001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.util.graph.transformer;
020
021import java.util.Collection;
022import java.util.HashSet;
023import java.util.Set;
024
025import org.eclipse.aether.RepositoryException;
026import org.eclipse.aether.util.artifact.JavaScopes;
027import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictContext;
028import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictItem;
029import org.eclipse.aether.util.graph.transformer.ConflictResolver.ScopeSelector;
030
031/**
032 * A scope selector for use with {@link ConflictResolver} that supports the scopes from {@link JavaScopes}. In general,
033 * this selector picks the widest scope present among conflicting dependencies where e.g. "compile" is wider than
034 * "runtime" which is wider than "test". If however a direct dependency is involved, its scope is selected.
035 */
036public final class JavaScopeSelector extends ScopeSelector {
037
038    /**
039     * Creates a new instance of this scope selector.
040     */
041    public JavaScopeSelector() {}
042
043    @Override
044    public void selectScope(ConflictContext context) throws RepositoryException {
045        String scope = context.getWinner().getDependency().getScope();
046        if (!JavaScopes.SYSTEM.equals(scope)) {
047            scope = chooseEffectiveScope(context.getItems());
048        }
049        context.setScope(scope);
050    }
051
052    private String chooseEffectiveScope(Collection<ConflictItem> items) {
053        Set<String> scopes = new HashSet<>();
054        for (ConflictItem item : items) {
055            if (item.getDepth() <= 1) {
056                return item.getDependency().getScope();
057            }
058            scopes.addAll(item.getScopes());
059        }
060        return chooseEffectiveScope(scopes);
061    }
062
063    private String chooseEffectiveScope(Set<String> scopes) {
064        if (scopes.size() > 1) {
065            scopes.remove(JavaScopes.SYSTEM);
066        }
067
068        String effectiveScope = "";
069
070        if (scopes.size() == 1) {
071            effectiveScope = scopes.iterator().next();
072        } else if (scopes.contains(JavaScopes.COMPILE)) {
073            effectiveScope = JavaScopes.COMPILE;
074        } else if (scopes.contains(JavaScopes.RUNTIME)) {
075            effectiveScope = JavaScopes.RUNTIME;
076        } else if (scopes.contains(JavaScopes.PROVIDED)) {
077            effectiveScope = JavaScopes.PROVIDED;
078        } else if (scopes.contains(JavaScopes.TEST)) {
079            effectiveScope = JavaScopes.TEST;
080        }
081
082        return effectiveScope;
083    }
084}