/**
 * 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.
 *
 */

package org.waveprotocol.box.server.frontend;


import com.google.common.base.Preconditions;

import org.waveprotocol.wave.model.version.HashedVersion;
import org.waveprotocol.wave.model.wave.data.ReadableWaveletData;

/**
 * A wavelet snapshot with committed version.
 *
 * @author anorth@google.com (Alex North)
*/
public final class CommittedWaveletSnapshot {
  public final ReadableWaveletData snapshot;
  public final HashedVersion committedVersion;

  public CommittedWaveletSnapshot(ReadableWaveletData snapshot,
      HashedVersion committedVersion) {
    Preconditions.checkNotNull(snapshot);
    Preconditions.checkNotNull(committedVersion);
    this.snapshot = snapshot;
    this.committedVersion = committedVersion;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) return true;
    if (obj != null && getClass() == obj.getClass()) {
      CommittedWaveletSnapshot other = (CommittedWaveletSnapshot) obj;
      return committedVersion.equals(other.committedVersion) && snapshot.equals(other.snapshot);
    }
    return false;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((committedVersion == null) ? 0 : committedVersion.hashCode());
    result = prime * result + ((snapshot == null) ? 0 : snapshot.hashCode());
    return result;
  }
}