source: TraumaOntologies/src/main/java/tudelft/healthpsychology/traumaontologies/answerstate/AnswersDepthFirstState.java@ 4

package tudelft.healthpsychology.traumaontologies.answerstate;

import java.util.Arrays;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

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

import tudelft.healthpsychology.traumaontologies.questiontypes.Bool;
import tudelft.healthpsychology.traumaontologies.questiontypes.QuestionType;
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.
 * 
 * Contains the state of a set of answers for a given OntologyNode, handling
 * depth first: first handle the Properties of a selected node, then deal with
 * the next object of given node class.
 *
 */
public class AnswersDepthFirstState implements AnswerState {

        private final String nodelabel; // root node that this answer is about
        private final List<OntoPropAnswerState> answerstates;
        private final boolean isFinal;

        private final Bool more; // eg "you have more items?"

        /**
         * Construct new state with one open OntologyAnswerState
         * 
         * @param node     the node that this answer is about.
         * @param havemore the message to show to ask user if he has more items.
         */
        public AnswersDepthFirstState(String node, String havemore,
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                this(node,
                                Arrays.asList(new OntoPropAnswerState(
                                                new OntologyAnswerState(tree.get(node), null), null)),
                                false, new Bool(havemore, "internal"));
        }

        /**
         * 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. Must contain at least 1
         *                     answerstate.
         * @param askedMore    true iff the state is final, no more new objects to
         *                     be added and all answerstates are complete.
         * @param fin          true iff the state is final
         * @param havemore     the Bool question to show to ask user if he has more
         *                     items.
         */
        @JsonCreator
        public AnswersDepthFirstState(@JsonProperty("nodelabel") String node,
                        @JsonProperty("answerstates") List<OntoPropAnswerState> answerstates,
                        @JsonProperty("isFinal") boolean fin,
                        @JsonProperty("more") Bool havemore) {
                this.nodelabel = node;
                this.answerstates = answerstates;
                this.isFinal = fin;
                this.more = havemore;
        }

        @Override
        public QuestionType getOptions(
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                OntoPropAnswerState lastState = answerstates
                                .get(answerstates.size() - 1);
                QuestionType options = lastState.getOptions(tree);
                if (options != null) {
                        return options;
                }

                if (!isFinal) {
                        return more;
                }

                return null;
        }

        @Override
        public AnswersDepthFirstState with(String answer,
                        Tree<String, Collection<Property>, OntologyNode> tree) {
                if (isFinal)
                        return this;
                QuestionType opts = getOptions(tree);
                if (!opts.fits(answer)) {
                        throw new IllegalArgumentException(
                                        "Answer " + answer + " does not fit " + opts);
                }
                // check what the question was
                OntoPropAnswerState lastState = answerstates
                                .get(answerstates.size() - 1);
                QuestionType options = lastState.getOptions(tree);
                if (options != null) {
                        // last question was about OntoProp
                        List<OntoPropAnswerState> newStates = new LinkedList<>(
                                        answerstates);
                        newStates.set(newStates.size() - 1, lastState.with(answer, tree));
                        return new AnswersDepthFirstState(nodelabel, newStates, false,
                                        more);
                }

                // current onto question is complete. So we asked boolean "more"
                // question. We set explanation to "" as we already gave explanation the
                // first time.
                if (Bool.matchesYes(answer)) {
                        List<OntoPropAnswerState> newStates = new LinkedList<>(
                                        answerstates);
                        newStates.add(new OntoPropAnswerState(
                                        new OntologyAnswerState(tree.get(nodelabel), null), null));
                        return new AnswersDepthFirstState(nodelabel, newStates, false,
                                        more);
                }

                // we're done. Set finished to true.
                return new AnswersDepthFirstState(nodelabel, answerstates, true, more);
        }

}