/*
    * 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 java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Objects;
  import java.util.SortedSet;
  import java.util.TreeSet;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.repository.LocalArtifactRegistration;
  import org.eclipse.aether.repository.LocalArtifactRequest;
  import org.eclipse.aether.repository.LocalArtifactResult;
  import org.eclipse.aether.repository.LocalMetadataRegistration;
  import org.eclipse.aether.repository.LocalMetadataRequest;
  import org.eclipse.aether.repository.LocalMetadataResult;
  import org.eclipse.aether.repository.LocalRepository;
  import org.eclipse.aether.repository.LocalRepositoryManager;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.util.StringDigestUtil;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * A local repository manager that realizes the classical Maven 2.0 local repository.
   */
  class SimpleLocalRepositoryManager implements LocalRepositoryManager {
  
      private final LocalRepository repository;
  
      private final LocalPathComposer localPathComposer;
  
      SimpleLocalRepositoryManager(Path basePath, String type, LocalPathComposer localPathComposer) {
          requireNonNull(basePath, "base directory cannot be null");
          repository = new LocalRepository(basePath.toAbsolutePath(), type);
          this.localPathComposer = requireNonNull(localPathComposer);
      }
  
      @Override
      public LocalRepository getRepository() {
          return repository;
      }
  
      @Override
      public String getPathForLocalArtifact(Artifact artifact) {
          requireNonNull(artifact, "artifact cannot be null");
          return localPathComposer.getPathForArtifact(artifact, true);
      }
  
      @Override
      public String getPathForRemoteArtifact(Artifact artifact, RemoteRepository repository, String context) {
          requireNonNull(artifact, "artifact cannot be null");
          requireNonNull(repository, "repository cannot be null");
          return localPathComposer.getPathForArtifact(artifact, false);
      }
  
      @Override
      public String getPathForLocalMetadata(Metadata metadata) {
          requireNonNull(metadata, "metadata cannot be null");
          return localPathComposer.getPathForMetadata(metadata, "local");
      }
  
      @Override
      public String getPathForRemoteMetadata(Metadata metadata, RemoteRepository repository, String context) {
          requireNonNull(metadata, "metadata cannot be null");
          requireNonNull(repository, "repository cannot be null");
          return localPathComposer.getPathForMetadata(metadata, getRepositoryKey(repository, context));
      }
  
      /**
       * Returns {@link RemoteRepository#getId()}, unless {@link RemoteRepository#isRepositoryManager()} returns
       * {@code true}, in which case this method creates unique identifier based on ID and current configuration
       * of the remote repository (as it may change).
       */
      protected String getRepositoryKey(RemoteRepository repository, String context) {
          String key;
  
          if (repository.isRepositoryManager()) {
              // repository serves dynamic contents, take request parameters into account for key
  
             StringBuilder buffer = new StringBuilder(128);
 
             buffer.append(repository.getId());
 
             buffer.append('-');
 
             SortedSet<String> subKeys = new TreeSet<>();
             for (RemoteRepository mirroredRepo : repository.getMirroredRepositories()) {
                 subKeys.add(mirroredRepo.getId());
             }
 
             StringDigestUtil sha1 = StringDigestUtil.sha1();
             sha1.update(context);
             for (String subKey : subKeys) {
                 sha1.update(subKey);
             }
             buffer.append(sha1.digest());
 
             key = buffer.toString();
         } else {
             // repository serves static contents, its id is sufficient as key
 
             key = repository.getId();
         }
 
         return key;
     }
 
     @Override
     public LocalArtifactResult find(RepositorySystemSession session, LocalArtifactRequest request) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(request, "request cannot be null");
         Artifact artifact = request.getArtifact();
         LocalArtifactResult result = new LocalArtifactResult(request);
 
         String path;
         Path filePath;
 
         // Local repository CANNOT have timestamped installed, they are created only during deploy
         if (Objects.equals(artifact.getVersion(), artifact.getBaseVersion())) {
             path = getPathForLocalArtifact(artifact);
             filePath = getRepository().getBasePath().resolve(path);
             if (Files.isRegularFile(filePath)) {
                 result.setPath(filePath);
                 result.setAvailable(true);
             }
         }
 
         if (!result.isAvailable()) {
             for (RemoteRepository repository : request.getRepositories()) {
                 path = getPathForRemoteArtifact(artifact, repository, request.getContext());
                 filePath = getRepository().getBasePath().resolve(path);
                 if (Files.isRegularFile(filePath)) {
                     result.setPath(filePath);
                     result.setAvailable(true);
                     break;
                 }
             }
         }
 
         return result;
     }
 
     @Override
     public void add(RepositorySystemSession session, LocalArtifactRegistration request) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(request, "request cannot be null");
         // noop
     }
 
     @Override
     public LocalMetadataResult find(RepositorySystemSession session, LocalMetadataRequest request) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(request, "request cannot be null");
         LocalMetadataResult result = new LocalMetadataResult(request);
 
         String path;
 
         Metadata metadata = request.getMetadata();
         String context = request.getContext();
         RemoteRepository remote = request.getRepository();
 
         if (remote != null) {
             path = getPathForRemoteMetadata(metadata, remote, context);
         } else {
             path = getPathForLocalMetadata(metadata);
         }
 
         Path filePath = getRepository().getBasePath().resolve(path);
         if (Files.isRegularFile(filePath)) {
             result.setPath(filePath);
         }
 
         return result;
     }
 
     @Override
     public void add(RepositorySystemSession session, LocalMetadataRegistration request) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(request, "request cannot be null");
         // noop
     }
 
     @Override
     public String toString() {
         return String.valueOf(getRepository());
     }
 }