package org.apache.maven.artifact.repository;

/*
 * 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.io.File;
import java.util.Collections;
import java.util.List;
import java.util.Objects;

import org.apache.maven.RepositoryUtils;
import org.apache.maven.artifact.metadata.ArtifactMetadata;
import org.apache.maven.artifact.repository.layout.ArtifactRepositoryLayout;
import org.apache.maven.artifact.repository.layout.DefaultRepositoryLayout;
import org.apache.maven.artifact.repository.metadata.RepositoryMetadataStoreException;
import org.apache.maven.repository.Proxy;
import org.eclipse.aether.DefaultRepositorySystemSession;
import org.eclipse.aether.RepositorySystem;
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;

/**
 * <strong>Warning:</strong> This is an internal utility class that is only public for technical reasons, it is not part
 * of the public API. In particular, this class can be changed or deleted without prior notice.
 *
 * @author Benjamin Bentmann
 */
public class LegacyLocalRepositoryManager
    implements LocalRepositoryManager
{

    private final ArtifactRepository delegate;

    private final LocalRepository repo;

    private final boolean realLocalRepo;

    public static RepositorySystemSession overlay( ArtifactRepository repository, RepositorySystemSession session,
                                                   RepositorySystem system )
    {
        if ( repository == null || repository.getBasedir() == null )
        {
            return session;
        }

        if ( session != null )
        {
            LocalRepositoryManager lrm = session.getLocalRepositoryManager();
            if ( lrm != null && lrm.getRepository().getBasedir().equals( new File( repository.getBasedir() ) ) )
            {
                return session;
            }
        }
        else
        {
            session = new DefaultRepositorySystemSession();
        }

        final LocalRepositoryManager llrm = new LegacyLocalRepositoryManager( repository );

        return new DefaultRepositorySystemSession( session ).setLocalRepositoryManager( llrm );
    }

    private LegacyLocalRepositoryManager( ArtifactRepository delegate )
    {
        this.delegate = Objects.requireNonNull( delegate, "delegate cannot be null" );

        ArtifactRepositoryLayout layout = delegate.getLayout();
        repo =
            new LocalRepository( new File( delegate.getBasedir() ),
                                 ( layout != null ) ? layout.getClass().getSimpleName() : "legacy" );

        /*
         * NOTE: "invoker:install" vs "appassembler:assemble": Both mojos use the artifact installer to put an artifact
         * into a repository. In the first case, the result needs to be a proper local repository that one can use for
         * local artifact resolution. In the second case, the result needs to precisely obey the path information of the
         * repository's layout to allow pointing at artifacts within the repository. Unfortunately,
         * DefaultRepositoryLayout does not correctly describe the layout of a local repository which unlike a remote
         * repository never uses timestamps in the filename of a snapshot artifact. The discrepancy gets notable when a
         * remotely resolved snapshot artifact gets passed into pathOf(). So producing a proper local artifact path
         * using DefaultRepositoryLayout requires us to enforce usage of the artifact's base version. This
         * transformation however contradicts the other use case of precisely obeying the repository's layout. The below
         * flag tries to detect which use case applies to make both plugins happy.
         */
        realLocalRepo = ( layout instanceof DefaultRepositoryLayout ) && "local".equals( delegate.getId() );
    }

    public LocalRepository getRepository()
    {
        return repo;
    }

    public String getPathForLocalArtifact( Artifact artifact )
    {
        if ( realLocalRepo )
        {
            return delegate.pathOf( RepositoryUtils.toArtifact( artifact.setVersion( artifact.getBaseVersion() ) ) );
        }
        return delegate.pathOf( RepositoryUtils.toArtifact( artifact ) );
    }

    public String getPathForRemoteArtifact( Artifact artifact, RemoteRepository repository, String context )
    {
        return delegate.pathOf( RepositoryUtils.toArtifact( artifact ) );
    }

    public String getPathForLocalMetadata( Metadata metadata )
    {
        return delegate.pathOfLocalRepositoryMetadata( new ArtifactMetadataAdapter( metadata ), delegate );
    }

    public String getPathForRemoteMetadata( Metadata metadata, RemoteRepository repository, String context )
    {
        return delegate.pathOfLocalRepositoryMetadata( new ArtifactMetadataAdapter( metadata ),
                                                       new ArtifactRepositoryAdapter( repository ) );
    }

    public LocalArtifactResult find( RepositorySystemSession session, LocalArtifactRequest request )
    {
        String path = getPathForLocalArtifact( request.getArtifact() );
        File file = new File( getRepository().getBasedir(), path );

        LocalArtifactResult result = new LocalArtifactResult( request );
        if ( file.isFile() )
        {
            result.setFile( file );
            result.setAvailable( true );
        }

        return result;
    }

    public LocalMetadataResult find( RepositorySystemSession session, LocalMetadataRequest request )
    {
        Metadata metadata = request.getMetadata();

        String path;
        if ( request.getRepository() == null )
        {
            path = getPathForLocalMetadata( metadata );
        }
        else
        {
            path = getPathForRemoteMetadata( metadata, request.getRepository(), request.getContext() );
        }

        File file = new File( getRepository().getBasedir(), path );

        LocalMetadataResult result = new LocalMetadataResult( request );
        if ( file.isFile() )
        {
            result.setFile( file );
        }

        return result;
    }

    public void add( RepositorySystemSession session, LocalArtifactRegistration request )
    {
        // noop
    }

    public void add( RepositorySystemSession session, LocalMetadataRegistration request )
    {
        // noop
    }

    static class ArtifactMetadataAdapter
        implements ArtifactMetadata
    {

        private final Metadata metadata;

        ArtifactMetadataAdapter( Metadata metadata )
        {
            this.metadata = metadata;
        }

        public boolean storedInArtifactVersionDirectory()
        {
            return metadata.getVersion().length() > 0;
        }

        public boolean storedInGroupDirectory()
        {
            return metadata.getArtifactId().length() <= 0;
        }

        public String getGroupId()
        {
            return nullify( metadata.getGroupId() );
        }

        public String getArtifactId()
        {
            return nullify( metadata.getArtifactId() );
        }

        public String getBaseVersion()
        {
            return nullify( metadata.getVersion() );
        }

        private String nullify( String str )
        {
            return ( str == null || str.length() <= 0 ) ? null : str;
        }

        public Object getKey()
        {
            return metadata.toString();
        }

        public String getRemoteFilename()
        {
            return metadata.getType();
        }

        public String getLocalFilename( ArtifactRepository repository )
        {
            return insertRepositoryKey( getRemoteFilename(), repository.getKey() );
        }

        private String insertRepositoryKey( String filename, String repositoryKey )
        {
            String result;
            int idx = filename.indexOf( '.' );
            if ( idx < 0 )
            {
                result = filename + '-' + repositoryKey;
            }
            else
            {
                result = filename.substring( 0, idx ) + '-' + repositoryKey + filename.substring( idx );
            }
            return result;
        }

        public void merge( org.apache.maven.repository.legacy.metadata.ArtifactMetadata metadata )
        {
            // not used
        }

        public void merge( ArtifactMetadata metadata )
        {
            // not used
        }

        public void storeInLocalRepository( ArtifactRepository localRepository, ArtifactRepository remoteRepository )
            throws RepositoryMetadataStoreException
        {
            // not used
        }

        public String extendedToString()
        {
            return metadata.toString();
        }

    }

    static class ArtifactRepositoryAdapter
        implements ArtifactRepository
    {

        private final RemoteRepository repository;

        ArtifactRepositoryAdapter( RemoteRepository repository )
        {
            this.repository = repository;
        }

        public String pathOf( org.apache.maven.artifact.Artifact artifact )
        {
            return null;
        }

        public String pathOfRemoteRepositoryMetadata( ArtifactMetadata artifactMetadata )
        {
            return null;
        }

        public String pathOfLocalRepositoryMetadata( ArtifactMetadata metadata, ArtifactRepository repository )
        {
            return null;
        }

        public String getUrl()
        {
            return repository.getUrl();
        }

        public void setUrl( String url )
        {
        }

        public String getBasedir()
        {
            return null;
        }

        public String getProtocol()
        {
            return repository.getProtocol();
        }

        public String getId()
        {
            return repository.getId();
        }

        public void setId( String id )
        {
        }

        public ArtifactRepositoryPolicy getSnapshots()
        {
            return null;
        }

        public void setSnapshotUpdatePolicy( ArtifactRepositoryPolicy policy )
        {
        }

        public ArtifactRepositoryPolicy getReleases()
        {
            return null;
        }

        public void setReleaseUpdatePolicy( ArtifactRepositoryPolicy policy )
        {
        }

        public ArtifactRepositoryLayout getLayout()
        {
            return null;
        }

        public void setLayout( ArtifactRepositoryLayout layout )
        {
        }

        public String getKey()
        {
            return getId();
        }

        public boolean isUniqueVersion()
        {
            return true;
        }

        public boolean isBlacklisted()
        {
            return false;
        }

        public void setBlacklisted( boolean blackListed )
        {
        }

        public org.apache.maven.artifact.Artifact find( org.apache.maven.artifact.Artifact artifact )
        {
            return null;
        }

        public List<String> findVersions( org.apache.maven.artifact.Artifact artifact )
        {
            return Collections.emptyList();
        }

        public boolean isProjectAware()
        {
            return false;
        }

        public void setAuthentication( Authentication authentication )
        {
        }

        public Authentication getAuthentication()
        {
            return null;
        }

        public void setProxy( Proxy proxy )
        {
        }

        public Proxy getProxy()
        {
            return null;
        }

        public List<ArtifactRepository> getMirroredRepositories()
        {
            return Collections.emptyList();
        }

        public void setMirroredRepositories( List<ArtifactRepository> mirroredRepositories )
        {
        }

    }

}
