TychoXpp3Utils.java

/*
 * Copyright 2014 Bernd Vogt and others.
 * 
 * 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.sourcepit.b2.internal.maven.util;

import static org.sourcepit.common.maven.util.Xpp3Utils.addValueNode;
import static org.sourcepit.common.maven.util.Xpp3Utils.clearChildren;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.maven.model.Dependency;
import org.apache.maven.model.Plugin;
import org.codehaus.plexus.util.xml.Xpp3Dom;
import org.sourcepit.common.constraints.NotNull;

import com.google.common.base.Strings;

public final class TychoXpp3Utils {
   private TychoXpp3Utils() {
      super();
   }

   public static void addExtraRequirements(Plugin plugin, List<Dependency> requirements) {
      if (requirements.isEmpty()) {
         return;
      }
      Xpp3Dom configuration = (Xpp3Dom) plugin.getConfiguration();
      if (configuration == null) {
         configuration = new Xpp3Dom("configuration");
         plugin.setConfiguration(configuration);
      }

      Xpp3Dom dependencyResolution = configuration.getChild("dependency-resolution");
      if (dependencyResolution == null) {
         dependencyResolution = new Xpp3Dom("dependency-resolution");
         configuration.addChild(dependencyResolution);
      }

      Xpp3Dom extraRequirements = dependencyResolution.getChild("extraRequirements");
      if (extraRequirements == null) {
         extraRequirements = new Xpp3Dom("extraRequirements");
         dependencyResolution.addChild(extraRequirements);
      }

      final List<Dependency> dependencyList = readRequirements(extraRequirements);
      addAllUnique(dependencyList, requirements);

      clearChildren(extraRequirements);

      for (Dependency dependency : dependencyList) {
         extraRequirements.addChild(toRequirementNode(dependency));
      }
   }

   private static void addAllUnique(List<Dependency> dest, List<Dependency> src) {
      final Set<String> managementKeys = new HashSet<String>();
      for (Dependency dependency : dest) {
         managementKeys.add(dependency.getManagementKey());
      }
      for (Dependency dependency : src) {
         if (managementKeys.add(dependency.getManagementKey())) {
            dest.add(dependency);
         }
      }
   }

   public static List<Dependency> readRequirements(Xpp3Dom requirements) {
      final List<Dependency> dependencyList = new ArrayList<Dependency>();
      for (Xpp3Dom requirement : requirements.getChildren("requirement")) {
         dependencyList.add(toRequirement(requirement));
      }
      return dependencyList;
   }

   public static Dependency toRequirement(Xpp3Dom requirement) {
      final Dependency result = new Dependency();
      result.setArtifactId(extractNonEmptyValue(requirement.getChild("id")));
      result.setVersion(extractNonEmptyValue(requirement.getChild("versionRange")));
      final String type = extractNonEmptyValue(requirement.getChild("type"));
      if (type != null) {
         result.setType(type);
      }
      return result;
   }

   public static Xpp3Dom toRequirementNode(@NotNull Dependency dependency) {
      final Xpp3Dom requirementNode = new Xpp3Dom("requirement");
      addRequirementValues(requirementNode, dependency);
      return requirementNode;
   }

   public static void addRequirementValues(@NotNull final Xpp3Dom dependencyNode, @NotNull Dependency dependency) {
      String value = dependency.getArtifactId();
      if (!Strings.isNullOrEmpty(value)) {
         addValueNode(dependencyNode, "id", value);
      }

      value = dependency.getVersion();
      if (!Strings.isNullOrEmpty(value)) {
         addValueNode(dependencyNode, "versionRange", value);
      }

      value = dependency.getType();
      if (!Strings.isNullOrEmpty(value) && !"jar".equals(value)) {
         addValueNode(dependencyNode, "type", value);
      }
   }

   private static String extractNonEmptyValue(Xpp3Dom node) {
      String value = node == null ? null : node.getValue();
      if (value != null) {
         value.trim();
         if (value.length() == 0) {
            value = null;
         }
      }
      return value;
   }
}