/*-
 * Copyright (c) 2014 Red Hat, Inc.
 *
 * Licensed 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.fedoraproject.xmvn.resolver.impl;

import java.nio.file.Path;
import java.nio.file.Paths;

import javax.inject.Named;
import javax.inject.Singleton;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.fedoraproject.xmvn.artifact.Artifact;
import org.fedoraproject.xmvn.metadata.ArtifactMetadata;
import org.fedoraproject.xmvn.resolver.ResolutionRequest;
import org.fedoraproject.xmvn.resolver.ResolutionResult;
import org.fedoraproject.xmvn.resolver.Resolver;
import org.fedoraproject.xmvn.utils.FileUtils;

/**
 * Default implementation of XMvn {@code Resolver} interface.
 * <p>
 * <strong>WARNING</strong>: This class is part of internal implementation of XMvn and it is marked as public only for
 * technical reasons. This class is not part of XMvn API. Client code using XMvn should <strong>not</strong> reference
 * it directly.
 * 
 * @author Mikolaj Izdebski
 */
@Named
@Singleton
public class DefaultResolver
    implements Resolver
{
    private final Logger logger = LoggerFactory.getLogger( DefaultResolver.class );

    private MetadataResolver metadataResolver;

    private static final RpmDb rpmdb = new RpmDb();

    @Override
    public ResolutionResult resolve( ResolutionRequest request )
    {
        // FIXME: bisect is not used
        Artifact artifact = request.getArtifact();
        logger.debug( "Trying to resolve artifact {}", artifact );

        String compatVersion;
        ArtifactMetadata metadata = metadataResolver.resolveArtifactMetadata( artifact );

        if ( metadata == null )
        {
            metadata = metadataResolver.resolveArtifactMetadata( artifact.setVersion( Artifact.DEFAULT_VERSION ) );
            compatVersion = null;
        }
        else
        {
            compatVersion = artifact.getVersion();
        }

        if ( metadata != null )
        {
            // TODO: interpolate paths to expand variables like Java home
            Path artifactPath = Paths.get( metadata.getPath() );
            artifactPath = FileUtils.followSymlink( artifactPath );

            DefaultResolutionResult result = new DefaultResolutionResult( artifactPath );
            result.setNamespace( metadata.getNamespace() );
            result.setCompatVersion( compatVersion );
            if ( request.isProviderNeeded() )
                result.setProvider( rpmdb.lookupPath( artifactPath ) );

            logger.debug( "Artifact {} was resolved to {}", artifact, artifactPath );
            return result;
        }

        logger.debug( "Failed to resolve artifact: {}", artifact );
        return new DefaultResolutionResult();
    }
}

Implement DefaultResolver