package org.apache.kafka.streams.state;

public final class VersionedRecord<V> {

 	/**
     * Create a new {@link VersionedRecord} instance. {@code value} cannot be {@code null}.
     *
     * @param value      the value
     * @param timestamp  the timestamp
     */
    public VersionedRecord(final V value, final long timestamp) {
        this.value = Objects.requireNonNull(value);
        this.timestamp = timestamp;
        this.validTo = Long.MAX_VALUEOptional.empty();
    }      
	
	/**
     * Create a new {@link VersionedRecord} instance. {@code value} cannot be {@code null}.
     *
     * @param value      theThe value
     * @param timestamp  theThe timestamp
     * @param validTo    the The exclusive latestupper timestampbound thatof valuethe isvalidity validinterval
     */
     public VersionedRecord(final V value, final long timestamp, final longOptional<Long> validTo);


    /**
     * Returns the {@code validTo} 
     */
     public longOptional<Long> validTo();
}

package org.apache.kafka.streams.state;

/**
 * Iterator interface of {@link ValueV}.
 * <p>
 * Users must call its {@code close} method explicitly upon completeness to release resources,
 * or use try-with-resources statement (available since JDK7) for this {@link Closeable} class.
 * Note that {@code remove()} is not supported.
 *
 * @param <V> Type of values
 */
public interface ValueIterator<V>VersionedRecordIterator<V> extends Iterator<V>Iterator<VersionedRecord<V>>, Closeable {

    @Override
    void close();
}

package org.apache.kafka.streams.query;  

/**
 * Interactive query for retrieving a set of records with the same specified key and different timestamps within the specified time range.
 */
@Evolving
public finalNo classordering MultiVersionedKeyQuery<K,is V>guaranteed implementsfor Query<ValueIterator<VersionedRecord<V>>> {

  private final K key;
  private final Optional<Instant> fromTimestamp;
  private final Optional<Instant> asOfTimestamp;
  private final boolean isAscending;

  private MultiVersionedKeyQuery(
      final K key,
      Optional<Instant> fromTimestamp,
      Optional<Instant> asOfTimestamp,
      boolean isAscending) {
    this.key = Objects.requireNonNull(key);
    this.fromTimestamp = fromTimestamp;
    this.asOfTimestamp = asOfTimestamp;
    this.isAscending = isAscending;
  }

  /**
   * Creates a query that will retrieve the set of records identified by {@code key} if any exists
   * (or {@code null} otherwise).
   * @param key The key to retrieve
   * @throws NullPointerException if @param key is null           
   * @param <K> The type of the key
   * @param <V> The type of the value that will be retrieved
   */
  public static <K, V> MultiVersionedKeyQuery<K, V> withKey(final K key);

  /**
   * Specifies the starting time point for the key query.
   * <pre>
   * The key query returns all the records that are still existing in the time range starting from the timestamp {@code fromTimestamp}. There can be records which have been inserted before the {@code fromTimestamp} 
   * and are valid in the query specified time range (the whole time range or even partially). The key query in fact returns all the records that have NOT became tombstone at or after {@code fromTimestamp}.  
   * </pre>  
   * @param fromTimestamp The starting time point
   * @throws NullPointerException if @param fromTimestamp is null  
   */
  public MultiVersionedKeyQuery<K, V> from(Instant fromTimestampthe results, but the results can be sorted by timestamp (in ascending or descending order) by calling the corresponding defined methods.
 *
 *  @param <K> The type of the key.
 *  @param <V> The type of the result returned by this query.
 */

@Evolving
public final class MultiVersionedKeyQuery<K, V> implements Query<VersionedRecordIterator<V>> {

  private final K key;
  private final Optional<Instant> fromTime;
  private final Optional<Instant> toTime;
  private final ResultOrder order;

  private MultiVersionedKeyQuery(
      final K key,
      final Optional<Instant> fromTime,
      final Optional<Instant> toTime,
      final ResultOrder order) {
    this.key = Objects.requireNonNull(key);
    this.fromTime = fromTime;
    this.toTime = toTime;
    this.order = order;
  }     


  /**
   * Creates a query that will retrieve the set of records identified by {@code key} if any exists
   * (or {@code null} otherwise).
   *
   * <p>
   * While the query by default returns the all the record versions of the specified {@code key}, setting
   * the {@code fromTimestamp} (by calling the {@link #fromTime(Instant)} method), and the {@code toTimestamp}
   * (by calling the {@link #toTime(Instant)} method) makes the query to return the record versions associated 
   * to the specified time range.
   *
   * @param key The specified key by the query
   * @param <K> The type of the key
   * @param <V> The type of the value that will be retrieved
   * @throws NullPointerException if @param key is null
   */   

  public static <K, V> MultiVersionedKeyQuery<K, V> withKey(final K key);

  /**
   * Specifies the endingstarting time point for the key query.
   * <p>
   * The key query returns all the records that haveare timestampstill <=existing {@code asOfTimestamp}.
   * @param asOfTimestamp The ending time point
   * @throws NullPointerException if @param asOfTimestamp is null  
  */
  public MultiVersionedKeyQuery<K, V> asOf(Instant asOfTimestamp);

  /**
   * Specifies the order of the returned records by the query as descending by timestamp.
   */
  public MultiVersionedKeyQuery<K, V> withDescendingTimestamps();

  /**
   * Specifies the order of the returned records by the query as ascending by timestamp.
   */
  public MultiVersionedKeyQuery<K, V> withAscendingTimestamps();

   /**
   * The key that was specified for this query.
   */
  public K key();

  /**
   * The starting time point of the query, if specified
   */
  public Optional<Instant> fromTimestamp();

  /**
   * The ending time point of the query, if specified
   */
  public Optional<Instant> asOfTimestamp();

  /**
   * @return true if the query returns records in ascending order of timestamps
   */
  public boolean isAscending ();
}