/*
    * 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
    *
   *   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.apache.maven.internal.impl;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.util.Map;
  import java.util.Objects;
  import java.util.concurrent.ConcurrentHashMap;
  
  import org.apache.maven.api.di.Inject;
  import org.apache.maven.api.di.Named;
  import org.apache.maven.api.di.Singleton;
  import org.apache.maven.api.model.Model;
  import org.apache.maven.api.services.SuperPomProvider;
  import org.apache.maven.api.services.model.ModelProcessor;
  import org.apache.maven.api.services.xml.XmlReaderRequest;
  
  @Named
  @Singleton
  public class DefaultSuperPomProvider implements SuperPomProvider {
  
      private final ModelProcessor modelProcessor;
  
      /**
       * The cached super POM, lazily created.
       */
      private static final Map<String, Model> SUPER_MODELS = new ConcurrentHashMap<>();
  
      @Inject
      public DefaultSuperPomProvider(ModelProcessor modelProcessor) {
          this.modelProcessor = modelProcessor;
      }
  
      @Override
      public Model getSuperPom(String version) {
          return SUPER_MODELS.computeIfAbsent(Objects.requireNonNull(version), v -> readModel(version, v));
      }
  
      private Model readModel(String version, String v) {
          String resource = "/org/apache/maven/model/pom-" + v + ".xml";
          URL url = getClass().getResource(resource);
          if (url == null) {
              throw new IllegalStateException("The super POM " + resource + " was not found"
                      + ", please verify the integrity of your Maven installation");
          }
          try (InputStream is = url.openStream()) {
              String modelId = "org.apache.maven:maven-model-builder:" + version + "-"
                      + this.getClass().getPackage().getImplementationVersion() + ":super-pom";
              return modelProcessor.read(XmlReaderRequest.builder()
                      .modelId(modelId)
                      .location(url.toExternalForm())
                      .inputStream(is)
                      .strict(false)
                      .build());
          } catch (IOException e) {
              throw new IllegalStateException(
                      "The super POM " + resource + " is damaged"
                              + ", please verify the integrity of your Maven installation",
                      e);
          }
      }
  }