/*
     This file is part of GNUnet.
     (C) 2010,2011 Christian Grothoff (and other contributing authors)

     GNUnet 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, or (at your
     option) any later version.

     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/
/**
 * @file transport/gnunet-service-transport_ats-new.h
 * @brief automatic transport selection and outbound bandwidth determination
 * @author Christian Grothoff
 * @author Matthias Wachs
 *
 * TODO:
 * - turn into service
 * - extend API to express communication preferences to ATS 
 *   (to be called DIRECTLY from apps, not from transport/core!)
 */
#ifndef GNUNET_SERVICE_TRANSPORT_ATS_H
#define GNUNET_SERVICE_TRANSPORT_ATS_H

#include "gnunet_constants.h"
#include "gnunet_util_lib.h"
#include "gnunet_transport_service.h"
#include "gnunet_transport_plugin.h"


/**
 * Handle to the ATS subsystem.
 */
struct GST_AtsHandle;


/**
 * Signature of a function called by ATS to notify the callee that the
 * assigned bandwidth or address for a given peer was changed.  If the
 * callback is called with address/bandwidth assignments of zero, the
 * ATS disconnect function will still be called once the disconnect 
 * actually happened.
 *
 * @param cls closure
 * @param peer identity of the peer
 * @param plugin_name name of the transport plugin, NULL to disconnect
 * @param session session to use (if available)
 * @param plugin_addr address to use (if available)
 * @param plugin_addr_len number of bytes in addr
 * @param bandwidth assigned outbound bandwidth for the connection
 */
typedef void (*GNUNET_TRANSPORT_ATS_AllocationNotification)(void *cls,
							    const struct GNUNET_PeerIdentity *peer,
							    const char *plugin_name,
							    struct Session *session,
							    const void *plugin_addr,
							    size_t plugin_addr_len,
							    struct GNUNET_BANDWIDTH_Value32NBO bandwidth);


/**
 * Initialize the ATS subsystem.
 *
 * @param cfg configuration to use
 * @param alloc_cb notification to call whenever the allocation changed
 * @param alloc_cb_cls closure for 'alloc_cb'
 * @return ats context
 */
struct GST_AtsHandle *
GST_ats_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
	      GNUNET_TRANSPORT_ATS_AllocationNotification alloc_cb,
	      void *alloc_cb_cls);

/**
 * Shutdown the ATS subsystem.
 *
 * @param atc handle
 */
void
GST_ats_shutdown (struct GST_AtsHandle *atc);


/**
 * We established a new connection with a peer (for example, because
 * core asked for it or because the other peer connected to us).
 * Calculate bandwidth assignments including the new peer.
 *
 * @param atc handle
 * @param peer identity of the new peer
 * @param plugin_name name of the currently used transport plugin
 * @param session session in use (if available)
 * @param plugin_addr address in use (if available)
 * @param plugin_addr_len number of bytes in plugin_addr
 * @param ats performance data for the connection
 * @param ats_count number of performance records in 'ats'
 */
void
GST_ats_peer_connect (struct GST_AtsHandle *atc,
		      const struct GNUNET_PeerIdentity *peer,
		      const char *plugin_name,
		      struct Session *session,
		      const void *plugin_addr,
		      size_t plugin_addr_len,
		      const struct GNUNET_TRANSPORT_ATS_Information *ats,
		      uint32_t ats_count);


/**
 * We disconnected from the given peer (for example, because ats, core
 * or blacklist asked for it or because the other peer disconnected).
 * Calculate bandwidth assignments without the peer.
 *
 * @param atc handle
 * @param peer identity of the peer
 */
void
GST_ats_peer_disconnect (struct GST_AtsHandle *atc,
			 const struct GNUNET_PeerIdentity *peer);


/**
 * A session got destroyed, stop including it as a valid address.
 *
 * @param atc handle
 * @param peer identity of the peer
 * @param session session handle that is no longer valid
 */
void
GST_ats_session_destroyed (struct GST_AtsHandle *atc,
			   const struct GNUNET_PeerIdentity *peer,
			   const struct Session *session);


/**
 * We have updated performance statistics for a given address.  Note
 * that this function can be called for addresses that are currently
 * in use as well as addresses that are valid but not actively in use.
 * Furthermore, the peer may not even be connected to us right now (in
 * which case the call may be ignored or the information may be stored
 * for later use).  Update bandwidth assignments.
 *
 * @param atc handle
 * @param peer identity of the new peer
 * @param plugin_name name of the transport plugin
 * @param session session handle (if available)
 * @param plugin_addr address  (if available)
 * @param plugin_addr_len number of bytes in plugin_addr
 * @param ats performance data for the address
 * @param ats_count number of performance records in 'ats'
 */
void
GST_ats_address_update (struct GST_AtsHandle *atc,
			const struct GNUNET_PeerIdentity *peer,
			const char *plugin_name,
			struct Session *session,
			const void *plugin_addr,
			size_t plugin_addr_len,
			const struct GNUNET_TRANSPORT_ATS_Information *ats,
			uint32_t ats_count);


#endif
/* end of file gnunet-service-transport_ats.h */