package geniusweb.profile.utilityspace;

import java.math.BigDecimal;

import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
import com.fasterxml.jackson.annotation.JsonTypeInfo;

import geniusweb.issuevalue.Value;
import geniusweb.issuevalue.ValueSet;

/**
 * Provides a mechanism to map {@link Value}s into a utility (value in range
 * [0,1]).
 */
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.WRAPPER_OBJECT)
@JsonSubTypes({ @Type(value = DiscreteValueSetUtilities.class),
		@Type(value = NumberValueSetUtilities.class) })
public interface ValueSetUtilities {
	/**
	 * 
	 * @param value the {@link Value} to get the utility for
	 * @return the utility of the given value. MUST be in [0,1]. Should return 0
	 *         if the value is unknown.
	 */
	BigDecimal getUtility(Value value);

	/**
	 * 
	 * @param valueset the valueset that is supposed match with this
	 * @return null if the ValueSetUtilities fits the given set of values , that
	 *         means it can give utilities for all possible values in valueset.
	 *         Or a string containing an explanation why not.
	 */
	String isFitting(ValueSet valueset);

}