/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Author: jefftk@google.com (Jeff Kaufman)

#include "pagespeed/kernel/http/domain_registry.h"

#include <cstddef>                     // for size_t

#include "third_party/domain_registry_provider/src/domain_registry/domain_registry.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"

namespace net_instaweb {
namespace domain_registry {

void Init() {
  InitializeDomainRegistry();
}

StringPiece MinimalPrivateSuffix(StringPiece hostname) {
  if (hostname.empty()) {
    return "";
  }

  size_t length_of_public_suffix =
      GetRegistryLength(hostname.as_string().c_str());
  if (length_of_public_suffix == 0) {
    // Unrecognized top level domain.  We don't know what kind of multi-level
    // public suffixes they might have created, so be on the safe side and
    // treat the entire hostname as a private suffix.
    return hostname;
  }

  stringpiece_ssize_type last_dot_before_private_suffix =
      hostname.rfind('.', hostname.size() - length_of_public_suffix
                     - 1 /* don't include the dot */
                     - 1 /* pos is inclusive */);
  if (last_dot_before_private_suffix == StringPiece::npos) {
    // Hostname is already a minimal private suffix.
    last_dot_before_private_suffix = 0;
  } else {
    last_dot_before_private_suffix++;  // Don't include the dot.
  }
  return hostname.substr(last_dot_before_private_suffix);
}

}  // namespace domain_registry
}  // namespace net_instaweb