/*
Copyright 2011 Canonical Ltd.

Authors:
    Conor Curran <conor.curran@canonical.com>

This program is free software: you can redistribute it and/or modify it 
under the terms of the GNU General Public License version 3, as published 
by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranties of 
MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR 
PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along 
with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <gio/gio.h>
#include <glib/gi18n.h>
#include "apt-watcher.h"
#include "apt-transaction.h"

static guint watcher_id;

struct _AptWatcher
{
	GObject parent_instance;
	GCancellable * proxy_cancel;
	GDBusProxy * proxy;  
  SessionDbus* session_dbus_interface;
  DbusmenuMenuitem* apt_item;
  AptState current_state;
  AptTransaction* current_transaction;
};

static void
apt_watcher_on_name_appeared (GDBusConnection *connection,
                              const gchar     *name,
                              const gchar     *name_owner,
                              gpointer         user_data);
static void
apt_watcher_on_name_vanished (GDBusConnection *connection,
                              const gchar     *name,
                              gpointer         user_data);
static void fetch_proxy_cb (GObject * object,
                            GAsyncResult * res,
                            gpointer user_data);

static void apt_watcher_upgrade_system_cb (GObject * obj,
                                           GAsyncResult * res,
                                           gpointer user_data);
                                                 
                
static void apt_watcher_show_apt_dialog (DbusmenuMenuitem* mi,
                                         guint timestamp,
                                         gchar * type);

static void apt_watcher_signal_cb (GDBusProxy* proxy,
                                   gchar* sender_name,
                                   gchar* signal_name,
                                   GVariant* parameters,
                                   gpointer user_data);
static void  apt_watcher_manage_transactions (AptWatcher* self,
                                              gchar* transaction_id);
                                   


G_DEFINE_TYPE (AptWatcher, apt_watcher, G_TYPE_OBJECT);

static void
apt_watcher_init (AptWatcher *self)
{
  self->current_state = UP_TO_DATE;
  self->proxy_cancel = g_cancellable_new();
  self->proxy = NULL;
  self->current_transaction = NULL;
  g_dbus_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
                            G_DBUS_PROXY_FLAGS_NONE,
                            NULL,
                            "org.debian.apt",
                            "/org/debian/apt",
                            "org.debian.apt",
                            self->proxy_cancel,
                            fetch_proxy_cb,
                            self);
}

static void
apt_watcher_finalize (GObject *object)
{
  g_bus_unwatch_name (watcher_id);  
  AptWatcher* self = APT_WATCHER (object);
           
  if (self->proxy != NULL)
    g_object_unref (self->proxy);

	G_OBJECT_CLASS (apt_watcher_parent_class)->finalize (object);
}

static void
apt_watcher_class_init (AptWatcherClass *klass)
{
	GObjectClass* object_class = G_OBJECT_CLASS (klass);
	object_class->finalize = apt_watcher_finalize;
}

static void
fetch_proxy_cb (GObject * object, GAsyncResult * res, gpointer user_data)
{
	GError * error = NULL;

	AptWatcher* self = APT_WATCHER(user_data);
	g_return_if_fail(self != NULL);

	GDBusProxy * proxy = g_dbus_proxy_new_for_bus_finish(res, &error);

	if (self->proxy_cancel != NULL) {
		g_object_unref(self->proxy_cancel);
		self->proxy_cancel = NULL;
	}

	if (error != NULL) {
		g_warning("Could not grab DBus proxy for %s: %s",
               "org.debian.apt", error->message);
		g_error_free(error);
		return;
	}

	self->proxy = proxy;
  // Set up the watch.
  watcher_id = g_bus_watch_name (G_BUS_TYPE_SYSTEM,
                                 "org.debian.apt",
                                 G_BUS_NAME_WATCHER_FLAGS_NONE,
                                 apt_watcher_on_name_appeared,
                                 apt_watcher_on_name_vanished,
                                 self,
                                 NULL);
  
	g_signal_connect (self->proxy,
                    "g-signal",
                    G_CALLBACK(apt_watcher_signal_cb),
                    self);  
}


static void
apt_watcher_on_name_appeared (GDBusConnection *connection,
                              const gchar     *name,
                              const gchar     *name_owner,
                              gpointer         user_data)
{
  g_return_if_fail (APT_IS_WATCHER (user_data));
  AptWatcher* watcher = APT_WATCHER (user_data);
  
  g_print ("Name %s on %s is owned by %s\n",
           name,
           "the system bus",
           name_owner);

  g_dbus_proxy_call (watcher->proxy,
                     "UpgradeSystem",
                     g_variant_new("(b)", TRUE),
                     G_DBUS_CALL_FLAGS_NONE,
                     -1,
                     NULL,
                     apt_watcher_upgrade_system_cb,
                     user_data);
}

static void
apt_watcher_on_name_vanished (GDBusConnection *connection,
                              const gchar     *name,
                              gpointer         user_data)
{
  g_debug ("Name %s does not exist or has just vanished",
           name);
  g_return_if_fail (APT_IS_WATCHER (user_data));
}

static void
apt_watcher_upgrade_system_cb (GObject * obj,
                               GAsyncResult * res,
                               gpointer user_data)
{
  g_return_if_fail (APT_IS_WATCHER (user_data));
  AptWatcher* self = APT_WATCHER (user_data);

	GError * error = NULL;
	GVariant * result;

	result = g_dbus_proxy_call_finish(self->proxy, res, &error);

	if (error != NULL) {
    g_warning ("unable to complete the UpgradeSystem apt call");
    g_error_free (error);
		return;
	}
  
  gchar* transaction_id = NULL;
  g_variant_get (result, "(s)", &transaction_id);

  if (transaction_id == NULL){
    g_warning ("apt_watcher_upgrade_system_cb - transaction id is null");
    return;
  }  
  
  apt_watcher_manage_transactions (self, transaction_id);
  
}

static void
apt_watcher_show_apt_dialog (DbusmenuMenuitem * mi,
                             guint timestamp,
                             gchar * type)
{
  GError * error = NULL;
  if (!g_spawn_command_line_async("update-manager", &error))
  {
    g_warning("Unable to show update-manager: %s", error->message);
    g_error_free(error);
  }  
}

static void
apt_watcher_transaction_state_update_cb (AptTransaction* trans,
                                         gint update,
                                         gpointer user_data)
{
  g_debug ("apt-watcher -transaction update %i", update);
  g_return_if_fail (APT_IS_WATCHER (user_data));
  AptWatcher* self = APT_WATCHER (user_data);
  
  AptState state = (AptState)update;
  
  if (state == UP_TO_DATE){
    dbusmenu_menuitem_property_set (self->apt_item,
                                    DBUSMENU_MENUITEM_PROP_LABEL,
                                    _("Software Up to Date"));   
    // Simulations don't send a finished signal for some reason
    // Anyway from a simulation we just need one state update 
    // (updates available or not)
    if (apt_transaction_get_transaction_type (self->current_transaction)
        == SIMULATION){
      g_object_unref (G_OBJECT(self->current_transaction));
      self->current_transaction = NULL;
    }                                                                   
  }
  else if (state == UPDATES_AVAILABLE){
    dbusmenu_menuitem_property_set (self->apt_item,
                                    DBUSMENU_MENUITEM_PROP_LABEL,
                                    _("Updates Available…"));    
    // Simulations don't send a finished signal for some reason
    // Anyway from a simulation we just need one state update 
    // (updates available or not)
    if (apt_transaction_get_transaction_type (self->current_transaction)
        == SIMULATION){
      g_object_unref (G_OBJECT(self->current_transaction));
      self->current_transaction = NULL;
    }                              
  }
  else if (state == UPGRADE_IN_PROGRESS){
    dbusmenu_menuitem_property_set (self->apt_item,
                                    DBUSMENU_MENUITEM_PROP_LABEL,
                                    _("Updates Installing…"));    
  }  
  else if (state == FINISHED){
    GVariant* reboot_result = g_dbus_proxy_get_cached_property (self->proxy,
                                                               "RebootRequired");
    gboolean reboot;
    g_variant_get (reboot_result, "b", &reboot);
    if (reboot == FALSE){
      dbusmenu_menuitem_property_set (self->apt_item,
                                      DBUSMENU_MENUITEM_PROP_LABEL,
                                      _("Software Up to Date"));
    }
    else{
      dbusmenu_menuitem_property_set (self->apt_item,
                                      DBUSMENU_MENUITEM_PROP_LABEL,
                                      _("Reboot Required"));
      session_dbus_restart_required (self->session_dbus_interface);
    }
    g_debug ("Finished with a reboot value of %i", reboot); 
    g_object_unref (G_OBJECT(self->current_transaction));
    self->current_transaction = NULL;                                    
  }
  self->current_state = state;
} 
 
static void
apt_watcher_manage_transactions (AptWatcher* self, gchar* transaction_id)
{
    if (self->current_transaction == NULL){
      self->current_transaction = apt_transaction_new (transaction_id, SIMULATION);
      g_signal_connect (G_OBJECT(self->current_transaction),
                        "state-update",
                        G_CALLBACK(apt_watcher_transaction_state_update_cb), self);
    }
}

// TODO - Ask MVO about this.
// Signal is of type s not sas which is on d-feet !!!
static void apt_watcher_signal_cb ( GDBusProxy* proxy,
                                    gchar* sender_name,
                                    gchar* signal_name,
                                    GVariant* parameters,
                                    gpointer user_data)
{
  g_return_if_fail (APT_IS_WATCHER (user_data));
  AptWatcher* self = APT_WATCHER (user_data);

  g_variant_ref (parameters);
  GVariant *value = g_variant_get_child_value (parameters, 0);

  if (g_strcmp0(signal_name, "ActiveTransactionsChanged") == 0){
    gchar* input = NULL;
    g_variant_get(value, "s", & input);
    if (g_str_has_prefix (input, "/org/debian/apt/transaction/") == TRUE){
      g_debug ("Active Transactions signal - input is null = %i", input == NULL);
      
      if (self->current_transaction != NULL)
      {
        g_object_unref (G_OBJECT(self->current_transaction));
        self->current_transaction = NULL;
      }

      self->current_transaction = apt_transaction_new (input, REAL);
      g_signal_connect (G_OBJECT(self->current_transaction),
                        "state-update",
                        G_CALLBACK(apt_watcher_transaction_state_update_cb), self);              
    }
  }
  g_variant_unref (parameters);
}

AptWatcher* apt_watcher_new (SessionDbus* session_dbus,
                             DbusmenuMenuitem* item)
{
  AptWatcher* watcher = g_object_new (APT_TYPE_WATCHER, NULL);
  watcher->session_dbus_interface = session_dbus;
  watcher->apt_item = item;
  g_signal_connect (G_OBJECT(watcher->apt_item),
                    DBUSMENU_MENUITEM_SIGNAL_ITEM_ACTIVATED,
                    G_CALLBACK(apt_watcher_show_apt_dialog), watcher);
  return watcher;
}