/*
    * 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.cling.extensions;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Set;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  
  import org.apache.maven.RepositoryUtils;
  import org.apache.maven.api.Service;
  import org.apache.maven.api.Session;
  import org.apache.maven.api.cli.extensions.CoreExtension;
  import org.apache.maven.api.model.Plugin;
  import org.apache.maven.api.services.ArtifactCoordinatesFactory;
  import org.apache.maven.api.services.ArtifactManager;
  import org.apache.maven.api.services.ArtifactResolver;
  import org.apache.maven.api.services.Interpolator;
  import org.apache.maven.api.services.InterpolatorException;
  import org.apache.maven.api.services.RepositoryFactory;
  import org.apache.maven.api.services.VersionParser;
  import org.apache.maven.api.services.VersionRangeResolver;
  import org.apache.maven.execution.DefaultMavenExecutionResult;
  import org.apache.maven.execution.MavenExecutionRequest;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.extension.internal.CoreExports;
  import org.apache.maven.extension.internal.CoreExtensionEntry;
  import org.apache.maven.internal.impl.DefaultArtifactCoordinatesFactory;
  import org.apache.maven.internal.impl.DefaultArtifactManager;
  import org.apache.maven.internal.impl.DefaultArtifactResolver;
  import org.apache.maven.internal.impl.DefaultModelVersionParser;
  import org.apache.maven.internal.impl.DefaultRepositoryFactory;
  import org.apache.maven.internal.impl.DefaultSession;
  import org.apache.maven.internal.impl.DefaultVersionParser;
  import org.apache.maven.internal.impl.DefaultVersionRangeResolver;
  import org.apache.maven.internal.impl.InternalSession;
  import org.apache.maven.internal.impl.model.DefaultInterpolator;
  import org.apache.maven.plugin.PluginResolutionException;
  import org.apache.maven.plugin.internal.DefaultPluginDependenciesResolver;
  import org.apache.maven.resolver.MavenChainedWorkspaceReader;
  import org.apache.maven.resolver.RepositorySystemSessionFactory;
  import org.codehaus.plexus.DefaultPlexusContainer;
  import org.codehaus.plexus.PlexusContainer;
  import org.codehaus.plexus.classworlds.ClassWorld;
  import org.codehaus.plexus.classworlds.realm.ClassRealm;
  import org.eclipse.aether.RepositorySystem;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.RepositorySystemSession.CloseableSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.graph.DependencyFilter;
  import org.eclipse.aether.internal.impl.DefaultChecksumPolicyProvider;
  import org.eclipse.aether.internal.impl.DefaultRemoteRepositoryManager;
  import org.eclipse.aether.internal.impl.DefaultUpdatePolicyAnalyzer;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.repository.WorkspaceReader;
  import org.eclipse.aether.resolution.ArtifactResult;
  import org.eclipse.aether.resolution.DependencyResult;
  import org.eclipse.aether.util.filter.ExclusionsDependencyFilter;
  import org.eclipse.aether.util.version.GenericVersionScheme;
  import org.eclipse.sisu.Nullable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * BootstrapCoreExtensionManager
   */
  @Named
  public class BootstrapCoreExtensionManager {
      public static final String STRATEGY_PARENT_FIRST = "parent-first";
      public static final String STRATEGY_PLUGIN = "plugin";
      public static final String STRATEGY_SELF_FIRST = "self-first";
  
      private final Logger log = LoggerFactory.getLogger(getClass());
  
      private final DefaultPluginDependenciesResolver pluginDependenciesResolver;
  
     private final RepositorySystemSessionFactory repositorySystemSessionFactory;
 
     private final CoreExports coreExports;
 
     private final ClassWorld classWorld;
 
     private final ClassRealm parentRealm;
 
     private final WorkspaceReader ideWorkspaceReader;
 
     private final RepositorySystem repoSystem;
 
     @Inject
     public BootstrapCoreExtensionManager(
             DefaultPluginDependenciesResolver pluginDependenciesResolver,
             RepositorySystemSessionFactory repositorySystemSessionFactory,
             CoreExports coreExports,
             PlexusContainer container,
             @Nullable @Named("ide") WorkspaceReader ideWorkspaceReader,
             RepositorySystem repoSystem) {
         this.pluginDependenciesResolver = pluginDependenciesResolver;
         this.repositorySystemSessionFactory = repositorySystemSessionFactory;
         this.coreExports = coreExports;
         this.classWorld = ((DefaultPlexusContainer) container).getClassWorld();
         this.parentRealm = container.getContainerRealm();
         this.ideWorkspaceReader = ideWorkspaceReader;
         this.repoSystem = repoSystem;
     }
 
     public List<CoreExtensionEntry> loadCoreExtensions(
             MavenExecutionRequest request, Set<String> providedArtifacts, List<CoreExtension> extensions)
             throws Exception {
         try (CloseableSession repoSession = repositorySystemSessionFactory
                 .newRepositorySessionBuilder(request)
                 .setWorkspaceReader(new MavenChainedWorkspaceReader(request.getWorkspaceReader(), ideWorkspaceReader))
                 .build()) {
             MavenSession mSession = new MavenSession(repoSession, request, new DefaultMavenExecutionResult());
             InternalSession iSession = new SimpleSession(mSession, repoSystem, null);
             InternalSession.associate(repoSession, iSession);
 
             List<RemoteRepository> repositories = RepositoryUtils.toRepos(request.getPluginArtifactRepositories());
             Function<String, String> interpolator = createInterpolator(request);
 
             return resolveCoreExtensions(repoSession, repositories, providedArtifacts, extensions, interpolator);
         }
     }
 
     private List<CoreExtensionEntry> resolveCoreExtensions(
             RepositorySystemSession repoSession,
             List<RemoteRepository> repositories,
             Set<String> providedArtifacts,
             List<CoreExtension> configuration,
             Function<String, String> interpolator)
             throws Exception {
         List<CoreExtensionEntry> extensions = new ArrayList<>();
 
         DependencyFilter dependencyFilter = new ExclusionsDependencyFilter(providedArtifacts);
 
         for (CoreExtension extension : configuration) {
             List<Artifact> artifacts =
                     resolveExtension(extension, repoSession, repositories, dependencyFilter, interpolator);
             if (!artifacts.isEmpty()) {
                 extensions.add(createExtension(extension, artifacts));
             }
         }
 
         return Collections.unmodifiableList(extensions);
     }
 
     private CoreExtensionEntry createExtension(CoreExtension extension, List<Artifact> artifacts) throws Exception {
         String realmId = "coreExtension>" + extension.getGroupId() + ":" + extension.getArtifactId() + ":"
                 + extension.getVersion();
         final ClassRealm realm = classWorld.newRealm(realmId, null);
         Set<String> providedArtifacts = Collections.emptySet();
         String classLoadingStrategy = extension.getClassLoadingStrategy();
         if (STRATEGY_PARENT_FIRST.equals(classLoadingStrategy)) {
             realm.importFrom(parentRealm, "");
         } else if (STRATEGY_PLUGIN.equals(classLoadingStrategy)) {
             coreExports.getExportedPackages().forEach((p, cl) -> realm.importFrom(cl, p));
             providedArtifacts = coreExports.getExportedArtifacts();
         } else if (STRATEGY_SELF_FIRST.equals(classLoadingStrategy)) {
             realm.setParentRealm(parentRealm);
         } else {
             throw new IllegalArgumentException("Unsupported class-loading strategy '"
                     + classLoadingStrategy + "'. Supported values are: " + STRATEGY_PARENT_FIRST
                     + ", " + STRATEGY_PLUGIN + " and " + STRATEGY_SELF_FIRST);
         }
         log.debug("Populating class realm {}", realm.getId());
         for (Artifact artifact : artifacts) {
             String id = artifact.getGroupId() + ":" + artifact.getArtifactId();
             if (providedArtifacts.contains(id)) {
                 log.debug("  Excluded {}", id);
             } else {
                 Path file = artifact.getPath();
                 log.debug("  Included {} located at {}", id, file);
                 realm.addURL(file.toUri().toURL());
             }
         }
         return CoreExtensionEntry.discoverFrom(
                 realm,
                 Collections.singleton(artifacts.get(0).getPath().toFile()),
                 extension.getGroupId() + ":" + extension.getArtifactId(),
                 extension.getConfiguration());
     }
 
     private List<Artifact> resolveExtension(
             CoreExtension extension,
             RepositorySystemSession repoSession,
             List<RemoteRepository> repositories,
             DependencyFilter dependencyFilter,
             Function<String, String> interpolator)
             throws ExtensionResolutionException {
         try {
             /* TODO: Enhance the PluginDependenciesResolver to provide a
              * resolveCoreExtension method which uses a CoreExtension
              * object instead of a Plugin as this makes no sense.
              */
             Plugin plugin = Plugin.newBuilder()
                     .groupId(interpolator.apply(extension.getGroupId()))
                     .artifactId(interpolator.apply(extension.getArtifactId()))
                     .version(interpolator.apply(extension.getVersion()))
                     .build();
 
             DependencyResult result = pluginDependenciesResolver.resolveCoreExtension(
                     new org.apache.maven.model.Plugin(plugin), dependencyFilter, repositories, repoSession);
             return result.getArtifactResults().stream()
                     .filter(ArtifactResult::isResolved)
                     .map(ArtifactResult::getArtifact)
                     .collect(Collectors.toList());
         } catch (PluginResolutionException | InterpolatorException e) {
             throw new ExtensionResolutionException(extension, e);
         }
     }
 
     private static Function<String, String> createInterpolator(MavenExecutionRequest request) {
         Interpolator interpolator = new DefaultInterpolator();
         Function<String, String> callback = v -> {
             String r = request.getUserProperties().getProperty(v);
             if (r == null) {
                 r = request.getSystemProperties().getProperty(v);
             }
             return r != null ? r : v;
         };
         return v -> interpolator.interpolate(v, callback);
     }
 
     static class SimpleSession extends DefaultSession {
         SimpleSession(
                 MavenSession session,
                 RepositorySystem repositorySystem,
                 List<org.apache.maven.api.RemoteRepository> repositories) {
             super(session, repositorySystem, repositories, null, null, null);
         }
 
         @Override
         protected Session newSession(
                 MavenSession mavenSession, List<org.apache.maven.api.RemoteRepository> repositories) {
             return new SimpleSession(mavenSession, getRepositorySystem(), repositories);
         }
 
         @Override
         public <T extends Service> T getService(Class<T> clazz) throws NoSuchElementException {
             if (clazz == ArtifactCoordinatesFactory.class) {
                 return (T) new DefaultArtifactCoordinatesFactory();
             } else if (clazz == VersionParser.class) {
                 return (T) new DefaultVersionParser(new DefaultModelVersionParser(new GenericVersionScheme()));
             } else if (clazz == VersionRangeResolver.class) {
                 return (T) new DefaultVersionRangeResolver(repositorySystem);
             } else if (clazz == ArtifactResolver.class) {
                 return (T) new DefaultArtifactResolver();
             } else if (clazz == ArtifactManager.class) {
                 return (T) new DefaultArtifactManager(this);
             } else if (clazz == RepositoryFactory.class) {
                 return (T) new DefaultRepositoryFactory(new DefaultRemoteRepositoryManager(
                         new DefaultUpdatePolicyAnalyzer(), new DefaultChecksumPolicyProvider()));
             } else if (clazz == Interpolator.class) {
                 return (T) new DefaultInterpolator();
                 // } else if (clazz == ModelResolver.class) {
                 //    return (T) new DefaultModelResolver();
             }
             throw new NoSuchElementException("No service for " + clazz.getName());
         }
     }
 }