#include <stdio.h>
#include <mpi.h>
#include <stdlib.h>
#include <time.h>
#define READY_TAG 998
#define EXIT_TAG 999
#define Products 10

int main(int argc, char **argv)
{
  int numprocs, myid;
  int i,j, ibuf, numcustomers, *bagboy_tallies, readyone, items, g;
  int working=1, expecting_messages=1;
  int item_tally, bagged_items;
  /* Note, Products below are defined in order of increasing weight */
  char Groceries[Products][20] = {"Chips","Lettuce","Bread","Eggs", \
   "Pork Chops","Carrots","Rice","Canned Beans","Spaghetti Sauce","Potatoes"};
  MPI_Status status;

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
  MPI_Comm_rank(MPI_COMM_WORLD, &myid);

  srand((unsigned)time(NULL)+myid);

  numcustomers = 10;
  if (myid == 0)
    {
      bagboy_tallies = (int *) malloc(numprocs*sizeof(int));
      for (i=0;i<numcustomers;i++)
	{
          MPI_Recv(&ibuf,1,MPI_INT,MPI_ANY_SOURCE,READY_TAG,MPI_COMM_WORLD, \
	       &status);
          readyone = status.MPI_SOURCE;
          items = (rand() % 5) + 1;
          for(j=1;j<=items;j++)
            {
              g = rand() % 10;
              printf("Customer %d sends %s to bagboy %d, item %d of %d\n", \
                     i,Groceries[g],readyone,j,items);
              MPI_Send(&items,1,MPI_INT,readyone,g,MPI_COMM_WORLD);
            }
        }
      for (i=1;i<numprocs;i++)
	{
          MPI_Recv(&ibuf,1,MPI_INT,MPI_ANY_SOURCE,READY_TAG,MPI_COMM_WORLD, \
	       &status);
          readyone = status.MPI_SOURCE;
          bagboy_tallies[readyone] = ibuf;
          ibuf = 0;
          MPI_Send(&ibuf,1,MPI_INT,readyone,EXIT_TAG,MPI_COMM_WORLD);
	}
      printf("Final tally of items bagged by each bagboy was:\n");
      for (i=1;i<numprocs;i++) printf("%d ",bagboy_tallies[i]);
      printf("\n");
    }
  else
    {
      item_tally = 0;
      while (working)
        {
          MPI_Send(&item_tally,1,MPI_INT,0,READY_TAG,MPI_COMM_WORLD);
          expecting_messages = 1;
          bagged_items = 0;
          while (expecting_messages)
            {
              MPI_Recv(&items,1,MPI_INT,0,MPI_ANY_TAG,MPI_COMM_WORLD,&status);
              if (items > 0)
                {
                  item_tally++;
                  bagged_items++;
                  printf("%d: Received %20s, item %d of %d\n", \
                         myid,Groceries[status.MPI_TAG],bagged_items,items);
                  if (bagged_items == items) expecting_messages = 0;
                }
              else
                {
                  expecting_messages = 0;
                  working = 0;
                }
            }
        }
    }
  MPI_Finalize();
  return 0;
}