CriteriaQueryRelationshipSource.java

/*
 * Copyright 2014 JBoss Inc
 *
 * 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.artificer.integration.artifactbuilder;

import org.artificer.common.query.ArtifactSummary;
import org.oasis_open.docs.s_ramp.ns.s_ramp_v1.Target;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Provides a {@link RelationshipSource} that resolves using a simple criteria-based repository query.  Sub-classes
 * are in charge of defining the actual criteria used in the search.  The query result's artifact is then set as the
 * relationship {@link Target} value.
 * 
 * @see QNameRelationshipSource
 * @see NamespaceRelationshipSource
 * 
 * @author Brett Meyer
 */
public abstract class CriteriaQueryRelationshipSource implements RelationshipSource {
    
    protected Target target;
    
    protected final Collection targetCollection;
    
    protected final String model;
    
    protected final String[] types;

    public CriteriaQueryRelationshipSource(Target target, Collection targetCollection, String model, String... types) {
        this.target = target;
        this.targetCollection = targetCollection;
        this.model = model;
        this.types = types;
    }
    
    @Override
    public void build(RelationshipContext context) throws Exception {
        // If a specific Target was not provided, assume it's generic and needs created/added.
        if (target == null) {
            target = new Target();
            
            // Only do this if the target is created above.  If the target was created higher up, that code should be
            // responsible for adding it to the collection.
            if (targetCollection != null) {
                targetCollection.add(target);
            }
        }
        
        Map<String, String> criteria = new HashMap<String, String>();
        addCriteria(criteria);
        List<ArtifactSummary> artifacts = new ArrayList<>();
        
        for (String type : types) {
            Collection<ArtifactSummary> results = context.findArtifacts(model, type, criteria);
            artifacts.addAll(results);
        }
        
        // This is a cheap fix for SRAMP-466.  If more than one artifact is found (most likely duplicates), we want to
        // place emphasis on the current batch.  For now, simply do so by comparing the created timestamp.  Newest
        // should be most "relevant".
        Collections.sort(artifacts, new CreationDateComparator());
        
        if (!artifacts.isEmpty()) {
            ArtifactSummary artifact = artifacts.iterator().next();
            target.setValue(artifact.getUuid());
        } else {
            notFound();
            if (targetCollection != null) {
                // TODO: This needs evaluated.  May not work for no-target relationships (supported by spec).
                targetCollection.remove(target);
            }
            // Important to null out the ref for non-collection artifact targets.
            target = null;
        }
    }
    
    protected abstract void addCriteria(Map<String, String> criteria);
    
    protected void notFound() {
        
    }
    
    private static class CreationDateComparator implements Comparator<ArtifactSummary> {
        public int compare(ArtifactSummary o1, ArtifactSummary o2) {
            // newest first
            return o2.getCreatedTimestamp().compareTo(o1.getCreatedTimestamp());
        }
    }
}