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

package tudelft.healthpsychology.traumaontologies.answerstate;

import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;

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

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

/**
 * {@link #node} points to a type of object of which there may be multiple
 * relevant instances , eg "Persoon". This keeps track of asking the user all
 * details about all instances.
 * 
 * So this contains the state of a set of answers for a given OntologyNode,
 * handling breath first:
 * <ol>
 * <li>The top level node eg #Persoon contains a main question (with the name as
 * indicated in the constructor).
 * 
 * <li>We repeat asking for this main question until user says he has no more
 * relevant items of this type (so no more relevant person)
 * 
 * <li>for each item, we determine the best fitting ontology class and ask the
 * questions for this class.
 * </ol>
 * 
 */
public class AnswersBreathFirstState implements AnswerState {

        private final String nodelabel; // root node that this answer is about
        private final List<OntoPropAnswerState> answerstates;
        // the main properties of the nodes.
        // We keep asking for more of these as long as this is not null.
        private final Property mainProperty;
        private final boolean askForMore;
        private final Bool morequestion;

        /**
         * Construct new state with a list of OntologyAnswerState, the last being
         * possibly nonfinal If the last is final and askedForMore=true
         * 
         * @param node         the node label that this answer is about.
         * @param answerstates the list of answer states about node/mainprop.
         * @param mainprop     the main question, eg the property related to "Naam".
         *                     This is the property to be asked first. node must
         *                     have a property with this question. If not null, the
         *                     user wants to add a mainprop. If mainprop=null, it
         *                     means the user does not want to add more items. This
         *                     can be null only if answerstates contains at least 1
         *                     item.
         * @param askMore      true if we need to ask {@link #MOREANSWER}. Can only
         *                     be true if mainprop is not null. If false, we look at
         *                     mainprop to see if we need to add more.
         * @param morequestion the question to ask for more, eg "zijn er nog meer
         *                     relevante personen?".
         */
        @JsonCreator
        public AnswersBreathFirstState(@JsonProperty("nodelabel") String node,
                        @JsonProperty("answerstates") List<OntoPropAnswerState> answerstates,
                        @JsonProperty("mainProperty") Property mainprop,
                        @JsonProperty("askForMore") boolean askMore,
                        @JsonProperty("morequestion") Bool morequestion) {
                if (answerstates.isEmpty() && mainprop == null) {
                        throw new IllegalArgumentException(
                                        "mainprop must be not null if answerstates is empty");
                }
                if (askMore && mainprop == null) {
                        throw new IllegalArgumentException(
                                        "If askForMore then mainprop must be not null");
                }
                this.nodelabel = node;
                this.answerstates = answerstates;
                this.mainProperty = mainprop;
                this.askForMore = askMore;
                this.morequestion = morequestion;
        }

        /**
         * Convenience constructor : new state with one open OntologyAnswerState
         * 
         * @param node         the node that this answer is about.
         * @param mainproperty the main question property, eg "Naam". This is the
         *                     question of the property to be asked first. The node
         *                     must have a property with this question.
         * @param havemore     the question to as if there are more items like this.
         */
        public AnswersBreathFirstState(OntologyNode node, String mainproperty,
                        String havemore) {
                this(node.getLabel(), new LinkedList<>(),
                                getMainProp(node, mainproperty), false,
                                new Bool(havemore, "internal"));
        }

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

                // now handle each one depth-first.
                for (OntoPropAnswerState state : answerstates) {
                        TypedQuestion opts = state.getOptions(tree);
                        if (opts != null)
                                return opts;
                }
                return null;
        }

        @Override
        public AnswersBreathFirstState with(String answer,
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                TypedQuestion opts = getOptions(tree);
                if (opts == null)
                        return this;
                if (!opts.fits(answer)) {
                        throw new IllegalArgumentException(
                                        "Answer " + answer + " does not fit " + opts);
                }
                OntologyNode node = tree.get(nodelabel);
                if (askForMore) {
                        /**
                         * question was MOREANSWER. Just handle the yes/no answer. if answer
                         * is no, set mainProperty to null
                         */
                        return new AnswersBreathFirstState(nodelabel, answerstates,
                                        Bool.matchesYes(answer) ? mainProperty : null, false,
                                        morequestion);

                }
                // askForMore may be true or false if we get here. Check mainproperty
                if (mainProperty != null) {
                        /*
                         * User answered main question. Add new OntoPropAnswerState with the
                         * first answer already there . NOTICE we create node here with
                         * WRONG NODE (Typically "Persoon" ipv eg "Collega" // as we do not
                         * know the correct node type at this point
                         */
                        LinkedList<OntoPropAnswerState> newAnswerStates = new LinkedList<>(
                                        answerstates);
                        Map<Property, String> answer1 = new HashMap<>();
                        answer1.put(mainProperty, answer);
                        PropertiesAnswerState firstAnswer = new PropertiesAnswerState(
                                        nodelabel, answer1);
                        newAnswerStates.add(new OntoPropAnswerState(
                                        new OntologyAnswerState(node, answer), firstAnswer));
                        return new AnswersBreathFirstState(nodelabel, newAnswerStates,
                                        mainProperty, true, morequestion);
                }

                /*
                 * If we get here, mainProperty=null. We're done collecting the main
                 * properties. Continue depth first now on collected answerstates
                 */
                int activeanswer = 0;
                while (answerstates.get(activeanswer).getOptions(tree) == null)
                        activeanswer++;

                LinkedList<OntoPropAnswerState> newAnswerStates = new LinkedList<>(
                                answerstates);
                newAnswerStates.set(activeanswer,
                                answerstates.get(activeanswer).with(answer, tree));

                return new AnswersBreathFirstState(nodelabel, newAnswerStates, null,
                                false, morequestion);
        }

        /**
         * 
         * @param node
         * @param mainquestion
         * @return the {@link Property} of the node of which the ID equals to the
         *         given mainquestion.
         */
        private static Property getMainProp(OntologyNode node,
                        String mainquestion) {
                Optional<Property> mainprop = node.getAttribute().stream().filter(
                                prop -> mainquestion.equals(prop.getQuestionType().getId()))
                                .findFirst();
                if (!mainprop.isPresent()) {
                        throw new IllegalArgumentException("Node " + node
                                        + " must have a property/attribute with the main question '"
                                        + mainquestion + "'");
                }
                return mainprop.get();

        }

}