#include <stdio.h>
#include <mpi.h>
#include <math.h>
#include <time.h>
#include <malloc.h>
#define Products 10

void main(int argc, char **argv )
 {
  int myid,numprocs;
  int true = 1;
  int false = 0;
  int messages = true;
  int i,j,k,tmp,g,items,flag;
  int customer_item;
  int *stuff_to_bag;
  char Groceries[Products][20] = {"Chips","Lettuce","Bread","Eggs","Pork Chops","Carrots","Rice","Potatoes","Canned Breans","Spagetti Sauce"};
  char GoodByes[3][32] = {"Have a Nice Day", "Thank you", "Come again"};
  MPI_Status status;

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
  MPI_Comm_rank(MPI_COMM_WORLD,&myid);
  if (numprocs >= 2)
   {
    srand((unsigned)time(NULL)+myid);
    if (myid == 0) // Master (Bag Boy)
     {
      for (i=1;i<numprocs;i++)
       {
        messages = true;
        customer_item=0;
        while (messages)
         {
          MPI_Iprobe(i,MPI_ANY_TAG,MPI_COMM_WORLD,&flag,&status);
          if (flag)
           {
            MPI_Recv(&items,1,MPI_INT,i,status.MPI_TAG,MPI_COMM_WORLD,&status);
            if (customer_item == 0)
             stuff_to_bag = (int *) malloc(items * sizeof(int));
            stuff_to_bag[customer_item] = status.MPI_TAG; 
            customer_item++;
           }
           if (customer_item == items) messages = false; 
         } // while messages (groceries)
        // Now sort the stuff to bag and bag it!
        for (j=0; j<customer_item-1; j++)
         for (k=customer_item-1; k>j; k--)
          if (stuff_to_bag[k-1] > stuff_to_bag[k])
           {
            tmp = stuff_to_bag[k];
            stuff_to_bag[k] = stuff_to_bag[k-1];
            stuff_to_bag[k-1] = tmp;
           }
        for (j=0; j<customer_item; j++) 
         printf("Customer %d %s\n",i,Groceries[stuff_to_bag[j]]);
        printf("%s\n\n",GoodByes[rand() % 3]);       
       } // for each process (customer)
     } // Master (Bag Boy)
    else  // Workers (Customers)
     {
      items = (rand() % 5) + 1;
      for(i=1;i<=items;i++)
       {
        g = rand() % 10;
        //printf("Sending %s\n",Groceries[g]);
        MPI_Send(&items,1,MPI_INT,0,g,MPI_COMM_WORLD);
       }       
     } // Workers (Customers)
   }
  else
   printf("ERROR:Must have at least 2 processes to run\n");
  MPI_Finalize();
 }