/*
     This file is part of GNUnet.
     (C) 2009, 2010 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.
*/
#include "platform.h"
#include "gnunet_client_lib.h"
#include "gnunet_arm_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_server_lib.h"
#include "gnunet_time_lib.h"
#include "gnunet_transport_service.h"
#include "transport.h"

/**
 * Context for the address lookup.
 */ 
struct AddressLookupCtx
{
  /**
   * Function to call with the human-readable address.
   */
  GNUNET_TRANSPORT_AddressLookUpCallback cb;

  /**
   * Closure for cb.
   */
  void *cb_cls;

  /**
   * Connection to the service.
   */
  struct GNUNET_CLIENT_Connection *client;

  /**
   * When should this operation time out?
   */
  struct GNUNET_TIME_Absolute timeout;
};


/**
 * Function called with responses from the service.
 *
 * @param cls our 'struct AddressLookupCtx*'
 * @param msg NULL on timeout or error, otherwise presumably a
 *        message with the human-readable address
 */
static void
address_response_processor (void *cls, 
			    const struct GNUNET_MessageHeader *msg)
{
  struct AddressLookupCtx *alucb = cls;
  const char *address;
  uint16_t size;

  if (msg == NULL)
    {
      alucb->cb (alucb->cb_cls, NULL);
      GNUNET_CLIENT_disconnect (alucb->client, GNUNET_NO);
      GNUNET_free (alucb);
      return;
    }
  GNUNET_break (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_ADDRESS_REPLY);
  size = ntohs (msg->size);
  if (size == sizeof (struct GNUNET_MessageHeader))
    {
      /* done! */
      alucb->cb (alucb->cb_cls, NULL);
      GNUNET_CLIENT_disconnect (alucb->client, GNUNET_NO);
      GNUNET_free (alucb);
      return;
    }
  address = (const char *) &msg[1];
  if (address[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
    {
      /* invalid reply */
      GNUNET_break (0);
      alucb->cb (alucb->cb_cls, NULL);
      GNUNET_CLIENT_disconnect (alucb->client, GNUNET_NO);
      GNUNET_free (alucb);
      return;
    }
  /* expect more replies */
  GNUNET_CLIENT_receive (alucb->client,
			 &address_response_processor, alucb,
			 GNUNET_TIME_absolute_get_remaining
			 (alucb->timeout));    
  alucb->cb (alucb->cb_cls, address);
}


/**
 * Convert a binary address into a human readable address.
 *
 * @param sched scheduler to use
 * @param cfg configuration to use
 * @param address address to convert (binary format)
 * @param addressLen number of bytes in address
 * @param numeric should (IP) addresses be displayed in numeric form 
 *                (otherwise do reverse DNS lookup)
 * @param nameTrans name of the transport to which the address belongs
 * @param timeout how long is the lookup allowed to take at most
 * @param aluc function to call with the results
 * @param aluc_cls closure for aluc
 */
void
GNUNET_TRANSPORT_address_lookup (struct GNUNET_SCHEDULER_Handle *sched,
                                 const struct GNUNET_CONFIGURATION_Handle  *cfg, 
				 const char *address, 
				 size_t addressLen,
				 int numeric,
                                 const char *nameTrans,
                                 struct GNUNET_TIME_Relative timeout,
                                 GNUNET_TRANSPORT_AddressLookUpCallback aluc,
                                 void *aluc_cls)
{
  size_t slen;
  size_t len;
  struct AddressLookupMessage *msg;
  struct GNUNET_TIME_Absolute abs_timeout;
  struct AddressLookupCtx *aluCB;
  struct GNUNET_CLIENT_Connection *client;
  char *addrbuf;

  slen = strlen (nameTrans) + 1;
  len = sizeof (struct AddressLookupMessage) + addressLen + slen;
  if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
    {
      GNUNET_break (0);
      aluc (aluc_cls, NULL);
      return;
    }
  client = GNUNET_CLIENT_connect (sched, "transport", cfg);
  if (client == NULL)
    {
      aluc (aluc_cls, NULL);
      return;
    }
  abs_timeout = GNUNET_TIME_relative_to_absolute (timeout);
  msg = GNUNET_malloc (len);
  msg->header.size = htons (len);
  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_ADDRESS_LOOKUP);
  msg->numeric_only = htonl (numeric);
  msg->timeout = GNUNET_TIME_absolute_hton (abs_timeout);
  msg->addrlen = htonl (addressLen);
  addrbuf = (char *) &msg[1];
  memcpy (addrbuf, address, addressLen);
  memcpy (&addrbuf[addressLen], nameTrans, slen);
  aluCB = GNUNET_malloc (sizeof (struct AddressLookupCtx));
  aluCB->cb = aluc;
  aluCB->cb_cls = aluc_cls;
  aluCB->timeout = abs_timeout;
  aluCB->client = client;
  GNUNET_assert (GNUNET_OK ==
		 GNUNET_CLIENT_transmit_and_get_response (client, 
							  &msg->header, 
							  timeout,
							  GNUNET_YES,
							  &address_response_processor,
							  aluCB));
  GNUNET_free (msg);
}

/* end of transport_api_address_lookup.c */