/* ==========================================================================
 * Copyright 2008 mkleint
 *
 * 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.codehaus.mojo.nbm;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.logging.Log;
import org.apache.maven.shared.dependency.graph.DependencyNode;
import org.apache.maven.shared.dependency.graph.traversal.DependencyNodeVisitor;
import org.codehaus.mojo.nbm.utils.ExamineManifest;

/**
 * A dependency node visitor that collects visited nodes that are known libraries or are
 * children of known libraries
 * @author milos kleint
 */
public class CollectLibrariesNodeVisitor
    implements DependencyNodeVisitor
{

    /**
     * The collected list of nodes.
     */
    private final List<Artifact> nodes;

    private Map<String, Artifact> artifacts;

    private Map<Artifact, ExamineManifest> examinerCache;

    private List<String> explicitLibs;

    private final Log log;

    private MojoExecutionException throwable;

    private DependencyNode root;

    private Set<String> duplicates;

    private Set<String> conflicts;

    private Set<String> includes;

    private final boolean useOsgiDependencies;

    /**
     * Creates a dependency node visitor that collects visited nodes for further processing.
     * @param explicitLibraries list of explicit libraries
     * @param runtimeArtifacts list of runtime artifacts
     * @param examinerCache cache of netbeans manifest for artifacts
     * @param log mojo logger
     * @param root dependency to start collect with
     * @param useOsgiDependencies whether to allow osgi dependencies or not
     */
    public CollectLibrariesNodeVisitor( List<String> explicitLibraries,
        List<Artifact> runtimeArtifacts, Map<Artifact, ExamineManifest> examinerCache,
        Log log, DependencyNode root, boolean useOsgiDependencies )
    {
        nodes = new ArrayList<Artifact>();
        artifacts = new HashMap<String, Artifact>();
        for ( Artifact a : runtimeArtifacts )
        {
            artifacts.put( a.getDependencyConflictId(), a );
        }
        this.examinerCache = examinerCache;
        this.explicitLibs = explicitLibraries;
        this.log = log;
        this.root = root;
        this.useOsgiDependencies = useOsgiDependencies;
        duplicates = new HashSet<String>();
        conflicts = new HashSet<String>();
        includes = new HashSet<String>();
    }

    /**
     * {@inheritDoc}
     */
    public boolean visit( DependencyNode node )
    {
        if ( throwable != null )
        {
            return false;
        }
        if ( root == node )
        {
            return true;
        }
        try
        {
            Artifact artifact = node.getArtifact();
            if ( !artifacts.containsKey( artifact.getDependencyConflictId() ) )
            {
                //ignore non-runtime stuff..
                return false;
            }
            // somehow the transitive artifacts in the  tree are not always resolved?
            artifact = artifacts.get( artifact.getDependencyConflictId() );

            ExamineManifest depExaminator = examinerCache.get( artifact );
            if ( depExaminator == null )
            {
                depExaminator = new ExamineManifest( log );
                depExaminator.setArtifactFile( artifact.getFile() );
                depExaminator.checkFile();
                examinerCache.put( artifact, depExaminator );
            }
            if ( AbstractNbmMojo.matchesLibrary( artifact, explicitLibs, depExaminator, log, useOsgiDependencies ) )
            {
                if ( depExaminator.isNetBeansModule() )
                {
                    log.warn(
                        "You are using a NetBeans Module as a Library (classpath extension): " + artifact.getId() );
                }

                nodes.add( artifact );
                includes.add( artifact.getDependencyConflictId() );
                // if a library, iterate to it's child nodes.
                return true;
            }
        }
        catch ( MojoExecutionException mojoExecutionException )
        {
            throwable = mojoExecutionException;
        }
        //don't bother iterating to childs if the current node is not a library.
        return false;
    }

    /**
     * {@inheritDoc}
     */
    public boolean endVisit( DependencyNode node )
    {
        if ( throwable != null )
        {
            return false;
        }
        if ( node == root )
        {
            if ( nodes.size() > 0 )
            {
                log.info( "Adding on module's Class-Path:" );
                for ( Artifact inc : nodes )
                {
                    log.info( "    " + inc.getId() );
                }
            }
        }
        return true;
    }

    /**
     * Gets the list of collected dependency nodes.
     * 
     * @return the list of collected dependency nodes
     * @throws MojoExecutionException if a throwable is set
     */
    public List<Artifact> getArtifacts()
        throws MojoExecutionException
    {
        if ( throwable != null )
        {
            throw throwable;
        }
        return nodes;
    }
}