/*
 * This program 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 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *   Peter Williams <peterw@ximian.com>
 *   Michael Zucchi <notzed@ximian.com>
 *   Jonathon Jongsma <jonathon.jongsma@collabora.co.uk>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 * Copyright (C) 2009 Intel Corporation
 *
 */

/**
 * SECTION: mail-folder-cache
 * @short_description: Stores information about open folders
 **/

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

#include <string.h>
#include <time.h>

#include <glib/gi18n.h>
#include <glib/gstdio.h>

#include <libedataserver/libedataserver.h>

#include <libemail-engine/mail-mt.h>

#include "mail-folder-cache.h"
#include "e-mail-utils.h"
#include "e-mail-folder-utils.h"
#include "e-mail-session.h"
#include "e-mail-store-utils.h"

#define w(x)
#define d(x)

#define MAIL_FOLDER_CACHE_GET_PRIVATE(obj) \
	(G_TYPE_INSTANCE_GET_PRIVATE \
	((obj), MAIL_TYPE_FOLDER_CACHE, MailFolderCachePrivate))

typedef struct _StoreInfo StoreInfo;
typedef struct _FolderInfo FolderInfo;
typedef struct _AsyncContext AsyncContext;
typedef struct _UpdateClosure UpdateClosure;

struct _MailFolderCachePrivate {
	GMainContext *main_context;

	/* source id for the ping timeout callback */
	guint ping_id;

	/* Store to storeinfo table, active stores */
	GHashTable *store_info_ht;
	GMutex store_info_ht_lock;

	/* hack for people who LIKE to have unsent count */
	gint count_sent;
	gint count_trash;

	GQueue local_folder_uris;
	GQueue remote_folder_uris;
};

enum {
	PROP_0,
	PROP_MAIN_CONTEXT,
};

enum {
	FOLDER_AVAILABLE,
	FOLDER_UNAVAILABLE,
	FOLDER_DELETED,
	FOLDER_RENAMED,
	FOLDER_UNREAD_UPDATED,
	FOLDER_CHANGED,
	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

struct _StoreInfo {
	volatile gint ref_count;

	GMutex lock;

	CamelStore *store;
	gulong folder_opened_handler_id;
	gulong folder_created_handler_id;
	gulong folder_deleted_handler_id;
	gulong folder_renamed_handler_id;
	gulong folder_subscribed_handler_id;
	gulong folder_unsubscribed_handler_id;

	GHashTable *folder_info_ht;	/* by full_name */
	gboolean first_update;		/* TRUE, then FALSE forever */

	/* Hold a reference to keep them alive. */
	CamelFolder *vjunk;
	CamelFolder *vtrash;

	/* Outstanding folderinfo requests */
	GQueue folderinfo_updates;
};

struct _FolderInfo {
	volatile gint ref_count;

	GMutex lock;

	CamelStore *store;
	gchar *full_name;
	CamelFolderInfoFlags flags;

	GWeakRef folder;
	gulong folder_changed_handler_id;
};

struct _AsyncContext {
	StoreInfo *store_info;
	CamelFolderInfo *info;
};

struct _UpdateClosure {
	GWeakRef cache;

	CamelStore *store;

	/* Signal ID for one of:
	 * AVAILABLE, DELETED, RENAMED, UNAVAILABLE */
	guint signal_id;

	gboolean new_messages;

	gchar *full_name;
	gchar *oldfull;

	gint unread;

	/* for only one new message... */
	gchar *msg_uid;
	gchar *msg_sender;
	gchar *msg_subject;
};

/* Forward Declarations */
static void	store_folder_created_cb		(CamelStore *store,
						 CamelFolderInfo *info,
						 MailFolderCache *cache);
static void	store_folder_deleted_cb		(CamelStore *store,
						 CamelFolderInfo *info,
						 MailFolderCache *cache);
static void	store_folder_opened_cb		(CamelStore *store,
						 CamelFolder *folder,
						 MailFolderCache *cache);
static void	store_folder_renamed_cb		(CamelStore *store,
						 const gchar *old_name,
						 CamelFolderInfo *info,
						 MailFolderCache *cache);
static void	store_folder_subscribed_cb	(CamelStore *store,
						 CamelFolderInfo *info,
						 MailFolderCache *cache);
static void	store_folder_unsubscribed_cb	(CamelStore *store,
						 CamelFolderInfo *info,
						 MailFolderCache *cache);

G_DEFINE_TYPE (MailFolderCache, mail_folder_cache, G_TYPE_OBJECT)

static FolderInfo *
folder_info_new (CamelStore *store,
                 const gchar *full_name,
                 CamelFolderInfoFlags flags)
{
	FolderInfo *folder_info;

	folder_info = g_slice_new0 (FolderInfo);
	folder_info->ref_count = 1;
	folder_info->store = g_object_ref (store);
	folder_info->full_name = g_strdup (full_name);
	folder_info->flags = flags;

	g_mutex_init (&folder_info->lock);

	return folder_info;
}

static FolderInfo *
folder_info_ref (FolderInfo *folder_info)
{
	g_return_val_if_fail (folder_info != NULL, NULL);
	g_return_val_if_fail (folder_info->ref_count > 0, NULL);

	g_atomic_int_inc (&folder_info->ref_count);

	return folder_info;
}

static void
folder_info_clear_folder (FolderInfo *folder_info)
{
	CamelFolder *folder;

	g_return_if_fail (folder_info != NULL);

	g_mutex_lock (&folder_info->lock);

	folder = g_weak_ref_get (&folder_info->folder);

	if (folder != NULL) {
		g_signal_handler_disconnect (
			folder,
			folder_info->folder_changed_handler_id);

		g_weak_ref_set (&folder_info->folder, NULL);
		folder_info->folder_changed_handler_id = 0;

		g_object_unref (folder);
	}

	g_mutex_unlock (&folder_info->lock);
}

static void
folder_info_unref (FolderInfo *folder_info)
{
	g_return_if_fail (folder_info != NULL);
	g_return_if_fail (folder_info->ref_count > 0);

	if (g_atomic_int_dec_and_test (&folder_info->ref_count)) {
		folder_info_clear_folder (folder_info);

		g_clear_object (&folder_info->store);
		g_free (folder_info->full_name);

		g_mutex_clear (&folder_info->lock);

		g_slice_free (FolderInfo, folder_info);
	}
}

static StoreInfo *
store_info_new (CamelStore *store)
{
	StoreInfo *store_info;

	store_info = g_slice_new0 (StoreInfo);
	store_info->ref_count = 1;
	store_info->store = g_object_ref (store);
	store_info->first_update = TRUE;

	store_info->folder_info_ht = g_hash_table_new_full (
		(GHashFunc) g_str_hash,
		(GEqualFunc) g_str_equal,
		(GDestroyNotify) NULL,
		(GDestroyNotify) folder_info_unref);

	g_mutex_init (&store_info->lock);

	/* If these are vfolders then they need to be opened
	 * now, otherwise they won't keep track of all folders. */
	if (store->flags & CAMEL_STORE_VJUNK)
		store_info->vjunk = camel_store_get_junk_folder_sync (
			store, NULL, NULL);
	if (store->flags & CAMEL_STORE_VTRASH)
		store_info->vtrash = camel_store_get_trash_folder_sync (
			store, NULL, NULL);

	return store_info;
}

static StoreInfo *
store_info_ref (StoreInfo *store_info)
{
	g_return_val_if_fail (store_info != NULL, NULL);
	g_return_val_if_fail (store_info->ref_count > 0, NULL);

	g_atomic_int_inc (&store_info->ref_count);

	return store_info;
}

static void
store_info_unref (StoreInfo *store_info)
{
	g_return_if_fail (store_info != NULL);
	g_return_if_fail (store_info->ref_count > 0);

	if (g_atomic_int_dec_and_test (&store_info->ref_count)) {

		g_warn_if_fail (
			g_queue_is_empty (
			&store_info->folderinfo_updates));

		if (store_info->folder_opened_handler_id > 0) {
			g_signal_handler_disconnect (
				store_info->store,
				store_info->folder_opened_handler_id);
		}

		if (store_info->folder_created_handler_id > 0) {
			g_signal_handler_disconnect (
				store_info->store,
				store_info->folder_created_handler_id);
		}

		if (store_info->folder_deleted_handler_id > 0) {
			g_signal_handler_disconnect (
				store_info->store,
				store_info->folder_deleted_handler_id);
		}

		if (store_info->folder_subscribed_handler_id > 0) {
			g_signal_handler_disconnect (
				store_info->store,
				store_info->folder_subscribed_handler_id);
		}

		if (store_info->folder_unsubscribed_handler_id > 0) {
			g_signal_handler_disconnect (
				store_info->store,
				store_info->folder_unsubscribed_handler_id);
		}

		g_hash_table_destroy (store_info->folder_info_ht);

		g_clear_object (&store_info->store);
		g_clear_object (&store_info->vjunk);
		g_clear_object (&store_info->vtrash);

		g_mutex_clear (&store_info->lock);

		g_slice_free (StoreInfo, store_info);
	}
}

static FolderInfo *
store_info_ref_folder_info (StoreInfo *store_info,
                            const gchar *folder_name)
{
	GHashTable *folder_info_ht;
	FolderInfo *folder_info;

	g_return_val_if_fail (store_info != NULL, NULL);
	g_return_val_if_fail (folder_name != NULL, NULL);

	g_mutex_lock (&store_info->lock);

	folder_info_ht = store_info->folder_info_ht;

	folder_info = g_hash_table_lookup (folder_info_ht, folder_name);
	if (folder_info != NULL)
		folder_info_ref (folder_info);

	g_mutex_unlock (&store_info->lock);

	return folder_info;
}

static void
store_info_insert_folder_info (StoreInfo *store_info,
                               FolderInfo *folder_info)
{
	GHashTable *folder_info_ht;

	g_return_if_fail (store_info != NULL);
	g_return_if_fail (folder_info != NULL);
	g_return_if_fail (folder_info->full_name != NULL);

	g_mutex_lock (&store_info->lock);

	folder_info_ht = store_info->folder_info_ht;

	g_hash_table_insert (
		folder_info_ht,
		folder_info->full_name,
		folder_info_ref (folder_info));

	g_mutex_unlock (&store_info->lock);
}

static GList *
store_info_list_folder_info (StoreInfo *store_info)
{
	GList *list;

	g_return_val_if_fail (store_info != NULL, NULL);

	g_mutex_lock (&store_info->lock);

	list = g_hash_table_get_values (store_info->folder_info_ht);
	g_list_foreach (list, (GFunc) folder_info_ref, NULL);

	g_mutex_unlock (&store_info->lock);

	return list;
}

static FolderInfo *
store_info_steal_folder_info (StoreInfo *store_info,
                              const gchar *folder_name)
{
	GHashTable *folder_info_ht;
	FolderInfo *folder_info;

	g_return_val_if_fail (store_info != NULL, NULL);
	g_return_val_if_fail (folder_name != NULL, NULL);

	g_mutex_lock (&store_info->lock);

	folder_info_ht = store_info->folder_info_ht;

	folder_info = g_hash_table_lookup (folder_info_ht, folder_name);
	if (folder_info != NULL) {
		folder_info_ref (folder_info);
		g_hash_table_remove (folder_info_ht, folder_name);
	}

	g_mutex_unlock (&store_info->lock);

	return folder_info;
}

static void
async_context_free (AsyncContext *async_context)
{
	if (async_context->info != NULL)
		camel_store_free_folder_info (
			async_context->store_info->store,
			async_context->info);

	store_info_unref (async_context->store_info);

	g_slice_free (AsyncContext, async_context);
}

static UpdateClosure *
update_closure_new (MailFolderCache *cache,
                    CamelStore *store)
{
	UpdateClosure *closure;

	closure = g_slice_new0 (UpdateClosure);
	g_weak_ref_set (&closure->cache, cache);
	closure->store = g_object_ref (store);

	return closure;
}

static void
update_closure_free (UpdateClosure *closure)
{
	g_weak_ref_set (&closure->cache, NULL);

	g_clear_object (&closure->store);

	g_free (closure->full_name);
	g_free (closure->oldfull);
	g_free (closure->msg_uid);
	g_free (closure->msg_sender);
	g_free (closure->msg_subject);

	g_slice_free (UpdateClosure, closure);
}

static StoreInfo *
mail_folder_cache_new_store_info (MailFolderCache *cache,
                                  CamelStore *store)
{
	StoreInfo *store_info;
	gulong handler_id;

	g_return_val_if_fail (store != NULL, NULL);

	store_info = store_info_new (store);

	handler_id = g_signal_connect (
		store, "folder-opened",
		G_CALLBACK (store_folder_opened_cb), cache);
	store_info->folder_opened_handler_id = handler_id;

	handler_id = g_signal_connect (
		store, "folder-created",
		G_CALLBACK (store_folder_created_cb), cache);
	store_info->folder_created_handler_id = handler_id;

	handler_id = g_signal_connect (
		store, "folder-deleted",
		G_CALLBACK (store_folder_deleted_cb), cache);
	store_info->folder_deleted_handler_id = handler_id;

	handler_id = g_signal_connect (
		store, "folder-renamed",
		G_CALLBACK (store_folder_renamed_cb), cache);
	store_info->folder_renamed_handler_id = handler_id;

	if (CAMEL_IS_SUBSCRIBABLE (store)) {
		handler_id = g_signal_connect (
			store, "folder-subscribed",
			G_CALLBACK (store_folder_subscribed_cb), cache);
		store_info->folder_subscribed_handler_id = handler_id;

		handler_id = g_signal_connect (
			store, "folder-unsubscribed",
			G_CALLBACK (store_folder_unsubscribed_cb), cache);
		store_info->folder_unsubscribed_handler_id = handler_id;
	}

	g_mutex_lock (&cache->priv->store_info_ht_lock);

	g_hash_table_insert (
		cache->priv->store_info_ht,
		g_object_ref (store),
		store_info_ref (store_info));

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	return store_info;
}

static StoreInfo *
mail_folder_cache_ref_store_info (MailFolderCache *cache,
                                  CamelStore *store)
{
	GHashTable *store_info_ht;
	StoreInfo *store_info;

	g_return_val_if_fail (store != NULL, NULL);

	g_mutex_lock (&cache->priv->store_info_ht_lock);

	store_info_ht = cache->priv->store_info_ht;

	store_info = g_hash_table_lookup (store_info_ht, store);
	if (store_info != NULL)
		store_info_ref (store_info);

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	return store_info;
}

static GList *
mail_folder_cache_list_stores (MailFolderCache *cache)
{
	GHashTable *store_info_ht;
	GList *list;

	g_mutex_lock (&cache->priv->store_info_ht_lock);

	store_info_ht = cache->priv->store_info_ht;

	list = g_hash_table_get_keys (store_info_ht);
	g_list_foreach (list, (GFunc) g_object_ref, NULL);

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	return list;
}

static StoreInfo *
mail_folder_cache_steal_store_info (MailFolderCache *cache,
                                    CamelStore *store)
{
	GHashTable *store_info_ht;
	StoreInfo *store_info;

	g_return_val_if_fail (store != NULL, NULL);

	g_mutex_lock (&cache->priv->store_info_ht_lock);

	store_info_ht = cache->priv->store_info_ht;

	store_info = g_hash_table_lookup (store_info_ht, store);
	if (store_info != NULL) {
		store_info_ref (store_info);
		g_hash_table_remove (store_info_ht, store);
	}

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	return store_info;
}

static FolderInfo *
mail_folder_cache_ref_folder_info (MailFolderCache *cache,
                                   CamelStore *store,
                                   const gchar *folder_name)
{
	StoreInfo *store_info;
	FolderInfo *folder_info = NULL;

	store_info = mail_folder_cache_ref_store_info (cache, store);
	if (store_info != NULL) {
		folder_info = store_info_ref_folder_info (
			store_info, folder_name);
		store_info_unref (store_info);
	}

	return folder_info;
}

static FolderInfo *
mail_folder_cache_steal_folder_info (MailFolderCache *cache,
                                     CamelStore *store,
                                     const gchar *folder_name)
{
	StoreInfo *store_info;
	FolderInfo *folder_info = NULL;

	store_info = mail_folder_cache_ref_store_info (cache, store);
	if (store_info != NULL) {
		folder_info = store_info_steal_folder_info (
			store_info, folder_name);
		store_info_unref (store_info);
	}

	return folder_info;
}

static gboolean
mail_folder_cache_update_idle_cb (gpointer user_data)
{
	MailFolderCache *cache;
	UpdateClosure *closure;

	closure = (UpdateClosure *) user_data;

	/* Sanity checks. */
	g_return_val_if_fail (closure->full_name != NULL, FALSE);

	cache = g_weak_ref_get (&closure->cache);

	if (cache != NULL) {
		if (closure->signal_id == signals[FOLDER_DELETED]) {
			g_signal_emit (
				cache,
				closure->signal_id, 0,
				closure->store,
				closure->full_name);
		}

		if (closure->signal_id == signals[FOLDER_UNAVAILABLE]) {
			g_signal_emit (
				cache,
				closure->signal_id, 0,
				closure->store,
				closure->full_name);
		}

		if (closure->signal_id == signals[FOLDER_AVAILABLE]) {
			g_signal_emit (
				cache,
				closure->signal_id, 0,
				closure->store,
				closure->full_name);
		}

		if (closure->signal_id == signals[FOLDER_RENAMED]) {
			g_signal_emit (
				cache,
				closure->signal_id, 0,
				closure->store,
				closure->oldfull,
				closure->full_name);
		}

		/* update unread counts */
		g_signal_emit (
			cache,
			signals[FOLDER_UNREAD_UPDATED], 0,
			closure->store,
			closure->full_name,
			closure->unread);

		/* XXX The old code excluded this on FOLDER_RENAMED.
		 *     Not sure if that was intentional (if so it was
		 *     very subtle!) but we'll preserve the behavior.
		 *     If it turns out to be a bug then just remove
		 *     the signal_id check. */
		if (closure->signal_id != signals[FOLDER_RENAMED]) {
			g_signal_emit (
				cache,
				signals[FOLDER_CHANGED], 0,
				closure->store,
				closure->full_name,
				closure->new_messages,
				closure->msg_uid,
				closure->msg_sender,
				closure->msg_subject);
		}

		if (CAMEL_IS_VEE_STORE (closure->store) &&
		   (closure->signal_id == signals[FOLDER_AVAILABLE] ||
		    closure->signal_id == signals[FOLDER_RENAMED])) {
			/* Normally the vfolder store takes care of the
			 * folder_opened event itself, but we add folder to
			 * the noting system later, thus we do not know about
			 * search folders to update them in a tree, thus
			 * ensure their changes will be tracked correctly. */
			CamelFolder *folder;

			/* FIXME camel_store_get_folder_sync() may block. */
			folder = camel_store_get_folder_sync (
				closure->store,
				closure->full_name,
				0, NULL, NULL);

			if (folder != NULL) {
				mail_folder_cache_note_folder (cache, folder);
				g_object_unref (folder);
			}
		}

		g_object_unref (cache);
	}

	return FALSE;
}

static void
mail_folder_cache_submit_update (UpdateClosure *closure)
{
	GMainContext *main_context;
	MailFolderCache *cache;
	GSource *idle_source;

	g_return_if_fail (closure != NULL);

	cache = g_weak_ref_get (&closure->cache);
	g_return_if_fail (cache != NULL);

	main_context = mail_folder_cache_ref_main_context (cache);

	idle_source = g_idle_source_new ();
	g_source_set_callback (
		idle_source,
		mail_folder_cache_update_idle_cb,
		closure,
		(GDestroyNotify) update_closure_free);
	g_source_attach (idle_source, main_context);
	g_source_unref (idle_source);

	g_main_context_unref (main_context);

	g_object_unref (cache);
}

/* This is how unread counts work (and don't work):
 *
 * camel_folder_unread_message_count() only gives a correct answer if
 * the store is paying attention to the folder. (Some stores always
 * pay attention to all folders, but IMAP can only pay attention to
 * one folder at a time.) But it doesn't have any way to know when
 * it's lying, so it's only safe to call it when you know for sure
 * that the store is paying attention to the folder, such as when it's
 * just been created, or you get a folder_changed signal on it.
 *
 * camel_store_get_folder_info() always gives correct answers for the
 * folders it checks, but it can also return -1 for a folder, meaning
 * it didn't check, and so you should stick with your previous answer.
 *
 * update_1folder is called from three places: with info != NULL when
 * the folder is created (or get_folder_info), with info == NULL when
 * a folder changed event is emitted.
 *
 * So if info is NULL, camel_folder_unread_message_count is correct,
 * and if it's not NULL and its unread_message_count isn't -1, then
 * it's correct.  */

static void
update_1folder (MailFolderCache *cache,
                FolderInfo *folder_info,
                gint new_messages,
                const gchar *msg_uid,
                const gchar *msg_sender,
                const gchar *msg_subject,
                CamelFolderInfo *info)
{
	ESourceRegistry *registry;
	CamelService *service;
	CamelSession *session;
	CamelFolder *folder;
	gint unread = -1;
	gint deleted;

	/* XXX This is a dirty way to obtain the ESourceRegistry,
	 *     but it avoids MailFolderCache requiring it up front
	 *     in mail_folder_cache_new(), which just complicates
	 *     application startup even more. */
	service = CAMEL_SERVICE (folder_info->store);
	session = camel_service_get_session (service);
	registry = e_mail_session_get_registry (E_MAIL_SESSION (session));
	g_return_if_fail (E_IS_SOURCE_REGISTRY (registry));

	folder = g_weak_ref_get (&folder_info->folder);

	if (folder != NULL) {
		gboolean folder_is_sent;
		gboolean folder_is_drafts;
		gboolean folder_is_outbox;
		gboolean folder_is_vtrash;
		gboolean special_case;

		folder_is_sent = em_utils_folder_is_sent (registry, folder);
		folder_is_drafts = em_utils_folder_is_drafts (registry, folder);
		folder_is_outbox = em_utils_folder_is_outbox (registry, folder);
		folder_is_vtrash = CAMEL_IS_VTRASH_FOLDER (folder);

		special_case =
			(cache->priv->count_trash && folder_is_vtrash) ||
			(cache->priv->count_sent && folder_is_sent) ||
			folder_is_drafts || folder_is_outbox;

		if (special_case) {
			d (printf (" total count\n"));
			unread = camel_folder_get_message_count (folder);
			if (folder_is_drafts || folder_is_outbox) {
				guint32 junked = 0;

				deleted = camel_folder_get_deleted_message_count (folder);
				if (deleted > 0)
					unread -= deleted;

				junked = camel_folder_summary_get_junk_count (folder->summary);
				if (junked > 0)
					unread -= junked;
			}
		} else {
			d (printf (" unread count\n"));
			if (info)
				unread = info->unread;
			else
				unread = camel_folder_get_unread_message_count (folder);
		}

		g_object_unref (folder);
	}

	d (printf (
		"folder updated: unread %d: '%s'\n",
		unread, folder_info->full_name));

	if (unread >= 0) {
		UpdateClosure *up;

		up = update_closure_new (cache, folder_info->store);
		up->full_name = g_strdup (folder_info->full_name);
		up->unread = unread;
		up->new_messages = new_messages;
		up->msg_uid = g_strdup (msg_uid);
		up->msg_sender = g_strdup (msg_sender);
		up->msg_subject = g_strdup (msg_subject);

		mail_folder_cache_submit_update (up);
	}
}

static void
folder_changed_cb (CamelFolder *folder,
                   CamelFolderChangeInfo *changes,
                   MailFolderCache *cache)
{
	static GHashTable *last_newmail_per_folder = NULL;
	time_t latest_received, new_latest_received;
	CamelFolder *local_drafts;
	CamelFolder *local_outbox;
	CamelFolder *local_sent;
	CamelSession *session;
	CamelStore *parent_store;
	CamelMessageInfo *info;
	FolderInfo *folder_info;
	const gchar *full_name;
	gint new = 0;
	gint i;
	guint32 flags;
	gchar *uid = NULL, *sender = NULL, *subject = NULL;

	full_name = camel_folder_get_full_name (folder);
	parent_store = camel_folder_get_parent_store (folder);
	session = camel_service_ref_session (CAMEL_SERVICE (parent_store));

	if (!last_newmail_per_folder)
		last_newmail_per_folder = g_hash_table_new (g_direct_hash, g_direct_equal);

	/* it's fine to hash them by folder pointer here */
	latest_received = GPOINTER_TO_INT (
		g_hash_table_lookup (last_newmail_per_folder, folder));
	new_latest_received = latest_received;

	local_drafts = e_mail_session_get_local_folder (
		E_MAIL_SESSION (session), E_MAIL_LOCAL_FOLDER_DRAFTS);
	local_outbox = e_mail_session_get_local_folder (
		E_MAIL_SESSION (session), E_MAIL_LOCAL_FOLDER_OUTBOX);
	local_sent = e_mail_session_get_local_folder (
		E_MAIL_SESSION (session), E_MAIL_LOCAL_FOLDER_SENT);

	if (!CAMEL_IS_VEE_FOLDER (folder)
	    && folder != local_drafts
	    && folder != local_outbox
	    && folder != local_sent
	    && changes && (changes->uid_added->len > 0)) {
		/* for each added message, check to see that it is
		 * brand new, not junk and not already deleted */
		for (i = 0; i < changes->uid_added->len; i++) {
			info = camel_folder_get_message_info (
				folder, changes->uid_added->pdata[i]);
			if (info) {
				flags = camel_message_info_flags (info);
				if (((flags & CAMEL_MESSAGE_SEEN) == 0) &&
				    ((flags & CAMEL_MESSAGE_JUNK) == 0) &&
				    ((flags & CAMEL_MESSAGE_DELETED) == 0) &&
				    (camel_message_info_date_received (info) > latest_received)) {
					if (camel_message_info_date_received (info) > new_latest_received)
						new_latest_received = camel_message_info_date_received (info);
					new++;
					if (new == 1) {
						uid = g_strdup (camel_message_info_uid (info));
						sender = g_strdup (camel_message_info_from (info));
						subject = g_strdup (camel_message_info_subject (info));
					} else {
						g_free (uid);
						g_free (sender);
						g_free (subject);

						uid = NULL;
						sender = NULL;
						subject = NULL;
					}
				}
				camel_folder_free_message_info (folder, info);
			}
		}
	}

	if (new > 0)
		g_hash_table_insert (
			last_newmail_per_folder, folder,
			GINT_TO_POINTER (new_latest_received));

	folder_info = mail_folder_cache_ref_folder_info (
		cache, parent_store, full_name);
	if (folder_info != NULL) {
		update_1folder (
			cache, folder_info, new,
			uid, sender, subject, NULL);
		folder_info_unref (folder_info);
	}

	g_free (uid);
	g_free (sender);
	g_free (subject);

	g_object_unref (session);
}

static void
unset_folder_info (MailFolderCache *cache,
                   FolderInfo *folder_info,
                   gint delete)
{
	d (printf ("unset folderinfo '%s'\n", folder_info->uri));

	folder_info_clear_folder (folder_info);

	if ((folder_info->flags & CAMEL_FOLDER_NOSELECT) == 0) {
		UpdateClosure *up;

		up = update_closure_new (cache, folder_info->store);
		up->full_name = g_strdup (folder_info->full_name);

		if (delete)
			up->signal_id = signals[FOLDER_DELETED];
		else
			up->signal_id = signals[FOLDER_UNAVAILABLE];

		mail_folder_cache_submit_update (up);
	}
}

static void
setup_folder (MailFolderCache *cache,
              CamelFolderInfo *fi,
              StoreInfo *store_info)
{
	FolderInfo *folder_info;

	folder_info = store_info_ref_folder_info (store_info, fi->full_name);
	if (folder_info != NULL) {
		update_1folder (cache, folder_info, 0, NULL, NULL, NULL, fi);
		folder_info_unref (folder_info);
	} else {
		UpdateClosure *up;

		folder_info = folder_info_new (
			store_info->store,
			fi->full_name,
			fi->flags);

		store_info_insert_folder_info (store_info, folder_info);

		up = update_closure_new (cache, store_info->store);
		up->full_name = g_strdup (fi->full_name);
		up->unread = fi->unread;

		if ((fi->flags & CAMEL_FOLDER_NOSELECT) == 0)
			up->signal_id = signals[FOLDER_AVAILABLE];

		mail_folder_cache_submit_update (up);

		folder_info_unref (folder_info);
	}
}

static void
create_folders (MailFolderCache *cache,
                CamelFolderInfo *fi,
                StoreInfo *store_info)
{
	while (fi) {
		setup_folder (cache, fi, store_info);

		if (fi->child)
			create_folders (cache, fi->child, store_info);

		fi = fi->next;
	}
}

static void
store_folder_subscribed_cb (CamelStore *store,
                            CamelFolderInfo *info,
                            MailFolderCache *cache)
{
	StoreInfo *store_info;

	store_info = mail_folder_cache_ref_store_info (cache, store);
	if (store_info != NULL) {
		setup_folder (cache, info, store_info);
		store_info_unref (store_info);
	}
}

static void
store_folder_created_cb (CamelStore *store,
                         CamelFolderInfo *info,
                         MailFolderCache *cache)
{
	/* We only want created events to do more work
	 * if we dont support subscriptions. */
	if (!CAMEL_IS_SUBSCRIBABLE (store))
		store_folder_subscribed_cb (store, info, cache);
}

static void
store_folder_opened_cb (CamelStore *store,
                        CamelFolder *folder,
                        MailFolderCache *cache)
{
	mail_folder_cache_note_folder (cache, folder);
}

static void
store_folder_unsubscribed_cb (CamelStore *store,
                              CamelFolderInfo *info,
                              MailFolderCache *cache)
{
	FolderInfo *folder_info;

	folder_info = mail_folder_cache_steal_folder_info (
		cache, store, info->full_name);
	if (folder_info != NULL) {
		unset_folder_info (cache, folder_info, TRUE);
		folder_info_unref (folder_info);
	}
}

static void
store_folder_deleted_cb (CamelStore *store,
                         CamelFolderInfo *info,
                         MailFolderCache *cache)
{
	/* We only want deleted events to do more work
	 * if we dont support subscriptions. */
	if (!CAMEL_IS_SUBSCRIBABLE (store))
		store_folder_unsubscribed_cb (store, info, cache);
}

static void
rename_folders (MailFolderCache *cache,
                StoreInfo *store_info,
                const gchar *oldbase,
                const gchar *newbase,
                CamelFolderInfo *fi)
{
	gchar *old, *olduri, *oldfile, *newuri, *newfile;
	FolderInfo *old_folder_info;
	FolderInfo *new_folder_info;
	UpdateClosure *up;
	const gchar *config_dir;

	up = update_closure_new (cache, store_info->store);
	up->signal_id = signals[FOLDER_AVAILABLE];

	/* Form what was the old name, and try and look it up */
	old = g_strdup_printf ("%s%s", oldbase, fi->full_name + strlen (newbase));
	old_folder_info = store_info_steal_folder_info (store_info, old);
	if (old_folder_info != NULL) {
		up->oldfull = g_strdup (old_folder_info->full_name);
		up->signal_id = signals[FOLDER_RENAMED];
		folder_info_unref (old_folder_info);
	}

	new_folder_info = folder_info_new (
		store_info->store,
		fi->full_name,
		fi->flags);

	store_info_insert_folder_info (store_info, new_folder_info);

	folder_info_unref (new_folder_info);

	up->full_name = g_strdup (fi->full_name);
	up->unread = fi->unread==-1 ? 0 : fi->unread;

	/* No signal emission for NOSELECT folders. */
	if ((fi->flags & CAMEL_FOLDER_NOSELECT) != 0)
		up->signal_id = 0;

	mail_folder_cache_submit_update (up);

	/* rename the meta-data we maintain ourselves */
	config_dir = mail_session_get_config_dir ();
	olduri = e_mail_folder_uri_build (store_info->store, old);
	e_filename_make_safe (olduri);
	newuri = e_mail_folder_uri_build (store_info->store, fi->full_name);
	e_filename_make_safe (newuri);
	oldfile = g_strdup_printf ("%s/custom_view-%s.xml", config_dir, olduri);
	newfile = g_strdup_printf ("%s/custom_view-%s.xml", config_dir, newuri);
	g_rename (oldfile, newfile);
	g_free (oldfile);
	g_free (newfile);
	oldfile = g_strdup_printf ("%s/current_view-%s.xml", config_dir, olduri);
	newfile = g_strdup_printf ("%s/current_view-%s.xml", config_dir, newuri);
	g_rename (oldfile, newfile);
	g_free (oldfile);
	g_free (newfile);
	g_free (olduri);
	g_free (newuri);

	g_free (old);
}

static void
get_folders (CamelFolderInfo *fi,
             GPtrArray *folders)
{
	while (fi) {
		g_ptr_array_add (folders, fi);

		if (fi->child)
			get_folders (fi->child, folders);

		fi = fi->next;
	}
}

static gint
folder_cmp (gconstpointer ap,
            gconstpointer bp)
{
	const CamelFolderInfo *a = ((CamelFolderInfo **) ap)[0];
	const CamelFolderInfo *b = ((CamelFolderInfo **) bp)[0];

	return strcmp (a->full_name, b->full_name);
}

static void
store_folder_renamed_cb (CamelStore *store,
                         const gchar *old_name,
                         CamelFolderInfo *info,
                         MailFolderCache *cache)
{
	StoreInfo *store_info;

	store_info = mail_folder_cache_ref_store_info (cache, store);
	if (store_info != NULL) {
		GPtrArray *folders = g_ptr_array_new ();
		CamelFolderInfo *top;
		gint ii;

		/* Ok, so for some reason the folderinfo we have comes in all
		 * messed up from imap, should find out why ... this makes it
		 * workable.
		 * XXX This refers to the old IMAP backend, not IMAPX, and so
		 *     this may not be needed anymore. */
		get_folders (info, folders);
		g_ptr_array_sort (folders, (GCompareFunc) folder_cmp);

		top = folders->pdata[0];
		for (ii = 0; ii < folders->len; ii++) {
			rename_folders (
				cache, store_info, old_name,
				top->full_name, folders->pdata[ii]);
		}

		g_ptr_array_free (folders, TRUE);

		store_info_unref (store_info);
	}
}

struct _ping_store_msg {
	MailMsg base;
	CamelStore *store;
};

static gchar *
ping_store_desc (struct _ping_store_msg *m)
{
	gchar *service_name;
	gchar *msg;

	service_name = camel_service_get_name (CAMEL_SERVICE (m->store), TRUE);
	msg = g_strdup_printf (_("Pinging %s"), service_name);
	g_free (service_name);

	return msg;
}

static void
ping_store_exec (struct _ping_store_msg *m,
                 GCancellable *cancellable,
                 GError **error)
{
	CamelServiceConnectionStatus status;
	CamelService *service;
	gboolean online = FALSE;

	service = CAMEL_SERVICE (m->store);
	status = camel_service_get_connection_status (service);

	if (status == CAMEL_SERVICE_CONNECTED) {
		if (CAMEL_IS_DISCO_STORE (m->store) &&
			camel_disco_store_status (
			CAMEL_DISCO_STORE (m->store)) !=CAMEL_DISCO_STORE_OFFLINE)
			online = TRUE;
		else if (CAMEL_IS_OFFLINE_STORE (m->store) &&
			camel_offline_store_get_online (
			CAMEL_OFFLINE_STORE (m->store)))
			online = TRUE;
	}
	if (online)
		camel_store_noop_sync (m->store, cancellable, error);
}

static void
ping_store_free (struct _ping_store_msg *m)
{
	g_object_unref (m->store);
}

static MailMsgInfo ping_store_info = {
	sizeof (struct _ping_store_msg),
	(MailMsgDescFunc) ping_store_desc,
	(MailMsgExecFunc) ping_store_exec,
	(MailMsgDoneFunc) NULL,
	(MailMsgFreeFunc) ping_store_free
};

static gboolean
ping_cb (MailFolderCache *cache)
{
	GList *list, *link;

	list = mail_folder_cache_list_stores (cache);

	for (link = list; link != NULL; link = g_list_next (link)) {
		CamelService *service;
		CamelServiceConnectionStatus status;
		struct _ping_store_msg *m;

		service = CAMEL_SERVICE (link->data);
		status = camel_service_get_connection_status (service);

		if (status != CAMEL_SERVICE_CONNECTED)
			continue;

		m = mail_msg_new (&ping_store_info);
		m->store = g_object_ref (service);

		mail_msg_slow_ordered_push (m);
	}

	g_list_free_full (list, (GDestroyNotify) g_object_unref);

	return TRUE;
}

static gboolean
store_has_folder_hierarchy (CamelStore *store)
{
	CamelProvider *provider;

	g_return_val_if_fail (store != NULL, FALSE);

	provider = camel_service_get_provider (CAMEL_SERVICE (store));
	g_return_val_if_fail (provider != NULL, FALSE);

	if (provider->flags & CAMEL_PROVIDER_IS_STORAGE)
		return TRUE;

	if (provider->flags & CAMEL_PROVIDER_IS_EXTERNAL)
		return TRUE;

	return FALSE;
}

static GList *
find_folder_uri (GQueue *queue,
                 CamelSession *session,
                 const gchar *folder_uri)
{
	GList *head, *link;

	head = g_queue_peek_head_link (queue);

	for (link = head; link != NULL; link = g_list_next (link))
		if (e_mail_folder_uri_equal (session, link->data, folder_uri))
			break;

	return link;
}

static void
mail_folder_cache_get_property (GObject *object,
                                guint property_id,
                                GValue *value,
                                GParamSpec *pspec)
{
	switch (property_id) {
		case PROP_MAIN_CONTEXT:
			g_value_take_boxed (
				value,
				mail_folder_cache_ref_main_context (
				MAIL_FOLDER_CACHE (object)));
			return;
	}

	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
mail_folder_cache_dispose (GObject *object)
{
	MailFolderCachePrivate *priv;

	priv = MAIL_FOLDER_CACHE_GET_PRIVATE (object);

	g_hash_table_remove_all (priv->store_info_ht);

	/* Chain up to parent's dispose() method. */
	G_OBJECT_CLASS (mail_folder_cache_parent_class)->dispose (object);
}

static void
mail_folder_cache_finalize (GObject *object)
{
	MailFolderCachePrivate *priv;

	priv = MAIL_FOLDER_CACHE_GET_PRIVATE (object);

	g_main_context_unref (priv->main_context);

	g_hash_table_destroy (priv->store_info_ht);
	g_mutex_clear (&priv->store_info_ht_lock);

	if (priv->ping_id > 0) {
		g_source_remove (priv->ping_id);
		priv->ping_id = 0;
	}

	while (!g_queue_is_empty (&priv->local_folder_uris))
		g_free (g_queue_pop_head (&priv->local_folder_uris));

	while (!g_queue_is_empty (&priv->remote_folder_uris))
		g_free (g_queue_pop_head (&priv->remote_folder_uris));

	/* Chain up to parent's finalize() method. */
	G_OBJECT_CLASS (mail_folder_cache_parent_class)->finalize (object);
}

static void
mail_folder_cache_folder_available (MailFolderCache *cache,
                                    CamelStore *store,
                                    const gchar *folder_name)
{
	CamelService *service;
	CamelSession *session;
	CamelProvider *provider;
	GQueue *queue;
	gchar *folder_uri;

	/* Disregard virtual stores. */
	if (CAMEL_IS_VEE_STORE (store))
		return;

	/* Disregard virtual Junk folders. */
	if (store->flags & CAMEL_STORE_VJUNK)
		if (g_strcmp0 (folder_name, CAMEL_VJUNK_NAME) == 0)
			return;

	/* Disregard virtual Trash folders. */
	if (store->flags & CAMEL_STORE_VTRASH)
		if (g_strcmp0 (folder_name, CAMEL_VTRASH_NAME) == 0)
			return;

	service = CAMEL_SERVICE (store);
	session = camel_service_ref_session (service);
	provider = camel_service_get_provider (service);

	/* Reuse the store info lock just because it's handy. */
	g_mutex_lock (&cache->priv->store_info_ht_lock);

	folder_uri = e_mail_folder_uri_build (store, folder_name);

	if (provider->flags & CAMEL_PROVIDER_IS_REMOTE)
		queue = &cache->priv->remote_folder_uris;
	else
		queue = &cache->priv->local_folder_uris;

	if (find_folder_uri (queue, session, folder_uri) == NULL)
		g_queue_push_tail (queue, folder_uri);
	else
		g_free (folder_uri);

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	g_object_unref (session);
}

static void
mail_folder_cache_folder_unavailable (MailFolderCache *cache,
                                      CamelStore *store,
                                      const gchar *folder_name)
{
	CamelService *service;
	CamelSession *session;
	CamelProvider *provider;
	GQueue *queue;
	GList *link;
	gchar *folder_uri;

	/* Disregard virtual stores. */
	if (CAMEL_IS_VEE_STORE (store))
		return;

	/* Disregard virtual Junk folders. */
	if (store->flags & CAMEL_STORE_VJUNK)
		if (g_strcmp0 (folder_name, CAMEL_VJUNK_NAME) == 0)
			return;

	/* Disregard virtual Trash folders. */
	if (store->flags & CAMEL_STORE_VTRASH)
		if (g_strcmp0 (folder_name, CAMEL_VTRASH_NAME) == 0)
			return;

	service = CAMEL_SERVICE (store);
	session = camel_service_ref_session (service);
	provider = camel_service_get_provider (service);

	/* Reuse the store info lock just because it's handy. */
	g_mutex_lock (&cache->priv->store_info_ht_lock);

	folder_uri = e_mail_folder_uri_build (store, folder_name);

	if (provider->flags & CAMEL_PROVIDER_IS_REMOTE)
		queue = &cache->priv->remote_folder_uris;
	else
		queue = &cache->priv->local_folder_uris;

	link = find_folder_uri (queue, session, folder_uri);
	if (link != NULL) {
		g_free (link->data);
		g_queue_delete_link (queue, link);
	}

	g_free (folder_uri);

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	g_object_unref (session);
}

static void
mail_folder_cache_folder_deleted (MailFolderCache *cache,
                                  CamelStore *store,
                                  const gchar *folder_name)
{
	CamelService *service;
	CamelSession *session;
	GQueue *queue;
	GList *link;
	gchar *folder_uri;

	/* Disregard virtual stores. */
	if (CAMEL_IS_VEE_STORE (store))
		return;

	/* Disregard virtual Junk folders. */
	if (store->flags & CAMEL_STORE_VJUNK)
		if (g_strcmp0 (folder_name, CAMEL_VJUNK_NAME) == 0)
			return;

	/* Disregard virtual Trash folders. */
	if (store->flags & CAMEL_STORE_VTRASH)
		if (g_strcmp0 (folder_name, CAMEL_VTRASH_NAME) == 0)
			return;

	service = CAMEL_SERVICE (store);
	session = camel_service_ref_session (service);

	/* Reuse the store info lock just because it's handy. */
	g_mutex_lock (&cache->priv->store_info_ht_lock);

	folder_uri = e_mail_folder_uri_build (store, folder_name);

	queue = &cache->priv->local_folder_uris;
	link = find_folder_uri (queue, session, folder_uri);
	if (link != NULL) {
		g_free (link->data);
		g_queue_delete_link (queue, link);
	}

	queue = &cache->priv->remote_folder_uris;
	link = find_folder_uri (queue, session, folder_uri);
	if (link != NULL) {
		g_free (link->data);
		g_queue_delete_link (queue, link);
	}

	g_free (folder_uri);

	g_mutex_unlock (&cache->priv->store_info_ht_lock);

	g_object_unref (session);
}

static void
mail_folder_cache_class_init (MailFolderCacheClass *class)
{
	GObjectClass *object_class;

	g_type_class_add_private (class, sizeof (MailFolderCachePrivate));

	object_class = G_OBJECT_CLASS (class);
	object_class->get_property = mail_folder_cache_get_property;
	object_class->dispose = mail_folder_cache_dispose;
	object_class->finalize = mail_folder_cache_finalize;

	class->folder_available = mail_folder_cache_folder_available;
	class->folder_unavailable = mail_folder_cache_folder_unavailable;
	class->folder_deleted = mail_folder_cache_folder_deleted;

	g_object_class_install_property (
		object_class,
		PROP_MAIN_CONTEXT,
		g_param_spec_boxed (
			"main-context",
			"Main Context",
			"The main loop context on "
			"which to attach event sources",
			G_TYPE_MAIN_CONTEXT,
			G_PARAM_READABLE |
			G_PARAM_STATIC_STRINGS));

	/**
	 * MailFolderCache::folder-available
	 * @store: the #CamelStore containing the folder
	 * @folder_name: the name of the folder
	 *
	 * Emitted when a folder becomes available
	 **/
	signals[FOLDER_AVAILABLE] = g_signal_new (
		"folder-available",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_available),
		NULL, NULL, NULL,
		G_TYPE_NONE, 2,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING);

	/**
	 * MailFolderCache::folder-unavailable
	 * @store: the #CamelStore containing the folder
	 * @folder_name: the name of the folder
	 *
	 * Emitted when a folder becomes unavailable.  This represents a
	 * transient condition.  See MailFolderCache::folder-deleted to be
	 * notified when a folder is permanently removed.
	 **/
	signals[FOLDER_UNAVAILABLE] = g_signal_new (
		"folder-unavailable",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_unavailable),
		NULL, NULL, NULL,
		G_TYPE_NONE, 2,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING);

	/**
	 * MailFolderCache::folder-deleted
	 * @store: the #CamelStore containing the folder
	 * @folder_name: the name of the folder
	 *
	 * Emitted when a folder is deleted
	 **/
	signals[FOLDER_DELETED] = g_signal_new (
		"folder-deleted",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_deleted),
		NULL, NULL, /* accumulator */
		NULL,
		G_TYPE_NONE, 2,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING);

	/**
	 * MailFolderCache::folder-renamed
	 * @store: the #CamelStore containing the folder
	 * @old_folder_name: the old name of the folder
	 * @new_folder_name: the new name of the folder
	 *
	 * Emitted when a folder is renamed
	 **/
	signals[FOLDER_RENAMED] = g_signal_new (
		"folder-renamed",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_renamed),
		NULL, NULL, NULL,
		G_TYPE_NONE, 3,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING,
		G_TYPE_STRING);

	/**
	 * MailFolderCache::folder-unread-updated
	 * @store: the #CamelStore containing the folder
	 * @folder_name: the name of the folder
	 * @unread: the number of unread mails in the folder
	 *
	 * Emitted when a we receive an update to the unread count for a folder
	 **/
	signals[FOLDER_UNREAD_UPDATED] = g_signal_new (
		"folder-unread-updated",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_unread_updated),
		NULL, NULL, NULL,
		G_TYPE_NONE, 3,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING,
		G_TYPE_INT);

	/**
	 * MailFolderCache::folder-changed
	 * @store: the #CamelStore containing the folder
	 * @folder_name: the name of the folder
	 * @new_messages: the number of new messages for the folder
	 * @msg_uid: uid of the new message, or NULL
	 * @msg_sender: sender of the new message, or NULL
	 * @msg_subject: subject of the new message, or NULL
	 *
	 * Emitted when a folder has changed.  If @new_messages is not
	 * exactly 1, @msg_uid, @msg_sender, and @msg_subject will be NULL.
	 **/
	signals[FOLDER_CHANGED] = g_signal_new (
		"folder-changed",
		G_OBJECT_CLASS_TYPE (object_class),
		G_SIGNAL_RUN_FIRST,
		G_STRUCT_OFFSET (MailFolderCacheClass, folder_changed),
		NULL, NULL, NULL,
		G_TYPE_NONE, 6,
		CAMEL_TYPE_STORE,
		G_TYPE_STRING,
		G_TYPE_INT,
		G_TYPE_STRING,
		G_TYPE_STRING,
		G_TYPE_STRING);
}

static void
mail_folder_cache_init (MailFolderCache *cache)
{
	GHashTable *store_info_ht;
	const gchar *buf;
	guint timeout;

	store_info_ht = g_hash_table_new_full (
		(GHashFunc) g_direct_hash,
		(GEqualFunc) g_direct_equal,
		(GDestroyNotify) g_object_unref,
		(GDestroyNotify) store_info_unref);

	cache->priv = MAIL_FOLDER_CACHE_GET_PRIVATE (cache);
	cache->priv->main_context = g_main_context_ref_thread_default ();

	cache->priv->store_info_ht = store_info_ht;
	g_mutex_init (&cache->priv->store_info_ht_lock);

	cache->priv->count_sent = getenv ("EVOLUTION_COUNT_SENT") != NULL;
	cache->priv->count_trash = getenv ("EVOLUTION_COUNT_TRASH") != NULL;

	buf = getenv ("EVOLUTION_PING_TIMEOUT");
	timeout = buf ? strtoul (buf, NULL, 10) : 600;
	cache->priv->ping_id = g_timeout_add_seconds (
		timeout, (GSourceFunc) ping_cb, cache);

	g_queue_init (&cache->priv->local_folder_uris);
	g_queue_init (&cache->priv->remote_folder_uris);
}

MailFolderCache *
mail_folder_cache_new (void)
{
	return g_object_new (MAIL_TYPE_FOLDER_CACHE, NULL);
}

/**
 * mail_folder_cache_ref_main_context:
 *
 * Returns the #GMainContext on which event sources for @cache are to be
 * attached.
 *
 * The returned #GMainContext is referenced for thread-safety and should
 * be unreferenced with g_main_context_unref() when finished with it.
 *
 * Returns: a #GMainContext
 **/
GMainContext *
mail_folder_cache_ref_main_context (MailFolderCache *cache)
{
	g_return_val_if_fail (MAIL_IS_FOLDER_CACHE (cache), NULL);

	return g_main_context_ref (cache->priv->main_context);
}

/* Helper for mail_folder_cache_note_store() */
static void
mail_folder_cache_first_update (MailFolderCache *cache,
                                StoreInfo *store_info)
{
	CamelService *service;
	CamelSession *session;
	const gchar *uid;

	service = CAMEL_SERVICE (store_info->store);
	session = camel_service_ref_session (service);
	uid = camel_service_get_uid (service);

	if (store_info->vjunk != NULL)
		mail_folder_cache_note_folder (cache, store_info->vjunk);

	if (store_info->vtrash != NULL)
		mail_folder_cache_note_folder (cache, store_info->vtrash);

	/* Some extra work for the "On This Computer" store. */
	if (g_strcmp0 (uid, E_MAIL_SESSION_LOCAL_UID) == 0) {
		CamelFolder *folder;
		gint ii;

		for (ii = 0; ii < E_MAIL_NUM_LOCAL_FOLDERS; ii++) {
			folder = e_mail_session_get_local_folder (
				E_MAIL_SESSION (session), ii);
			mail_folder_cache_note_folder (cache, folder);
		}
	}

	g_object_unref (session);
}

/* Helper for mail_folder_cache_note_store() */
static void
mail_folder_cache_note_store_thread (GSimpleAsyncResult *simple,
                                     GObject *source_object,
                                     GCancellable *cancellable)
{
	MailFolderCache *cache;
	CamelService *service;
	CamelSession *session;
	StoreInfo *store_info;
	GQueue result_queue = G_QUEUE_INIT;
	AsyncContext *async_context;
	GError *local_error = NULL;

	cache = MAIL_FOLDER_CACHE (source_object);
	async_context = g_simple_async_result_get_op_res_gpointer (simple);
	store_info = async_context->store_info;

	service = CAMEL_SERVICE (store_info->store);
	session = camel_service_ref_session (service);

	/* We might get a race when setting up a store, such that it is
	 * still left in offline mode, after we've gone online.  This
	 * catches and fixes it up when the shell opens us.
	 *
	 * XXX This is a Bonobo-era artifact.  Do we really still need
	 *     to do this?  Also, CamelDiscoStore needs to die already!
	 */
	if (camel_session_get_online (session)) {
		gboolean store_online = TRUE;

		if (CAMEL_IS_DISCO_STORE (service)) {
			CamelDiscoStore *disco_store;
			CamelDiscoStoreStatus status;

			disco_store = CAMEL_DISCO_STORE (service);
			status = camel_disco_store_status (disco_store);
			store_online = (status != CAMEL_DISCO_STORE_OFFLINE);
		}

		if (CAMEL_IS_OFFLINE_STORE (service)) {
			store_online = camel_offline_store_get_online (
				CAMEL_OFFLINE_STORE (service));
		}

		if (!store_online) {
			e_mail_store_go_online_sync (
				CAMEL_STORE (service),
				cancellable, &local_error);

			if (local_error != NULL) {
				g_simple_async_result_take_error (
					simple, local_error);
				goto exit;
			}
		}
	}

	/* No folder hierarchy means we're done. */
	if (!store_has_folder_hierarchy (store_info->store))
		goto exit;

	/* XXX This can return NULL without setting a GError if no
	 *     folders match the search criteria or the store does
	 *     not support folders.
	 *
	 *     The function signature should be changed to return a
	 *     boolean with the CamelFolderInfo returned through an
	 *     "out" parameter so it's easier to distinguish errors
	 *     from empty results.
	 */
	async_context->info = camel_store_get_folder_info_sync (
		store_info->store, NULL,
		CAMEL_STORE_FOLDER_INFO_FAST |
		CAMEL_STORE_FOLDER_INFO_RECURSIVE |
		CAMEL_STORE_FOLDER_INFO_SUBSCRIBED,
		cancellable, &local_error);

	if (local_error != NULL) {
		g_warn_if_fail (async_context->info == NULL);
		g_simple_async_result_take_error (simple, local_error);
		goto exit;
	}

	create_folders (cache, async_context->info, store_info);

	/* Do some extra work for the first update. */
	if (store_info->first_update) {
		mail_folder_cache_first_update (cache, store_info);
		store_info->first_update = FALSE;
	}

exit:
	/* We don't want finish() functions being invoked while holding a
	 * locked mutex, so flush the StoreInfo's queue to a local queue. */
	g_mutex_lock (&store_info->lock);
	e_queue_transfer (&store_info->folderinfo_updates, &result_queue);
	g_mutex_unlock (&store_info->lock);

	while (!g_queue_is_empty (&result_queue)) {
		GSimpleAsyncResult *queued_result;

		queued_result = g_queue_pop_head (&result_queue);

		/* Skip the GSimpleAsyncResult passed into this function.
		 * g_simple_async_result_run_in_thread() will complete it
		 * for us, and we don't want to complete it twice. */
		if (queued_result != simple)
			g_simple_async_result_complete_in_idle (queued_result);

		g_clear_object (&queued_result);
	}

	g_object_unref (session);
}

/**
 * mail_folder_cache_note_store:
 *
 * Add a store whose folders should appear in the shell The folders are scanned
 * from the store, and/or added at runtime via the folder_created event.  The
 * @done function returns if we can free folder info.
 */
void
mail_folder_cache_note_store (MailFolderCache *cache,
                              CamelStore *store,
                              GCancellable *cancellable,
                              GAsyncReadyCallback callback,
                              gpointer user_data)
{
	StoreInfo *store_info;
	GSimpleAsyncResult *simple;
	AsyncContext *async_context;

	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (CAMEL_IS_STORE (store));

	store_info = mail_folder_cache_ref_store_info (cache, store);
	if (store_info == NULL)
		store_info = mail_folder_cache_new_store_info (cache, store);

	async_context = g_slice_new0 (AsyncContext);
	async_context->store_info = store_info_ref (store_info);

	simple = g_simple_async_result_new (
		G_OBJECT (cache), callback, user_data,
		mail_folder_cache_note_store);

	g_simple_async_result_set_check_cancellable (simple, cancellable);

	g_simple_async_result_set_op_res_gpointer (
		simple, async_context, (GDestroyNotify) async_context_free);

	g_mutex_lock (&store_info->lock);

	g_queue_push_tail (
		&store_info->folderinfo_updates,
		g_object_ref (simple));

	/* Queue length > 1 means there's already an operation for
	 * this store in progress so we'll just pick up the result
	 * when it finishes. */
	if (g_queue_get_length (&store_info->folderinfo_updates) == 1)
		g_simple_async_result_run_in_thread (
			simple,
			mail_folder_cache_note_store_thread,
			G_PRIORITY_DEFAULT, cancellable);

	g_mutex_unlock (&store_info->lock);

	g_object_unref (simple);

	store_info_unref (store_info);
}

gboolean
mail_folder_cache_note_store_finish (MailFolderCache *cache,
                                     GAsyncResult *result,
                                     CamelFolderInfo **out_info,
                                     GError **error)
{
	GSimpleAsyncResult *simple;
	AsyncContext *async_context;

	g_return_val_if_fail (
		g_simple_async_result_is_valid (
		result, G_OBJECT (cache),
		mail_folder_cache_note_store), FALSE);

	simple = G_SIMPLE_ASYNC_RESULT (result);
	async_context = g_simple_async_result_get_op_res_gpointer (simple);

	if (g_simple_async_result_propagate_error (simple, error))
		return FALSE;

	if (out_info != NULL) {
		if (async_context->info != NULL)
			*out_info = camel_folder_info_clone (
				async_context->info);
		else
			*out_info = NULL;
	}

	return TRUE;
}

/**
 * mail_folder_cache_note_folder:
 *
 * When a folder has been opened, notify it for watching.  The folder must have
 * already been created on the store (which has already been noted) before the
 * folder can be opened
 */
void
mail_folder_cache_note_folder (MailFolderCache *cache,
                               CamelFolder *folder)
{
	CamelStore *parent_store;
	CamelFolder *cached_folder;
	FolderInfo *folder_info;
	const gchar *full_name;

	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (CAMEL_IS_FOLDER (folder));

	full_name = camel_folder_get_full_name (folder);
	parent_store = camel_folder_get_parent_store (folder);

	folder_info = mail_folder_cache_ref_folder_info (
		cache, parent_store, full_name);

	/* XXX Not sure we should just be returning quietly here, but
	 *     the old code did.  Using g_return_if_fail() causes a few
	 *     warnings on startup which might be worth tracking down. */
	if (folder_info == NULL)
		return;

	g_mutex_lock (&folder_info->lock);

	cached_folder = g_weak_ref_get (&folder_info->folder);
	if (cached_folder != NULL) {
		g_signal_handler_disconnect (
			cached_folder,
			folder_info->folder_changed_handler_id);
		g_object_unref (cached_folder);
	}

	g_weak_ref_set (&folder_info->folder, folder);

	update_1folder (cache, folder_info, 0, NULL, NULL, NULL, NULL);

	folder_info->folder_changed_handler_id =
		g_signal_connect (
			folder, "changed",
			G_CALLBACK (folder_changed_cb), cache);

	g_mutex_unlock (&folder_info->lock);

	folder_info_unref (folder_info);
}

/**
 * mail_folder_cache_has_folder_info:
 * @cache: a #MailFolderCache
 * @store: a #CamelStore
 * @folder_name: a folder name
 *
 * Returns whether @cache has information about the folder described by
 * @store and @folder_name.  This does not necessarily mean it has the
 * #CamelFolder instance, but it at least has some meta-data about it.
 *
 * You can use this function as a folder existence test.
 *
 * Returns: %TRUE if @cache has folder info, %FALSE otherwise
 **/
gboolean
mail_folder_cache_has_folder_info (MailFolderCache *cache,
                                   CamelStore *store,
                                   const gchar *folder_name)
{
	FolderInfo *folder_info;
	gboolean has_info = FALSE;

	g_return_val_if_fail (MAIL_IS_FOLDER_CACHE (cache), FALSE);
	g_return_val_if_fail (CAMEL_IS_STORE (store), FALSE);
	g_return_val_if_fail (folder_name != NULL, FALSE);

	folder_info = mail_folder_cache_ref_folder_info (
		cache, store, folder_name);
	if (folder_info != NULL) {
		folder_info_unref (folder_info);
		has_info = TRUE;
	}

	return has_info;
}

/**
 * mail_folder_cache_ref_folder:
 * @cache: a #MailFolderCache
 * @store: a #CamelStore
 * @folder_name: a folder name
 *
 * Returns the #CamelFolder for @store and @folder_name if available, or
 * else %NULL if a #CamelFolder instance is not yet cached.  This function
 * does not block.
 *
 * The returned #CamelFolder is referenced for thread-safety and must be
 * unreferenced with g_object_unref() when finished with it.
 *
 * Returns: a #CamelFolder, or %NULL
 **/
CamelFolder *
mail_folder_cache_ref_folder (MailFolderCache *cache,
                              CamelStore *store,
                              const gchar *folder_name)
{
	FolderInfo *folder_info;
	CamelFolder *folder = NULL;

	g_return_val_if_fail (MAIL_IS_FOLDER_CACHE (cache), NULL);
	g_return_val_if_fail (CAMEL_IS_STORE (store), NULL);
	g_return_val_if_fail (folder_name != NULL, NULL);

	folder_info = mail_folder_cache_ref_folder_info (
		cache, store, folder_name);
	if (folder_info != NULL) {
		folder = g_weak_ref_get (&folder_info->folder);
		folder_info_unref (folder_info);
	}

	return folder;
}

/**
 * mail_folder_cache_get_folder_info_flags:
 * @cache: a #MailFolderCache
 * @store: a #CamelStore
 * @folder_name: a folder name
 * @flags: return location for #CamelFolderInfoFlags
 *
 * Obtains #CamelFolderInfoFlags for @store and @folder_name if available,
 * and returns %TRUE to indicate @flags was set.  If no folder information
 * is available for @store and @folder_name, the function returns %FALSE.
 *
 * Returns: whether @flags was set
 **/
gboolean
mail_folder_cache_get_folder_info_flags (MailFolderCache *cache,
                                         CamelStore *store,
                                         const gchar *folder_name,
                                         CamelFolderInfoFlags *flags)
{
	FolderInfo *folder_info;
	gboolean flags_set = FALSE;

	g_return_val_if_fail (MAIL_IS_FOLDER_CACHE (cache), FALSE);
	g_return_val_if_fail (CAMEL_IS_STORE (store), FALSE);
	g_return_val_if_fail (folder_name != NULL, FALSE);
	g_return_val_if_fail (flags != NULL, FALSE);

	folder_info = mail_folder_cache_ref_folder_info (
		cache, store, folder_name);
	if (folder_info != NULL) {
		*flags = folder_info->flags;
		folder_info_unref (folder_info);
		flags_set = TRUE;
	}

	return flags_set;
}

void
mail_folder_cache_get_local_folder_uris (MailFolderCache *cache,
                                         GQueue *out_queue)
{
	GList *head, *link;

	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (out_queue != NULL);

	/* Reuse the store_info_ht_lock just because it's handy. */
	g_mutex_lock (&cache->priv->store_info_ht_lock);

	head = g_queue_peek_head_link (&cache->priv->local_folder_uris);

	for (link = head; link != NULL; link = g_list_next (link))
		g_queue_push_tail (out_queue, g_strdup (link->data));

	g_mutex_unlock (&cache->priv->store_info_ht_lock);
}

void
mail_folder_cache_get_remote_folder_uris (MailFolderCache *cache,
                                          GQueue *out_queue)
{
	GList *head, *link;

	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (out_queue != NULL);

	/* Reuse the store_info_ht_lock just because it's handy. */
	g_mutex_lock (&cache->priv->store_info_ht_lock);

	head = g_queue_peek_head_link (&cache->priv->remote_folder_uris);

	for (link = head; link != NULL; link = g_list_next (link))
		g_queue_push_tail (out_queue, g_strdup (link->data));

	g_mutex_unlock (&cache->priv->store_info_ht_lock);
}

void
mail_folder_cache_service_removed (MailFolderCache *cache,
                                   CamelService *service)
{
	StoreInfo *store_info;

	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (CAMEL_IS_SERVICE (service));

	if (!CAMEL_IS_STORE (service))
		return;

	store_info = mail_folder_cache_steal_store_info (
		cache, CAMEL_STORE (service));
	if (store_info != NULL) {
		GList *list, *link;

		list = store_info_list_folder_info (store_info);

		for (link = list; link != NULL; link = g_list_next (link))
			unset_folder_info (cache, link->data, FALSE);

		g_list_free_full (list, (GDestroyNotify) folder_info_unref);

		store_info_unref (store_info);
	}
}

void
mail_folder_cache_service_enabled (MailFolderCache *cache,
                                   CamelService *service)
{
	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (CAMEL_IS_SERVICE (service));

	/* XXX This has no callback and it swallows errors.  Maybe
	 *     we don't want a service_enabled() function after all?
	 *     Call mail_folder_cache_note_store() directly instead
	 *     and handle errors appropriately. */
	mail_folder_cache_note_store (
		cache, CAMEL_STORE (service), NULL, NULL, NULL);
}

void
mail_folder_cache_service_disabled (MailFolderCache *cache,
                                    CamelService *service)
{
	g_return_if_fail (MAIL_IS_FOLDER_CACHE (cache));
	g_return_if_fail (CAMEL_IS_SERVICE (service));

	/* To the folder cache, disabling a service is the same as
	 * removing it.  We keep a separate callback function only
	 * to use as a breakpoint target in a debugger. */
	mail_folder_cache_service_removed (cache, service);
}