Cartographer quickstart attempt

Test.java

package org.commonjava.maven.plugins.betterdep.impl;

import org.commonjava.maven.atlas.graph.RelationshipGraph;
import org.commonjava.maven.atlas.graph.ViewParams;
import org.commonjava.maven.atlas.graph.filter.ProjectRelationshipFilter;
import org.commonjava.maven.atlas.graph.mutate.ManagedDependencyMutator;
import org.commonjava.maven.atlas.graph.spi.neo4j.FileNeo4jConnectionFactory;
import org.commonjava.maven.atlas.ident.ref.ProjectVersionRef;
import org.commonjava.maven.cartographer.Cartographer;
import org.commonjava.maven.cartographer.CartographerBuilder;
import org.commonjava.maven.cartographer.discover.DefaultDiscoveryConfig;
import org.commonjava.maven.cartographer.discover.DiscoveryResult;
import org.commonjava.maven.cartographer.preset.PresetSelector;
import org.commonjava.maven.galley.model.Location;
import org.commonjava.maven.galley.model.SimpleLocation;

import java.io.File;
import java.nio.file.Files;
import java.util.*;

public class Test {
    public static void main(String[] args) throws Exception {

        // just create temp dirs that cartographer seems to need.
        File tempDir = Files.createTempDirectory("test").toFile();
        File tempDirFac = Files.createTempDirectory("test2").toFile();

        // tell cartographer where to look for stuff
        Location loc = new SimpleLocation(MavenLocationExpander.EXPANSION_TARGET);
        List<Location> haha = new LinkedList<Location>();
        haha.add(loc);

        // TODO: need to tell it where to look for artifacts.
        // TODO: so what is the simple location thing then?
        MavenLocationExpander mavenLocations = new MavenLocationExpander(haha, null, null);

        // build the cartographer builder
        CartographerBuilder cartoBuilder =
                new CartographerBuilder(tempDir,
                        1,
                        new FileNeo4jConnectionFactory(tempDirFac, true))
                .withLocationExpander(mavenLocations)
                .withSourceManager(mavenLocations)
                .withDefaultTransports();

        // get the carto object
        Cartographer carto = cartoBuilder.build();

        Set<ProjectVersionRef> roots = new HashSet<ProjectVersionRef>();

        // why do we need a preset selector?
        PresetSelector presets = new PresetSelector();
        String preset = "betterdep";

        Map<String, Object> presetParams = new HashMap<String, Object>();

        // ?
        ProjectRelationshipFilter filter = presets.getPresetFilter(preset, "betterdep", presetParams);

        // so here we specify which GAV we want to see.
        ProjectVersionRef projectRef = new ProjectVersionRef("com.google.code.gson", "gson", "2.3.1");
        roots.add(projectRef);

        // ?
        RelationshipGraph graph = carto.getGraphFactory().open(new ViewParams("betterdep", filter, new ManagedDependencyMutator(), roots), true);

        // ?
        DefaultDiscoveryConfig config = new DefaultDiscoveryConfig(MavenLocationExpander.EXPANSION_TARGET);

        // get the result of the relationship?
        DiscoveryResult result = cartoBuilder.getDiscoverer().discoverRelationships(projectRef, graph, config);

        // print out the result
        System.out.println(result);

        // debug line to see if we've reached here.
        System.out.println("Hello world");
    }
}