/*
 * Copyright (C) 2005 Red Hat, 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 of the
 * License, 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., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Authors:
 *    Mark McLouglin <markmc@redhat.com>
 */

/*
 * Compile with:
 *  gcc -g -O2 -Wall $(shell pkg-config --cflags evolution-plugin-2.4) \
 *      -fPIC -shared -c delete-resolved-bugs.c -o libdelete-resolved-bugs.o
 *
 * Add this to delete-resolved-bugs.eplug:
 *  <e-plugin-list>
 *    <e-plugin id="org.gnome.mail.folder.delete_resolved_bugs"
 *              type="shlib"
 *              domain="foobar"
 *              name="Delete Resolved Bugs"
 *              location="/usr/lib/evolution/2.4/plugins/libdelete-resolved-bugs.so">
 *      <description>
 *        Delete all mails related to bugzilla bugs which have been resolved.
 *      </description>
 *      <author name="Mark McLoughlin" email="markmc@redhat.com" />
 *      <hook class="org.gnome.evolution.mail.popup:1.0">
 *        <menu id="org.gnome.evolution.mail.foldertree.popup" target="folder">
 *          <item type="item"
 *                path="10.emc.01"
 *                label="Delete Resolved Bugs"
 *                activate="delete_resolved_bugs"
 *                enable="folder"
 *                visible="folder" />
 *        </menu>
 *      </hook>
 *    </e-plugin>
 *  </e-plugin-list>
 *
 * And copy the .so and the .eplug to /usr/lib/evolution/2.4/plugins
 */

#include <string.h>
#include <e-util/e-plugin.h>
#include <mail/mail-ops.h>
#include <mail/mail-mt.h>
#include <mail/em-popup.h>

enum
{
  INVALID = 0,
  UNCONFIRMED,
  NEW,
  ASSIGNED,
  NEEDINFO,
  CLOSED,
  REOPENED,
  RESOLVED
};

void delete_resolved_bugs (EPlugin             *plugin,
			   EMPopupTargetFolder *folder);

static int
get_bug_status (CamelMimeMessage *message)
{
  const char *header;
  int         status;

  header = camel_medium_get_header (CAMEL_MEDIUM (message), "X-Bugzilla-Status");
  if (!header)
    return INVALID;

  status = INVALID;
  if (strcmp (header, " UNCONFIRMED") == 0)
    {
      status = UNCONFIRMED;
    }
  else if (strcmp (header, " NEW") == 0)
    {
      status = NEW;
    }
  else if (strcmp (header, " ASSIGNED") == 0)
    {
      status = ASSIGNED;
    }
  else if (strcmp (header, " NEEDINFO") == 0)
    {
      status = NEEDINFO;
    }
  else if (strcmp (header, " CLOSED") == 0)
    {
      status = CLOSED;
    }
  else if (strcmp (header, " REOPENED") == 0)
    {
      status = REOPENED;
    }
  else if (strcmp (header, " RESOLVED") == 0)
    {
      status = RESOLVED;
    }

  return status;
}

static long
get_bug_id (CamelMimeMessage *message)
{
  const char *subject;
  
  subject = camel_mime_message_get_subject (message);

  if (strncmp (subject, "[Bug ", 5) != 0)
    return 0;

  return strtol (subject + 5, NULL, 10);
}

static void
free_message_uids (GPtrArray *uids)
{
  int i;

  for (i = 0; i < uids->len; i++)
    g_free (uids->pdata[i]);

  g_ptr_array_free (uids, TRUE);
}

static GHashTable *
get_bug_mails (void)
{
  return g_hash_table_new_full (g_str_hash,
				g_str_equal,
				g_free,
				(GDestroyNotify) free_message_uids);
}

static void
queue_bug_mail (GHashTable *bug_mails,
		long        bug_id,
		const char *uid)
{
  GPtrArray *uids;
  char      *bug_id_str;

  bug_id_str = g_strdup_printf ("%ld", bug_id);

  uids = g_hash_table_lookup (bug_mails, bug_id_str);
  if (uids == NULL)
    {
      uids = g_ptr_array_new ();
      g_hash_table_insert (bug_mails, bug_id_str, uids);
    }
  else
    {
      g_free (bug_id_str);
    }

  g_assert (uids != NULL);

  g_ptr_array_add (uids, g_strdup (uid));
}

static void
delete_queued_bug_mails (CamelFolder *folder,
			 GHashTable  *bug_mails,
			 long         bug_id,
			 const char  *uid)
{
  GPtrArray *uids;
  char *bug_id_str;

  camel_folder_delete_message (folder, uid);

  bug_id_str = g_strdup_printf ("%ld", bug_id);

  uids = g_hash_table_lookup (bug_mails, bug_id_str);
  if (uids != NULL)
    {
      int i;

      for (i = 0; i < uids->len; i++)
	{
	  uid = uids->pdata[i];

	  camel_folder_delete_message (folder, uid);
	}

      g_hash_table_remove (bug_mails, bug_id_str);
    }

  g_free (bug_id_str);
}

typedef struct
{
  char             *uid;
  CamelMimeMessage *message;
  time_t            date;
} Message;

static int
sort_by_date (Message     **a,
	      Message     **b,
	      CamelFolder  *folder)
{
  g_assert (a && b);

  return (*a)->date - (*b)->date;
}

static void 
handle_folder (char        *uri,
	       CamelFolder *folder,
	       gpointer     data)
{
  GHashTable *bug_mails;
  GPtrArray  *uids;
  Message    *messages;
  int         i;

  bug_mails = get_bug_mails ();

  camel_folder_freeze (folder);

  uids = camel_folder_get_uids (folder);

  messages = g_new0 (Message, uids->len);

  for (i = 0; i < uids->len; i++)
    {
      CamelException ex;

      messages[i].uid = uids->pdata[i];

      camel_exception_init (&ex);

      messages[i].message = camel_folder_get_message (folder, messages[i].uid, &ex);
      if (camel_exception_is_set (&ex))
	{
	  g_assert (messages[i].message == NULL);
	  g_warning ("Failed to get message %s: %s",
		     messages[i].uid,
		     camel_exception_get_description (&ex));
	  camel_exception_clear (&ex);
	}

      if (messages[i].message != NULL)
	{
	  time_t date;
	  int    offset;

	  date = camel_mime_message_get_date (messages[i].message, &offset);

	  messages[i].date = date + (offset * 60 * 60);
	}

      uids->pdata[i] = &messages[i];
    }

  g_ptr_array_sort_with_data (uids,
			      (GCompareDataFunc) sort_by_date,
			      folder);

  for (i = 0; i < uids->len; i++)
    {
      Message          *msg     = uids->pdata[i];
      CamelMimeMessage *message = msg->message;
      const char       *uid     = msg->uid;
      long              bug_id;
      int               status;

      uids->pdata[i] = (char *) uid;

      if (message == NULL)
	continue;

      if (!(bug_id = get_bug_id (message)))
	{
	  camel_object_unref (message);
	  continue;
	}

      switch (status = get_bug_status (message))
	{
	case INVALID:
	  break;

	case UNCONFIRMED:
	case NEW:
	case ASSIGNED:
	case REOPENED:
	  queue_bug_mail (bug_mails, bug_id, uid);
	  break;

	case NEEDINFO:
	case CLOSED:
	case RESOLVED:
	  delete_queued_bug_mails (folder, bug_mails, bug_id, uid);
	  break;

	default:
	  g_assert_not_reached ();
	  break;
	}

      camel_object_unref (message);
    }

  g_free (messages);

  camel_folder_free_uids (folder, uids);

  camel_folder_thaw (folder);

  g_hash_table_destroy (bug_mails);
}

void
delete_resolved_bugs (EPlugin             *plugin,
		      EMPopupTargetFolder *folder)
{
  mail_get_folder (folder->uri,
		   0,
		   handle_folder,
		   NULL,
		   mail_thread_new);
}