/* Be-Guiled version of the program */
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

#include <X11/Xlib.h>
#define WINDOW_SIZE 500
#include <guile/gh.h>

#include <mpi.h>
int myid, serv, nproc;


Display *theDisplay;
Window theWindow;
Screen *theScreen;
GC theGC;
double currentX;
double currentY;
double currentDirection;
int penDown;

#include <math.h>
#define DEGREES_TO_RADIANS  (3.1415926535897932384626433832795029L/180.0)

SCM tortoise_reset() 
{
    currentX = currentY = WINDOW_SIZE/2;
    currentDirection = 0;
    penDown = 1;
    return SCM_EOL;
}
SCM tortoise_pendown()
{
    penDown = 1;
    return SCM_EOL;
}
SCM tortoise_penup()
{
    penDown = 0;
    return SCM_EOL;
}
SCM tortoise_turn(SCM s_degrees)
{
    int degrees = SCM_INUM(s_degrees);
    currentDirection += (double)degrees;
    return SCM_EOL;
}
SCM tortoise_move(SCM s_steps)
{
    double newX, newY;
    int steps = SCM_INUM(s_steps);
    /* first work out the new endpoint */
    newX = currentX + sin(currentDirection*DEGREES_TO_RADIANS)*(double)steps;
    newY = currentY - cos(currentDirection*DEGREES_TO_RADIANS)*(double)steps;
    /* if the pen is down, draw a line */
    if (penDown) XDrawLine(theDisplay, theWindow, theGC, 
                           (int)currentX, (int)currentY, (int)newX, (int)newY);
    /* in either case, move the tortoise */
    currentX = newX;
    currentY = newY;
    return SCM_EOL;
}

void register_procs(void)
{
    gh_new_procedure("tortoise-reset",   tortoise_reset,   0, 0, 0);
    gh_new_procedure("tortoise-pendown", tortoise_pendown, 0, 0, 0);
    gh_new_procedure("tortoise-penup",   tortoise_penup,   0, 0, 0);
    gh_new_procedure("tortoise-turn",    tortoise_turn,    1, 0, 0);
    gh_new_procedure("tortoise-move",    tortoise_move,    1, 0, 0);
}
void inner_main(int argc, char **argv)
{
  register_procs();

  scm_shell(argc, argv);

  MPI_Finalize();
}

int main(int argc, char *argv[])
{

  char pname[256];
  char fname[256];
  int reslen;

  MPI_Comm world;
  serv = 0;
  world = MPI_COMM_WORLD;

  MPI_Init(&argc,&argv);

  MPI_Comm_rank     (world,  &myid);
  MPI_Comm_size     (world,  &nproc);

  if(myid != 0){
    char *name;
    asprintf(&name, "so-%d", myid);
    stdout =  freopen(name, "w", stdout);
    if(!stdout){
      printf("Error: can not reopen stdout (%s:%d)\n", __FILE__, __LINE__);
      exit(2);
    }
    free(name);
  }

  theDisplay = XOpenDisplay(NULL);
  XSynchronize(theDisplay, True);
  theScreen = DefaultScreenOfDisplay(theDisplay);
  theWindow = XCreateSimpleWindow(theDisplay, RootWindowOfScreen(theScreen), 
				  0, 0, 
				  WINDOW_SIZE, WINDOW_SIZE, 0, 
				  BlackPixelOfScreen(theScreen), 
				  WhitePixelOfScreen(theScreen));
  theGC = XCreateGC(theDisplay, theWindow, 0L, NULL);
  XSetForeground(theDisplay, theGC, BlackPixelOfScreen(theScreen));
  XMapWindow(theDisplay,theWindow);  


  /* more stuff to come here . . */
  tortoise_reset();
  gh_enter(argc, argv, inner_main);

  return(0);			/* never reached */
  return 0;
}