/*
    *
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.hadoop.hbase.io;
  
  import java.io.IOException;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.util.Bytes;
  
  /**
   * Represents an interval of version timestamps.
   * <p>
   * Evaluated according to minStamp <= timestamp < maxStamp
   * or [minStamp,maxStamp) in interval notation.
   * <p>
   * Only used internally; should not be accessed directly by clients.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class TimeRange {
    private long minStamp = 0L;
    private long maxStamp = Long.MAX_VALUE;
    private boolean allTime = false;
  
    /**
     * Default constructor.
     * Represents interval [0, Long.MAX_VALUE) (allTime)
     */
    public TimeRange() {
      allTime = true;
    }
  
    /**
     * Represents interval [minStamp, Long.MAX_VALUE)
     * @param minStamp the minimum timestamp value, inclusive
     */
    public TimeRange(long minStamp) {
      this.minStamp = minStamp;
    }
  
    /**
     * Represents interval [minStamp, Long.MAX_VALUE)
     * @param minStamp the minimum timestamp value, inclusive
     */
    public TimeRange(byte [] minStamp) {
      this.minStamp = Bytes.toLong(minStamp);
    }
  
    /**
     * Represents interval [minStamp, maxStamp)
     * @param minStamp the minimum timestamp, inclusive
     * @param maxStamp the maximum timestamp, exclusive
     * @throws IOException
     */
    public TimeRange(long minStamp, long maxStamp)
    throws IOException {
      if (minStamp < 0 || maxStamp < 0) {
        throw new IllegalArgumentException("Timestamp cannot be negative. minStamp:" + minStamp
          + ", maxStamp:" + maxStamp);
      }
      if(maxStamp < minStamp) {
        throw new IOException("maxStamp is smaller than minStamp");
      }
      this.minStamp = minStamp;
      this.maxStamp = maxStamp;
    }
  
    /**
     * Represents interval [minStamp, maxStamp)
     * @param minStamp the minimum timestamp, inclusive
     * @param maxStamp the maximum timestamp, exclusive
     * @throws IOException
     */
    public TimeRange(byte [] minStamp, byte [] maxStamp)
    throws IOException {
      this(Bytes.toLong(minStamp), Bytes.toLong(maxStamp));
    }
  
    /**
     * @return the smallest timestamp that should be considered
     */
   public long getMin() {
     return minStamp;
   }
 
   /**
    * @return the biggest timestamp that should be considered
    */
   public long getMax() {
     return maxStamp;
   }
 
   /**
    * Check if it is for all time
    * @return true if it is for all time
    */
   public boolean isAllTime() {
     return allTime;
   }
 
   /**
    * Check if the specified timestamp is within this TimeRange.
    * <p>
    * Returns true if within interval [minStamp, maxStamp), false
    * if not.
    * @param bytes timestamp to check
    * @param offset offset into the bytes
    * @return true if within TimeRange, false if not
    */
   public boolean withinTimeRange(byte [] bytes, int offset) {
     if(allTime) return true;
     return withinTimeRange(Bytes.toLong(bytes, offset));
   }
 
   /**
    * Check if the specified timestamp is within this TimeRange.
    * <p>
    * Returns true if within interval [minStamp, maxStamp), false
    * if not.
    * @param timestamp timestamp to check
    * @return true if within TimeRange, false if not
    */
   public boolean withinTimeRange(long timestamp) {
     if(allTime) return true;
     // check if >= minStamp
     return (minStamp <= timestamp && timestamp < maxStamp);
   }
 
   /**
    * Check if the specified timestamp is within this TimeRange.
    * <p>
    * Returns true if within interval [minStamp, maxStamp), false
    * if not.
    * @param timestamp timestamp to check
    * @return true if within TimeRange, false if not
    */
   public boolean withinOrAfterTimeRange(long timestamp) {
     if(allTime) return true;
     // check if >= minStamp
     return (timestamp >= minStamp);
   }
 
   /**
    * Compare the timestamp to timerange
    * @param timestamp
    * @return -1 if timestamp is less than timerange,
    * 0 if timestamp is within timerange,
    * 1 if timestamp is greater than timerange
    */
   public int compare(long timestamp) {
     if (allTime) return 0;
     if (timestamp < minStamp) {
       return -1;
     } else if (timestamp >= maxStamp) {
       return 1;
     } else {
       return 0;
     }
   }
 
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("maxStamp=");
     sb.append(this.maxStamp);
     sb.append(", minStamp=");
     sb.append(this.minStamp);
     return sb.toString();
   }
 }