/********************************************************
% 
% Written by:
% -- 
% John L. Weatherwax                2006-08-07
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

*/

#include <math.h>
#include <stdio.h>
#include "mpi.h"
#include "global_grid.h"
#include "sim_consts.h"
#include "exportForces.h"

/* 
*/ 
void exportForces(void){

  const int TAG_OFFSET=1*9+1; 
  MPI_Status status; 

  /* 
     Send NW <-> Receive SE 
  */ 
  /*printf("Send NW <-> Receive SE\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[NW], 2*procInfo.numToReceive[NW], MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+0, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[SE], 2*procInfo.numToExport[SE],  MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+0, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[SE], 2*procInfo.numToExport[SE],  MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+0, MPI_COMM_WORLD, &status);
    MPI_Send(procInfo.forcesOnReceivedPart[NW], 2*procInfo.numToReceive[NW], MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+0, MPI_COMM_WORLD); 
  } 

  /*printf("NW=%d; N=%d; NE=%d; W=%d; I=%d; E=%d; SW=%d; S=%d; SE=%d\n",NW,N,NE,W,I,E,SW,S,SE); */

  /*
  if( procInfo.my_rank==2 ){
    printf("NW<->SE: NW = %d; procInfo.forcesOnExportedPart[2][0]=%20.8f; procInfo.forcesOnReceivedPart[2][1]=%20.8f\n", 
	   NW,procInfo.forcesOnExportedPart[2][0],procInfo.forcesOnExportedPart[2][1]);
	   }*/

  /* 
     Send N <-> Receive S 
  */ 
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[N], 2*procInfo.numToReceive[N], MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+1, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[S], 2*procInfo.numToExport[S],  MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+1, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[S], 2*procInfo.numToExport[S],  MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+1, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[N], 2*procInfo.numToReceive[N], MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+1, MPI_COMM_WORLD); 
  }

  /*
  if( procInfo.my_rank==2 ){
    printf("N<->S: procInfo.forcesOnExportedPart[1][0]=%20.8f; procInfo.forcesOnReceivedPart[1][1]=%20.8f\n", 
	   procInfo.forcesOnExportedPart[1][0],procInfo.forcesOnExportedPart[1][1]);
	   }*/

  /* 
     Send NE <-> Receive SW 
  */ 
  /*printf("Send NE <-> Receive SW\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[NE], 2*procInfo.numToReceive[NE], MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+2, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[SW], 2*procInfo.numToExport[SW],  MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+2, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[SW], 2*procInfo.numToExport[SW],  MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+2, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[NE], 2*procInfo.numToReceive[NE], MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+2, MPI_COMM_WORLD);     
  }

  /* 
     Send W <-> Receive E 
  */ 
  /*
  if( procInfo.my_rank==3 ){
    printf("before send: procInfo.forcesOnReceivedPart[3][0]=%20.8f; procInfo.forcesOnReceivedPart[3][1]=%20.8f\n", 
	   procInfo.forcesOnReceivedPart[3][0],procInfo.forcesOnReceivedPart[3][1]);
    printf("procInfo.numToReceive[W]=%d\n",procInfo.numToReceive[W]); 
  }
  if( procInfo.my_rank==2 ){
    printf("procInfo.numToExport[E]=%d\n",procInfo.numToExport[E]); 
  }
  */
  if( procInfo.my_col % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[W], 2*procInfo.numToReceive[W], MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+3, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[E], 2*procInfo.numToExport[E],  MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+3, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[E], 2*procInfo.numToExport[E],  MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+3, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[W], 2*procInfo.numToReceive[W], MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+3, MPI_COMM_WORLD); 
  }

  /*
  if( procInfo.my_rank==2 ){
    printf("procInfo.forcesOnExportedPart[3][0]=%20.8f; procInfo.forcesOnReceivedPart[3][1]=%20.8f\n", 
	   procInfo.forcesOnExportedPart[3][0],procInfo.forcesOnExportedPart[3][1]);
  }
  */

  /* No sending to the IDENTITY */ 

  /* 
     Send E <-> Receive W 
  */ 
  if( procInfo.my_col % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[E], 2*procInfo.numToReceive[E], MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+5, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[W], 2*procInfo.numToExport[W],  MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+5, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[W], 2*procInfo.numToExport[W],  MPI_DOUBLE, procInfo.neighbor[W], TAG_OFFSET+5, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[E], 2*procInfo.numToReceive[E], MPI_DOUBLE, procInfo.neighbor[E], TAG_OFFSET+5, MPI_COMM_WORLD); 
  }

  /* 
     Send SW <-> Receive NE 
  */ 
  /*printf("Send SW <-> Receive NE\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[SW], 2*procInfo.numToReceive[SW], MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+6, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[NE], 2*procInfo.numToExport[NE],  MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+6, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[NE], 2*procInfo.numToExport[NE],  MPI_DOUBLE, procInfo.neighbor[NE], TAG_OFFSET+6, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[SW], 2*procInfo.numToReceive[SW], MPI_DOUBLE, procInfo.neighbor[SW], TAG_OFFSET+6, MPI_COMM_WORLD);     
  }

  /* 
     Send S <-> Receive N 
  */ 
  if( procInfo.my_row % 2 == 0 ){    /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[S], 2*procInfo.numToReceive[S], MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+7, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[N], 2*procInfo.numToExport[N], MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+7, MPI_COMM_WORLD, &status);
  }else{                             /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[N], 2*procInfo.numToExport[N],  MPI_DOUBLE, procInfo.neighbor[N], TAG_OFFSET+7, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[S], 2*procInfo.numToReceive[S], MPI_DOUBLE, procInfo.neighbor[S], TAG_OFFSET+7, MPI_COMM_WORLD); 
  }

  /* 
     Send SE <-> Receive NW 
  */ 
  /*printf("Send SE <-> Receive NW\n");*/
  if( procInfo.my_row % 2 == 0 ){   /* these processors will SEND    and then RECEIVE */ 
    MPI_Send(procInfo.forcesOnReceivedPart[SE], 2*procInfo.numToReceive[SE], MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+8, MPI_COMM_WORLD); 
    MPI_Recv(procInfo.forcesOnExportedPart[NW], 2*procInfo.numToExport[NW],  MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+8, MPI_COMM_WORLD, &status);
  }else{                            /* these processors will RECEIVE and then SEND */ 
    MPI_Recv(procInfo.forcesOnExportedPart[NW], 2*procInfo.numToExport[NW],  MPI_DOUBLE, procInfo.neighbor[NW], TAG_OFFSET+8, MPI_COMM_WORLD, &status); 
    MPI_Send(procInfo.forcesOnReceivedPart[SE], 2*procInfo.numToReceive[SE], MPI_DOUBLE, procInfo.neighbor[SE], TAG_OFFSET+8, MPI_COMM_WORLD);     
  }

}