/* file.c -- file loading and saving for ASpringies
 * Copyright (C) 1991  Douglas M. DeCarlo
 *
 * Modifications for the Amiga port Copyright (C) 1994  Torsten Klein
 *
 * This file is part of ASpringies, a mass and spring simulation system for the Amiga
 *
 * ASpringies is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 1, or (at your option)
 * any later version.
 *
 * ASpringies is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ASpringies; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: file.c,v 1.6 1994/08/19 11:46:17 Torsten_Klein Exp $
 */

#include <strings.h>
#include <stdio.h>
#include "defs.h"
#include "obj.h"

#define MAGIC_CMD	"#1.0"


void skip_to_eol(FILE *f)
{
  int ch;

  while ((ch = fgetc(f)) != EOF && ch != '\n');
}


#define IS_CMD(s)	(!strncmp(cmd, s, 4))

boolean file_command(char *file, int command)
{
  FILE *f;
  char cmd[5];
  int i, which, spring_start, temp;
  int *mapfrom, *mapto, num_map, num_map_alloc;
  boolean selectnew = FALSE;
  
  if (strlen(file) == 0)
    return FALSE;

  switch (command) 
    {
    case F_INSERT:
    case F_LOAD:
      if ((f = fopen(file, "r")) == NULL) {
	return FALSE;
      }

      /* Check first line */
      if (fgets(cmd, 5, f) != NULL && IS_CMD(MAGIC_CMD)) {
	skip_to_eol(f);

	if (command == F_LOAD) {
	  delete_all();
	  init_objects();
	} else {
	  if (!anything_selected())
	    selectnew = TRUE;
	}
	spring_start = num_spring;

	num_map = 0;
	num_map_alloc = ALLOC_SIZE;
	mapfrom = (int *)xmalloc(sizeof(int) * num_map_alloc);
	mapto = (int *)xmalloc(sizeof(int) * num_map_alloc);

	while (fgets(cmd, 5, f) != NULL) {
	  if (IS_CMD("mass")) {
	    if (num_map >= num_map_alloc) {
	      num_map_alloc += ALLOC_SIZE;
	      mapfrom = (int *)xrealloc((char *)mapfrom,
					sizeof(int) * num_map_alloc);
	      mapto =   (int *)xrealloc((char *)mapto, 
					sizeof(int) * num_map_alloc);
	    }

	    which = create_mass();
	    mapto[num_map] = which;
	    fscanf(f, "%d %lf %lf %lf %lf %lf %lf\n", &mapfrom[num_map],
		   &masses[which].x, &masses[which].y,
		   &masses[which].vx, &masses[which].vy, 
		   &masses[which].mass,
		   &masses[which].elastic);
	    num_map++;
	    if (masses[which].mass < 0) {
	      masses[which].mass = -masses[which].mass;
	      masses[which].status |= S_FIXED;
	    }
	    masses[which].radius = mass_radius(masses[which].mass);
	    if (selectnew) {
	      select_object(which, TRUE, FALSE);
	    }
	  } else if (IS_CMD("spng")) {
	    int bogus;

	    which = create_spring();
	    fscanf(f, "%d %d %d %lf %lf %lf\n", 
		   &bogus, &springs[which].m1, &springs[which].m2,
		   &springs[which].ks, &springs[which].kd, 
		   &springs[which].restlen);
	    if (selectnew) {
	      select_object(which, FALSE, FALSE);
	    }

	  } else if (command == F_INSERT) {
	    /* skip non mass/spring commands if in insert mode */
	  } else if (IS_CMD("cmas")) {
	    fscanf(f, "%lf\n", &(mst.cur_mass));
	  } else if (IS_CMD("elas")) {
	    fscanf(f, "%lf\n", &(mst.cur_rest));
	  } else if (IS_CMD("kspr")) {
	    fscanf(f, "%lf\n", &(mst.cur_ks));
	  } else if (IS_CMD("kdmp")) {
	    fscanf(f, "%lf\n", &(mst.cur_kd));
	  } else if (IS_CMD("fixm")) {
	    fscanf(f, "%d\n", &temp);
	    mst.fix_mass = temp ? TRUE : FALSE;
	  } else if (IS_CMD("shws")) {
	    fscanf(f, "%d\n", &temp);
	    mst.show_spring = temp ? TRUE : FALSE;
	  } else if (IS_CMD("cent")) {
	    fscanf(f, "%d\n", &(mst.center_id));

	  } else if (IS_CMD("frce")) {
	    int which;

	    fscanf(f, "%d", &which);
	    if (which >= 0 && which < BF_NUM) {
	      fscanf(f, "%d %lf %lf\n", &(mst.bf_mode[which]),
		     &(mst.cur_grav_val[which]), &(mst.cur_misc_val[which]));
	    }
	  } else if (IS_CMD("visc")) {
	    fscanf(f, "%lf\n", &(mst.cur_visc));
	  } else if (IS_CMD("stck")) {
	    fscanf(f, "%lf\n", &(mst.cur_stick));
	  } else if (IS_CMD("step")) {
	    fscanf(f, "%lf\n", &(mst.cur_dt));
	  } else if (IS_CMD("prec")) {
	    fscanf(f, "%lf\n", &(mst.cur_prec));
	  } else if (IS_CMD("adpt")) {
	    fscanf(f, "%d\n", &temp);
	    mst.adaptive_step = temp ? TRUE : FALSE;

	  } else if (IS_CMD("gsnp")) {
	    fscanf(f, "%lf %d\n", &(mst.cur_gsnap), &temp);
	    mst.grid_snap = temp ? TRUE : FALSE;
	  } else if (IS_CMD("wall")) {
	    int wt, wl, wr, wb;
	    fscanf(f, "%d %d %d %d\n", &wt, &wl, &wr, &wb);
	    mst.w_top = (boolean)wt;
	    mst.w_left = (boolean)wl;
	    mst.w_right = (boolean)wr;
	    mst.w_bottom = (boolean)wb;
	  } else {
	    /* unknown command */
/*	    fprintf(stderr, "Unknown command: %4.4s\n", cmd); */
	    skip_to_eol(f);
	  }
	}

	/* Connect springs to masses */
	for (i = spring_start; i < num_spring; i++) {
	  int j;
	  boolean m1done, m2done;
	  
	  m1done = m2done = FALSE;
	  
	  if (i == fake_spring)
	    continue;

	  for (j = 0; (!m1done || !m2done) && j < num_map; j++) {
	    if (!m1done && springs[i].m1 == mapfrom[j]) {
	      springs[i].m1 = mapto[j];
	      m1done = TRUE;
	    }
	    if (!m2done && springs[i].m2 == mapfrom[j]) {
	      springs[i].m2 = mapto[j];
	      m2done = TRUE;
	    }
	  }
	  if (!m1done && !m2done) {
	    /* delete spring */
	    delete_spring(i);
	    fprintf(stderr, "Spring %d not connected to existing mass\n", i);
	  }
	}

	free(mapfrom);
	free(mapto);
	reconnect_masses();
	review_system();
	redisplay_widgets();
      } else {
	return FALSE;
      }

      (void)fclose(f);
      
      break;

    case F_SAVEAS:
    case F_SAVE:
      if ((f = fopen(file, "w")) == NULL) {
	return FALSE;
      }
      fprintf(f, "%s *** ASpringies data file\n", MAGIC_CMD);
      /* Settings */
      fprintf(f, "cmas %lf\n", mst.cur_mass);
      fprintf(f, "elas %lf\n", mst.cur_rest);
      fprintf(f, "kspr %lf\n", mst.cur_ks);
      fprintf(f, "kdmp %lf\n", mst.cur_kd);
      fprintf(f, "fixm %d\n", mst.fix_mass);
      fprintf(f, "shws %d\n", mst.show_spring);
      fprintf(f, "cent %d\n", mst.center_id);

      for (i = 0; i < BF_NUM; i++)
	fprintf(f, "frce %d %d %lf %lf\n", i, (mst.bf_mode[i] > 0) ? 1 : 0, 
		mst.cur_grav_val[i], mst.cur_misc_val[i]);

      fprintf(f, "visc %lf\n", mst.cur_visc);
      fprintf(f, "stck %lf\n", mst.cur_stick);
      fprintf(f, "step %lf\n", mst.cur_dt);
      fprintf(f, "prec %lf\n", mst.cur_prec);
      fprintf(f, "adpt %d\n", mst.adaptive_step);
      
      fprintf(f, "gsnp %lf %d\n", mst.cur_gsnap, mst.grid_snap);
      fprintf(f, "wall %d %d %d %d\n", (int)mst.w_top, (int)mst.w_left,
	      (int)mst.w_right, (int)mst.w_bottom);

      /* Masses and springs */
      for (i = 0; i < num_mass; i++) {
	if (masses[i].status & S_ALIVE) {
	  fprintf(f, "mass %d %lf %lf %lf %lf %lf %lf\n", 
		  i, masses[i].x, masses[i].y, masses[i].vx, masses[i].vy,
		  (masses[i].status & S_FIXED) 
		  ? -masses[i].mass : masses[i].mass,
		  masses[i].elastic);
	}
      }
      for (i = 0; i < num_spring; i++) {
	if (springs[i].status & S_ALIVE) {
	  fprintf(f, "spng %d %d %d %lf %lf %lf\n", i, springs[i].m1, 
		  springs[i].m2,
		  springs[i].ks, springs[i].kd, springs[i].restlen);
	}
      }

      if (fclose(f) == EOF)
	return FALSE;
      break;
    }

  return(TRUE);
}