/* $Id$ */
/*
 * Cantus Tag Editor
 * Copyright © 2002-2004 by Samuel Abels <spam@debain.org>
 * Copyright © 2007 by Tim Huetz <tim.huetz@futures-net.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 **/

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

#include <cantus/eventbus.h>

//#define _DEBUG_


/******************************************************************************
 * Constructor/Destructor
 ******************************************************************************/
/* Constructor.
 */
EventBus::EventBus(void)
{
  idpool    = 0;
  listeners = NULL;
}


/* Destructor.
 */
EventBus::~EventBus(void)
{
  // Destroy all listeners.
  GList *item = listeners;
  while (item) {
    EventBusListener *listener = (EventBusListener*)item->data;
    g_assert(listener != NULL);
    if (listener->closure)
      g_closure_unref(listener->closure);
    delete listener;
    item = item->next;
  }
  g_list_free(listeners);
}


/******************************************************************************
 * Public
 ******************************************************************************/
/* Registers a listener for a specific event pattern; use the returned
 * id to unregister the listener. The function to be called is passed as a
 * GClosure.
 */
glong EventBus::add_listener(const gchar *event_pattern, GClosure *closure)
{
#ifdef _DEBUG_
  std::cout << "EventBus::add_listener(): " << event_pattern << "\n";
#endif
  EventBusListener *listener = new EventBusListener;
  g_closure_ref(closure);
  g_assert(++idpool > 0);       // Idpool exceeded?
  listener->id      = idpool;
  listener->invalid = FALSE;
  listener->pattern = event_pattern;
  listener->type    = EVENTBUS_SIG_GCLOSURE;
  listener->closure = closure;
  listeners         = g_list_append(listeners, listener);
  return(idpool);
}


/* Registers a listener for a specific event pattern; use the returned
 * id to unregister the listener. The function to be called is a SigC slot.
 */
glong EventBus::add_listener_sigc(const gchar *event_pattern,
                                  sigc::slot1<void, void*> slot)
{
#ifdef _DEBUG_
  std::cout << "EventBus::add_listener_sigc(): " << event_pattern << "\n";
#endif
  EventBusListener *listener = new EventBusListener;
  g_assert(++idpool > 0);       // Idpool exceeded?
  listener->id        = idpool;
  listener->invalid   = FALSE;
  listener->pattern   = event_pattern;
  listener->type      = EVENTBUS_SIG_SIGC;
  listener->closure   = NULL;
  listener->sigcslot  = slot;
  listeners           = g_list_append(listeners, listener);
#ifdef _DEBUG_
  printf("EventBus::add_listener_sigc(): ID%i.\n", idpool);
#endif
  return(idpool);
}


/* Invalidate the listener with the given id.
 */
void EventBus::remove_listener(glong id)
{
#ifdef _DEBUG_
  printf("EventBus::remove_listener(): ID%i.\n", id);
#endif
  GList *item = listeners;
  while (item) {
    EventBusListener *listener = (EventBusListener*)item->data;
    g_assert(listener != NULL);
    if (listener->id == id) {
      listener->invalid = TRUE;
      return;
    }
    item = item->next;
  }
  g_assert("Specified listener not found.\n");
}


/* Unregister all invalid listeners.
 */
void EventBus::delete_invalid_listeners(void)
{
#ifdef _DEBUG_
  printf("EventBus::delete_invalid_listeners(): Called.\n");
#endif
  GList *item = listeners;
  while (item) {
    EventBusListener *listener = (EventBusListener*)item->data;
    g_assert(listener != NULL);
    if (listener->invalid) {
      listeners = g_list_remove(listeners, listener);
      if (listener->closure)
        g_closure_unref(listener->closure);
      delete listener;
      return;
    }
    item = item->next;
  }
  g_assert("Specified listener not found.\n");
}


/* Emits an event in the bus.
 */
void EventBus::emit_event(const gchar *event, const GValue *value)
{
#ifdef _DEBUG_
  printf("EventBus::emit_event(): Called. (%s).\n", event);
#endif
  GValue ret_val = {0, };
  GList *item = listeners;
  g_value_init(&ret_val, G_TYPE_POINTER);
  while (item) {
    EventBusListener *listener = (EventBusListener*)item->data;
    g_assert(listener != NULL);
    
    // Check whether the listener is still valid.
    if (listener->invalid) {
      item = item->next;
      continue;
    }
    
    // Check whether the listener matches the pattern.
    if (!shellpattern_match(event, listener->pattern, TRUE)) {
      item = item->next;
      continue;
    }
    
    // Invoke the listener function.
    switch (listener->type) {
    case EVENTBUS_SIG_GCLOSURE:
      g_closure_invoke(listener->closure, &ret_val, 1, value, NULL);
      break;
      
    case EVENTBUS_SIG_SIGC:
      listener->sigcslot(g_value_peek_pointer(value));
      break;
      
    default:
      g_assert_not_reached();
      break;
    }
    
    item = item->next;
  }
  g_value_unset(&ret_val);
}


/* Emits an event in the bus, convenience wrapper.
 */
void EventBus::emit_event_with_pointer(const gchar *event, gpointer value)
{
  GValue arg = {0, };
  g_value_init(&arg, G_TYPE_POINTER);
  g_value_set_pointer(&arg, value);
  this->emit_event(event, &arg);
  g_value_unset(&arg);
}


/* Emits an event in the bus, convenience wrapper.
 */
void EventBus::emit_event_with_char(const gchar *event, const gchar *value)
{
  GValue arg = {0, };
  g_value_init(&arg, G_TYPE_POINTER);
  g_value_set_pointer(&arg, (gpointer)value);
  this->emit_event(event, &arg);
  g_value_unset(&arg);
}


/* Emits an event in the bus, convenience wrapper.
 */
void EventBus::emit_event_with_int(const gchar *event, gint value)
{
  GValue arg = {0, };
  g_value_init(&arg, G_TYPE_INT);
  g_value_set_int(&arg, value);
  this->emit_event(event, &arg);
  g_value_unset(&arg);
}