em-utils.c

/*
 * 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:
 *		Jeffrey Stedfast <fejj@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

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

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <time.h>

#include <glib/gstdio.h>

#ifdef G_OS_WIN32
/* Work around namespace clobbage in <windows.h> */
#define DATADIR windows_DATADIR
#include <windows.h>
#undef DATADIR
#undef interface
#endif

#include <libebook/e-book.h>

#include "em-filter-editor.h"

#include <glib/gi18n.h>

#include <gio/gio.h>

#include "mail-mt.h"
#include "mail-ops.h"
#include "mail-tools.h"
#include "e-mail-tag-editor.h"

#include <libedataserver/e-data-server-util.h>
#include <libedataserver/e-flag.h>
#include <libedataserver/e-proxy.h>
#include "e-util/e-util.h"
#include "e-util/e-util-private.h"
#include "e-util/e-mktemp.h"
#include "e-util/e-account-utils.h"
#include "e-util/e-dialog-utils.h"
#include "e-util/e-alert-dialog.h"
#include "shell/e-shell.h"
#include "widgets/misc/e-attachment.h"

#include "em-utils.h"
#include "em-composer-utils.h"
#include "em-format-quote.h"
#include "e-mail-folder-utils.h"
#include "e-mail-local.h"
#include "e-mail-session.h"

/* XXX This is a dirty hack on a dirty hack.  We really need
 *     to rework or get rid of the functions that use this. */
extern const gchar *shell_builtin_backend;

/* How many is too many? */
/* Used in em_util_ask_open_many() */
#define TOO_MANY 10

#define d(x)

gboolean
em_utils_ask_open_many (GtkWindow *parent,
                        gint how_many)
{
	gchar *string;
	gboolean proceed;

	if (how_many < TOO_MANY)
		return TRUE;

	string = g_strdup_printf (ngettext (
		/* Translators: This message is shown only for ten or more
		 * messages to be opened.  The %d is replaced with the actual
		 * count of messages. If you need a '%' in your text, then
		 * write it doubled, like '%%'. */
		"Are you sure you want to open %d message at once?",
		"Are you sure you want to open %d messages at once?",
		how_many), how_many);
	proceed = em_utils_prompt_user (
		parent, "/apps/evolution/mail/prompts/open_many",
		"mail:ask-open-many", string, NULL);
	g_free (string);

	return proceed;
}

/**
 * em_utils_prompt_user:
 * @parent: parent window
 * @promptkey: gconf key to check if we should prompt the user or not.
 * @tag: e_alert tag.
 *
 * Convenience function to query the user with a Yes/No dialog and a
 * "Do not show this dialog again" checkbox. If the user checks that
 * checkbox, then @promptkey is set to %FALSE, otherwise it is set to
 * %TRUE.
 *
 * Returns %TRUE if the user clicks Yes or %FALSE otherwise.
 **/
gboolean
em_utils_prompt_user (GtkWindow *parent,
                      const gchar *promptkey,
                      const gchar *tag,
                      ...)
{
	GtkWidget *dialog;
	GtkWidget *check = NULL;
	GtkWidget *container;
	va_list ap;
	gint button;
	GConfClient *client;
	EAlert *alert = NULL;

	client = gconf_client_get_default ();

	if (promptkey && !gconf_client_get_bool (client, promptkey, NULL)) {
		g_object_unref (client);
		return TRUE;
	}

	va_start (ap, tag);
	alert = e_alert_new_valist (tag, ap);
	va_end (ap);

	dialog = e_alert_dialog_new (parent, alert);
	g_object_unref (alert);

	container = e_alert_dialog_get_content_area (E_ALERT_DIALOG (dialog));

	if (promptkey) {
		check = gtk_check_button_new_with_mnemonic (
			_("_Do not show this message again"));
		gtk_box_pack_start (
			GTK_BOX (container), check, FALSE, FALSE, 0);
		gtk_widget_show (check);
	}

	button = gtk_dialog_run (GTK_DIALOG (dialog));
	if (promptkey)
		gconf_client_set_bool (
			client, promptkey,
			!gtk_toggle_button_get_active (
			GTK_TOGGLE_BUTTON (check)), NULL);

	gtk_widget_destroy (dialog);

	g_object_unref (client);

	return button == GTK_RESPONSE_YES;
}

/**
 * em_utils_uids_copy:
 * @uids: array of uids
 *
 * Duplicates the array of uids held by @uids into a new
 * GPtrArray. Use em_utils_uids_free() to free the resultant uid
 * array.
 *
 * Returns a duplicate copy of @uids.
 **/
GPtrArray *
em_utils_uids_copy (GPtrArray *uids)
{
	GPtrArray *copy;
	gint i;

	copy = g_ptr_array_new ();
	g_ptr_array_set_size (copy, uids->len);

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

	return copy;
}

/**
 * em_utils_uids_free:
 * @uids: array of uids
 *
 * Frees the array of uids pointed to by @uids back to the system.
 **/
void
em_utils_uids_free (GPtrArray *uids)
{
	gint i;

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

	g_ptr_array_free (uids, TRUE);
}

/**
 * em_utils_check_user_can_send_mail:
 *
 * Returns %TRUE if the user has an account configured (to send mail)
 * or %FALSE otherwise.
 **/
gboolean
em_utils_check_user_can_send_mail (void)
{
	EAccountList *account_list;
	EAccount *account;

	account_list = e_get_account_list ();

	if (e_list_length (E_LIST (account_list)) == 0)
		return FALSE;

	if (!(account = e_get_default_account ()))
		return FALSE;

	/* Check for a transport */
	if (!account->transport->url)
		return FALSE;

	return TRUE;
}

/* Editing Filters/Search Folders... */

static GtkWidget *filter_editor = NULL;

static void
em_filter_editor_response (GtkWidget *dialog, gint button, gpointer user_data)
{
	EMFilterContext *fc;

	if (button == GTK_RESPONSE_OK) {
		const gchar *config_dir;
		gchar *user;

		config_dir = mail_session_get_config_dir ();
		fc = g_object_get_data ((GObject *) dialog, "context");
		user = g_build_filename (config_dir, "filters.xml", NULL);
		e_rule_context_save ((ERuleContext *) fc, user);
		g_free (user);
	}

	gtk_widget_destroy (dialog);

	filter_editor = NULL;
}

static EMFilterSource em_filter_source_element_names[] = {
	{ "incoming", },
	{ "outgoing", },
	{ NULL }
};

/**
 * em_utils_edit_filters:
 * @parent: parent window
 * @backend: an #EMailBAckend
 *
 * Opens or raises the filters editor dialog so that the user may edit
 * his/her filters. If @parent is non-NULL, then the dialog will be
 * created as a child window of @parent's toplevel window.
 **/
void
em_utils_edit_filters (GtkWidget *parent,
                       EMailBackend *backend)
{
	const gchar *config_dir;
	gchar *user, *system;
	EMFilterContext *fc;

	g_return_if_fail (E_IS_MAIL_BACKEND (backend));

	if (filter_editor) {
		gtk_window_present (GTK_WINDOW (filter_editor));
		return;
	}

	config_dir = mail_session_get_config_dir ();

	fc = em_filter_context_new (backend);
	user = g_build_filename (config_dir, "filters.xml", NULL);
	system = g_build_filename (EVOLUTION_PRIVDATADIR, "filtertypes.xml", NULL);
	e_rule_context_load ((ERuleContext *) fc, system, user);
	g_free (user);
	g_free (system);

	if (((ERuleContext *) fc)->error) {
		e_mail_backend_submit_alert (
			backend, "mail:filter-load-error",
			((ERuleContext *) fc)->error, NULL);
		return;
	}

	if (em_filter_source_element_names[0].name == NULL) {
		em_filter_source_element_names[0].name = _("Incoming");
		em_filter_source_element_names[1].name = _("Outgoing");
	}

	filter_editor = (GtkWidget *) em_filter_editor_new (
		fc, em_filter_source_element_names);
	if (parent != NULL)
		gtk_window_set_transient_for (
			GTK_WINDOW (filter_editor),
			GTK_WINDOW (parent));

	gtk_window_set_title (
		GTK_WINDOW (filter_editor), _("Message Filters"));
	g_object_set_data_full (
		G_OBJECT (filter_editor), "context", fc,
		(GDestroyNotify) g_object_unref);
	g_signal_connect (
		filter_editor, "response",
		G_CALLBACK (em_filter_editor_response), NULL);
	gtk_widget_show (GTK_WIDGET (filter_editor));
}

/*
 * Picked this from e-d-s/libedataserver/e-data.
 * But it allows more characters to occur in filenames, especially
 * when saving attachment.
 */
void
em_filename_make_safe (gchar *string)
{
	gchar *p, *ts;
	gunichar c;
#ifdef G_OS_WIN32
	const gchar *unsafe_chars = "/\":*?<>|\\#";
#else
	const gchar *unsafe_chars = "/#";
#endif

	g_return_if_fail (string != NULL);
	p = string;

	while (p && *p) {
		c = g_utf8_get_char (p);
		ts = p;
		p = g_utf8_next_char (p);
		/* I wonder what this code is supposed to actually
		 * achieve, and whether it does that as currently
		 * written?
		 */
		if (!g_unichar_isprint (c) || ( c < 0xff && strchr (unsafe_chars, c&0xff ))) {
			while (ts<p)
				*ts++ = '_';
		}
	}
}

/* ********************************************************************** */
/* Flag-for-Followup... */

/**
 * em_utils_flag_for_followup:
 * @reader: an #EMailReader
 * @folder: folder containing messages to flag
 * @uids: uids of messages to flag
 *
 * Open the Flag-for-Followup editor for the messages specified by
 * @folder and @uids.
 **/
void
em_utils_flag_for_followup (EMailReader *reader,
                            CamelFolder *folder,
                            GPtrArray *uids)
{
	EShell *shell;
	EMailBackend *backend;
	EShellSettings *shell_settings;
	EShellBackend *shell_backend;
	EMFormatHTML *formatter;
	GtkWidget *editor;
	GtkWindow *window;
	CamelTag *tags;
	gint i;

	g_return_if_fail (E_IS_MAIL_READER (reader));
	g_return_if_fail (CAMEL_IS_FOLDER (folder));
	g_return_if_fail (uids != NULL);

	window = e_mail_reader_get_window (reader);
	backend = e_mail_reader_get_backend (reader);

	editor = e_mail_tag_editor_new ();
	gtk_window_set_transient_for (GTK_WINDOW (editor), window);

	shell_backend = E_SHELL_BACKEND (backend);
	shell = e_shell_backend_get_shell (shell_backend);
	shell_settings = e_shell_get_shell_settings (shell);

	/* These settings come from the calendar module. */
	g_object_bind_property (
		shell_settings, "cal-use-24-hour-format",
		editor, "use-24-hour-format",
		G_BINDING_SYNC_CREATE);
	g_object_bind_property (
		shell_settings, "cal-week-start-day",
		editor, "week-start-day",
		G_BINDING_SYNC_CREATE);

	for (i = 0; i < uids->len; i++) {
		CamelMessageInfo *info;

		info = camel_folder_get_message_info (folder, uids->pdata[i]);

		if (info == NULL)
			continue;

		e_mail_tag_editor_add_message (
			E_MAIL_TAG_EDITOR (editor),
			camel_message_info_from (info),
			camel_message_info_subject (info));

		camel_folder_free_message_info (folder, info);
	}

	/* special-case... */
	if (uids->len == 1) {
		CamelMessageInfo *info;
		const gchar *message_uid;

		message_uid = g_ptr_array_index (uids, 0);
		info = camel_folder_get_message_info (folder, message_uid);
		if (info) {
			tags = (CamelTag *) camel_message_info_user_tags (info);

			if (tags)
				e_mail_tag_editor_set_tag_list (
					E_MAIL_TAG_EDITOR (editor), tags);
			camel_folder_free_message_info (folder, info);
		}
	}

	if (gtk_dialog_run (GTK_DIALOG (editor)) != GTK_RESPONSE_OK)
		goto exit;

	tags = e_mail_tag_editor_get_tag_list (E_MAIL_TAG_EDITOR (editor));
	if (tags == NULL)
		goto exit;

	camel_folder_freeze (folder);
	for (i = 0; i < uids->len; i++) {
		CamelMessageInfo *info;
		CamelTag *iter;

		info = camel_folder_get_message_info (folder, uids->pdata[i]);

		if (info == NULL)
			continue;

		for (iter = tags; iter != NULL; iter = iter->next)
			camel_message_info_set_user_tag (
				info, iter->name, iter->value);

		camel_folder_free_message_info (folder, info);
	}

	camel_folder_thaw (folder);
	camel_tag_list_free (&tags);

	formatter = e_mail_reader_get_formatter (reader);
	em_format_queue_redraw (EM_FORMAT (formatter));

exit:
	/* XXX We shouldn't be freeing this. */
	em_utils_uids_free (uids);

	gtk_widget_destroy (GTK_WIDGET (editor));
}

/**
 * em_utils_flag_for_followup_clear:
 * @parent: parent window
 * @folder: folder containing messages to unflag
 * @uids: uids of messages to unflag
 *
 * Clears the Flag-for-Followup flag on the messages referenced by
 * @folder and @uids.
 **/
void
em_utils_flag_for_followup_clear (GtkWindow *parent,
                                  CamelFolder *folder,
                                  GPtrArray *uids)
{
	gint i;

	g_return_if_fail (GTK_IS_WINDOW (parent));
	g_return_if_fail (CAMEL_IS_FOLDER (folder));
	g_return_if_fail (uids != NULL);

	camel_folder_freeze (folder);
	for (i = 0; i < uids->len; i++) {
		CamelMessageInfo *mi = camel_folder_get_message_info (folder, uids->pdata[i]);

		if (mi) {
			camel_message_info_set_user_tag(mi, "follow-up", NULL);
			camel_message_info_set_user_tag(mi, "due-by", NULL);
			camel_message_info_set_user_tag(mi, "completed-on", NULL);
			camel_folder_free_message_info (folder, mi);
		}
	}

	camel_folder_thaw (folder);

	em_utils_uids_free (uids);
}

/**
 * em_utils_flag_for_followup_completed:
 * @parent: parent window
 * @folder: folder containing messages to 'complete'
 * @uids: uids of messages to 'complete'
 *
 * Sets the completed state (and date/time) for each message
 * referenced by @folder and @uids that is marked for
 * Flag-for-Followup.
 **/
void
em_utils_flag_for_followup_completed (GtkWindow *parent,
                                      CamelFolder *folder,
                                      GPtrArray *uids)
{
	gchar *now;
	gint i;

	g_return_if_fail (GTK_IS_WINDOW (parent));
	g_return_if_fail (CAMEL_IS_FOLDER (folder));
	g_return_if_fail (uids != NULL);

	now = camel_header_format_date (time (NULL), 0);

	camel_folder_freeze (folder);
	for (i = 0; i < uids->len; i++) {
		const gchar *tag;
		CamelMessageInfo *mi = camel_folder_get_message_info (folder, uids->pdata[i]);

		if (mi) {
			tag = camel_message_info_user_tag(mi, "follow-up");
			if (tag && tag[0])
				camel_message_info_set_user_tag(mi, "completed-on", now);
			camel_folder_free_message_info (folder, mi);
		}
	}

	camel_folder_thaw (folder);

	g_free (now);

	em_utils_uids_free (uids);
}

/* This kind of sucks, because for various reasons most callers need to run
 * synchronously in the gui thread, however this could take a long, blocking
 * time to run. */
static gint
em_utils_write_messages_to_stream (CamelFolder *folder,
                                   GPtrArray *uids,
                                   CamelStream *stream)
{
	CamelStream *filtered_stream;
	CamelMimeFilter *from_filter;
	gint i, res = 0;

	from_filter = camel_mime_filter_from_new ();
	filtered_stream = camel_stream_filter_new (stream);
	camel_stream_filter_add (
		CAMEL_STREAM_FILTER (filtered_stream), from_filter);
	g_object_unref (from_filter);

	for (i=0; i<uids->len; i++) {
		CamelMimeMessage *message;
		gchar *from;

		/* FIXME camel_folder_get_message_sync() may block. */
		message = camel_folder_get_message_sync (
			folder, uids->pdata[i], NULL, NULL);
		if (message == NULL) {
			res = -1;
			break;
		}

		/* We need to flush after each stream write since we are
		 * writing to the same stream. */
		from = camel_mime_message_build_mbox_from (message);

		if (camel_stream_write_string (stream, from, NULL, NULL) == -1
		    || camel_stream_flush (stream, NULL, NULL) == -1
		    || camel_data_wrapper_write_to_stream_sync (
			(CamelDataWrapper *) message, (CamelStream *)
			filtered_stream, NULL, NULL) == -1
		    || camel_stream_flush (
			(CamelStream *) filtered_stream, NULL, NULL) == -1)
			res = -1;

		g_free (from);
		g_object_unref (message);

		if (res == -1)
			break;
	}

	g_object_unref (filtered_stream);

	return res;
}

/* This kind of sucks, because for various reasons most callers need to run
 * synchronously in the gui thread, however this could take a long, blocking
 * time to run. */
static gint
em_utils_read_messages_from_stream (CamelFolder *folder,
                                    CamelStream *stream)
{
	CamelMimeParser *mp = camel_mime_parser_new ();
	gboolean success = TRUE;

	camel_mime_parser_scan_from (mp, TRUE);
	camel_mime_parser_init_with_stream (mp, stream, NULL);

	while (camel_mime_parser_step (mp, NULL, NULL) == CAMEL_MIME_PARSER_STATE_FROM) {
		CamelMimeMessage *msg;
		gboolean success;

		/* NB: de-from filter, once written */
		msg = camel_mime_message_new ();
		if (!camel_mime_part_construct_from_parser_sync (
			(CamelMimePart *) msg, mp, NULL, NULL)) {
			g_object_unref (msg);
			break;
		}

		/* FIXME camel_folder_append_message_sync() may block. */
		success = camel_folder_append_message_sync (
			folder, msg, NULL, NULL, NULL, NULL);
		g_object_unref (msg);

		if (!success)
			break;

		camel_mime_parser_step (mp, NULL, NULL);
	}

	g_object_unref (mp);

	return success ? 0 : -1;
}

/**
 * em_utils_selection_set_mailbox:
 * @data: selection data
 * @folder: folder containign messages to copy into the selection
 * @uids: uids of the messages to copy into the selection
 *
 * Creates a mailbox-format selection.
 * Warning: Could be BIG!
 * Warning: This could block the ui for an extended period.
 **/
void
em_utils_selection_set_mailbox (GtkSelectionData *data,
                                CamelFolder *folder,
                                GPtrArray *uids)
{
	GByteArray *byte_array;
	CamelStream *stream;
	GdkAtom target;

	target = gtk_selection_data_get_target (data);

	byte_array = g_byte_array_new ();
	stream = camel_stream_mem_new_with_byte_array (byte_array);

	if (em_utils_write_messages_to_stream (folder, uids, stream) == 0)
		gtk_selection_data_set (
			data, target, 8,
			byte_array->data, byte_array->len);

	g_object_unref (stream);
}

/**
 * em_utils_selection_get_mailbox:
 * @selection_data: selection data
 * @folder:
 *
 * Receive a mailbox selection/dnd
 * Warning: Could be BIG!
 * Warning: This could block the ui for an extended period.
 * FIXME: Exceptions?
 **/
void
em_utils_selection_get_mailbox (GtkSelectionData *selection_data,
                                CamelFolder *folder)
{
	CamelStream *stream;
	const guchar *data;
	gint length;

	data = gtk_selection_data_get_data (selection_data);
	length = gtk_selection_data_get_length (selection_data);

	if (data == NULL || length == -1)
		return;

	/* TODO: a stream mem with read-only access to existing data? */
	/* NB: Although copying would let us run this async ... which it should */
	stream = (CamelStream *)
		camel_stream_mem_new_with_buffer ((gchar *) data, length);
	em_utils_read_messages_from_stream (folder, stream);
	g_object_unref (stream);
}

/**
 * em_utils_selection_get_message:
 * @selection_data:
 * @folder:
 *
 * get a message/rfc822 data.
 **/
void
em_utils_selection_get_message (GtkSelectionData *selection_data,
                                CamelFolder *folder)
{
	CamelStream *stream;
	CamelMimeMessage *msg;
	const guchar *data;
	gint length;

	data = gtk_selection_data_get_data (selection_data);
	length = gtk_selection_data_get_length (selection_data);

	if (data == NULL || length == -1)
		return;

	stream = (CamelStream *)
		camel_stream_mem_new_with_buffer ((gchar *) data, length);
	msg = camel_mime_message_new ();
	if (camel_data_wrapper_construct_from_stream_sync (
		(CamelDataWrapper *) msg, stream, NULL, NULL))
		/* FIXME camel_folder_append_message_sync() may block. */
		camel_folder_append_message_sync (
			folder, msg, NULL, NULL, NULL, NULL);
	g_object_unref (msg);
	g_object_unref (stream);
}

/**
 * em_utils_selection_set_uidlist:
 * @selection_data: selection data
 * @folder:
 * @uids:
 *
 * Sets a "x-uid-list" format selection data.
 **/
void
em_utils_selection_set_uidlist (GtkSelectionData *selection_data,
                                CamelFolder *folder,
                                GPtrArray *uids)
{
	GByteArray *array = g_byte_array_new ();
	GdkAtom target;
	gchar *folder_uri;
	gint i;

	/* format: "uri\0uid1\0uid2\0uid3\0...\0uidn\0" */

	folder_uri = e_mail_folder_uri_from_folder (folder);

	g_byte_array_append (
		array, (guchar *) folder_uri, strlen (folder_uri) + 1);

	for (i=0; i<uids->len; i++)
		g_byte_array_append (array, uids->pdata[i], strlen (uids->pdata[i])+1);

	target = gtk_selection_data_get_target (selection_data);
	gtk_selection_data_set (
		selection_data, target, 8, array->data, array->len);
	g_byte_array_free (array, TRUE);

	g_free (folder_uri);
}

/**
 * em_utils_selection_get_uidlist:
 * @data: selection data
 * @session: an #EMailSession
 * @move: do we delete the messages.
 *
 * Convert a uid list into a copy/move operation.
 *
 * Warning: Could take some time to run.
 **/
void
em_utils_selection_get_uidlist (GtkSelectionData *selection_data,
                                EMailSession *session,
                                CamelFolder *dest,
                                gint move,
                                GCancellable *cancellable,
                                GError **error)
{
	/* format: "uri\0uid1\0uid2\0uid3\0...\0uidn" */
	gchar *inptr, *inend;
	GPtrArray *uids;
	CamelFolder *folder;
	const guchar *data;
	gint length;

	g_return_if_fail (selection_data != NULL);
	g_return_if_fail (E_IS_MAIL_SESSION (session));

	data = gtk_selection_data_get_data (selection_data);
	length = gtk_selection_data_get_length (selection_data);

	if (data == NULL || length == -1)
		return;

	uids = g_ptr_array_new ();

	inptr = (gchar *) data;
	inend = (gchar *) (data + length);
	while (inptr < inend) {
		gchar *start = inptr;

		while (inptr < inend && *inptr)
			inptr++;

		if (start > (gchar *) data)
			g_ptr_array_add (uids, g_strndup (start, inptr-start));

		inptr++;
	}

	if (uids->len == 0) {
		g_ptr_array_free (uids, TRUE);
		return;
	}

	/* FIXME e_mail_session_uri_to_folder_sync() may block. */
	folder = e_mail_session_uri_to_folder_sync (
		session, (gchar *) data, 0, cancellable, error);
	if (folder) {
		/* FIXME camel_folder_transfer_messages_to_sync() may block. */
		camel_folder_transfer_messages_to_sync (
			folder, uids, dest, move, NULL, cancellable, error);
		g_object_unref (folder);
	}

	em_utils_uids_free (uids);
}

/**
 * em_utils_selection_set_urilist:
 * @data:
 * @folder:
 * @uids:
 *
 * Set the selection data @data to a uri which points to a file, which is
 * a berkely mailbox format mailbox.  The file is automatically cleaned
 * up when the application quits.
 **/
void
em_utils_selection_set_urilist (GtkSelectionData *data,
                                CamelFolder *folder,
                                GPtrArray *uids)
{
	gchar *tmpdir;
	CamelStream *fstream;
	gchar *uri, *file = NULL, *tmpfile;
	gint fd;
	CamelMessageInfo *info;

	tmpdir = e_mkdtemp("drag-n-drop-XXXXXX");
	if (tmpdir == NULL)
		return;

	/* Try to get the drop filename from the message or folder */
	if (uids->len == 1) {
		const gchar *message_uid;

		message_uid = g_ptr_array_index (uids, 0);
		info = camel_folder_get_message_info (folder, message_uid);
		if (info) {
			file = g_strdup (camel_message_info_subject (info));
			camel_folder_free_message_info (folder, info);
		}
	}

	/* TODO: Handle conflicts? */
	if (file == NULL) {
		/* Drop filename for messages from a mailbox */
		file = g_strdup_printf (
			_("Messages from %s"),
			camel_folder_get_display_name (folder));
	}

	e_filename_make_safe (file);

	tmpfile = g_build_filename (tmpdir, file, NULL);
	g_free (tmpdir);
	g_free (file);

	fd = g_open (tmpfile, O_WRONLY | O_CREAT | O_EXCL | O_BINARY, 0666);
	if (fd == -1) {
		g_free (tmpfile);
		return;
	}

	uri = g_filename_to_uri (tmpfile, NULL, NULL);
	g_free (tmpfile);
	fstream = camel_stream_fs_new_with_fd (fd);
	if (fstream) {
		if (em_utils_write_messages_to_stream (folder, uids, fstream) == 0) {
			/* terminate with \r\n to be compliant with the spec */
			gchar *uri_crlf = g_strconcat(uri, "\r\n", NULL);
			GdkAtom target;

			target = gtk_selection_data_get_target (data);
			gtk_selection_data_set (
				data, target, 8, (guchar *)
				uri_crlf, strlen (uri_crlf));
			g_free (uri_crlf);
		}

		g_object_unref (fstream);
	} else
		close (fd);

	g_free (uri);