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.version;
020
021import java.util.Arrays;
022import java.util.Collection;
023import java.util.Collections;
024import java.util.HashSet;
025import java.util.Set;
026import java.util.stream.Collectors;
027
028import org.eclipse.aether.version.Version;
029import org.eclipse.aether.version.VersionRange;
030
031/**
032 * A union of version ranges.
033 */
034public final class UnionVersionRange implements VersionRange {
035
036    private final Set<VersionRange> ranges;
037
038    private final Bound lowerBound;
039
040    private final Bound upperBound;
041
042    /**
043     * Creates union {@link VersionRange}s out of passed in {@link VersionRange} instances.
044     *
045     * @param ranges The ranges, may be empty array or even {@code null}.
046     */
047    public static VersionRange from(VersionRange... ranges) {
048        if (ranges == null || ranges.length == 0) {
049            return from(Collections.emptySet());
050        }
051        return from(Arrays.asList(ranges));
052    }
053
054    /**
055     * Creates union {@link VersionRange}s out of passed in {@link VersionRange} collection.
056     *
057     * @param ranges The ranges, may be empty collection or even {@code null}.
058     */
059    public static VersionRange from(Collection<? extends VersionRange> ranges) {
060        if (ranges != null && ranges.size() == 1) {
061            return ranges.iterator().next();
062        }
063        return new UnionVersionRange(ranges);
064    }
065
066    private UnionVersionRange(Collection<? extends VersionRange> ranges) {
067        if (ranges == null || ranges.isEmpty()) {
068            this.ranges = Collections.emptySet();
069            lowerBound = null;
070            upperBound = null;
071        } else {
072            this.ranges = new HashSet<>(ranges);
073            Bound lowerBound = null, upperBound = null;
074            for (VersionRange range : this.ranges) {
075                Bound lb = range.getLowerBound();
076                if (lb == null) {
077                    lowerBound = null;
078                    break;
079                } else if (lowerBound == null) {
080                    lowerBound = lb;
081                } else {
082                    int c = lb.getVersion().compareTo(lowerBound.getVersion());
083                    if (c < 0 || (c == 0 && !lowerBound.isInclusive())) {
084                        lowerBound = lb;
085                    }
086                }
087            }
088            for (VersionRange range : this.ranges) {
089                Bound ub = range.getUpperBound();
090                if (ub == null) {
091                    upperBound = null;
092                    break;
093                } else if (upperBound == null) {
094                    upperBound = ub;
095                } else {
096                    int c = ub.getVersion().compareTo(upperBound.getVersion());
097                    if (c > 0 || (c == 0 && !upperBound.isInclusive())) {
098                        upperBound = ub;
099                    }
100                }
101            }
102            this.lowerBound = lowerBound;
103            this.upperBound = upperBound;
104        }
105    }
106
107    @Override
108    public boolean containsVersion(Version version) {
109        for (VersionRange range : ranges) {
110            if (range.containsVersion(version)) {
111                return true;
112            }
113        }
114        return false;
115    }
116
117    @Override
118    public Bound getLowerBound() {
119        return lowerBound;
120    }
121
122    @Override
123    public Bound getUpperBound() {
124        return upperBound;
125    }
126
127    @Override
128    public boolean equals(Object obj) {
129        if (obj == this) {
130            return true;
131        } else if (obj == null || !getClass().equals(obj.getClass())) {
132            return false;
133        }
134
135        UnionVersionRange that = (UnionVersionRange) obj;
136
137        return ranges.equals(that.ranges);
138    }
139
140    @SuppressWarnings("checkstyle:magicnumber")
141    @Override
142    public int hashCode() {
143        return 97 * ranges.hashCode();
144    }
145
146    @Override
147    public String toString() {
148        return ranges.stream().map(VersionRange::toString).collect(Collectors.joining(", "));
149    }
150}