package org.apache.maven.repository.internal;

/*
 * 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.
 */

import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.Map;

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;

/**
 * @author Benjamin Bentmann
 */
class RemoteSnapshotMetadataGenerator
    implements MetadataGenerator
{

    private final Map<Object, RemoteSnapshotMetadata> snapshots;

    private final boolean legacyFormat;

    private final Date timestamp;

    RemoteSnapshotMetadataGenerator( RepositorySystemSession session, DeployRequest request )
    {
        legacyFormat = ConfigUtils.getBoolean( session, false, "maven.metadata.legacy" );

        timestamp = (Date) ConfigUtils.getObject( session, new Date(), "maven.startTime" );

        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 );
            }
        }
    }

    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, legacyFormat, timestamp );
                    snapshots.put( key, snapshotMetadata );
                }
                snapshotMetadata.bind( artifact );
            }
        }

        return snapshots.values();
    }

    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;
    }

    public Collection<? extends Metadata> finish( Collection<? extends Artifact> artifacts )
    {
        return Collections.emptyList();
    }

}
