/*
    * 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.resolver;
  
  import java.time.Instant;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import org.apache.maven.api.Constants;
  import org.apache.maven.api.MonotonicClock;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.deployment.DeployRequest;
  import org.eclipse.aether.impl.MetadataGenerator;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.util.ConfigUtils;
  
  /**
   * Maven remote GAV level metadata generator.
   * <p>
   * Remote snapshot metadata converts artifact on-the-fly to use timestamped snapshot version, and enlist it accordingly.
   */
  class RemoteSnapshotMetadataGenerator implements MetadataGenerator {
  
      private final Map<Object, RemoteSnapshotMetadata> snapshots;
  
      private final Instant timestamp;
  
      private final Integer buildNumber;
  
      RemoteSnapshotMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
          timestamp = (Instant) ConfigUtils.getObject(session, MonotonicClock.now(), Constants.MAVEN_START_INSTANT);
          Object bn = ConfigUtils.getObject(session, null, Constants.MAVEN_DEPLOY_SNAPSHOT_BUILD_NUMBER);
          if (bn instanceof Integer) {
              this.buildNumber = (Integer) bn;
          } else if (bn instanceof String) {
              this.buildNumber = Integer.valueOf((String) bn);
          } else {
              this.buildNumber = null;
          }
  
          snapshots = new LinkedHashMap<>();
  
          /*
           * NOTE: This should be considered a quirk to support interop with Maven's legacy ArtifactDeployer which
           * processes one artifact at a time and hence cannot associate the artifacts from the same project to use the
           * same timestamp+buildno for the snapshot versions. Allowing the caller to pass in metadata from a previous
           * deployment allows to re-establish the association between the artifacts of the same project.
           */
          for (Metadata metadata : request.getMetadata()) {
              if (metadata instanceof RemoteSnapshotMetadata) {
                  RemoteSnapshotMetadata snapshotMetadata = (RemoteSnapshotMetadata) metadata;
                  snapshots.put(snapshotMetadata.getKey(), snapshotMetadata);
              }
          }
      }
  
      @Override
      public Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts) {
          for (Artifact artifact : artifacts) {
              if (artifact.isSnapshot()) {
                  Object key = RemoteSnapshotMetadata.getKey(artifact);
                  RemoteSnapshotMetadata snapshotMetadata = snapshots.get(key);
                  if (snapshotMetadata == null) {
                      snapshotMetadata = new RemoteSnapshotMetadata(artifact, timestamp, buildNumber);
                      snapshots.put(key, snapshotMetadata);
                  }
                  snapshotMetadata.bind(artifact);
              }
          }
  
          return snapshots.values();
      }
  
      @Override
      public Artifact transformArtifact(Artifact artifact) {
          if (artifact.isSnapshot() && artifact.getVersion().equals(artifact.getBaseVersion())) {
              Object key = RemoteSnapshotMetadata.getKey(artifact);
              RemoteSnapshotMetadata snapshotMetadata = snapshots.get(key);
              if (snapshotMetadata != null) {
                  artifact = artifact.setVersion(snapshotMetadata.getExpandedVersion(artifact));
             }
         }
 
         return artifact;
     }
 
     @Override
     public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
         return Collections.emptyList();
     }
 }