/*******************************************************************************
 * Copyright (c) 2010-present Sonatype, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Stuart McCulloch (Sonatype, Inc.) - initial API and implementation
 *******************************************************************************/
package org.eclipse.sisu.mojos;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.plugins.annotations.ResolutionScope;
import org.apache.maven.project.MavenProject;
import org.apache.maven.shared.artifact.filter.collection.ArtifactFilterException;
import org.apache.maven.shared.artifact.filter.collection.ArtifactIdFilter;
import org.apache.maven.shared.artifact.filter.collection.ClassifierFilter;
import org.apache.maven.shared.artifact.filter.collection.FilterArtifacts;
import org.apache.maven.shared.artifact.filter.collection.GroupIdFilter;
import org.apache.maven.shared.artifact.filter.collection.ProjectTransitivityFilter;
import org.apache.maven.shared.artifact.filter.collection.ScopeFilter;
import org.apache.maven.shared.artifact.filter.collection.TypeFilter;
import org.codehaus.plexus.util.StringUtils;
import org.eclipse.sisu.space.SisuIndex;
import org.eclipse.sisu.space.URLClassSpace;

/**
 * Generates a qualified class index for the current project and its dependencies.
 */
@Mojo( name = "index", requiresDependencyResolution = ResolutionScope.TEST, threadSafe = true )
public class IndexMojo
    extends AbstractMojo
{
    // ----------------------------------------------------------------------
    // Configurable parameters
    // ----------------------------------------------------------------------

    /**
     * The output directory.
     */
    @Parameter( property = "outputDirectory", defaultValue = "${project.build.outputDirectory}" )
    protected File outputDirectory;

    /**
     * If we should include project dependencies when indexing.
     */
    @Parameter( property = "includeDependencies", defaultValue = "true" )
    protected boolean includeDependencies;

    /**
     * Comma separated list of GroupIds to exclude when indexing.
     */
    @Parameter( property = "excludeGroupIds", defaultValue = "" )
    protected String excludeGroupIds;

    /**
     * Comma separated list of GroupIds to include when indexing.
     */
    @Parameter( property = "includeGroupIds", defaultValue = "" )
    protected String includeGroupIds;

    /**
     * Comma separated list of ArtifactIds to exclude when indexing.
     */
    @Parameter( property = "excludeArtifactIds", defaultValue = "" )
    protected String excludeArtifactIds;

    /**
     * Comma separated list of ArtifactIds to include when indexing.
     */
    @Parameter( property = "includeArtifactIds", defaultValue = "" )
    protected String includeArtifactIds;

    /**
     * Comma Separated list of Classifiers to exclude when indexing.
     */
    @Parameter( property = "excludeClassifiers", defaultValue = "" )
    protected String excludeClassifiers;

    /**
     * Comma Separated list of Classifiers to include when indexing.
     */
    @Parameter( property = "includeClassifiers", defaultValue = "" )
    protected String includeClassifiers;

    /**
     * Comma Separated list of Types to exclude when indexing.
     */
    @Parameter( property = "excludeTypes", defaultValue = "" )
    protected String excludeTypes;

    /**
     * Comma Separated list of Types to include when indexing.
     */
    @Parameter( property = "includeTypes", defaultValue = "" )
    protected String includeTypes;

    /**
     * Scope to exclude. Empty string indicates no scopes (default).
     */
    @Parameter( property = "excludeScope", defaultValue = "" )
    protected String excludeScope;

    /**
     * Scope to include. Empty string indicates all scopes (default).
     */
    @Parameter( property = "includeScope", defaultValue = "" )
    protected String includeScope;

    /**
     * If we should exclude transitive dependencies when indexing.
     */
    @Parameter( property = "excludeTransitive", defaultValue = "false" )
    protected boolean excludeTransitive;

    // ----------------------------------------------------------------------
    // Implementation fields
    // ----------------------------------------------------------------------

    /**
     * The Maven project to index.
     */
    @Parameter( property = "project", required = true, readonly = true )
    private MavenProject project;

    // ----------------------------------------------------------------------
    // Public methods
    // ----------------------------------------------------------------------

    public void setProject( final MavenProject project )
    {
        this.project = project;
    }

    public void setOutputDirectory( final File outputDirectory )
    {
        this.outputDirectory = outputDirectory;
    }

    public void execute()
    {
        synchronized ( project )
        {
            new SisuIndex( outputDirectory )
            {
                @Override
                protected void info( final String message )
                {
                    getLog().info( message );
                }

                @Override
                protected void warn( final String message )
                {
                    getLog().warn( message );
                }
            }.index( new URLClassSpace( getProjectClassLoader(), getIndexPath() ) );
        }
    }

    // ----------------------------------------------------------------------
    // Implementation methods
    // ----------------------------------------------------------------------

    private ClassLoader getProjectClassLoader()
    {
        final List<URL> classPath = new ArrayList<URL>();
        appendToClassPath( classPath, outputDirectory );
        appendToClassPath( classPath, new File( project.getBuild().getOutputDirectory() ) );
        for ( final Object artifact : project.getArtifacts() )
        {
            appendToClassPath( classPath, ( (Artifact) artifact ).getFile() );
        }
        return URLClassLoader.newInstance( classPath.toArray( new URL[classPath.size()] ) );
    }

    private URL[] getIndexPath()
    {
        final List<URL> indexPath = new ArrayList<URL>();
        appendToClassPath( indexPath, outputDirectory );
        if ( includeDependencies )
        {
            final FilterArtifacts filter = new FilterArtifacts();

            filter.addFilter( new ProjectTransitivityFilter( project.getDependencyArtifacts(), excludeTransitive ) );
            filter.addFilter( new ScopeFilter( cleanList( includeScope ), cleanList( excludeScope ) ) );
            filter.addFilter( new TypeFilter( cleanList( includeTypes ), cleanList( excludeTypes ) ) );
            filter.addFilter( new ClassifierFilter( cleanList( includeClassifiers ),
                                                    cleanList( excludeClassifiers ) ) );
            filter.addFilter( new GroupIdFilter( cleanList( includeGroupIds ), cleanList( excludeGroupIds ) ) );
            filter.addFilter( new ArtifactIdFilter( cleanList( includeArtifactIds ),
                                                    cleanList( excludeArtifactIds ) ) );

            try
            {
                for ( final Object artifact : filter.filter( project.getArtifacts() ) )
                {
                    appendToClassPath( indexPath, ( (Artifact) artifact ).getFile() );
                }
            }
            catch ( final ArtifactFilterException e )
            {
                getLog().warn( e.getLocalizedMessage() );
            }
        }
        return indexPath.toArray( new URL[indexPath.size()] );
    }

    private void appendToClassPath( final List<URL> urls, final File file )
    {
        if ( null != file )
        {
            try
            {
                urls.add( file.toURI().toURL() );
            }
            catch ( final MalformedURLException e )
            {
                getLog().warn( e.getLocalizedMessage() );
            }
        }
    }

    private static String cleanList( final String list )
    {
        return StringUtils.isEmpty( list ) ? "" : StringUtils.join( StringUtils.split( list ), "," );
    }
}