/* This program reads an sgf file and breaks it up into separate
   files, one for each variation. The file is prefaced by a line
   of the form: 

   sgf2tex -n -im -il -break [nn] [filename]

   where nn is the move number at which the variation begins.
   This is a command which can be used to invoke sgf2tex,
   producing a diagram in which the variation begins as move
   1. (Actually two diagrams are produced. The first may be
   discarded.)

   sgfsplit is copyright 1997 by Daniel Bump, and is published
   under the GNU General Public Licence, version 2. Consult the
   file COPYING for details, or write the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*/

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/stat.h>

#define MAXSIZE 16384
#define PERMISSIONS 0700

int parse(char str[],char sgfout[],char name[],int filecount,int movebreak);
 
char sgf[MAXSIZE],sgfout[MAXSIZE];
char name[128],oname[128],bname[128],extra_args[128];
FILE *bp;

main(int argc,char *argv[])
{
  FILE *fp;
  int c,i;
  char *name;
  if (argc==1) {
    fprintf(stderr,"sgfsplit: no filename specified\n");
    return(1);
  }
  if (!strcmp(argv[1],"-h")) {
    printf(
"\n\nUsage: sgfsplit (filename) [extra arguments].\
\
This will split a Smart Go Format file into a series of\
files with names (filename).0.sgf, (filename).1.sgf,\
(filename).2.sgf ...  representing the individual variations\
in the file.  The file (filename).0.sgf is the main line;\
the remaining files contain variations.\
\
Also produced is an executable file (with permissions\
rwx------) called (filename).sgf2tex containing shell\
commands invoking sgf2tex for processing these files into\
TeX. The sgf2tex commands in (filename).sgf2tex for\
processing the variation files each specify a breakpoint,\
producing two diagrams. The first may be discarded, but the\
second represents the variation. Extra arguments (such as\
-simple) given to sgfsplit will be incorporated in the\
suggested sgf2tex commands.\n\n");
    return(1);
  }
  name=argv[1];
  extra_args[0]='\0';
  for (i=2; i<argc; i++) {
    strcat(extra_args,argv[i]);
    strcat(extra_args," ");
  }
  if (((fp=fopen(name,"r"))==NULL) &&
      ((fp=fopen(strcat(name,".sgf"),"r"))==NULL)) {
    fprintf(stderr,"sgfsplit: can't open file %s\n",argv[1]);
    return(1);
  }
  if (!strcmp(name+strlen(name)-4,".sgf")) name[strlen(name)-4]='\0';
  i=0;
  while ((c=getc(fp))!=EOF) sgf[i++]=c;
  if (i>=MAXSIZE) {
    fprintf(stderr,"%d: file too long\n",argv[0]);
    return(1);
  }
  sprintf(bname,"%s.sgf2tex",name);
  if ((bp=fopen(bname,"w"))==NULL) {
    fprintf(stderr, "sgfsplit: can't open file %s for output\n",bname);
  } else
    fprintf(bp,"#\
# File automatically generated by sgfsplit.\
# Edit this file if you will but remember: it will be\
# overwritten if sgfsplit %s is invoked again.\n#\n", name);
  sgf[i]='\0';
  parse(sgf,sgfout,name,0,0);
  fclose(bp);
  printf("Writing %s.\n\n",bname);
  chmod(bname,PERMISSIONS);
}

/* cuts a piece from a string */

cutstr(char str[],int left,int right)
{
  int i=left;
  while ((str[i]=str[i-left+right+1])!='\0') i++;
}
  
/* parse() is an LR parser for Smart Go Format, paying attention
   only to sgf structure relevant to finding variations and counting
   moves. State of the parser is determined by three four variables,
   pstate, mstate, bracecount and escape. pstate parses the structure
   for variations, keeping track of '(' and ')'. mstate parses the
   sgftags enough to recognize moves B[] and W[]. bracecount and
   escape count non-escaped braces, i.e. [ counts as +1, ] as -1,
   and \[, \] do not count. This feeds back into the pstate machine
   since '(' and ')' in regions where bracecount is positive are
   not counted. These could be parentheses within comments.

   Actions taken by the pstate parser are as follows. If after reading
   the game record we are in state 4, this means that a structure of
   the form (a(b(c ...(d(e)(f) ... has been recognized. Then
   (abc ... de) is written to a file, the sgf string is replaced by
   (a(b(c( ...(d(f) ...) and fed back to the parser. If the game
   record is in state 5, this means that a structure of the form
   (a(b(c ...(d(e))... has been recognized. The braces surrounding
   e are discarded, and the sgf string is fed back to the parser.
   State 6 indicates a structure (abc ... f). This is written to
   a file and the program terminates. */


parse(char str[],char sgfout[],char name[],int filecount,int movebreak)
{
  int i=0,j=0,lparen,rparen,pstate=0,mstate=0;
  int bracecount=0,movenum=0,nextbreak=0,escape=0;
  char oname[128];
  FILE *fp;
  while (str[i]!='\0') {
    if ((escape==0)&&(str[i]=='[')) bracecount++;
    if ((escape==0)&&(str[i]==']')) bracecount--;
    if (str[i]=='\\') {escape=1;
    } else escape=0;
    if (bracecount<0) {
      fprintf(stderr,"sgfsplit: unmatched ] in %d\n",name);
      return(1);
    }
    switch (pstate) {
    case 0:
      switch (str[i]) {
      case '(':	if (bracecount==0) {pstate=1; break;}
      case ')':	fprintf(stderr,"sgfsplit: unmatched ) in %d",name); 
	return(1);
      default: sgfout[j++]=str[i];
      } break;
    case 1:
      switch (str[i]) {
      case '(': if (bracecount==0) {
	pstate=2; nextbreak=movenum; lparen=i; break;
      }
      case ')': if (bracecount==0) {pstate=6; break;}
      default: sgfout[j++]=str[i];
      } break;
    case 2:
      switch (str[i]) {
      case '(': if (bracecount==0) {
	pstate=2; nextbreak=movenum; lparen=i; break;
      }
      case ')': if (bracecount==0) {pstate=3; rparen=i; break;}
      default: sgfout[j++]=str[i];
      } break;
    case 3:
      switch (str[i]) {
      case '(': if (bracecount==0) {pstate=4; break;}
      case ')': if (bracecount==0) {pstate=5; break;}
      default: sgfout[j++]=str[i];
      } break;
    }
    if ((bracecount==0)&&(pstate>0)) {
      if ((sgf[i]==';')||(sgf[i]==']')) {
	mstate=0;
      } else if (isupper(sgf[i])&&(sgf[i]!='B')&&(sgf[i]!='W')) {mstate=2;
      } else if ((mstate==0)&&((sgf[i]=='B')||(sgf[i]=='W'))) {mstate=1;
      } else if ((mstate==1)&&(isupper(sgf[i]))) {mstate=2;}
    }
    if ((bracecount==1)&&(sgf[i]=='[')&&(mstate==1)) {
      movenum++;
    }
    i++;
  }
  sgfout[j]='\0';
  if (pstate==4) {
    cutstr(str,lparen,rparen);
    sprintf(oname,"%s.%d.sgf",name,filecount++);
    if((fp=fopen(oname,"w"))==NULL) {
      fprintf(stderr,"sgfsplit: can't open output file\n");
      return(1);
    }
    if (movebreak!=0) {
      fprintf(bp,"sgf2tex -n -im -il -firstDiagram 2 -break %d %s%s\n",movebreak,extra_args,oname);
    } else fprintf(bp,"sgf2tex -n -im -il %s%s\n",extra_args,oname);
    fprintf(fp,"(%s)",sgfout);
    fclose(fp);
      printf("Writing %s. Break is at %d.\n",oname,movebreak);
    parse(str,sgfout,name,filecount,nextbreak);
  } else if (pstate==5) {
    cutstr(str,rparen,rparen);
    cutstr(str,lparen,lparen);
    parse(str,sgfout,name,filecount,movebreak);
  } 
  else if (pstate==6)
    {
      sprintf(oname,"%s.%d.sgf",name,filecount++);
      if((fp=fopen(oname,"w"))==NULL) {
	fprintf(stderr,"sgfsplit: can't open output file\n");
	return(1);
      }
      if (movebreak!=0) {
	fprintf(bp,"sgf2tex -n -im -il -firstDiagram 2 -break %d %s%s\n",movebreak,extra_args,oname);
      } else fprintf(bp,"sgf2tex -n -im -il %s%s\n",extra_args,oname);
      fprintf(fp,"%s",str);
      fclose(fp);
      printf("Writing %s. Break is at %d.\n",oname,movebreak);
   }
}