/*
 * Copyright 2018 Google
 *
 * 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.
 */

#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_MODEL_SNAPSHOT_VERSION_H_
#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_MODEL_SNAPSHOT_VERSION_H_

#include "Firestore/core/include/firebase/firestore/timestamp.h"

namespace firebase {
namespace firestore {
namespace model {

/**
 * A version of a document in Firestore. This corresponds to the version
 * timestamp, such as update_time or read_time.
 */
class SnapshotVersion {
 public:
#if __OBJC__
  SnapshotVersion() {
  }
#endif  // __OBJC__

  explicit SnapshotVersion(const Timestamp& timestamp);

  const Timestamp& timestamp() const {
    return timestamp_;
  }

  /** Creates a new version that is smaller than all other versions. */
  static const SnapshotVersion& None();

#if __OBJC__
  size_t Hash() const {
    return std::hash<Timestamp>{}(timestamp_);
  }
#endif  // __OBJC__

 private:
  Timestamp timestamp_;
};

/** Compares against another SnapshotVersion. */
inline bool operator<(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() < rhs.timestamp();
}

inline bool operator>(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() > rhs.timestamp();
}

inline bool operator>=(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() >= rhs.timestamp();
}

inline bool operator<=(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() <= rhs.timestamp();
}

inline bool operator!=(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() != rhs.timestamp();
}

inline bool operator==(const SnapshotVersion& lhs, const SnapshotVersion& rhs) {
  return lhs.timestamp() == rhs.timestamp();
}

}  // namespace model
}  // namespace firestore
}  // namespace firebase

#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_MODEL_SNAPSHOT_VERSION_H_