/*
    * 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.eclipse.aether.internal.impl;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.Objects;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.function.Consumer;
  import java.util.stream.Collectors;
  
  import org.eclipse.aether.ConfigurationProperties;
  import org.eclipse.aether.RepositorySystem;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.RequestTrace;
  import org.eclipse.aether.SyncContext;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.collection.CollectRequest;
  import org.eclipse.aether.collection.CollectResult;
  import org.eclipse.aether.collection.DependencyCollectionException;
  import org.eclipse.aether.deployment.DeployRequest;
  import org.eclipse.aether.deployment.DeployResult;
  import org.eclipse.aether.deployment.DeploymentException;
  import org.eclipse.aether.graph.DependencyFilter;
  import org.eclipse.aether.graph.DependencyNode;
  import org.eclipse.aether.graph.DependencyVisitor;
  import org.eclipse.aether.impl.ArtifactDescriptorReader;
  import org.eclipse.aether.impl.ArtifactResolver;
  import org.eclipse.aether.impl.DependencyCollector;
  import org.eclipse.aether.impl.Deployer;
  import org.eclipse.aether.impl.Installer;
  import org.eclipse.aether.impl.LocalRepositoryProvider;
  import org.eclipse.aether.impl.MetadataResolver;
  import org.eclipse.aether.impl.RemoteRepositoryManager;
  import org.eclipse.aether.impl.RepositorySystemLifecycle;
  import org.eclipse.aether.impl.VersionRangeResolver;
  import org.eclipse.aether.impl.VersionResolver;
  import org.eclipse.aether.installation.InstallRequest;
  import org.eclipse.aether.installation.InstallResult;
  import org.eclipse.aether.installation.InstallationException;
  import org.eclipse.aether.internal.impl.session.DefaultSessionBuilder;
  import org.eclipse.aether.repository.Authentication;
  import org.eclipse.aether.repository.LocalRepository;
  import org.eclipse.aether.repository.LocalRepositoryManager;
  import org.eclipse.aether.repository.NoLocalRepositoryManagerException;
  import org.eclipse.aether.repository.Proxy;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.resolution.ArtifactDescriptorException;
  import org.eclipse.aether.resolution.ArtifactDescriptorRequest;
  import org.eclipse.aether.resolution.ArtifactDescriptorResult;
  import org.eclipse.aether.resolution.ArtifactRequest;
  import org.eclipse.aether.resolution.ArtifactResolutionException;
  import org.eclipse.aether.resolution.ArtifactResult;
  import org.eclipse.aether.resolution.DependencyRequest;
  import org.eclipse.aether.resolution.DependencyResolutionException;
  import org.eclipse.aether.resolution.DependencyResult;
  import org.eclipse.aether.resolution.MetadataRequest;
  import org.eclipse.aether.resolution.MetadataResult;
  import org.eclipse.aether.resolution.VersionRangeRequest;
  import org.eclipse.aether.resolution.VersionRangeResolutionException;
  import org.eclipse.aether.resolution.VersionRangeResult;
  import org.eclipse.aether.resolution.VersionRequest;
  import org.eclipse.aether.resolution.VersionResolutionException;
  import org.eclipse.aether.resolution.VersionResult;
  import org.eclipse.aether.spi.synccontext.SyncContextFactory;
  import org.eclipse.aether.util.ConfigUtils;
  import org.eclipse.aether.util.graph.visitor.FilteringDependencyVisitor;
  import org.eclipse.aether.util.graph.visitor.LevelOrderDependencyNodeConsumerVisitor;
  import org.eclipse.aether.util.graph.visitor.PostorderDependencyNodeConsumerVisitor;
  import org.eclipse.aether.util.graph.visitor.PreorderDependencyNodeConsumerVisitor;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   *
   */
  @Singleton
 @Named
 public class DefaultRepositorySystem implements RepositorySystem {
     private final AtomicBoolean shutdown;
 
     private final AtomicInteger sessionIdCounter;
 
     private final VersionResolver versionResolver;
 
     private final VersionRangeResolver versionRangeResolver;
 
     private final ArtifactResolver artifactResolver;
 
     private final MetadataResolver metadataResolver;
 
     private final ArtifactDescriptorReader artifactDescriptorReader;
 
     private final DependencyCollector dependencyCollector;
 
     private final Installer installer;
 
     private final Deployer deployer;
 
     private final LocalRepositoryProvider localRepositoryProvider;
 
     private final SyncContextFactory syncContextFactory;
 
     private final RemoteRepositoryManager remoteRepositoryManager;
 
     private final RepositorySystemLifecycle repositorySystemLifecycle;
 
     @SuppressWarnings("checkstyle:parameternumber")
     @Inject
     public DefaultRepositorySystem(
             VersionResolver versionResolver,
             VersionRangeResolver versionRangeResolver,
             ArtifactResolver artifactResolver,
             MetadataResolver metadataResolver,
             ArtifactDescriptorReader artifactDescriptorReader,
             DependencyCollector dependencyCollector,
             Installer installer,
             Deployer deployer,
             LocalRepositoryProvider localRepositoryProvider,
             SyncContextFactory syncContextFactory,
             RemoteRepositoryManager remoteRepositoryManager,
             RepositorySystemLifecycle repositorySystemLifecycle) {
         this.shutdown = new AtomicBoolean(false);
         this.sessionIdCounter = new AtomicInteger(0);
         this.versionResolver = requireNonNull(versionResolver, "version resolver cannot be null");
         this.versionRangeResolver = requireNonNull(versionRangeResolver, "version range resolver cannot be null");
         this.artifactResolver = requireNonNull(artifactResolver, "artifact resolver cannot be null");
         this.metadataResolver = requireNonNull(metadataResolver, "metadata resolver cannot be null");
         this.artifactDescriptorReader =
                 requireNonNull(artifactDescriptorReader, "artifact descriptor reader cannot be null");
         this.dependencyCollector = requireNonNull(dependencyCollector, "dependency collector cannot be null");
         this.installer = requireNonNull(installer, "installer cannot be null");
         this.deployer = requireNonNull(deployer, "deployer cannot be null");
         this.localRepositoryProvider =
                 requireNonNull(localRepositoryProvider, "local repository provider cannot be null");
         this.syncContextFactory = requireNonNull(syncContextFactory, "sync context factory cannot be null");
         this.remoteRepositoryManager =
                 requireNonNull(remoteRepositoryManager, "remote repository provider cannot be null");
         this.repositorySystemLifecycle =
                 requireNonNull(repositorySystemLifecycle, "repository system lifecycle cannot be null");
     }
 
     @Override
     public VersionResult resolveVersion(RepositorySystemSession session, VersionRequest request)
             throws VersionResolutionException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return versionResolver.resolveVersion(session, request);
     }
 
     @Override
     public VersionRangeResult resolveVersionRange(RepositorySystemSession session, VersionRangeRequest request)
             throws VersionRangeResolutionException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return versionRangeResolver.resolveVersionRange(session, request);
     }
 
     @Override
     public ArtifactDescriptorResult readArtifactDescriptor(
             RepositorySystemSession session, ArtifactDescriptorRequest request) throws ArtifactDescriptorException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return artifactDescriptorReader.readArtifactDescriptor(session, request);
     }
 
     @Override
     public ArtifactResult resolveArtifact(RepositorySystemSession session, ArtifactRequest request)
             throws ArtifactResolutionException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return artifactResolver.resolveArtifact(session, request);
     }
 
     @Override
     public List<ArtifactResult> resolveArtifacts(
             RepositorySystemSession session, Collection<? extends ArtifactRequest> requests)
             throws ArtifactResolutionException {
         validateSession(session);
         requireNonNull(requests, "requests cannot be null");
 
         return artifactResolver.resolveArtifacts(session, requests);
     }
 
     @Override
     public List<MetadataResult> resolveMetadata(
             RepositorySystemSession session, Collection<? extends MetadataRequest> requests) {
         validateSession(session);
         requireNonNull(requests, "requests cannot be null");
 
         return metadataResolver.resolveMetadata(session, requests);
     }
 
     @Override
     public CollectResult collectDependencies(RepositorySystemSession session, CollectRequest request)
             throws DependencyCollectionException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return dependencyCollector.collectDependencies(session, request);
     }
 
     @Override
     public DependencyResult resolveDependencies(RepositorySystemSession session, DependencyRequest request)
             throws DependencyResolutionException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);
 
         DependencyResult result = new DependencyResult(request);
 
         DependencyCollectionException dce = null;
         ArtifactResolutionException are = null;
 
         if (request.getRoot() != null) {
             result.setRoot(request.getRoot());
         } else if (request.getCollectRequest() != null) {
             CollectResult collectResult;
             try {
                 request.getCollectRequest().setTrace(trace);
                 collectResult = dependencyCollector.collectDependencies(session, request.getCollectRequest());
             } catch (DependencyCollectionException e) {
                 dce = e;
                 collectResult = e.getResult();
             }
             result.setRoot(collectResult.getRoot());
             result.setCycles(collectResult.getCycles());
             result.setCollectExceptions(collectResult.getExceptions());
         } else {
             throw new NullPointerException("dependency node and collect request cannot be null");
         }
 
         final ArrayList<DependencyNode> dependencyNodes = new ArrayList<>();
         DependencyVisitor builder = getDependencyVisitor(session, dependencyNodes::add);
         DependencyFilter filter = request.getFilter();
         DependencyVisitor visitor = (filter != null) ? new FilteringDependencyVisitor(builder, filter) : builder;
         if (result.getRoot() != null) {
             result.getRoot().accept(visitor);
         }
 
         final List<ArtifactRequest> requests = dependencyNodes.stream()
                 .map(n -> {
                     if (n.getDependency() != null) {
                         ArtifactRequest artifactRequest = new ArtifactRequest(n);
                         artifactRequest.setTrace(trace);
                         return artifactRequest;
                     } else {
                         return null;
                     }
                 })
                 .filter(Objects::nonNull)
                 .collect(Collectors.toList());
         List<ArtifactResult> results;
         try {
             results = artifactResolver.resolveArtifacts(session, requests);
         } catch (ArtifactResolutionException e) {
             are = e;
             results = e.getResults();
         }
         result.setDependencyNodeResults(dependencyNodes);
         result.setArtifactResults(results);
 
         updateNodesWithResolvedArtifacts(results);
 
         if (dce != null) {
             throw new DependencyResolutionException(result, dce);
         } else if (are != null) {
             throw new DependencyResolutionException(result, are);
         }
 
         return result;
     }
 
     @Override
     public List<DependencyNode> flattenDependencyNodes(RepositorySystemSession session, DependencyNode root) {
         validateSession(session);
         requireNonNull(root, "root cannot be null");
 
         final ArrayList<DependencyNode> dependencyNodes = new ArrayList<>();
         root.accept(getDependencyVisitor(session, dependencyNodes::add));
         return dependencyNodes;
     }
 
     private DependencyVisitor getDependencyVisitor(
             RepositorySystemSession session, Consumer<DependencyNode> nodeConsumer) {
         String strategy = ConfigUtils.getString(
                 session,
                 ConfigurationProperties.REPOSITORY_SYSTEM_DEPENDENCY_VISITOR_PREORDER,
                 ConfigurationProperties.REPOSITORY_SYSTEM_DEPENDENCY_VISITOR);
         switch (strategy) {
             case PreorderDependencyNodeConsumerVisitor.NAME:
                 return new PreorderDependencyNodeConsumerVisitor(nodeConsumer);
             case PostorderDependencyNodeConsumerVisitor.NAME:
                 return new PostorderDependencyNodeConsumerVisitor(nodeConsumer);
             case LevelOrderDependencyNodeConsumerVisitor.NAME:
                 return new LevelOrderDependencyNodeConsumerVisitor(nodeConsumer);
             default:
                 throw new IllegalArgumentException("Invalid dependency visitor strategy: " + strategy);
         }
     }
 
     private void updateNodesWithResolvedArtifacts(List<ArtifactResult> results) {
         for (ArtifactResult result : results) {
             Artifact artifact = result.getArtifact();
             if (artifact != null) {
                 result.getRequest().getDependencyNode().setArtifact(artifact);
             }
         }
     }
 
     @Override
     public InstallResult install(RepositorySystemSession session, InstallRequest request) throws InstallationException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return installer.install(session, request);
     }
 
     @Override
     public DeployResult deploy(RepositorySystemSession session, DeployRequest request) throws DeploymentException {
         validateSession(session);
         requireNonNull(request, "request cannot be null");
 
         return deployer.deploy(session, request);
     }
 
     @Override
     public LocalRepositoryManager newLocalRepositoryManager(
             RepositorySystemSession session, LocalRepository localRepository) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(localRepository, "localRepository cannot be null");
         validateSystem();
 
         try {
             return localRepositoryProvider.newLocalRepositoryManager(session, localRepository);
         } catch (NoLocalRepositoryManagerException e) {
             throw new IllegalArgumentException(e.getMessage(), e);
         }
     }
 
     @Override
     public SyncContext newSyncContext(RepositorySystemSession session, boolean shared) {
         validateSession(session);
         return syncContextFactory.newInstance(session, shared);
     }
 
     @Override
     public List<RemoteRepository> newResolutionRepositories(
             RepositorySystemSession session, List<RemoteRepository> repositories) {
         validateSession(session);
         validateRepositories(repositories);
 
         repositories = remoteRepositoryManager.aggregateRepositories(session, new ArrayList<>(), repositories, true);
         return repositories;
     }
 
     @Override
     public RemoteRepository newDeploymentRepository(RepositorySystemSession session, RemoteRepository repository) {
         validateSession(session);
         requireNonNull(repository, "repository cannot be null");
 
         RemoteRepository.Builder builder = new RemoteRepository.Builder(repository);
         Authentication auth = session.getAuthenticationSelector().getAuthentication(repository);
         builder.setAuthentication(auth);
         Proxy proxy = session.getProxySelector().getProxy(repository);
         builder.setProxy(proxy);
         return builder.build();
     }
 
     @Override
     public void addOnSystemEndedHandler(Runnable handler) {
         validateSystem();
         repositorySystemLifecycle.addOnSystemEndedHandler(handler);
     }
 
     @Override
     public RepositorySystemSession.SessionBuilder createSessionBuilder() {
         validateSystem();
         return new DefaultSessionBuilder(
                 this, repositorySystemLifecycle, () -> "id-" + sessionIdCounter.incrementAndGet());
     }
 
     @Override
     public void shutdown() {
         if (shutdown.compareAndSet(false, true)) {
             repositorySystemLifecycle.systemEnded();
         }
     }
 
     private void validateSession(RepositorySystemSession session) {
         requireNonNull(session, "repository system session cannot be null");
         invalidSession(session.getLocalRepositoryManager(), "local repository manager");
         invalidSession(session.getSystemProperties(), "system properties");
         invalidSession(session.getUserProperties(), "user properties");
         invalidSession(session.getConfigProperties(), "config properties");
         invalidSession(session.getMirrorSelector(), "mirror selector");
         invalidSession(session.getProxySelector(), "proxy selector");
         invalidSession(session.getAuthenticationSelector(), "authentication selector");
         invalidSession(session.getArtifactTypeRegistry(), "artifact type registry");
         invalidSession(session.getData(), "data");
         validateSystem();
     }
 
     private void validateSystem() {
         if (shutdown.get()) {
             throw new IllegalStateException("repository system is already shut down");
         }
     }
 
     private void validateRepositories(List<RemoteRepository> repositories) {
         requireNonNull(repositories, "repositories cannot be null");
         for (RemoteRepository repository : repositories) {
             requireNonNull(repository, "repository cannot be null");
         }
     }
 
     private void invalidSession(Object obj, String name) {
         requireNonNull(obj, "repository system session's " + name + " cannot be null");
     }
 }