#include "stralloc.h"
#include "alloc.h"
#include "slurpclose.h"
#include "strerr.h"
#include "substdio.h"
#include "readwrite.h"
#include "exit.h"

#define FATAL "columnt: fatal: "

char outbuf[4096];
substdio ssout = SUBSTDIO_FDBUF(write,1,outbuf,sizeof outbuf);

void nomem() { strerr_die2x(111,FATAL,"out of memory"); }
void die_read() { strerr_die2sys(111,FATAL,"unable to read input: "); }
void die_write() { strerr_die2sys(111,FATAL,"unable to write output: "); }

stralloc file = {0};
int *width;
int maxfield = 0;

void nothing()
{
  ;
}

void printline()
{
  if (substdio_put(&ssout,"\n",1) == -1) die_write();
}

void maxfield_check(fieldnum,buf,len) int fieldnum; char *buf; int len;
{
  if (fieldnum > maxfield) maxfield = fieldnum;
}

void width_check(fieldnum,buf,len) int fieldnum; char *buf; int len;
{
  if (len > width[fieldnum]) width[fieldnum] = len;
}

void width_init()
{
  int i;

  width = (int *) alloc((maxfield + 1) * sizeof(int));
  if (!width) nomem();
  for (i = 0;i <= maxfield;++i) width[i] = 0;
}

void printfield(fieldnum,buf,len) int fieldnum; char *buf; int len;
{
  int i;

  if (fieldnum < maxfield)
    for (i = len;i < width[fieldnum];++i)
      if (substdio_put(&ssout," ",1) == -1) die_write();

  if (substdio_put(&ssout,buf,len) == -1) die_write();

  if (fieldnum < maxfield)
    if (substdio_put(&ssout,"  ",2) == -1) die_write();
}

void split(dofield,doline)
void (*dofield)();
void (*doline)();
{
  int i;
  int j;
  int fieldpos;
  int fieldnum;

  for (j = i = 0;j < file.len;++j)
    if (file.s[j] == '\n') {
      fieldnum = 0;
      for (;;) {
        while ((file.s[i] == ' ') || (file.s[i] == '\t')) ++i;
        if (i == j) break;
        fieldpos = i;
        while ((file.s[i] != ' ') && (file.s[i] != '\t') && (file.s[i] != '\n')) ++i;
        dofield(fieldnum++,file.s + fieldpos,i - fieldpos);
      }
      doline();
      i = j + 1;
    }
}

void main()
{
  if (slurpclose(0,&file,4096) == -1) die_read();
  if (!file.len) _exit(0);
  if (file.s[file.len - 1] != '\n')
    if (!stralloc_append(&file,"\n")) nomem();

  split(maxfield_check,nothing);
  width_init();
  split(width_check,nothing);
  split(printfield,printline);

  if (substdio_flush(&ssout) == -1) die_write();
  _exit(0);
}