001/*
002 * SPDX-FileCopyrightText: none
003 * SPDX-License-Identifier: CC0-1.0
004 */
005
006package gov.nist.secauto.oscal.lib.model.control.catalog;
007
008import gov.nist.secauto.metaschema.core.util.CollectionUtil;
009import gov.nist.secauto.metaschema.core.util.ObjectUtils;
010import gov.nist.secauto.oscal.lib.model.Catalog;
011import gov.nist.secauto.oscal.lib.model.CatalogGroup;
012import gov.nist.secauto.oscal.lib.model.Control;
013import gov.nist.secauto.oscal.lib.model.Parameter;
014
015import java.util.Objects;
016
017import edu.umd.cs.findbugs.annotations.NonNull;
018
019public abstract class AbstractCatalogVisitor<RESULT, CONTEXT> implements ICatalogVisitor<RESULT, CONTEXT> {
020
021  /**
022   * Get a new initial/default result for the visitor.
023   *
024   * @return the result
025   */
026  protected abstract RESULT defaultResult();
027
028  /**
029   * Aggregate two results into one.
030   *
031   * @param previous
032   *          the first result
033   * @param current
034   *          the next result
035   * @return the result produced by combining the two results
036   */
037  protected RESULT aggregateResult(RESULT previous, RESULT current) {
038    return current;
039  }
040
041  @Override
042  public RESULT visitCatalog(Catalog catalog, CONTEXT context) {
043    RESULT result = CollectionUtil.listOrEmpty(catalog.getGroups()).stream()
044        .filter(Objects::nonNull)
045        .map(childGroup -> visitGroup(ObjectUtils.notNull(childGroup), context))
046        .reduce(defaultResult(), this::aggregateResult);
047    result = CollectionUtil.listOrEmpty(catalog.getControls()).stream()
048        .filter(Objects::nonNull)
049        .map(childControl -> visitControl(ObjectUtils.notNull(childControl), context))
050        .reduce(result, this::aggregateResult);
051    return CollectionUtil.listOrEmpty(catalog.getParams()).stream()
052        .filter(Objects::nonNull)
053        .map(childParameter -> visitParameter(ObjectUtils.notNull(childParameter), context))
054        .reduce(result, this::aggregateResult);
055  }
056
057  @Override
058  public RESULT visitGroup(@NonNull CatalogGroup group, CONTEXT context) {
059    RESULT result = CollectionUtil.listOrEmpty(group.getGroups()).stream()
060        .filter(Objects::nonNull)
061        .map(childGroup -> visitGroup(ObjectUtils.notNull(childGroup), context))
062        .reduce(defaultResult(), this::aggregateResult);
063    result = CollectionUtil.listOrEmpty(group.getControls()).stream()
064        .filter(Objects::nonNull)
065        .map(childControl -> visitControl(ObjectUtils.notNull(childControl), context))
066        .reduce(result, this::aggregateResult);
067    return CollectionUtil.listOrEmpty(group.getParams()).stream()
068        .filter(Objects::nonNull)
069        .map(childParameter -> visitParameter(ObjectUtils.notNull(childParameter), context))
070        .reduce(result, this::aggregateResult);
071  }
072
073  @Override
074  public RESULT visitControl(Control control, CONTEXT context) {
075    RESULT result = CollectionUtil.listOrEmpty(control.getControls()).stream()
076        .filter(Objects::nonNull)
077        .map(childControl -> visitControl(ObjectUtils.notNull(childControl), context))
078        .reduce(defaultResult(), this::aggregateResult);
079    return CollectionUtil.listOrEmpty(control.getParams()).stream()
080        .filter(Objects::nonNull)
081        .map(childParameter -> visitParameter(ObjectUtils.notNull(childParameter), context))
082        .reduce(result, this::aggregateResult);
083  }
084
085  @Override
086  public RESULT visitParameter(Parameter parameter, CONTEXT context) {
087    return defaultResult();
088  }
089
090}