/**
 * Represents a predicate. Implementations of this interface are basic building blocks for performing criteria queries.
 */
public interface Criteria {
    /**
     * Creates a predicate that tests whether the column value is equal to the given condition.
     *
     * @param columnName Column name.
     * @param condition Target condition. 
     */
    static Expression columnValue(String columnName, Condition condition);
 
    /**
     * Creates a condition that test the examined object is equal to the specified {@code value}.
     *
     * @param value Target value.
     */
    static <R> Condition equalTo(Comparable<R> value);

    /**
     * Creates a condition that test the examined object is equal to the specified {@code value}.
     *
     * @param value Target value.
     */
    static Condition equalTo(byte[] value);

    /**
     * Creates a condition that test the examined object is not equal to the specified {@code value}.
     *
     * @param value Target value.
     */
    static <R> Condition greaterThan(Comparable<R> value);

    /**
     * Creates a condition that test the examined object is greater than or equal than the specified {@code value}.
     *
     * @param value Target value.
     */
    static <R> Condition greaterThanOrEqualTo(Comparable<R> value);

    /**
     * Creates a condition that test the examined object is less than the specified {@code value}.
     *
     * @param value Column value.
     */
    static <R> Condition lessThan(Comparable<R> value);

    /**
     * Creates a condition that test the examined object is less than or equal than the specified {@code value}.
     *
     * @param value Column value.
     */
    static <R> Condition lessThanOrEqualTo(Comparable<R> value);

    /**
     * Creates a condition that test the examined object is is found within the specified {@code collection}.
     *
     * @param values Column values.
     * @return the created <b>in</b> predicate instance.
     */
    static <R> Condition in(Comparable<R>... values);

    /**
     * Creates a condition that test the examined object is is found within the specified {@code collection}.
     *
     * @param values Column values.
     * @return the created <b>in</b> predicate instance.
     */
    static <R> Condition in(byte[]... values);

    /**
     * Creates the {@code and} of the expressions.
     *
     * @param expressions Expressions.
     */
    static Expression and(Expression... expressions);

    /**
     * Creates the {@code or} of the expressions.
     *
     * @param expressions Expressions.
     */
    static Expression or(Expression... expressions);

    /**
     * Creates the negation of the predicate.
     *
     * @param expression Expression.
     */
    static Expression not(Expression expression);
}

/**
 * Provides methods to iterate over operation results and release underlying resources.
 */
public interface Cursor<T> extends Iterator<T>, AutoCloseable {
    /**
     * Closes this cursor and releases any underlying resources.
     */
    @Override void close();
}

/**
 * Provides methods to iterate over operation results and release underlying resources in an asynchronous way.
 */
public interface AsyncCursor<T> {
    /**
     * Returns the current page content if the operation returns results.
     */
    Iterable<T> currentPage();

    /**
     * Returns the current page size if the operation return results.
     */
    int currentPageSize();

    /**
     * Fetches the next page of results asynchronously.
     */
    CompletableFuture<? extends AsyncCursor<T>> fetchNextPage();

    /**
     * Indicates whether there are more pages of results.
     */
    boolean hasMorePages();

    /**
     * Closes this cursor and releases any underlying resources.
     */
    CompletableFuture<Void> closeAsync();
}

/**
 * Criteria query options.
 */
public class CriteriaQueryOptions {
    /** Default options. */
    public static final CriteriaQueryOptions DEFAULT = builder().build();

    private final int pageSize;

    /**
     * Constructor.
     *
     * @param pageSize Page size.
     */
    private CriteriaQueryOptions(int pageSize) {
        this.pageSize = pageSize;
    }

    /**
     * Creates a new builder.
     *
     * @return Builder.
     */
    public static Builder builder() {
        return new Builder();
    }

    /**
     * Gets a page size - the maximum number of result rows that can be fetched at a time.
     *
     * @return Batch size.
     */
    public int pageSize() {
        return pageSize;
    }

    /**
     * Builder.
     */
    public static class Builder {
        private int pageSize = 1000;

        /**
         * Sets the page size (the number of entries that will be sent to the cluster in one network call).
         *
         * @param pageSize Page size.
         * @return This builder instance.
         */
        public Builder pageSize(int pageSize) {
            if (pageSize <= 0) {
                throw new IllegalArgumentException("Page size must be positive: " + pageSize);
            }

            this.pageSize = pageSize;

            return this;
        }

        /**
         * Builds the options.
         *
         * @return Criteria query options.
         */
        public CriteriaQueryOptions build() {
            return new CriteriaQueryOptions(pageSize);
        }
    }
}

/**
 * Represents an object which can be queried with criteria.
 *
 * @param <T> Entry type.
 */
public interface CriteriaQuerySource<T> {
    /**
     * Criteria query over cache entries.
     *
     * @param tx Transaction to execute the query within or {@code null}.
     * @param criteria If {@code null} then all entries will be returned.
     * @throws SqlException If failed.
     */
    default Cursor<T> query(@Nullable Transaction tx, @Nullable Criteria criteria) {
        return query(tx, criteria, CriteriaQueryOptions.DEFAULT);
    }

    /**
     * Criteria query over cache entries.
     *
     * @param tx Transaction to execute the query within or {@code null}.
     * @param criteria If {@code null} then all entries will be returned.
     * @param opts Criteria query options.
     * @throws SqlException If failed.
     */
    Cursor<T> query(@Nullable Transaction tx, @Nullable Criteria criteria, @Nullable CriteriaQueryOptions opts);

    /**
     * Execute criteria query over cache entries in an asynchronous way.
     *
     * @param tx Transaction to execute the query within or {@code null}.
     * @param criteria If {@code null} then all entries will be returned.
     * @return Operation future.
     * @throws SqlException If failed.
     */
    default CompletableFuture<AsyncCursor<T>> queryAsync(@Nullable Transaction tx, @Nullable Criteria criteria) {
        return queryAsync(tx, criteria, CriteriaQueryOptions.DEFAULT);
    }

    /**
     * Execute criteria query over cache entries in an asynchronous way.
     *
     * @param tx Transaction to execute the query within or {@code null}.
     * @param criteria If {@code null} then all entries will be returned.
     * @param opts Criteria query options.
     * @return Operation future.
     * @throws SqlException If failed.
     */
    CompletableFuture<AsyncCursor<T>> queryAsync(
            @Nullable Transaction tx,
            @Nullable Criteria criteria,
            @Nullable CriteriaQueryOptions opts
    );
}

public interface KeyValueView<K, V> extends DataStreamerTarget<Entry<K, V>>, CriteriaQuerySource<Entry<K, V>> {
    // ...
}

public interface RecordView<R> extends DataStreamerTarget<R>, CriteriaQuerySource<R> {
    // ...
}