/*
      This file is part of GNUnet.
      (C) 2013 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 include/gnunet_scalarproduct_service.h
 * @brief API to the scalarproduct service
 * @author Christian M. Fuchs
 * @author Gaurav Kukreja
 */
#ifndef GNUNET_SCALARPRODUCT_SERVICE_H
#define GNUNET_SCALARPRODUCT_SERVICE_H
#define GCRYPT_NO_DEPRECATED
#include <gcrypt.h>

#ifdef __cplusplus
extern "C" {
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif

/**
 * Version of the scalarproduct API.
 */
#define GNUNET_SCALARPRODUCT_VERSION 0x00000042

enum GNUNET_SCALARPRODUCT_ResponseStatus
{
  GNUNET_SCALARPRODUCT_Status_Success = 0,
  GNUNET_SCALARPRODUCT_Status_Failure,
  GNUNET_SCALARPRODUCT_Status_InvalidResponse,
  GNUNET_SCALARPRODUCT_Status_ServiceDisconnected
};


/**
 * Opaque declaration of the SP-Handle
 */
struct GNUNET_SCALARPRODUCT_Handle;


/**
 * Continuation called to notify client about result of the
 * operation.
 *
 * @param cls closure
 * @param status Status of the request
 */
typedef void (*GNUNET_SCALARPRODUCT_ContinuationWithStatus) (void *cls,
                                                             enum GNUNET_SCALARPRODUCT_ResponseStatus status);


/**
 * Process a datum that was stored in the scalarproduct.
 *
 * @param cls closure
 * @param status Status of the request
 * @param result result of the computation
 */
typedef void (*GNUNET_SCALARPRODUCT_DatumProcessor) (void *cls,
                                                     enum GNUNET_SCALARPRODUCT_ResponseStatus status,
                                                     gcry_mpi_t result);

/**
 * Entry in the request queue per client
 */
struct GNUNET_SCALARPRODUCT_ComputationHandle;

/**
 * Request by Alice's client for computing a scalar product
 *
 * @param cfg the gnunet configuration handle
 * @param key Session key should be unique to the requesting client
 * @param peer PeerID of the other peer
 * @param elements Array of elements of the vector
 * @param element_count Number of elements in the vector
 * @param mask Array of the mask
 * @param mask_bytes number of bytes in the mask
 * @param cont Callback function
 * @param cont_cls Closure for @a cont
 * @return a new handle for this computation
 */
struct GNUNET_SCALARPRODUCT_ComputationHandle *
GNUNET_SCALARPRODUCT_request (const struct GNUNET_CONFIGURATION_Handle *cfg,
                              const struct GNUNET_HashCode *key,
                              const struct GNUNET_PeerIdentity *peer,
                              const int32_t *elements,
                              uint32_t element_count,
                              const unsigned char *mask,
                              uint32_t mask_bytes,
                              GNUNET_SCALARPRODUCT_DatumProcessor cont,
                              void * cont_cls);

/**
 * Used by Bob's client to cooperate with Alice,
 *
 * @param cfg the gnunet configuration handle
 * @param key Session key unique to the requesting client
 * @param elements Array of elements of the vector
 * @param element_count Number of elements in the vector
 * @param cont Callback function
 * @param cont_cls Closure for @a cont
 * @return a new handle for this computation
 */
struct GNUNET_SCALARPRODUCT_ComputationHandle *
GNUNET_SCALARPRODUCT_response (const struct GNUNET_CONFIGURATION_Handle *cfg,
                               const struct GNUNET_HashCode *key,
                               const int32_t *elements,
                               uint32_t element_count,
                               GNUNET_SCALARPRODUCT_ContinuationWithStatus cont,
                               void *cont_cls);


/**
 * Cancel an ongoing computation or revoke our collaboration offer.
 * Closes the connection to the service
 *
 * @param h computation handle to terminate
 */
void
GNUNET_SCALARPRODUCT_cancel (struct GNUNET_SCALARPRODUCT_ComputationHandle *h);


/**
 * Cancel ALL ongoing computation or revoke our collaboration offer.
 * Closes ALL connections to the service
 *
 * FIXME: this should take an argument, and we should
 * have an explicit 'connect' API which returns an opaque
 * connection handle.  Avoid (globals) in the library!
 * @deprecated in this form
 */
void
GNUNET_SCALARPRODUCT_disconnect ();


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif

#endif