/*
Serval Project testing framework utility - create fixture file
Copyright (C) 2012 Serval Project, Inc.

This program 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 2
of the License, or (at your option) any later version.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>
#include "str.h"

static const char *argv0 = "test_createfile";

static void fatal(const char *fmt, ...)
{
  va_list ap;
  va_start(ap, fmt);
  char buf[1024];
  setbuffer(stderr, buf, sizeof buf);
  fprintf(stderr, "%s: ", argv0);
  vfprintf(stderr, fmt, ap);
  fputc('\n', stderr);
  va_end(ap);
  fflush(stderr);
  setbuf(stderr, NULL);
  exit(1);
}

static inline char stripe(int i)
{
  return (i >= ' ' && i <= '~') ? i : '.';
}

int main(int argc, char **argv)
{
  argv0 = argv[0];
  uint64_t size = 0;
  const char *label = "";
  int i;
  for (i = 1; i < argc; ++i) {
    const char *arg = argv[i];
    if (str_startswith(arg, "--size=", &arg)) {
      if (!str_to_uint64_scaled(arg, 10, &size, NULL) || size < 0)
	fatal("illegal --size= argument: %s", arg);
    }
    else if (str_startswith(arg, "--label=", &arg))
      label = arg;
    else
      fatal("unrecognised argument: %s", arg);
  }
  uint64_t offset = 0;
  char buf[127];
  for (i = 0; i != sizeof buf; ++i)
    buf[i] = stripe(i);
  const size_t labellen = strlen(label);
  int bouncemax = sizeof buf - labellen;
  if (bouncemax < 0)
    bouncemax = sizeof buf;
  int bounce = 3;
  int bouncedelta = 1;
  while (!ferror(stdout) && offset < size) {
    int n = sprintf(buf, "%lld", offset);
    buf[n] = stripe(n);
    size_t labelsiz = labellen;
    if (labelsiz && bounce < sizeof buf) {
      if (labelsiz > sizeof buf - bounce)
	labelsiz = sizeof buf - bounce;
      memcpy(buf + bounce, label, labelsiz);
    }
    int remain = size - offset - 1;
    if (remain > sizeof buf)
      remain = sizeof buf;
    fwrite(buf, remain, 1, stdout);
    fputc('\n', stdout);
    offset += remain + 1;
    if (bounce <= n || bounce >= bouncemax)
      bouncedelta *= -1;
    if (labelsiz) {
      if (bouncedelta > 0)
	buf[bounce] = stripe(bounce);
      else
	buf[bounce + labelsiz - 1] = stripe(bounce + labelsiz - 1);
    }
    bounce += bouncedelta;
  }
  fflush(stdout);
  if (ferror(stdout))
    fatal("write error: %s [errno=%d]", strerror(errno), errno);
  exit(0);
}