/*
    * 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;
  
  import java.util.Collection;
  import java.util.List;
  
  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.DependencyNode;
  import org.eclipse.aether.installation.InstallRequest;
  import org.eclipse.aether.installation.InstallResult;
  import org.eclipse.aether.installation.InstallationException;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.repository.LocalRepository;
  import org.eclipse.aether.repository.LocalRepositoryManager;
  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;
  
  /**
   * The main entry point to the repository system and its functionality. Note that obtaining a concrete implementation of
   * this interface (e.g. via dependency injection, service locator, etc.) is dependent on the application and its
   * specific needs, please consult the online documentation for examples and directions on booting the system.
   * <p>
   * When the repository system or the application integrating it is about to exit, invoke the {@link #shutdown()} to let
   * resolver system perform possible resource cleanups.
   *
   * @noimplement This interface is not intended to be implemented by clients.
   * @noextend This interface is not intended to be extended by clients.
   */
  public interface RepositorySystem {
  
      /**
       * Expands a version range to a list of matching versions, in ascending order. For example, resolves "[3.8,4.0)" to
       * "3.8", "3.8.1", "3.8.2". Note that the returned list of versions is only dependent on the configured repositories
       * and their contents, the list is not processed by the {@link RepositorySystemSession#getVersionFilter() session's
       * version filter}.
       * <p>
       * The supplied request may also refer to a single concrete version rather than a version range. In this case
       * though, the result contains simply the (parsed) input version, regardless of the repositories and their contents.
       *
       * @param session The repository session, must not be {@code null}.
       * @param request The version range request, must not be {@code null}.
       * @return The version range result, never {@code null}.
       * @throws VersionRangeResolutionException If the requested range could not be parsed. Note that an empty range does
       *                                         not raise an exception.
       * @see #newResolutionRepositories(RepositorySystemSession, List)
       */
      VersionRangeResult resolveVersionRange(RepositorySystemSession session, VersionRangeRequest request)
              throws VersionRangeResolutionException;
  
      /**
       * Resolves an artifact's meta version (if any) to a concrete version. For example, resolves "1.0-SNAPSHOT" to
       * "1.0-20090208.132618-23".
       *
       * @param session The repository session, must not be {@code null}.
       * @param request The version request, must not be {@code null}.
       * @return The version result, never {@code null}.
       * @throws VersionResolutionException If the metaversion could not be resolved.
       * @see #newResolutionRepositories(RepositorySystemSession, List)
       */
      VersionResult resolveVersion(RepositorySystemSession session, VersionRequest request)
             throws VersionResolutionException;
 
     /**
      * Gets information about an artifact like its direct dependencies and potential relocations.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The descriptor request, must not be {@code null}.
      * @return The descriptor result, never {@code null}.
      * @throws ArtifactDescriptorException If the artifact descriptor could not be read.
      * @see RepositorySystemSession#getArtifactDescriptorPolicy()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     ArtifactDescriptorResult readArtifactDescriptor(RepositorySystemSession session, ArtifactDescriptorRequest request)
             throws ArtifactDescriptorException;
 
     /**
      * Collects the transitive dependencies of an artifact and builds a dependency graph. Note that this operation is
      * only concerned about determining the coordinates of the transitive dependencies. To also resolve the actual
      * artifact files, use {@link #resolveDependencies(RepositorySystemSession, DependencyRequest)}.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The collection request, must not be {@code null}.
      * @return The collection result, never {@code null}.
      * @throws DependencyCollectionException If the dependency tree could not be built.
      * @see RepositorySystemSession#getDependencyTraverser()
      * @see RepositorySystemSession#getDependencyManager()
      * @see RepositorySystemSession#getDependencySelector()
      * @see RepositorySystemSession#getVersionFilter()
      * @see RepositorySystemSession#getDependencyGraphTransformer()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     CollectResult collectDependencies(RepositorySystemSession session, CollectRequest request)
             throws DependencyCollectionException;
 
     /**
      * Collects and resolves the transitive dependencies of an artifact. This operation is essentially a combination of
      * {@link #collectDependencies(RepositorySystemSession, CollectRequest)} and
      * {@link #resolveArtifacts(RepositorySystemSession, Collection)}.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The dependency request, must not be {@code null}.
      * @return The dependency result, never {@code null}.
      * @throws DependencyResolutionException If the dependency tree could not be built or any dependency artifact could
      *                                       not be resolved.
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     DependencyResult resolveDependencies(RepositorySystemSession session, DependencyRequest request)
             throws DependencyResolutionException;
 
     /**
      * Flattens the provided graph as {@link DependencyNode} into a {@link List}{@code <DependencyNode>} according to session
      * configuration.
      *
      * @param session The repository session, must not be {@code null}.
      * @param root The dependency node root of the graph, must not be {@code null}.
      * @return The flattened list of dependency nodes, never {@code null}.
      * @since TBD
      */
     List<DependencyNode> flattenDependencyNodes(RepositorySystemSession session, DependencyNode root);
 
     /**
      * Resolves the path for an artifact. The artifact will be downloaded to the local repository if necessary. An
      * artifact that is already resolved will be skipped and is not re-resolved. In general, callers must not assume any
      * relationship between an artifact's resolved filename and its coordinates. Note that this method assumes that any
      * relocations have already been processed.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The resolution request, must not be {@code null}.
      * @return The resolution result, never {@code null}.
      * @throws ArtifactResolutionException If the artifact could not be resolved.
      * @see Artifact#getFile()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     ArtifactResult resolveArtifact(RepositorySystemSession session, ArtifactRequest request)
             throws ArtifactResolutionException;
 
     /**
      * Resolves the paths for a collection of artifacts. Artifacts will be downloaded to the local repository if
      * necessary. Artifacts that are already resolved will be skipped and are not re-resolved. In general, callers must
      * not assume any relationship between an artifact's filename and its coordinates. Note that this method assumes
      * that any relocations have already been processed.
      *
      * @param session  The repository session, must not be {@code null}.
      * @param requests The resolution requests, must not be {@code null}.
      * @return The resolution results (in request order), never {@code null}.
      * @throws ArtifactResolutionException If any artifact could not be resolved.
      * @see Artifact#getFile()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     List<ArtifactResult> resolveArtifacts(
             RepositorySystemSession session, Collection<? extends ArtifactRequest> requests)
             throws ArtifactResolutionException;
 
     /**
      * Resolves the paths for a collection of metadata. Metadata will be downloaded to the local repository if
      * necessary, e.g. because it hasn't been cached yet or the cache is deemed outdated.
      *
      * @param session  The repository session, must not be {@code null}.
      * @param requests The resolution requests, must not be {@code null}.
      * @return The resolution results (in request order), never {@code null}.
      * @see Metadata#getFile()
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     List<MetadataResult> resolveMetadata(
             RepositorySystemSession session, Collection<? extends MetadataRequest> requests);
 
     /**
      * Installs a collection of artifacts and their accompanying metadata to the local repository.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The installation request, must not be {@code null}.
      * @return The installation result, never {@code null}.
      * @throws InstallationException If any artifact/metadata from the request could not be installed.
      */
     InstallResult install(RepositorySystemSession session, InstallRequest request) throws InstallationException;
 
     /**
      * Uploads a collection of artifacts and their accompanying metadata to a remote repository.
      *
      * @param session The repository session, must not be {@code null}.
      * @param request The deployment request, must not be {@code null}.
      * @return The deployment result, never {@code null}.
      * @throws DeploymentException If any artifact/metadata from the request could not be deployed.
      * @see #newDeploymentRepository(RepositorySystemSession, RemoteRepository)
      */
     DeployResult deploy(RepositorySystemSession session, DeployRequest request) throws DeploymentException;
 
     /**
      * Creates a new manager for the specified local repository. If the specified local repository has no type, the
      * default local repository type of the system will be used. <em>Note:</em> It is expected that this method
      * invocation is one of the last steps of setting up a new session, in particular any configuration properties
      * should have been set already.
      *
      * @param session         The repository system session from which to configure the manager, must not be
      *                        {@code null}.
      * @param localRepository The local repository to create a manager for, must not be {@code null}.
      * @return The local repository manager, never {@code null}.
      * @throws IllegalArgumentException If the specified repository type is not recognized or no base directory is
      *                                  given.
      */
     LocalRepositoryManager newLocalRepositoryManager(RepositorySystemSession session, LocalRepository localRepository);
 
     /**
      * Creates a new synchronization context.
      *
      * @param session The repository session during which the context will be used, must not be {@code null}.
      * @param shared  A flag indicating whether access to the artifacts/metadata associated with the new context can be
      *                shared among concurrent readers or whether access needs to be exclusive to the calling thread.
      * @return The synchronization context, never {@code null}.
      */
     SyncContext newSyncContext(RepositorySystemSession session, boolean shared);
 
     /**
      * Forms remote repositories suitable for artifact resolution by applying the session's authentication selector and
      * similar network configuration to the given repository prototypes. As noted for
      * {@link RepositorySystemSession#getAuthenticationSelector()} etc. the remote repositories passed to e.g.
      * {@link #resolveArtifact(RepositorySystemSession, ArtifactRequest) resolveArtifact()} are used as is and expected
      * to already carry any required authentication or proxy configuration. This method can be used to apply the
      * authentication/proxy configuration from a session to a bare repository definition to obtain the complete
      * repository definition for use in the resolution request.
      *
      * @param session      The repository system session from which to configure the repositories, must not be
      *                     {@code null}.
      * @param repositories The repository prototypes from which to derive the resolution repositories, must not be
      *                     {@code null} or contain {@code null} elements.
      * @return The resolution repositories, never {@code null}. Note that there is generally no 1:1 relationship of the
      * obtained repositories to the original inputs due to mirror selection potentially aggregating multiple
      * repositories.
      * @see #newDeploymentRepository(RepositorySystemSession, RemoteRepository)
      */
     List<RemoteRepository> newResolutionRepositories(
             RepositorySystemSession session, List<RemoteRepository> repositories);
 
     /**
      * Forms a remote repository suitable for artifact deployment by applying the session's authentication selector and
      * similar network configuration to the given repository prototype. As noted for
      * {@link RepositorySystemSession#getAuthenticationSelector()} etc. the remote repository passed to
      * {@link #deploy(RepositorySystemSession, DeployRequest) deploy()} is used as is and expected to already carry any
      * required authentication or proxy configuration. This method can be used to apply the authentication/proxy
      * configuration from a session to a bare repository definition to obtain the complete repository definition for use
      * in the deploy request.
      *
      * @param session    The repository system session from which to configure the repository, must not be {@code null}.
      * @param repository The repository prototype from which to derive the deployment repository, must not be
      *                   {@code null}.
      * @return The deployment repository, never {@code null}.
      * @see #newResolutionRepositories(RepositorySystemSession, List)
      */
     RemoteRepository newDeploymentRepository(RepositorySystemSession session, RemoteRepository repository);
 
     /**
      * Registers an "on repository system end" handler, executed after repository system is shut down.
      *
      * @param handler The handler, must not be {@code null}.
      * @since 1.9.0
      */
     void addOnSystemEndedHandler(Runnable handler);
 
     /**
      * Signals to repository system to shut down. Shut down instance is not usable anymore.
      * <p>
      * Repository system may perform some resource cleanup, if applicable. Not using this method may cause leaks or
      * unclean shutdown of some subsystem.
      * <p>
      * When shutdown happens, all the registered on-close handlers will be invoked (even if some throws), and at end
      * of operation a {@link MultiRuntimeException} may be thrown, signaling that some handler(s) failed. This exception
      * may be ignored, is at the discretion of caller.
      *
      * @since 1.9.0
      */
     void shutdown();
 }