/* GNU mailutils - a suite of utilities for electronic mail
   Copyright (C) 1999, 2001 Free Software Foundation, Inc.

   This program 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 2, or (at your option)
   any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "imap4d.h"

/*

 */
struct _uid_table
{
  size_t uid;
  size_t msgno;
  int notify;
  attribute_t attr;
};

static struct _uid_table *uid_table;
static size_t uid_table_count;

static void
add_flag (char **pbuf, const char *f)
{
  char *abuf = *pbuf;
  abuf = realloc (abuf, strlen (abuf) + strlen (f) + 2);
  if (abuf == NULL)
    imap4d_bye (ERR_NO_MEM);
  if (*abuf)
    strcat (abuf, " ");
  strcat (abuf, "\\Seen");
  *pbuf = abuf;
}

static void
notify_flag (size_t msgno, attribute_t oattr)
{
  message_t msg = NULL;
  attribute_t nattr = NULL;
  int status ;
  mailbox_get_message (mbox, msgno, &msg);
  message_get_attribute (msg, &nattr);
  status = attribute_is_equal (oattr, nattr);

  if (status == 0)
    {
      char *abuf = malloc (1);;
      if (!abuf)
	imap4d_bye (ERR_NO_MEM);
      *abuf = '\0';
      if (attribute_is_seen (nattr) && attribute_is_read (nattr))
	if (!attribute_is_seen (oattr) && !attribute_is_read (oattr))
	  {
	    attribute_set_seen (oattr);
	    attribute_set_read (oattr);
	    add_flag (&abuf, "\\Seen");
	  }
      if (attribute_is_answered (nattr))
	if (!attribute_is_answered (oattr))
	  {
	    attribute_set_answered (oattr);
	    add_flag (&abuf, "\\Answered");
	  }
      if (attribute_is_flagged (nattr))
	if (!attribute_is_flagged (oattr))
	  {
	    attribute_set_flagged (oattr);
	    add_flag (&abuf, "\\Flagged");
	  }
      if (attribute_is_deleted (nattr))
	if (!attribute_is_deleted (oattr))
	  {
	    attribute_set_deleted (oattr);
	    add_flag (&abuf, "\\Deleted");
	  }
      if (attribute_is_draft (nattr))
	if (!attribute_is_draft (oattr))
	  {
	    attribute_set_draft (oattr);
	    add_flag (&abuf, "\\Draft");
	  }
      if (attribute_is_recent (nattr))
	if (!attribute_is_recent (oattr))
	  {
	    attribute_set_recent (oattr);
	    add_flag (&abuf, "\\Recent");
	  }
      if (*abuf)
	util_out (RESP_NONE, "%d FETCH FLAGS (%s)", msgno, abuf);
      free (abuf);
    }
}

/* The EXPUNGE response reports that the specified message sequence
   number has been permanently removed from the mailbox.  The message
   sequence number for each successive message in the mailbox is
   immediately decremented by 1, and this decrement is reflected in
   message sequence numbers in subsequent responses (including other
   untagged EXPUNGE responses). */
static void
notify_deleted (void)
{
  if (uid_table)
    {
      size_t i;
      size_t decr = 0;
      for (i = 0; i < uid_table_count; i++)
	{
	  if (!(uid_table[i].notify))
	    {
	      util_out (RESP_NONE, "%d EXPUNGED", uid_table[i].msgno-decr);
	      uid_table[i].notify = 1;
	      decr++;
	    }
	}
    }
}


static int
notify_uid (size_t uid)
{
  if (uid_table)
    {
      size_t i;
      for (i = 0; i < uid_table_count; i++)
	{
	  if (uid_table[i].uid == uid)
	    {
	      notify_flag (uid_table[i].msgno, uid_table[i].attr);
	      uid_table[i].notify = 1;
	      return 1;
	    }
	}
    }
  return 0;
}

static void
free_uids (void)
{
  if (uid_table)
    {
      size_t i;
      for (i = 0; i < uid_table_count; i++)
	attribute_destroy (&(uid_table[i].attr), NULL);
      free (uid_table);
      uid_table = NULL;
    }
  uid_table_count = 0;
}

static void
reset_notify (void)
{
  size_t i;

  for (i = 0; i < uid_table_count; i++)
    uid_table[i].notify = 0;
}

static void
reset_uids (void)
{
  size_t total = 0;
  size_t i;

  free_uids ();

  mailbox_messages_count (mbox, &total);
  for (i = 1; i <= total; i++)
    {
      message_t msg = NULL;
      attribute_t attr = NULL;
      size_t uid = 0;
      uid_table = realloc (uid_table, sizeof (*uid_table) *
			   (uid_table_count + 1));
      if (!uid_table)
	imap4d_bye (ERR_NO_MEM);
      mailbox_get_message (mbox, i, &msg);
      message_get_attribute (msg, &attr);
      message_get_uid (msg, &uid);
      uid_table[uid_table_count].uid = uid;
      uid_table[uid_table_count].msgno = i;
      uid_table[uid_table_count].notify = 0;
      attribute_create (&(uid_table[uid_table_count].attr), NULL);
      attribute_copy (uid_table[uid_table_count].attr, attr);
      uid_table_count++;
    }
}

static void
notify (void)
{
  size_t total = 0;
  int reset = 0;
  
  mailbox_messages_count (mbox, &total);

  if (!uid_table)
    {
      reset = 1;
      reset_uids ();
    }
  
  if (uid_table)
    {
      size_t i;
      size_t recent = 0;

      for (i = 1; i <= total; i++)
	{
	  message_t msg = NULL;
	  size_t uid = 0;
	  mailbox_get_message (mbox, i, &msg);
	  message_get_uid (msg, &uid);
	  if (!notify_uid (uid))
	    recent++;
	}
      notify_deleted ();
      util_out (RESP_NONE, "%d EXISTS", total);
      if (recent)
	util_out (RESP_NONE, "%d RECENT", recent);
    }

  if (!reset)
    reset_uids ();
  else
    reset_notify ();
}

size_t
uid_to_msgno (size_t uid)
{
  size_t i;
  for (i = 0; i < uid_table_count; i++)
    if (uid_table[i].uid == uid)
      return uid_table[i].msgno;
  return 0;
}

int
imap4d_sync_flags (size_t msgno)
{
  size_t i;
  for (i = 0; i < uid_table_count; i++)
    if (uid_table[i].msgno == msgno)
      {
	message_t msg = NULL;
	attribute_t attr = NULL;
	mailbox_get_message (mbox, msgno, &msg);
	message_get_attribute (msg, &attr);
	attribute_copy (uid_table[i].attr, attr);
	break;
      }
  return 0;
}

int
imap4d_sync (void)
{
  /* If mbox --> NULL, it means to free all the ressources.
     It may be because of close or before select/examine a new mailbox.
     If it was a close we do not send any notification.  */
  if (mbox == NULL)
    free_uids ();
  else if (uid_table == NULL || !mailbox_is_updated (mbox))
    notify ();
  else
    {
      size_t count = 0;
      mailbox_messages_count (mbox, &count);
      if (count != uid_table_count)
	notify ();
    }
  return 0;
}