/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ 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 "libc/alg/arraylist.internal.h"
#include "libc/dns/dns.h"
#include "libc/dns/hoststxt.h"
#include "libc/errno.h"
#include "libc/runtime/runtime.h"
#include "libc/sock/sock.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/af.h"

/**
 * Parses HOSTS.TXT contents.
 *
 * Hostnames were invented by Peggy Karp; her format looks like this:
 *
 *     # this is a comment
 *     # IP            CANON [ALT...]
 *     203.0.113.1     lol.example. lol
 *     203.0.113.2     cat.example. cat
 *
 * @param htp points to a HostsTxt object, which should be zero
 *     initialized by the caller; or if it already contains items,
 *     this function will append
 * @param f is the file content; see fopen() and fmemopen()
 * @return 0 on success, or -1 w/ errno
 * @see hoststxtsort() which is the logical next step
 */
int parsehoststxt(struct HostsTxt *ht, FILE *f) {
  char *line;
  size_t linesize;
  struct HostsTxtEntry entry;
  char *addr, *name, *tok, *comment;
  line = NULL;
  linesize = 0;
  while ((getline(&line, &linesize, f)) != -1) {
    if ((comment = strchr(line, '#'))) *comment = '\0';
    if ((addr = strtok_r(line, " \t\r\n\v", &tok)) &&
        inet_pton(AF_INET, addr, entry.ip) == 1) {
      entry.canon = ht->strings.i;
      while ((name = strtok_r(NULL, " \t\r\n\v", &tok))) {
        entry.name = ht->strings.i;
        concat(&ht->strings, name, strnlen(name, DNS_NAME_MAX) + 1);
        append(&ht->entries, &entry);
      }
    }
  }
  free(line);
  if (ferror(f)) {
    errno = ferror(f);
    return -1;
  }
  return 0;
}
