package org.aroundthecode.pathfinder.crawler;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.maven.repository.internal.MavenRepositorySystemUtils;
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.artifact.DefaultArtifact;
import org.eclipse.aether.collection.CollectRequest;
import org.eclipse.aether.collection.CollectResult;
import org.eclipse.aether.collection.DependencyCollectionException;
import org.eclipse.aether.collection.DependencySelector;
import org.eclipse.aether.connector.basic.BasicRepositoryConnectorFactory;
import org.eclipse.aether.graph.Dependency;
import org.eclipse.aether.graph.DependencyFilter;
import org.eclipse.aether.graph.DependencyNode;
import org.eclipse.aether.graph.DependencyVisitor;
import org.eclipse.aether.impl.DefaultServiceLocator;
import org.eclipse.aether.repository.LocalRepository;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.resolution.DependencyResolutionException;
import org.eclipse.aether.spi.connector.RepositoryConnectorFactory;
import org.eclipse.aether.spi.connector.transport.TransporterFactory;
import org.eclipse.aether.transport.file.FileTransporterFactory;
import org.eclipse.aether.transport.http.HttpTransporterFactory;
import org.eclipse.aether.util.artifact.JavaScopes;
import org.eclipse.aether.util.filter.DependencyFilterUtils;
import org.eclipse.aether.util.graph.selector.AndDependencySelector;
import org.eclipse.aether.util.graph.selector.ExclusionDependencySelector;
import org.eclipse.aether.util.graph.selector.OptionalDependencySelector;
import org.eclipse.aether.util.graph.selector.ScopeDependencySelector;
import org.eclipse.aether.util.graph.visitor.FilteringDependencyVisitor;
import org.eclipse.aether.util.graph.visitor.TreeDependencyVisitor;

public class CrawlerManager {

    LocalRepository localRepo = null;
    RepositorySystem system = null;
    RepositorySystemSession session = null;
    List<RemoteRepository> repositories = new ArrayList<RemoteRepository>();

    public CrawlerManager(String localRepoPath) throws IOException {
        localRepo = new LocalRepository( localRepoPath );
        system = newRepositorySystem();
        session = newSession(system);
        repositories.add((new RemoteRepository.Builder("central", "default", "http://central.maven.org/maven2/")).build());
    }

    private RepositorySystem newRepositorySystem()
    {
        DefaultServiceLocator locator = MavenRepositorySystemUtils.newServiceLocator();
        locator.addService( RepositoryConnectorFactory.class, BasicRepositoryConnectorFactory.class );
        locator.addService( TransporterFactory.class, FileTransporterFactory.class );
        locator.addService( TransporterFactory.class, HttpTransporterFactory.class );
        return locator.getService( RepositorySystem.class );
    }

    private RepositorySystemSession newSession( RepositorySystem system )
    {
        DefaultRepositorySystemSession session = MavenRepositorySystemUtils.newSession();
        session.setLocalRepositoryManager( system.newLocalRepositoryManager( session, localRepo ) );

        DependencySelector depFilter = new AndDependencySelector(
                new ScopeDependencySelector("provided" ),
                new OptionalDependencySelector(),
                new ExclusionDependencySelector()
                );

        session.setDependencySelector(depFilter);
        return session;
    }

    public void getRecursiveDependencies(Artifact artifact) throws DependencyResolutionException, DependencyCollectionException{
        {RepositorySystem system = newRepositorySystem();

        RepositorySystemSession session = newSession(system);

        artifact = new DefaultArtifact("org.aroundthecode.pathfinder:pathfinder-server:0.1.0-SNAPSHOT");

        DependencyFilter classpathFlter = DependencyFilterUtils.classpathFilter(JavaScopes.TEST);

        CollectRequest collectRequest = new CollectRequest();
        collectRequest.setRoot(new Dependency(artifact, JavaScopes.COMPILE));
        collectRequest.setRepositories(repositories);

        //use collectDependencies to collect
        CollectResult collectResult = system.collectDependencies(session, collectRequest);
        DependencyNode node = collectResult.getRoot();
        node.accept(new TreeDependencyVisitor(new FilteringDependencyVisitor(new DependencyVisitor() {
            String indent = "";
            @Override
            public boolean visitEnter(DependencyNode dependencyNode) {
                System.out.println(indent + dependencyNode.getArtifact());
                indent += "    ";
                return true;
            }

            @Override
            public boolean visitLeave(DependencyNode dependencyNode) {
                indent = indent.substring(0, indent.length() - 4);
                return true;
            }
        }, classpathFlter)));
        }
    }


}