/*
 * UNG's Not GNU
 * 
 * Copyright (c) 2011, Jakob Kaivo <jakob@kaivo.net>
 * 
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

const char *uuencode_desc = "encode a binary file";
const char *uuencode_inv  = "uuencode [-m] [file] decode_pathname";

static const char *b64s =
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static int encode (FILE *in, char *out, int mode, int b64)
{
  char bin[3], bout[76];
  int nread = 0, lread = 0, lpos = 0;
  int linelength = b64 ? 54 : 43;
  int i;

  printf ("begin%s %03o %s\n", b64 ? "-base64" : "", mode, out);

  while (!feof(in)) {
    nread = fread (bin, sizeof(char), 3, in);
    if (nread > 0) {
      bout[lpos++] = (bin[0] >> 2) & 0x3f;
      bout[lpos++] = ((bin[0] << 4) | ((bin[1] >> 4) & 0xf)) & 0x3f;
      bout[lpos++] = ((bin[1] << 2) | ((bin[2] >> 6) & 0x3)) & 0x3f;
      bout[lpos++] = (bin[2]) & 0x3f;
      bin[0] = bin[1] = bin[2] = 0;
      lread += nread;
    }

    if (feof (in) || nread == 0 || lread > linelength) {
      for (i = 0; i < lpos; i++)
          bout[i] = b64 ? b64s[bout[i]] : bout[i] + 0x20;

      if (b64) {
        if (nread == 1)
          bout[lpos-2] = '=';
        if (nread == 1 || nread == 2)
          bout[lpos-1] = '=';
      }

      if (!b64)
        putchar (0x20 + lread);
      fwrite (bout, sizeof (char), lpos, stdout);
      fputc ('\n', stdout);
      lread = 0;
      lpos = 0;
    }
  }

  if (b64)
    printf ("====\n");
  else
    printf ("%c\nend\n", 0x20);

  return 0;
}

int
main(int argc, char **argv)
{
  int b64 = 0, mode = 0644, c;
  FILE *input;
  struct stat st;

  while ((c = getopt(argc, argv, ":m")) != -1) {
    switch (c) {
      case 'm':
        b64 = 1;
        break;
      default:
        return 1;
    }
  }

  if (argc - optind == 2) {
    input = fopen (argv[optind++], "r");
    if (fstat (fileno(input), &st) == 0)
      mode = st.st_mode & 0777;
  } else if (argc - optind == 1)
    input = stdin;
  else
    return 1;

  if (input == NULL)
    return 1;	// File I/O error

  return encode (input, argv[optind], mode, b64);
}