package eu.dnetlib.functionality.index.model;

import java.util.Iterator;

/**
 * Interface for metadata objects.
 */
public interface Any extends Iterable<Any> {

	/**
	 * Enumeration with the possible value types.
	 * 
	 */
	public enum ValueType {

		/**
		 * The list with the possible value types. MAP map, SEQ sequence, STRING string value, DOUBLE double value,
		 * BOOLEAN Boolean value, LONG long value, DATE date (without time), DATETIME date with time
		 */
		MAP, SEQ, STRING, DOUBLE, BOOLEAN, LONG, DATE, DATETIME
	};

	/**
	 * @return value type
	 */
	ValueType getValueType();

	/**
	 * @return true if value is of type map
	 */
	boolean isMap();

	/**
	 * @return true if value is of type sequence
	 */
	boolean isSeq();

	/**
	 * @return true if value is of type value
	 */
	boolean isValue();

	/**
	 * @return true if value is of type string
	 */
	boolean isString();

	/**
	 * @return true if value is of type double
	 */
	boolean isDouble();

	/**
	 * @return true if value is of type boolean
	 */
	boolean isBoolean();

	/**
	 * @return true if value is of type long
	 */
	boolean isLong();

	/**
	 * @return true if value is of type date
	 */
	boolean isDate();

	/**
	 * @return true if value is of type date time
	 */
	boolean isDateTime();

	/**
	 * @return true if value is of type long or double
	 */
	boolean isNumber();

	/**
	 * @return data factory to create Anys of the same kind.
	 */
	DataFactory getFactory();

	/**
	 * @return iterator over elements. For {@link Value}, this return an iterator about the value itself. For
	 *         {@link AnyMap} it returns an iterator on the values.
	 */
	@Override
	Iterator<Any> iterator();

	/**
	 * @return true, if the Any does not have content. For {@link Value}: returns always false.
	 */
	boolean isEmpty();

	/**
	 * @return size of Any. For {@link Value} this is always 1.
	 */
	int size();

	/**
	 * returns this Any as an {@link Value} object or throws an {@link InvalidValueTypeException}.
	 */
	Value asValue();

	/**
	 * returns this Any as an {@link AnyMap} object or throws an {@link InvalidValueTypeException}.
	 */
	AnyMap asMap();

	/**
	 * returns this Any as an {@link AnySeq} object or throws an {@link InvalidValueTypeException}.
	 */
	AnySeq asSeq();

}