source: TraumaOntologies/src/main/java/tudelft/healthpsychology/traumaontologies/answerstate/PropertiesAnswerState.java@ 5

package tudelft.healthpsychology.traumaontologies.answerstate;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.util.StdConverter;

import tudelft.healthpsychology.traumaontologies.questiontypes.TypedQuestion;
import tudelft.utilities.tree.Tree;

/**
 * Handles the process in filling in the properties of an {@link OntologyNode}.
 * The most accurate available {@link OntologyNode} was determined already. The
 * process here is to get answers to all the questions relevant for such a node.
 * Properties are picked up from the comment fields behind the given
 * OntologyNode and its parents. <br>
 * immutable.
 *
 */
public class PropertiesAnswerState implements AnswerState {

        private final String nodelabel;

        @JsonSerialize(converter = PropMapSerializer.class)
        private final Map<Property, String> answers;

        /**
         * 
         * @param object  the ontologynode class for which all properties need to be
         *                collected and answered.
         * @param answers the already collected answers to the properties
         */
        @JsonCreator
        public PropertiesAnswerState(@JsonProperty("nodelabel") String objectlabel,
                        @JsonProperty("answers") @JsonDeserialize(converter = PropMapDeserializer.class) Map<Property, String> answers) {
                this.nodelabel = objectlabel;
                this.answers = answers;
        }

        /**
         * Convenience constructor for initial state
         * 
         * @param nodelabel the label of initial node
         */
        @SuppressWarnings("unchecked")
        public PropertiesAnswerState(String nodelabel) {
                this(nodelabel, Collections.EMPTY_MAP);
        }

        @Override
        public PropertiesAnswerState with(String answer,
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                Property property = getProperty(tree);
                if (property == null)
                        return this;
                if (!property.getQuestionType().fits(answer)) {
                        throw new IllegalArgumentException("The answer string must fit an "
                                        + property.getQuestionType());
                }
                Map<Property, String> newanswers = new HashMap<Property, String>(
                                answers);
                newanswers.put(property, answer);
                return new PropertiesAnswerState(nodelabel, newanswers);
        }

        /**
         * 
         * @return the main node label for this object. Mainly for testing
         */
        public String getNode() {
                return nodelabel;
        }

        @Override
        public TypedQuestion getOptions(
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                Property prop = getProperty(tree);
                if (prop == null)
                        return null;
                return prop.getQuestionType();
        }

        /**
         * 
         * @return the answers given so far.
         */
        public Map<Property, String> getAnswers() {
                return answers;
        }

        /**
         * 
         * @return the property to be answered, or null if no such property (all
         *         have been answered)
         */
        private Property getProperty(
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                Set<Property> remaining = new HashSet<>(
                                tree.get(nodelabel).getAttribute());
                remaining.removeAll(answers.keySet());
                if (remaining.isEmpty()) {
                        return null;
                }
                return remaining.iterator().next();
        }

        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((answers == null) ? 0 : answers.hashCode());
                result = prime * result
                                + ((nodelabel == null) ? 0 : nodelabel.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;
                PropertiesAnswerState other = (PropertiesAnswerState) obj;
                if (answers == null) {
                        if (other.answers != null)
                                return false;
                } else if (!answers.equals(other.answers))
                        return false;
                if (nodelabel == null) {
                        if (other.nodelabel != null)
                                return false;
                } else if (!nodelabel.equals(other.nodelabel))
                        return false;
                return true;
        }

}

/****** serialization of key-value pair of Map<Property,String> **********/

class PropString {
        @JsonProperty
        private final Property prop;
        @JsonProperty
        private final String answer;

        @JsonCreator
        public PropString(@JsonProperty("prop") Property prop,
                        @JsonProperty("answer") String answer) {
                this.prop = prop;
                this.answer = answer;
        }

        public Property getProp() {
                return prop;
        }

        public String getAnswer() {
                return answer;
        }
}

/**
 * Custom serializer to map the Map into a List
 *
 */
class PropMapSerializer
                extends StdConverter<Map<Property, String>, List<PropString>> {
        private final ObjectMapper mapper = new ObjectMapper();

        @Override
        public List<PropString> convert(Map<Property, String> propstringmap) {
                List<PropString> list = new LinkedList<PropString>();
                for (Map.Entry<Property, String> pair : propstringmap.entrySet()) {
                        list.add(new PropString(pair.getKey(), pair.getValue()));
                }
                return list;
        }

}

/**
 * Custom deserializer to map the List back to a Map
 *
 */
class PropMapDeserializer
                extends StdConverter<List<PropString>, Map<Property, String>> {
        private final ObjectMapper mapper = new ObjectMapper();

        @Override
        public Map<Property, String> convert(List<PropString> valuelist) {
                Map<Property, String> propsmap = new HashMap<>();
                for (PropString prop : valuelist) {
                        propsmap.put(prop.getProp(), prop.getAnswer());
                }
                return propsmap;
        }

}