#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mpi.h>

#define MYSERVICE "myfriend"
#define MASTER 0

int main(int argc, char* argv[])
{
  int rank, count;
  int i;
  float data[100];
  char amsg[64];
  char myport[MPI_MAX_PORT_NAME];
  char myservice[64];
  MPI_Status status;
  MPI_Comm intercomm;
  int intercomm_size;

  MPI_Init(&argc, &argv);
  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  printf("Processor %d (%d, Receiver) initialized\n", rank, getpid());

  MPI_Open_port(MPI_INFO_NULL, myport);
  printf("Processor %d opened port %s\n", rank, myport);

  sprintf(myservice, "%s-%d", MYSERVICE, rank);
  printf("Publishing port %s as service %s\n", myport, myservice);
  MPI_Publish_name(myservice, MPI_INFO_NULL, myport);
  
  printf("Processor %d waiting for connections on %s, service %s...\n", rank, myport, myservice);
  MPI_Comm_accept(myport, MPI_INFO_NULL, 0, MPI_COMM_SELF, &intercomm);
  printf("Processor %d new connection on port %s\n", rank, myport);

  printf("Processor %d closing port %s\n", rank, myport);
  MPI_Close_port(myport);

  printf("Processor %d unpublishing service %s\n", rank, myservice);
  MPI_Unpublish_name(myservice, MPI_INFO_NULL, myport);

  MPI_Comm_remote_size(intercomm, &intercomm_size);
  printf("Processor %d remote comm size is %d\n", rank, intercomm_size);

  printf("Processor %d waiting for data from new intercomm...\n", rank);
  MPI_Recv(data, 100, MPI_FLOAT, MPI_ANY_SOURCE, MPI_ANY_TAG, intercomm, &status);
  MPI_Get_count(&status, MPI_FLOAT, &count);
  printf("Processor %d got %d elements from rank %d, tag %d: %f, %f, %f...\n", rank, count, status.MPI_SOURCE, status.MPI_TAG, data[0], data[1], data[2]);

  printf("Processor %d sending string back...\n", rank);
  strcpy(amsg, "ciao client");
  MPI_Send(amsg, 12, MPI_CHAR, 0, 0, intercomm);
  printf("Processor %d data sent\n", rank);

  sleep(10);

  printf("Processor %d disconnecting communicator\n", rank);
  MPI_Comm_disconnect(&intercomm);

  printf("Processor %d finalizing\n", rank);
  MPI_Finalize();
  printf("Processor %d Goodbye!\n", rank);
}