\n"
"@multitable @columnfractions 0.20 0.70\n"
"@headitem @var{mode} @tab Meaning\n"
"@item r @tab Open for reading.\n"
"@item w @tab Open for writing.\n"
"@item a @tab Open for appending to the end of the mailbox.\n"
"@item c @tab Create the mailbox if it does not exist.\n"
"@end multitable\n"
)
#define FUNC_NAME s_scm_mu_mailbox_open
{
  mu_mailbox_t mbox = NULL;
  char *mode_str;
  int mode_bits = 0;
  int status;
  SCM ret;
  
  SCM_ASSERT (scm_is_bool (url) || scm_is_string (url), url, SCM_ARG1, FUNC_NAME);
  SCM_ASSERT (scm_is_string (mode), mode, SCM_ARG2, FUNC_NAME);
  
  scm_dynwind_begin (0);
  
  mode_str = scm_to_locale_string (mode);
  scm_dynwind_free (mode_str);
  for (; *mode_str; mode_str++)
    switch (*mode_str)
      {
      case 'r':
	mode_bits |= MU_STREAM_READ;
	break;
      case 'w':
	mode_bits |= MU_STREAM_WRITE;
	break;
      case 'a':
	mode_bits |= MU_STREAM_APPEND;
	break;
      case 'c':
	mode_bits |= MU_STREAM_CREAT;
	break;
      }
  
  if (mode_bits & MU_STREAM_READ && mode_bits & MU_STREAM_WRITE)
    mode_bits = (mode_bits & ~(MU_STREAM_READ | MU_STREAM_WRITE)) | MU_STREAM_RDWR;

  if (scm_is_bool (url))
    {
      if (url == SCM_BOOL_F)
	mode_str = NULL;
      else
	mu_scm_error (FUNC_NAME, EINVAL,
		      "value #t for URL is reserved for future use",
		      scm_list_1 (url));
    }
  else
    {
      mode_str = scm_to_locale_string (url);
      scm_dynwind_free (mode_str);
    }
  
  status = mu_mailbox_create_default (&mbox, mode_str);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Cannot create default mailbox ~A",
		  scm_list_1 (url));


  status = mu_mailbox_open (mbox, mode_bits);
  if (status)
    {
      mu_mailbox_destroy (&mbox);
      mu_scm_error (FUNC_NAME, status,
		    "Cannot open default mailbox ~A",
		    scm_list_1 (url));
    }
  ret = mu_scm_mailbox_create (mbox);
  scm_dynwind_end ();
  return ret;
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_close, "mu-mailbox-close", 1, 0, 0,
		   (SCM mbox),
		   "Closes mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_close
{
  struct mu_mailbox *mum;

  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  mu_mailbox_close (mum->mbox);
  mu_mailbox_destroy (&mum->mbox);
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_get_url, "mu-mailbox-get-url", 1, 0, 0,
		   (SCM mbox), 
		   "Returns URL of the mailbox @var{MBOX}.")
#define FUNC_NAME s_scm_mu_mailbox_get_url
{
  struct mu_mailbox *mum;
  mu_url_t url;
  int status;
 
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  status = mu_mailbox_get_url (mum->mbox, &url);
  if (status)
    mu_scm_error (FUNC_NAME, status,
                  "Cannot get mailbox url",
                  SCM_BOOL_F);

  return scm_from_locale_string (mu_url_to_string (url));
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_get_message, "mu-mailbox-get-message", 2, 0, 0,
		   (SCM mbox, SCM msgno), 
"Retrieve from message #@var{msgno} from the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_get_message
{
  size_t n;
  struct mu_mailbox *mum;
  mu_message_t msg;
  int status;
    
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  SCM_ASSERT (scm_is_integer (msgno), msgno, SCM_ARG2, FUNC_NAME);

  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  n = scm_to_size_t (msgno);

  status = mu_mailbox_get_message (mum->mbox, n, &msg);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Cannot get message ~A from mailbox ~A",
		  scm_list_2 (msgno, mbox));
    
  return mu_scm_message_create (mbox, msg);
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_messages_count, "mu-mailbox-messages-count", 1, 0, 0,
		   (SCM mbox), 
"Returns number of messages in the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_messages_count
{
  struct mu_mailbox *mum;
  size_t nmesg;
  int status;
  
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);

  status = mu_mailbox_messages_count (mum->mbox, &nmesg);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Cannot count messages in mailbox ~A",
		  scm_list_1 (mbox));
  return scm_from_size_t (nmesg);
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_expunge, "mu-mailbox-expunge", 1, 0, 0,
		   (SCM mbox), 
"Expunges deleted messages from the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_expunge
{
  struct mu_mailbox *mum;
  int status;
    
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  status = mu_mailbox_expunge (mum->mbox);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Cannot expunge messages in mailbox ~A",
		  scm_list_1 (mbox));
  return SCM_BOOL_T;
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_sync, "mu-mailbox-sync", 1, 0, 0,
		   (SCM mbox), 
"Synchronize changes to @var{mbox} with its storage.")
#define FUNC_NAME s_scm_mu_mailbox_sync
{
  struct mu_mailbox *mum;
  int status;
    
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  status = mu_mailbox_sync (mum->mbox);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Sync failed for mailbox ~A",
		  scm_list_1 (mbox));
  return SCM_BOOL_T;
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_flush, "mu-mailbox-flush", 1, 1, 0,
		   (SCM mbox, SCM expunge), 
"Mark all messages in @var{mbox} as seen and synchronize all changes with "
"its storage.  If @var{expunge} is @samp{#t}, expunge deleted messages "
"as well.")
#define FUNC_NAME s_scm_mu_mailbox_flush
{
  struct mu_mailbox *mum;
  int status, do_expunge = 0;
    
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  if (!SCM_UNBNDP (expunge))
    {
      SCM_ASSERT (scm_is_bool (expunge), expunge, SCM_ARG2, FUNC_NAME);
      do_expunge = expunge == SCM_BOOL_T;
    }
  status = mu_mailbox_flush (mum->mbox, do_expunge);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Flush failed for mailbox ~A",
		  scm_list_1 (mbox));
  return SCM_BOOL_T;
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_append_message, "mu-mailbox-append-message", 2, 0, 0,
		   (SCM mbox, SCM mesg),
		   "Appends message @var{mesg} to the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_append_message
{
  struct mu_mailbox *mum;
  mu_message_t msg;
  int status;
    
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  SCM_ASSERT (mu_scm_is_message (mesg), mesg, SCM_ARG2, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  msg = mu_scm_message_get (mesg);
  status = mu_mailbox_append_message (mum->mbox, msg);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "Cannot append message ~A to mailbox ~A",
		  scm_list_2 (mesg, mbox));
  return SCM_BOOL_T;
}
#undef FUNC_NAME

/* Iterations */
#define ITROP(op, descr)			\
  do						\
    {						\
      int status = op;				\
      if (status == MU_ERR_NOENT)		\
	return SCM_EOF_VAL;			\
      if (status)				\
	mu_scm_error (FUNC_NAME, status,	\
		      "~A: " descr ": ~A",	\
		      scm_list_2 (mbox,		\
				  scm_from_locale_string (mu_strerror (status)))); \
    }									\
  while (0)

SCM_DEFINE_PUBLIC (scm_mu_mailbox_first_message, "mu-mailbox-first-message", 1, 0, 0,
	    (SCM mbox),
	    "Returns first message from the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_first_message
{
  struct mu_mailbox *mum;
  int status;
  mu_message_t msg;
  
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  if (!mum->itr)
    {
      status = mu_mailbox_get_iterator (mum->mbox, &mum->itr);
      if (status)
	mu_scm_error (FUNC_NAME, status,
		      "~A: cannot create iterator: ~A",
		      scm_list_2 (mbox,
				  scm_from_locale_string (mu_strerror (status))));
    }
  ITROP (mu_iterator_first (mum->itr), "moving to the first message");
  ITROP (mu_iterator_current (mum->itr, (void**)&msg),
	 "getting current message");
  return mu_scm_message_create (mbox, msg);
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_next_message, "mu-mailbox-next-message", 1, 0, 0,
		   (SCM mbox),
	    "Returns next message from the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_next_message
{
  struct mu_mailbox *mum;
  int status;
  mu_message_t msg;
  
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  if (!mum->itr)
    {
      status = mu_mailbox_get_iterator (mum->mbox, &mum->itr);
      if (status)
	mu_scm_error (FUNC_NAME, status,
		      "~A: cannot create iterator: ~A",
		      scm_list_2 (mbox,
				  scm_from_locale_string (mu_strerror (status))));
      ITROP (mu_iterator_first (mum->itr), "moving to the first message");
    }
  else
    ITROP (mu_iterator_next (mum->itr), "advancing iterator");
  
  ITROP (mu_iterator_current (mum->itr, (void**)&msg),
	 "getting current message");
  return mu_scm_message_create (mbox, msg);
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_more_messages_p, "mu-mailbox-more-messages?", 1, 0, 0,
		   (SCM mbox),
"Returns @samp{#t} if there are more messages in the mailbox @var{mbox}\n"
"ahead of current iterator position.  Usually this function is used after\n"
"a call to @samp{mu-mailbox-first-message} or @samp{mu-mailbox-next-message}.\n"
"If not, it initializes the iterator and points it to the first message in"
"the mailbox.")
#define FUNC_NAME s_scm_mu_mailbox_more_messages_p
{
  struct mu_mailbox *mum;
  int status;
  
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  if (!mum->itr)
    {
      status = mu_mailbox_get_iterator (mum->mbox, &mum->itr);
      if (status)
	mu_scm_error (FUNC_NAME, status,
		      "~A: cannot create iterator: ~A",
		      scm_list_2 (mbox,
				  scm_from_locale_string (mu_strerror (status))));
      status = mu_iterator_first (mum->itr);
      if (status == MU_ERR_NOENT)
	return SCM_BOOL_F;
      if (status)
	mu_scm_error (FUNC_NAME, status,
		      "~A: cannot set iterator to the first message: ~A",
		      scm_list_2 (mbox,
				  scm_from_locale_string (mu_strerror (status))));
    }
  return scm_from_bool (!mu_iterator_is_done (mum->itr));
}
#undef FUNC_NAME

SCM_DEFINE_PUBLIC (scm_mu_mailbox_get_size, "mu-mailbox-get-size", 1, 0, 0,
		   (SCM mbox),
		   "Return size of the mailbox @var{mbox}.")
#define FUNC_NAME s_scm_mu_mailbox_get_size
{
  struct mu_mailbox *mum;
  int status;
  mu_off_t size;
  
  SCM_ASSERT (mu_scm_is_mailbox (mbox), mbox, SCM_ARG1, FUNC_NAME);
  mum = (struct mu_mailbox *) SCM_CDR (mbox);
  status = mu_mailbox_get_size (mum->mbox, &size);
  if (status)
    mu_scm_error (FUNC_NAME, status,
		  "~A: cannot determine mailbox size: ~A",
		  scm_list_2 (mbox,
			      scm_from_locale_string (mu_strerror (status))));
  return scm_from_uintmax (size);
}

/* Initialize the module */
void
mu_scm_mailbox_init ()
{
  mailbox_tag = scm_make_smob_type ("mailbox", sizeof (struct mu_mailbox));
  scm_set_smob_free (mailbox_tag, mu_scm_mailbox_free);
  scm_set_smob_print (mailbox_tag, mu_scm_mailbox_print);

#include "mu_mailbox.x"

}