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.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.
 * 
 * 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 TypedQuestion getOptions(
			Tree<String, Collection<Property>, OntologyNode> tree) {
		OntoPropAnswerState lastState = answerstates
				.get(answerstates.size() - 1);
		TypedQuestion 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;
		TypedQuestion 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);
		TypedQuestion 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);
	}

}