AbstractDrlFileIndexer.java

/*
 * Copyright 2016 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.services.refactoring.backend.server.indexing.drools;

import java.util.List;

import org.drools.compiler.compiler.DrlParser;
import org.drools.compiler.compiler.DroolsError;
import org.drools.compiler.lang.descr.PackageDescr;
import org.drools.workbench.models.datamodel.oracle.ProjectDataModelOracle;
import org.kie.api.io.ResourceType;
import org.kie.workbench.common.services.refactoring.backend.server.indexing.AbstractFileIndexer;
import org.kie.workbench.common.services.refactoring.backend.server.indexing.DefaultIndexBuilder;
import org.kie.workbench.common.services.refactoring.backend.server.indexing.ErrorMessageUtilities;
import org.kie.workbench.common.services.refactoring.backend.server.indexing.PackageDescrIndexVisitor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.uberfire.backend.server.util.Paths;
import org.uberfire.ext.metadata.engine.Indexer;
import org.uberfire.java.nio.file.Path;

/**
 * All Drools-related {@link Indexer} implemenations should implement this class in order to avoid duplicate code.
 */
public abstract class AbstractDrlFileIndexer extends AbstractFileIndexer {

    private static final Logger logger = LoggerFactory.getLogger( AbstractDrlFileIndexer.class );

    /**
     * All Drools-related {@link Indexer} implemenations end up extracting the DRL from the related Rule representation
     * (see {@link ResourceType}).
     * </p>
     * The following method then parses the DRL and returns all relevant reference information.
     * @param path The {@link Path} of the asset/resource, necessary for extracting reference information.
     * @param drl A {@link String} representation of the DRL.
     * @return The {@link DefaultIndexBuilder}
     * @throws Exception
     */
    public DefaultIndexBuilder fillDrlIndexBuilder( final Path path, final String drl ) throws Exception {

            final DrlParser drlParser = new DrlParser();
            final PackageDescr packageDescr = drlParser.parse( true, drl );

            if ( drlParser.hasErrors() ) {
                final List<DroolsError> errors = drlParser.getErrors();
                logger.warn( ErrorMessageUtilities.makeErrorMessage( path,
                                                                         errors.toArray( new DroolsError[ errors.size() ] ) ) );
                return null;
            }
            if ( packageDescr == null ) {
                    logger.warn( ErrorMessageUtilities.makeErrorMessage( path ) );
                    return null;
            }

            final ProjectDataModelOracle dmo = getProjectDataModelOracle( path );

            // responsible for basic index info: project name, branch, etc
            final DefaultIndexBuilder builder = getIndexBuilder(path);
            if( builder == null ) {
                return null;
            }
            builder.setPackageName(packageDescr.getName());

            // Retrieves info from the parsed syntac tree (PackageDescr)
            final PackageDescrIndexVisitor visitor = new PackageDescrIndexVisitor( dmo, builder, packageDescr );
            visitor.visit();
            addReferencedResourcesToIndexBuilder(builder, visitor);

            return builder;
    }

    /**
     * Delegate resolution of package name to method to assist testing
     *
     * @param path The {@link Path} of the file being indexed
     * @return The package name, as a {@link String}
     */
    protected String getPackageName( final Path path ) {
        return projectService.resolvePackage( Paths.convert( path ) ).getPackageName();
    }

    /**
     * Delegate resolution of DMO to method to assist testing
     *
     * @param path The {@link Path} of the file being indexed
     * @return The all-seeing, all-knowing {@link ProjectDataModelOracle}
     */
    protected abstract ProjectDataModelOracle getProjectDataModelOracle( final Path path );

}