source: profile/src/main/java/geniusweb/profile/utilityspace/PartsUtilities.java

package geniusweb.profile.utilityspace;

import java.math.BigDecimal;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

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

/**
 * Contains utilities of a ProductOfValue of a {@link SumOfGroupsUtilitySpace}.
 * So this is similar to a {@link DiscreteValueSetUtilities} but instead of
 * issues this contains an (ordered) list of issues. This object serializes to
 * something like <code> 
 * {"partsutils":
 * {"issues":["issue1","issue2"],
 * "utilslist":[{"values":["low","low"],"util":0.3},{"values":["high","high"],"util":0.9}]}}
 </code> The issues field contains a list of N issues in the domain, The
 * utilslist contains a list of dictionaries, with "values" containing a list of
 * N issue values, in the same order as the issues list and with "util"
 * containng the utility value of that set of values.
 */
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE, isGetterVisibility = Visibility.NONE)
public class PartsUtilities implements ValueSetUtilities {
        private final List<String> issues;
        // the real but not-serializable values (because Map can only have String
        // keys in jackson)
        private transient final Map<ProductOfValue, BigDecimal> utilities = new HashMap<>();
        // copy only for serializing
        private final List<PartUtil> utilslist = new LinkedList<>();

        /**
         * 
         * @param issues list of issues
         * @param utils  with keys: list of values and value: utility value for that
         *               list of values. All list-of-values missing from the map are
         *               assumed to have utility 0. This includes partial bids where
         *               list-of-values contain null objects.
         */
        public PartsUtilities(List<String> issues,
                        Map<ProductOfValue, BigDecimal> utils) {
                if (issues == null || utils == null) {
                        throw new IllegalArgumentException(
                                        "issues and utils must be not null");
                }

                this.issues = issues;
                this.utilities.putAll(utils);

                checkUtilities();
                for (ProductOfValue pval : utils.keySet()) {
                        utilslist.add(new PartUtil(pval.getValues(), utils.get(pval)));
                }
        }

        @JsonCreator
        public PartsUtilities(@JsonProperty("issues") List<String> issues,
                        @JsonProperty("utilslist") List<PartUtil> utilslist) {
                this(issues, list2map(utilslist));
        }

        /**
         * 
         * @param pval the {@link ProductOfValue} value
         * @return the utility of the value, in the same order as
         *         {@link #getIssues()}. Returns 0 if there is no utility set for
         *         the given combination of values. Notice, partial bids will
         *         usually have utility 0.
         * 
         */
        @Override
        public BigDecimal getUtility(Value pval) {
                BigDecimal val = utilities.get(pval);
                if (val == null)
                        return BigDecimal.ZERO;
                return val;
        }

        @Override
        public String isFitting(ValueSet valueset) {
                return null; // what can we tests here?
        }

        /**
         * @return the issues that are contained here.
         */
        public List<String> getIssues() {
                return issues;
        }

        /**
         * 
         * @return map with all available values and their utilities. The map and
         *         its contents should all be immutable.
         */
        public Map<ProductOfValue, BigDecimal> getUtilities() {
                return Collections.unmodifiableMap(utilities);
        }

        /**
         * 
         * @param other another {@link PartsUtilities} map. The issues in the other
         *              map must be different from {@link #issues}.
         * @return new PartsUtils, with the powermap of all combinations of one
         *         element from this and one from the other map, and with the
         *         utilities computed as the sum of thisvalue + othervalue.
         */
        public PartsUtilities add(PartsUtilities other) {
                for (String issue : issues) {
                        if (other.issues.contains(issue)) {
                                throw new IllegalArgumentException(
                                                "Issue " + issue + " exists already");
                        }
                }

                List<String> combinedissues = new LinkedList<String>(issues);
                combinedissues.addAll(other.issues);

                Map<ProductOfValue, BigDecimal> combinedvalues = new HashMap<>();
                for (ProductOfValue productOfValue : this.utilities.keySet()) {
                        for (ProductOfValue otherProductOfValue : other.utilities
                                        .keySet()) {
                                BigDecimal combinedutil = getUtility(productOfValue)
                                                .add(other.getUtility(otherProductOfValue));
                                combinedvalues.put(productOfValue.merge(otherProductOfValue),
                                                combinedutil);
                        }
                }
                return new PartsUtilities(combinedissues, combinedvalues);

        }

        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((issues == null) ? 0 : issues.hashCode());
                result = prime * result
                                + ((utilities == null) ? 0 : utilities.hashCode());
                return result;
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                PartsUtilities other = (PartsUtilities) obj;
                if (issues == null) {
                        if (other.issues != null)
                                return false;
                } else if (!issues.equals(other.issues))
                        return false;
                if (utilities == null) {
                        if (other.utilities != null)
                                return false;
                } else if (!utilities.equals(other.utilities))
                        return false;
                return true;
        }

        @Override
        public String toString() {
                return "PartsUtilities[" + issues + "," + utilities + "]";
        }

        private void checkUtilities() {
                if (utilities.values().stream()
                                .anyMatch(v -> v == null || v.compareTo(BigDecimal.ZERO) < 0
                                                || v.compareTo(BigDecimal.ONE) > 0)) {
                        throw new IllegalArgumentException(
                                        "part weights must all be in [0,1]");
                }
        }

        private static Map<ProductOfValue, BigDecimal> list2map(
                        List<PartUtil> list) {
                Map<ProductOfValue, BigDecimal> map = new HashMap<>();
                for (PartUtil partutil : list) {
                        map.put(new ProductOfValue(partutil.getValues()),
                                        partutil.getUtil());
                }
                return map;
        }

        /**
         * 
         * @return the max utility of all values contained here.
         */
        public BigDecimal getMaxUtility() {
                BigDecimal maxutil = BigDecimal.ZERO;
                for (ProductOfValue vakye : utilities.keySet()) {
                        if (utilities.get(vakye).compareTo(maxutil) > 0) {
                                maxutil = utilities.get(vakye);
                        }

                }
                return maxutil;
        }

}

/**
 * contains list of values, and the utility for this combi of values. The values
 * make only sense with a corresponding list of issues, but that is managed in
 * (see {@link PartsUtilities}.
 * <p>
 * immutable.
 */
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE, isGetterVisibility = Visibility.NONE)
class PartUtil {
        private final List<Value> values;

        private final BigDecimal util;

        @JsonCreator
        public PartUtil(@JsonProperty("values") List<Value> values,
                        @JsonProperty("util") BigDecimal util) {
                this.values = values;
                this.util = util;
        }

        public List<Value> getValues() {
                return values;
        }

        public BigDecimal getUtil() {
                return util;
        }
}