/* GIO - GLib Input, Output and Streaming Library
 * 
 * Copyright (C) 2006-2007 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * Author: Alexander Larsson <alexl@redhat.com>
 */

#include <config.h>
#include <string.h>

#include "gdaemonfilemonitor.h"
#include <gio/gio.h>
#include <gvfsdaemondbus.h>
#include <gvfsdaemonprotocol.h>
#include "gmountspec.h"
#include "gdaemonfile.h"
#include <gvfsdbus.h>

#define OBJ_PATH_PREFIX "/org/gtk/vfs/client/filemonitor/"

/* atomic */
static volatile gint path_counter = 1;

static gboolean g_daemon_file_monitor_cancel (GFileMonitor* monitor);


struct _GDaemonFileMonitor
{
  GFileMonitor parent_instance;

  char *object_path;
  char *remote_obj_path;
  char *remote_id;
  GVfsDBusMonitor *proxy;              /* Non-null if we're subscribed */
  GVfsDBusMonitorClient *skeleton;
};

G_DEFINE_TYPE (GDaemonFileMonitor, g_daemon_file_monitor, G_TYPE_FILE_MONITOR)

static void
g_daemon_file_monitor_finalize (GObject* object)
{
  GDaemonFileMonitor *daemon_monitor;

  daemon_monitor = G_DAEMON_FILE_MONITOR (object);

  if (daemon_monitor->skeleton)
    {
      g_dbus_interface_skeleton_unexport (G_DBUS_INTERFACE_SKELETON (daemon_monitor->skeleton));
      g_object_unref (daemon_monitor->skeleton);
    }

  g_clear_object (&daemon_monitor->proxy);

  g_free (daemon_monitor->object_path);
  g_free (daemon_monitor->remote_id);
  g_free (daemon_monitor->remote_obj_path);

  if (G_OBJECT_CLASS (g_daemon_file_monitor_parent_class)->finalize)
    (*G_OBJECT_CLASS (g_daemon_file_monitor_parent_class)->finalize) (object);
}

static void
g_daemon_file_monitor_class_init (GDaemonFileMonitorClass* klass)
{
  GObjectClass* gobject_class = G_OBJECT_CLASS (klass);
  GFileMonitorClass *file_monitor_class = G_FILE_MONITOR_CLASS (klass);
  gobject_class->finalize = g_daemon_file_monitor_finalize;

  file_monitor_class->cancel = g_daemon_file_monitor_cancel;
}

static gboolean
handle_changed (GVfsDBusMonitorClient *object,
                GDBusMethodInvocation *invocation,
                guint arg_event_type,
                GVariant *arg_mount_spec,
                const gchar *arg_file_path,
                GVariant *arg_other_mount_spec,
                const gchar *arg_other_file_path,
                gpointer user_data)
{
  GDaemonFileMonitor *monitor = G_DAEMON_FILE_MONITOR (user_data);
  GMountSpec *spec1, *spec2;
  GFile *file1, *file2;

  spec1 = g_mount_spec_from_dbus (arg_mount_spec);
  file1 = g_daemon_file_new (spec1, arg_file_path);
  g_mount_spec_unref (spec1);

  file2 = NULL;

  if (strlen (arg_other_file_path) > 0)
    {
      spec2 = g_mount_spec_from_dbus (arg_other_mount_spec);
      file2 = g_daemon_file_new (spec2, arg_other_file_path);
      g_mount_spec_unref (spec2);
    }

  g_file_monitor_emit_event (G_FILE_MONITOR (monitor),
                             file1, file2,
                             arg_event_type);

  gvfs_dbus_monitor_client_complete_changed (object, invocation);

  return TRUE;
}

static void
g_daemon_file_monitor_init (GDaemonFileMonitor* daemon_monitor)
{
  gint id;

  id = g_atomic_int_add (&path_counter, 1);

  daemon_monitor->object_path = g_strdup_printf (OBJ_PATH_PREFIX"%d", id);

  daemon_monitor->skeleton = gvfs_dbus_monitor_client_skeleton_new ();
  g_signal_connect (daemon_monitor->skeleton, "handle-changed", G_CALLBACK (handle_changed), daemon_monitor);
}

static void
subscribe_cb (GVfsDBusMonitor *proxy,
              GAsyncResult *res,
              GDaemonFileMonitor* monitor)
{
  GError *error = NULL;

  if (! gvfs_dbus_monitor_call_subscribe_finish (proxy, res, &error))
    {
      g_printerr ("Error calling org.gtk.vfs.Monitor.Subscribe(): %s (%s, %d)\n",
                  error->message, g_quark_to_string (error->domain), error->code);
      g_error_free (error);
    }

  /* If its cancelled already, unsubscribe and don't save stuff */
  if (g_file_monitor_is_cancelled (G_FILE_MONITOR (monitor)))
    {
      gvfs_dbus_monitor_call_unsubscribe (proxy,
                                          monitor->object_path,
                                          NULL, NULL, NULL);
      g_object_unref (monitor);
      return;
    }

  monitor->proxy = g_object_ref (proxy);

  g_object_unref (monitor);
}

GFileMonitor*
g_daemon_file_monitor_new (const char *remote_id,
                           const char *remote_obj_path)
{
  GDaemonFileMonitor* daemon_monitor;
  GDBusConnection *connection;
  GError *error = NULL;
  GVfsDBusMonitor *proxy;

  daemon_monitor = g_object_new (G_TYPE_DAEMON_FILE_MONITOR, NULL);

  daemon_monitor->remote_id = g_strdup (remote_id);
  daemon_monitor->remote_obj_path = g_strdup (remote_obj_path);

  connection = _g_dbus_connection_get_sync (daemon_monitor->remote_id, NULL, &error);
  if (connection == NULL && !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
    {
      g_dbus_error_strip_remote_error (error);
      g_warning ("The peer-to-peer connection failed: %s. Falling back to the "
                 "session bus. Your application is probably missing "
                 "--filesystem=xdg-run/gvfsd privileges.", error->message);
      g_clear_error (&error);

      connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
    }

  if (connection == NULL)
    {
      g_printerr ("Error getting connection for monitoring: %s (%s, %d)\n",
                  error->message, g_quark_to_string (error->domain), error->code);
      g_error_free (error);
    }
  else
    {
      if (!g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (daemon_monitor->skeleton),
                                             connection,
                                             daemon_monitor->object_path,
                                             &error))
        {
          g_warning ("Error registering path: %s (%s, %d)\n",
                     error->message, g_quark_to_string (error->domain), error->code);
          g_error_free (error);
        }

      /* This looks like a sync call, but since the remote_id is a
         unique id we don't actually send any messages */
      proxy = gvfs_dbus_monitor_proxy_new_sync (connection,
                                                G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES | G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS,
                                                daemon_monitor->remote_id,
                                                daemon_monitor->remote_obj_path,
                                                NULL,
                                                &error);
      if (proxy == NULL)
        {
          g_printerr ("Error creating monitor proxy: %s (%s, %d)\n",
                      error->message, g_quark_to_string (error->domain), error->code);
          g_error_free (error);
        }
      else
        {
          /* We set the proxy in the callback, meaning we're subscribed if it is set */
          gvfs_dbus_monitor_call_subscribe (proxy,
                                            daemon_monitor->object_path,
                                            NULL,
                                            (GAsyncReadyCallback) subscribe_cb,
                                            g_object_ref (daemon_monitor));
          g_object_unref (proxy);

          /* At this point it is safe to return the monitor, even if we have not gotten
             the reply to the subscribe yet, because any i/o we do to the mount such
             as listing a directory will happen after the mount receives the subscribe
             message */
        }
    }

  return G_FILE_MONITOR (daemon_monitor);
}

static gboolean
g_daemon_file_monitor_cancel (GFileMonitor* monitor)
{
  GDaemonFileMonitor *daemon_monitor = G_DAEMON_FILE_MONITOR (monitor);

  if (daemon_monitor->proxy != NULL)
    gvfs_dbus_monitor_call_unsubscribe (daemon_monitor->proxy,
					daemon_monitor->object_path,
					NULL, NULL, NULL);

  return TRUE;
}