content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one or more
   *  contributor license agreements.  See the NOTICE file distributed with
   *  this work for additional information regarding copyright ownership.
   *  The ASF licenses this file to You 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
   *
   *      https://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.apache.ivy.osgi.core;
  
  import java.text.ParseException;
  import java.util.Comparator;
  
  import org.apache.ivy.core.IvyContext;
  import org.apache.ivy.core.module.descriptor.DependencyDescriptor;
  import org.apache.ivy.core.module.descriptor.ModuleDescriptor;
  import org.apache.ivy.core.module.id.ModuleRevisionId;
  import org.apache.ivy.core.resolve.ResolvedModuleRevision;
  import org.apache.ivy.osgi.util.Version;
  import org.apache.ivy.plugins.latest.ArtifactInfo;
  import org.apache.ivy.plugins.latest.ComparatorLatestStrategy;
  import org.apache.ivy.plugins.resolver.util.MDResolvedResource;
  import org.apache.ivy.plugins.version.VersionMatcher;
  
  public class OsgiLatestStrategy extends ComparatorLatestStrategy {
  
      final class MridComparator implements Comparator<ModuleRevisionId> {
  
          public int compare(ModuleRevisionId o1, ModuleRevisionId o2) {
              Version v1 = new Version(o1.getRevision());
              Version v2 = new Version(o2.getRevision());
              try {
                  return v1.compareTo(v2);
              } catch (RuntimeException e) {
                  if (e.getCause() instanceof ParseException) {
                      throw new RuntimeException("Uncomparable versions:" + o1.getRevision()
                              + " and " + o2.getRevision() + " (" + e.getMessage() + ")");
                  }
                  throw e;
              }
          }
  
      }
  
      final class ArtifactInfoComparator implements Comparator<ArtifactInfo> {
  
          public int compare(ArtifactInfo o1, ArtifactInfo o2) {
              String rev1 = o1.getRevision();
              String rev2 = o2.getRevision();
  
              /*
               * The revisions can still be not resolved, so we use the current version matcher to
               * know if one revision is dynamic, and in this case if it should be considered greater
               * or lower than the other one. Note that if the version matcher compare method returns
               * 0, it's because it's not possible to know which revision is greater. In this case we
               * consider the dynamic one to be greater, because most of the time it will then be
               * actually resolved and a real comparison will occur.
               */
              VersionMatcher vmatcher = IvyContext.getContext().getSettings().getVersionMatcher();
              ModuleRevisionId mrid1 = ModuleRevisionId.newInstance("", "", rev1);
              ModuleRevisionId mrid2 = ModuleRevisionId.newInstance("", "", rev2);
  
              if (vmatcher.isDynamic(mrid1)) {
                  int c = vmatcher.compare(mrid1, mrid2, mridComparator);
                  return c >= 0 ? 1 : -1;
              } else if (vmatcher.isDynamic(mrid2)) {
                  int c = vmatcher.compare(mrid2, mrid1, mridComparator);
                  return c >= 0 ? -1 : 1;
              }
  
              int res = mridComparator.compare(mrid1, mrid2);
  
              if (res == 0) {
                  // if same requirements, maybe we can make a difference on the implementation ?
                  ModuleRevisionId implMrid1 = getImplMrid(o1);
                  ModuleRevisionId implMrid2 = getImplMrid(o2);
                  if (implMrid1 != null && implMrid2 != null) {
                      if (implMrid1.getModuleId().equals(implMrid2.getModuleId())) {
                          // same implementation, compare the versions
                          res = mridComparator.compare(implMrid1, implMrid2);
                      } else {
                          // not same bundle
                          // to keep a total order, compare module names even if it means nothing
                          res = implMrid1.getModuleId().compareTo(implMrid2.getModuleId());
                      }
                  }
  
              }
  
              return res;
          }
  
          /*
           * In the resolve process, a resolved requirement is represented in a special way. Here we
           * deconstruct the resolved resource to know which implementation is actually resolved. See
           * AbstractOSGiResolver.buildResolvedCapabilityMd()
           */
          private ModuleRevisionId getImplMrid(ArtifactInfo o) {
              if (!(o instanceof MDResolvedResource)) {
                  return null;
              }
              MDResolvedResource mdrr = (MDResolvedResource) o;
              ResolvedModuleRevision rmr = mdrr.getResolvedModuleRevision();
              if (rmr == null) {
                  return null;
              }
              ModuleDescriptor md = rmr.getDescriptor();
              if (md == null) {
                  return null;
              }
              if (!md.getModuleRevisionId().getOrganisation().equals(BundleInfo.PACKAGE_TYPE)) {
                  return null;
              }
              DependencyDescriptor[] dds = md.getDependencies();
              if (dds == null || dds.length != 1) {
                  return null;
              }
              return dds[0].getDependencyRevisionId();
          }
      }
  
      private final Comparator<ModuleRevisionId> mridComparator = new MridComparator();
  
      private final Comparator<ArtifactInfo> artifactInfoComparator = new ArtifactInfoComparator();
  
      public OsgiLatestStrategy() {
          setComparator(artifactInfoComparator);
          setName("latest-osgi");
      }
  
  }
  