/*

  Cremona Table Input and Ellini

*/

#include "pari.h"

static int ctopened = 0;
static FILE *ctfp;

GEN ellcremona(char *instr) {
  long ltop;
  long a = 11,c = 1;
  char b = 'A';
  long aa,cc,ee,ff;
  char bb,dd[100];
  char linein[200],*l;
  FILE *fp;
  GEN cremonatable,outvec;
  long j=0;

  ltop = avma;
  cremonatable = flisexpr("cremonatable");
  if (typ(cremonatable) != t_STR) err(talker,"the cremona table has not been correctly set");
  fp = fopen(GSTR(cremonatable),"r");
  avma = ltop;

  sscanf(instr,"%i%c%i",&a,&b,&c);
  while ((l = fgets(linein,200,fp)) != NULL) {
    sscanf(linein,"%i %c %i",&aa,&bb,&cc);
    if ((a == aa) && (b == bb) && (c == cc)) {
      sscanf(linein,"%i %c %i %s",&aa,&bb,&cc,dd);
      break;
    }
  }
  if (l == NULL) err(talker,"could not find elliptic curve in table");
  fclose(fp);

  return flisexpr(dd);
}

void ellctopen(void) {
  long ltop;
  GEN cremonatable;

  if (ctopened) err(talker,"cremona table already open");

  ltop = avma;
  cremonatable = flisexpr("cremonatable");
  if (typ(cremonatable) != t_STR) err(talker,"the cremona table has not been correctly set");
  ctfp = fopen(GSTR(cremonatable),"r");
  avma = ltop;

  ctopened = 1;
}

GEN ellctgetline(void) {
  long aa,cc,ee,ff;
  char bb,dd[100];
  char linein[200],lineout[300];

  if (!ctopened) err(talker,"the cremona table must first be opened with ellctopen");

  if (fgets(linein,200,ctfp) != NULL) {
    sscanf(linein,"%i %c %i %s %i %i",&aa,&bb,&cc,dd,&ee,&ff);
    sprintf(lineout,"[%i,\"%c\",%i,%s,%i,%i]",aa,bb,cc,dd,ee,ff);
  } else {
    sprintf(lineout,"\"EOF\"");
  }

  return flisexpr(lineout);
}

void ellctclose(void) {
  ctopened = 0;
  fclose(ctfp);
}