* under the License.
 */
package org.apache.maven.project;

import java.util.*;

class Graph {
    private enum DfsState {
        VISITING,
        VISITED
    }

    final Map<String, Vertex> vertices = new LinkedHashMap<>();

    public Vertex getVertex(String id) {
        return vertices.get(id);
    }

    public Collection<Vertex> getVertices() {

                        "Edge between '" + from + "' and '" + to + "' introduces to cycle in the graph", cycle);
            }
        }
    }

    private enum DfsState {
        VISITING,
        VISITED
    }

    private static List<String> visitCycle(
            Map<String, Set<String>> graph,
            Collection<String> children,
            Map<String, DfsState> stateMap,

                                BuilderProblem.Severity.WARNING));
                        return value;
                    }
                })
                .visit(toolchains);
    }

    /**
     * Collects the output of the toolchains builder.
     *
     */
    static class DefaultToolchainsBuilderResult implements ToolchainsBuilderResult {

        InnerInterpolator innerInterpolator = createInterpolator(valueSources, postProcessors, request, problems);

        return new MavenTransformer(innerInterpolator::interpolate).visit(model);
    }

    private InnerInterpolator createInterpolator(
            List<? extends ValueSource> valueSources,
            List<? extends InterpolationPostProcessor> postProcessors,

/**
 * Defines a hierarchical visitor for collecting dependency node trees.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer
public interface NodeVisitor {
    /**
     * Starts the visit to the specified dependency node.
     *
     * @param node the dependency node to visit
     * @return <code>true</code> to visit the specified dependency node's children, <code>false</code> to skip the

        protected void visit(MetadataGraphVertex node) // , String version, String artifactUri )
                {
            ArtifactMetadata md = node.getMd();
            if (visited.contains(node)) {
                return;
            }

            cpc.add(md);
            //
            //            TreeSet<MetadataGraphEdge> deps = new TreeSet<MetadataGraphEdge>(

    /**
     * Traverses this node and potentially its children using the specified visitor.
     *
     * @param visitor the visitor to call back, must not be {@code null}
     * @return {@code true} to visit siblings nodes of this node as well, {@code false} to skip siblings
     */
    boolean accept(@Nonnull NodeVisitor visitor);

    /**
     * Returns a new tree starting at this node, filtering the children.

 * <ul>
 * <li>mixing of '<code>-</code>' (hyphen) and '<code>.</code>' (dot) separators,</li>
 * <li>transition between characters and digits also constitutes a separator:
 *     <code>1.0alpha1 =&gt; [1, [alpha, 1]]</code></li>
 * <li>unlimited number of version components,</li>
 * <li>version components in the text can be digits or strings,</li>
 * <li>strings are checked for well-known qualifiers and the qualifier ordering is used for version ordering.

    @Override
    public boolean accept(NodeVisitor visitor) {
        if (visitor.enter(this)) {
            for (Node child : getChildren()) {
                if (!child.accept(visitor)) {
                    break;
                }
            }
        }
        return visitor.leave(this);
    }

    @Override
    public Node filter(Predicate<Node> filter) {

        assertEquals(p.getRepositories().size(), clone.getRepositories().size());
        // TODO deep compare the lists
        assertEquals(
                p.getPluginRepositories().size(), clone.getPluginRepositories().size());
        // TODO deep compare the lists
    }