module Win32::Resolv

# File ext/win32/lib/win32/resolv.rb, line 24
def self.get_hosts_path
  path = get_hosts_dir
  path = File.expand_path('hosts', path)
  File.exist?(path) ? path : nil
end

# File ext/win32/lib/win32/resolv.rb, line 30
def self.get_resolv_info
  search, nameserver = get_info
  if search.empty?
    search = nil
  else
    search.delete("")
    search.uniq!
  end
  if nameserver.empty?
    nameserver = nil
  else
    nameserver.delete("")
    nameserver.delete("0.0.0.0")
    nameserver.uniq!
  end
  [ search, nameserver ]
end

static VALUE
get_dns_server_list(VALUE self)
{
    FIXED_INFO *fixedinfo = NULL;
    ULONG buflen = 0;
    DWORD ret;
    VALUE buf, nameservers = Qnil;

    ret = GetNetworkParams(NULL, &buflen);
    if (ret != ERROR_BUFFER_OVERFLOW) w32error_check(ret);
    fixedinfo = ALLOCV(buf, buflen);
    ret = GetNetworkParams(fixedinfo, &buflen);
    if (ret == NO_ERROR) {
        const IP_ADDR_STRING *ipaddr = &fixedinfo->DnsServerList;
        nameservers = rb_ary_new();
        do {
            const char *s = ipaddr->IpAddress.String;
            if (!*s) continue;
            if (strcmp(s, "0.0.0.0") == 0) continue;
            rb_ary_push(nameservers, rb_str_new_cstr(s));
        } while ((ipaddr = ipaddr->Next) != NULL);
    }
    ALLOCV_END(buf);
    w32error_check(ret);

    return nameservers;
}

# File ext/win32/lib/win32/resolv.rb, line 50
def get_hosts_dir
  tcpip_params do |params|
    params.value('DataBasePath')
  end
end

# File ext/win32/lib/win32/resolv.rb, line 56
def get_info
  search = nil
  nameserver = get_dns_server_list

  tcpip_params do |params|
    slist = params.value('SearchList')
    search = slist.split(/,\s*/) if slist and !slist.empty?

    if add_search = search.nil?
      search = []
      nvdom = params.value('NV Domain')

      if nvdom and !nvdom.empty?
        search = [ nvdom ]
        udmnd = params.value('UseDomainNameDevolution')
        if udmnd&.nonzero?
          if /^\w+\./ =~ nvdom
            devo = $'
          end
        end
      end
    end

    params.open('Interfaces') do |reg|
      reg.each_key do |iface|
        next unless ns = %w[NameServer DhcpNameServer].find do |key|
          ns = iface.value(key)
          break ns.split(/[,\s]\s*/) if ns and !ns.empty?
        end

        next if (nameserver & ns).empty?

        if add_search
          [ 'Domain', 'DhcpDomain' ].each do |key|
            dom = iface.value(key)
            if dom and !dom.empty?
              search.concat(dom.split(/,\s*/))
              break
            end
          end
        end
      end
    end

    search << devo if add_search and devo
  end
  [ search.uniq, nameserver.uniq ]
end

static VALUE
tcpip_params_open(VALUE klass)
{
    return reg_open_key(reg_key_class, HKEY_LOCAL_MACHINE, TCPIP_Params);
}