#include "hfield.h"

static char *(hname[]) = {
    "unknown-header",
    "sender",
    "from",
    "reply-to",
    "to",
    "cc",
    "bcc",
    "date",
    "message-id",
    "subject",
    "resent-sender",
    "resent-from",
    "resent-reply-to",
    "resent-to",
    "resent-cc",
    "resent-bcc",
    "resent-date",
    "resent-message-id",
    "return-receipt-to",
    "errors-to",
    "apparently-to",
    "received",
    "return-path",
    "delivered-to",
    "content-length",
    "content-type",
    "content-transfer-encoding",
    "notice-requested-upon-delivery-to",
    "mail-followup-to",
    0};

static int hmatch(char *s, int len, char *t)
{
  int i;
  char ch;

  for (i = 0; (ch = t[i]); ++i) {
    if (i >= len) return 0;
    if (ch != s[i]) {
      if (ch == '-') return 0;
      if (ch - 32 != s[i]) return 0;
    }
  }
  for (;;) {
    if (i >= len) return 0;
    ch = s[i];
    if (ch == ':') return 1;
    if ((ch != ' ') && (ch != '\t')) return 0;
    ++i;
  }
}

int hfield_known(char *s, int len)
{
  int i;
  char *t;

  for (i = 1; (t = hname[i]); ++i)
    if (hmatch(s, len, t)) return i;

  return 0;
}

int hfield_valid(char *s, int len)
{
  int i;
  int j;
  char ch;

  for (j = 0; j < len; ++j)
    if (s[j] == ':') break;

  if (j >= len) return 0;

  while (j) {
    ch = s[j - 1];
    if ((ch != ' ') && (ch != '\t')) break;
    --j;
  }
  if (!j) return 0;

  for (i = 0; i < j; ++i) {
    ch = s[i];
    if (ch <= 32) return 0;
    if (ch >= 127) return 0;
  }
  return 1;
}

unsigned int hfield_skipname(char *s, int len)
{
  int i;
  char ch;

  for (i = 0; i < len; ++i)
    if (s[i] == ':') break;

  if (i < len) ++i;
  while (i < len) {
    ch = s[i];
    if ((ch != '\t') && (ch != '\n') && (ch != '\r') && (ch != ' ')) break;
    ++i;
  }

  return i;
}