ElementCardinalityEvaluationHandler.java

/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.kie.workbench.common.stunner.core.rule.handler.impl;

import java.util.Collections;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Inject;

import org.kie.workbench.common.stunner.core.api.DefinitionManager;
import org.kie.workbench.common.stunner.core.graph.Element;
import org.kie.workbench.common.stunner.core.graph.Graph;
import org.kie.workbench.common.stunner.core.graph.Node;
import org.kie.workbench.common.stunner.core.graph.content.view.View;
import org.kie.workbench.common.stunner.core.graph.util.GraphUtils;
import org.kie.workbench.common.stunner.core.rule.RuleEvaluationHandler;
import org.kie.workbench.common.stunner.core.rule.RuleViolations;
import org.kie.workbench.common.stunner.core.rule.context.CardinalityContext;
import org.kie.workbench.common.stunner.core.rule.context.ElementCardinalityContext;
import org.kie.workbench.common.stunner.core.rule.context.impl.RuleContextBuilder;
import org.kie.workbench.common.stunner.core.rule.impl.Occurrences;
import org.kie.workbench.common.stunner.core.rule.violations.DefaultRuleViolations;

@ApplicationScoped
public class ElementCardinalityEvaluationHandler implements RuleEvaluationHandler<Occurrences, ElementCardinalityContext> {

    private final CardinalityEvaluationHandler cardinalityEvaluationHandler;
    private final GraphEvaluationHandlerUtils evalUtils;

    protected ElementCardinalityEvaluationHandler() {
        this(null,
             null);
    }

    @Inject
    public ElementCardinalityEvaluationHandler(final DefinitionManager definitionManager,
                                               final CardinalityEvaluationHandler cardinalityEvaluationHandler) {
        this.cardinalityEvaluationHandler = cardinalityEvaluationHandler;
        this.evalUtils = new GraphEvaluationHandlerUtils(definitionManager);
    }

    @Override
    public Class<Occurrences> getRuleType() {
        return Occurrences.class;
    }

    @Override
    public Class<ElementCardinalityContext> getContextType() {
        return ElementCardinalityContext.class;
    }

    @Override
    @SuppressWarnings("unchecked")
    public boolean accepts(final Occurrences rule,
                           final ElementCardinalityContext context) {
        if (context.getCandidate().isPresent()) {
            final Set<String> candidateLabels = evalUtils.getLabels(context.getCandidate().get());
            return cardinalityEvaluationHandler
                    .accepts(rule,
                             RuleContextBuilder.DomainContexts.cardinality(
                                     candidateLabels,
                                     -1,
                                     context.getOperation()));
        }
        return true;
    }

    @Override
    @SuppressWarnings("unchecked")
    public RuleViolations evaluate(final Occurrences rule,
                                   final ElementCardinalityContext context) {
        final DefaultRuleViolations results = new DefaultRuleViolations();
        final Optional<Element<? extends View<?>>> candidate = context.getCandidate();
        final String role = rule.getRole();
        final Set<String> roles = Collections.singleton(role);
        final Map<String, Integer> graphLabelCount = countLabels(context.getGraph(),
                                                                 roles);
        // Ensure processing the role even if not used along the graph, so
        // cardinality min rules can be evaluated.
        final int count = graphLabelCount.isEmpty() ? 0 : graphLabelCount.get(role);
        final Optional<CardinalityContext.Operation> operation = context.getOperation();
        results.addViolations(
                cardinalityEvaluationHandler
                        .evaluate(rule,
                                  RuleContextBuilder.DomainContexts.cardinality(roles,
                                                                                count,
                                                                                operation))
        );
        if (candidate.isPresent()) {
            return GraphEvaluationHandlerUtils.addViolationsSourceUUID(candidate.get().getUUID(),
                                                                       results);
        }
        return results;
    }

    Map<String, Integer> countLabels(final Graph<?, ? extends Node> target,
                                     final Set<String> filter) {
        return GraphUtils.getLabelsCount(target,
                                         filter);
    }
}