/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.apache.myfaces.buildtools.maven2.plugin.builder.unpack;

import java.io.File;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.repository.ArtifactRepositoryFactory;
import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
import org.apache.maven.artifact.resolver.ArtifactResolutionException;
import org.apache.maven.artifact.versioning.InvalidVersionSpecificationException;
import org.apache.maven.artifact.versioning.VersionRange;
import org.apache.maven.model.Dependency;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.dependency.utils.DependencyUtil;
import org.apache.maven.plugin.dependency.utils.filters.ArtifactItemFilter;
import org.apache.maven.project.MavenProject;
import org.apache.maven.shared.artifact.filter.collection.ArtifactFilterException;
import org.codehaus.plexus.util.StringUtils;

/**
 * Abstract Parent class used by mojos that get Artifact information from the plugin configuration as an ArrayList of
 * ArtifactItems
 * 
 * @see ArtifactItem
 * @author <a href="mailto:brianf@apache.org">Brian Fox</a>
 * @version $Id$
 */
public abstract class AbstractFromConfigurationMojo
    extends AbstractDependencyMojo
{
    /**
     * Skip the execution
     * 
     * @optional
     * @since 2.2
     * @parameter expression="${mdep.skip}" default-value="false"
     */
    private boolean skip;

    /**
     * Default location used for mojo unless overridden in ArtifactItem
     * 
     * @parameter expression="${outputDirectory}" default-value="${project.build.directory}/dependency"
     * @optional
     * @since 1.0
     */
    private File outputDirectory;

    /**
     * Overwrite release artifacts
     * 
     * @optional
     * @since 1.0
     * @parameter expression="${mdep.overWriteReleases}" default-value="false"
     */
    private boolean overWriteReleases;

    /**
     * Overwrite snapshot artifacts
     * 
     * @optional
     * @since 1.0
     * @parameter expression="${mdep.overWriteSnapshots}" default-value="false"
     */
    private boolean overWriteSnapshots;

    /**
     * Overwrite if newer
     * 
     * @optional
     * @since 2.0
     * @parameter expression="${mdep.overIfNewer}" default-value="true"
     */
    private boolean overWriteIfNewer;

    /**
     * To search for artifacts within the reactor and ensure consistent behaviour between Maven 2 and Maven 3.
     *
     * @parameter expression="${reactorProjects}"
     * @required
     * @readonly
     */
    protected List<MavenProject> reactorProjects;

    /**
     * Collection of ArtifactItems to work on. (ArtifactItem contains groupId, artifactId, version, type, classifier,
     * location, destFileName, markerFile and overwrite.) See <a href="./usage.html">Usage</a> for details.
     * 
     * @parameter
     * @required
     * @since 1.0
     */
    private List<ArtifactItem> artifactItems;

    /**
     * To look up ArtifactRepository implementation
     * 
     * @component
     * @readonly
     */
    private ArtifactRepositoryFactory artifactRepositoryManager;

    /**
     * Path to override default local repository during plugin's execution. To remove all downloaded artifacts as part
     * of the build, set this value to a location under your project's target directory
     * 
     * @parameter
     * @since 2.2
     */
    private File localRepositoryDirectory;

    /**
     * To host and cache localRepositoryDirectory
     */
    private ArtifactRepository overrideLocalRepository;

    abstract ArtifactItemFilter getMarkedArtifactFilter( ArtifactItem item );

    /**
     * Preprocesses the list of ArtifactItems. This method defaults the outputDirectory if not set and creates the
     * output Directory if it doesn't exist.
     * 
     * @param removeVersion remove the version from the filename.
     * @return An ArrayList of preprocessed ArtifactItems
     * @throws MojoExecutionException with a message if an error occurs.
     * @see ArtifactItem
     */
    protected List<ArtifactItem> getProcessedArtifactItems( boolean removeVersion )
        throws MojoExecutionException
    {
        if ( artifactItems == null || artifactItems.size() < 1 )
        {
            throw new MojoExecutionException( "There are no artifactItems configured." );
        }

        for ( ArtifactItem artifactItem : artifactItems )
        {
            this.getLog().info( "Configured Artifact: " + artifactItem.toString() );

            if ( artifactItem.getOutputDirectory() == null )
            {
                artifactItem.setOutputDirectory( this.outputDirectory );
            }
            artifactItem.getOutputDirectory().mkdirs();

            // make sure we have a version.
            if ( StringUtils.isEmpty( artifactItem.getVersion() ) )
            {
                fillMissingArtifactVersion( artifactItem );
            }

            artifactItem.setArtifact( this.getArtifact( artifactItem ) );

            if ( StringUtils.isEmpty( artifactItem.getDestFileName() ) )
            {
                artifactItem.setDestFileName( DependencyUtil.getFormattedFileName( artifactItem.getArtifact(),
                                                                                   removeVersion ) );
            }

            try
            {
                artifactItem.setNeedsProcessing( checkIfProcessingNeeded( artifactItem ) );
            }
            catch ( ArtifactFilterException e )
            {
                throw new MojoExecutionException( e.getMessage(), e );
            }
        }
        return artifactItems;
    }

    private boolean checkIfProcessingNeeded( ArtifactItem item )
        throws MojoExecutionException, ArtifactFilterException
    {
        boolean result = false;
        if ( StringUtils.equalsIgnoreCase( item.getOverWrite(), "true" ) )
        {
            result = true;
        }
        else
        {
            ArtifactItemFilter filter = getMarkedArtifactFilter( item );
            result = filter.isArtifactIncluded( item );
        }
        return result;
    }

    /**
     * Resolves the Artifact from the remote repository if necessary. If no version is specified, it will be retrieved
     * from the dependency list or from the DependencyManagement section of the pom.
     * 
     * @param artifactItem containing information about artifact from plugin configuration.
     * @return Artifact object representing the specified file.
     * @throws MojoExecutionException with a message if the version can't be found in DependencyManagement.
     */
    protected Artifact getArtifact( ArtifactItem artifactItem )
        throws MojoExecutionException
    {
        Artifact artifact;

        // Map managedVersions = createManagedVersionMap( factory,
        // project.getId(), project.getDependencyManagement() );
        VersionRange vr;
        try
        {
            vr = VersionRange.createFromVersionSpec( artifactItem.getVersion() );
        }
        catch ( InvalidVersionSpecificationException e1 )
        {
            // TODO Auto-generated catch block
            e1.printStackTrace();
            vr = VersionRange.createFromVersion( artifactItem.getVersion() );
        }

        if ( StringUtils.isEmpty( artifactItem.getClassifier() ) )
        {
            artifact =
                factory.createDependencyArtifact( artifactItem.getGroupId(), artifactItem.getArtifactId(), vr,
                                                  artifactItem.getType(), null, Artifact.SCOPE_COMPILE );
        }
        else
        {
            artifact =
                factory.createDependencyArtifact( artifactItem.getGroupId(), artifactItem.getArtifactId(), vr,
                                                  artifactItem.getType(), artifactItem.getClassifier(),
                                                  Artifact.SCOPE_COMPILE );
        }

        // Maven 3 will search the reactor for the artifact but Maven 2 does not
        // to keep consistent behaviour, we search the reactor ourselves.
        Artifact result = getArtifactFomReactor( artifact );
        if ( result != null )
        {
            return result;
        }
        try
        {
            // mdep-50 - rolledback for now because it's breaking some functionality.
            /*
             * List listeners = new ArrayList(); Set theSet = new HashSet(); theSet.add( artifact );
             * ArtifactResolutionResult artifactResolutionResult = artifactCollector.collect( theSet, project
             * .getArtifact(), managedVersions, this.local, project.getRemoteArtifactRepositories(),
             * artifactMetadataSource, null, listeners ); Iterator iter =
             * artifactResolutionResult.getArtifactResolutionNodes().iterator(); while ( iter.hasNext() ) {
             * ResolutionNode node = (ResolutionNode) iter.next(); artifact = node.getArtifact(); }
             */

            resolver.resolve( artifact, remoteRepos, getLocal() );
        }
        catch ( ArtifactResolutionException e )
        {
            throw new MojoExecutionException( "Unable to resolve artifact.", e );
        }
        catch ( ArtifactNotFoundException e )
        {
            throw new MojoExecutionException( "Unable to find artifact.", e );
        }

        return artifact;
    }

    /**
     * Checks to see if the specified artifact is available from the reactor.
     * @param artifact The artifact we are looking for.
     * @return The resolved artifact that is the same as the one we were looking for or <code>null</code> if one could
     * not be found.
     */
    private Artifact getArtifactFomReactor( Artifact artifact )
    {
        // check project dependencies first off
        for ( Artifact a : (Set<Artifact>) project.getArtifacts() )
        {
            if ( equals( artifact, a ) && hasFile( a ) )
            {
                return a;
            }
        }
        // check reactor projects
        for ( MavenProject p : reactorProjects == null ? Collections.<MavenProject>emptyList() : reactorProjects )
        {
            // check the main artifact
            if ( equals( artifact, p.getArtifact() ) && hasFile( p.getArtifact() ) )
            {
                return p.getArtifact();
            }
            // check any side artifacts
            for ( Artifact a : (List<Artifact>) p.getAttachedArtifacts() )
            {
                if ( equals( artifact, a ) && hasFile( a ) )
                {
                    return a;
                }
            }
        }
        // not available
        return null;
    }

    /**
     * Returns <code>true</code> if the artifact has a file.
     * @param artifact the artifact (may be null)
     * @return <code>true</code> if and only if the artifact is non-null and has a file.
     */
    private static boolean hasFile( Artifact artifact )
    {
        return artifact != null && artifact.getFile() != null && artifact.getFile().isFile();
    }

    /**
     * Null-safe compare of two artifacts based on groupId, artifactId, version, type and classifier.
     * @param a the first artifact.
     * @param b the second artifact.
     * @return <code>true</code> if and only if the two artifacts have the same groupId, artifactId, version,
     * type and classifier.
     */
    private static boolean equals( Artifact a, Artifact b )
    {
        return a == b
            || !( a == null || b == null )
            && StringUtils.equals( a.getGroupId(), b.getGroupId() )
            && StringUtils.equals( a.getArtifactId(), b.getArtifactId() )
            && StringUtils.equals( a.getVersion(), b.getVersion() )
            && StringUtils.equals( a.getType(), b.getType() )
            && StringUtils.equals( a.getClassifier(), b.getClassifier() );
    }

    /**
     * Tries to find missing version from dependency list and dependency management. If found, the artifact is updated
     * with the correct version. It will first look for an exact match on artifactId/groupId/classifier/type and if it
     * doesn't find a match, it will try again looking for artifactId and groupId only.
     * 
     * @param artifact representing configured file.
     * @throws MojoExecutionException
     */
    private void fillMissingArtifactVersion( ArtifactItem artifact )
        throws MojoExecutionException
    {
        List<Dependency> deps = project.getDependencies();
        List<Dependency> depMngt = project.getDependencyManagement() == null
            ? Collections.<Dependency>emptyList()
            : project.getDependencyManagement().getDependencies();

        if ( !findDependencyVersion( artifact, deps, false )
            && ( project.getDependencyManagement() == null || !findDependencyVersion( artifact, depMngt, false ) )
            && !findDependencyVersion( artifact, deps, true )
            && ( project.getDependencyManagement() == null || !findDependencyVersion( artifact, depMngt, true ) ) )
        {
            throw new MojoExecutionException( "Unable to find artifact version of " + artifact.getGroupId() + ":"
                + artifact.getArtifactId() + " in either dependency list or in project's dependency management." );
        }
    }

    /**
     * Tries to find missing version from a list of dependencies. If found, the artifact is updated with the correct
     * version.
     * 
     * @param artifact representing configured file.
     * @param dependencies list of dependencies to search.
     * @param looseMatch only look at artifactId and groupId
     * @return the found dependency
     */
    private boolean findDependencyVersion( ArtifactItem artifact, List<Dependency> dependencies, boolean looseMatch )
    {
        for ( Dependency dependency : dependencies )
        {
            if ( StringUtils.equals( dependency.getArtifactId(), artifact.getArtifactId() )
                && StringUtils.equals( dependency.getGroupId(), artifact.getGroupId() )
                && ( looseMatch || StringUtils.equals( dependency.getClassifier(), artifact.getClassifier() ) )
                && ( looseMatch || StringUtils.equals( dependency.getType(), artifact.getType() ) ) )
            {
                artifact.setVersion( dependency.getVersion() );

                return true;
            }
        }

        return false;
    }

    /*
     * private Map createManagedVersionMap( ArtifactFactory artifactFactory, String projectId, DependencyManagement
     * dependencyManagement ) throws MojoExecutionException { Map map; if ( dependencyManagement != null &&
     * dependencyManagement.getDependencies() != null ) { map = new HashMap(); for ( Iterator i =
     * dependencyManagement.getDependencies().iterator(); i.hasNext(); ) { Dependency d = (Dependency) i.next(); try {
     * VersionRange versionRange = VersionRange.createFromVersionSpec( d.getVersion() ); Artifact artifact =
     * artifactFactory.createDependencyArtifact( d.getGroupId(), d.getArtifactId(), versionRange, d.getType(), d
     * .getClassifier(), d.getScope(), d .isOptional() ); map.put( d.getManagementKey(), artifact ); } catch (
     * InvalidVersionSpecificationException e ) { throw new MojoExecutionException( "Unable to parse version", e ); } }
     * } else { map = Collections.EMPTY_MAP; } return map; }
     */

    /**
     * Override the base to
     * 
     * @return Returns the local.
     */
    protected ArtifactRepository getLocal()
    {
        if ( this.overrideLocalRepository != null )
        {
            return this.overrideLocalRepository;
        }

        ArtifactRepository local = super.getLocal();

        if ( this.localRepositoryDirectory != null )
        {
            // create a new local repo using existing layout, snapshots, and releases policy
            String url = "file://" + this.localRepositoryDirectory.getAbsolutePath();
            this.overrideLocalRepository =
                artifactRepositoryManager.createArtifactRepository( local.getId(), url, local.getLayout(),
                                                                    local.getSnapshots(), local.getReleases() );

            this.getLog().debug( "Execution local repository is at: " + this.overrideLocalRepository.getBasedir() );
        }
        else
        {
            this.overrideLocalRepository = local;
        }

        return this.overrideLocalRepository;
    }

    /**
     * @return Returns the artifactItems.
     */
    public List<ArtifactItem> getArtifactItems()
    {
        return this.artifactItems;
    }

    /**
     * @param theArtifactItems The artifactItems to set.
     */
    public void setArtifactItems( List<ArtifactItem> theArtifactItems )
    {
        this.artifactItems = theArtifactItems;
    }

    /**
     * @return Returns the outputDirectory.
     */
    public File getOutputDirectory()
    {
        return this.outputDirectory;
    }

    /**
     * @param theOutputDirectory The outputDirectory to set.
     */
    public void setOutputDirectory( File theOutputDirectory )
    {
        this.outputDirectory = theOutputDirectory;
    }

    /**
     * @return Returns the overWriteIfNewer.
     */
    public boolean isOverWriteIfNewer()
    {
        return this.overWriteIfNewer;
    }

    /**
     * @param theOverWriteIfNewer The overWriteIfNewer to set.
     */
    public void setOverWriteIfNewer( boolean theOverWriteIfNewer )
    {
        this.overWriteIfNewer = theOverWriteIfNewer;
    }

    /**
     * @return Returns the overWriteReleases.
     */
    public boolean isOverWriteReleases()
    {
        return this.overWriteReleases;
    }

    /**
     * @param theOverWriteReleases The overWriteReleases to set.
     */
    public void setOverWriteReleases( boolean theOverWriteReleases )
    {
        this.overWriteReleases = theOverWriteReleases;
    }

    /**
     * @return Returns the overWriteSnapshots.
     */
    public boolean isOverWriteSnapshots()
    {
        return this.overWriteSnapshots;
    }

    /**
     * @param theOverWriteSnapshots The overWriteSnapshots to set.
     */
    public void setOverWriteSnapshots( boolean theOverWriteSnapshots )
    {
        this.overWriteSnapshots = theOverWriteSnapshots;
    }

    public void setLocalRepositoryDirectory( File localRepositoryDirectory )
    {
        this.localRepositoryDirectory = localRepositoryDirectory;
    }

    public boolean isSkip()
    {
        return skip;
    }

    public void setSkip( boolean skip )
    {
        this.skip = skip;
    }
}