/*
 * 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.codehaus.mojo.archetypeng;

import org.apache.maven.model.Build;
import org.apache.maven.model.Dependency;
import org.apache.maven.model.Model;
import org.apache.maven.model.Parent;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.ReportPlugin;
import org.apache.maven.model.Reporting;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.apache.maven.model.io.xpp3.MavenXpp3Writer;

import org.codehaus.mojo.archetypeng.exception.InvalidPackaging;

import org.codehaus.plexus.logging.AbstractLogEnabled;
import org.codehaus.plexus.util.FileUtils;
import org.codehaus.plexus.util.IOUtil;
import org.codehaus.plexus.util.StringUtils;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;

import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

import org.jdom.JDOMException;

import org.jdom.input.SAXBuilder;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * @plexus.component
 */
public class DefaultPomManager
extends AbstractLogEnabled
implements PomManager
{
    public void addModule ( File pom, String artifactId )
    throws FileNotFoundException,
        IOException,
        XmlPullParserException,
        DocumentException,
        InvalidPackaging
    {
        boolean found = false;

        StringWriter writer = new StringWriter ();
        Reader fileReader = new FileReader ( pom );

        try
        {
            fileReader = new FileReader ( pom );

            SAXReader reader = new SAXReader ();
            Document document = reader.read ( fileReader );
            Element project = document.getRootElement ();

            String packaging = null;
            Element packagingElement = project.element ( "packaging" );
            if ( packagingElement != null )
            {
                packaging = packagingElement.getStringValue ();
            }
            if ( !"pom".equals ( packaging ) )
            {
                throw new InvalidPackaging (
                    "Unable to add module to the current project as it is not of packaging type 'pom'"
                );
            }

            Element modules = project.element ( "modules" );
            if ( modules == null )
            {
                modules = project.addText ( "  " ).addElement ( "modules" );
                modules.setText ( "\n  " );
                project.addText ( "\n" );
            }
            // TODO: change to while loop
            for ( Iterator i = modules.elementIterator ( "module" ); i.hasNext () && !found; )
            {
                Element module = (Element) i.next ();
                if ( module.getText ().equals ( artifactId ) )
                {
                    found = true;
                }
            }
            if ( !found )
            {
                Node lastTextNode = null;
                for ( Iterator i = modules.nodeIterator (); i.hasNext (); )
                {
                    Node node = (Node) i.next ();
                    if ( node.getNodeType () == Node.ELEMENT_NODE )
                    {
                        lastTextNode = null;
                    }
                    else if ( node.getNodeType () == Node.TEXT_NODE )
                    {
                        lastTextNode = node;
                    }
                }

                if ( lastTextNode != null )
                {
                    modules.remove ( lastTextNode );
                }

                modules.addText ( "\n    " );
                modules.addElement ( "module" ).setText ( artifactId );
                modules.addText ( "\n  " );

                XMLWriter xmlWriter = new XMLWriter ( writer );
                xmlWriter.write ( document );

                FileUtils.fileWrite ( pom.getAbsolutePath (), writer.toString () );
            } // end if
        }
        finally
        {
            IOUtil.close ( fileReader );
        }
    }

    public void addParent ( File pom, File parentPom )
    throws FileNotFoundException, IOException, XmlPullParserException
    {
        Model generatedModel = readPom ( pom );

        Model parentModel = readPom ( parentPom );

        Parent parent = new Parent ();
        parent.setGroupId ( parentModel.getGroupId () );
        if ( parent.getGroupId () == null )
        {
            parent.setGroupId ( parentModel.getParent ().getGroupId () );
        }
        parent.setArtifactId ( parentModel.getArtifactId () );
        parent.setVersion ( parentModel.getVersion () );
        if ( parent.getVersion () == null )
        {
            parent.setVersion ( parentModel.getParent ().getVersion () );
        }
        generatedModel.setParent ( parent );

        writePom ( generatedModel, pom );
    }

    public void mergePoms ( File pom, File temporaryPom )
    throws FileNotFoundException, IOException, XmlPullParserException
    {
        Model model = readPom ( pom );
        Model generatedModel = readPom ( temporaryPom );
        mergeDependencies ( model, generatedModel );
        mergeBuildPlugins ( model, generatedModel );
        mergeReportPlugins ( model, generatedModel );

//
//        // Potential merging
//
//        model.getModelEncoding ();
//        model.getModelVersion ();
//
//        model.getGroupId ();
//        model.getArtifactId ();
//        model.getVersion ();
//        model.getParent ();
//
//        model.getId ();
//        model.getName ();
//        model.getInceptionYear ();
//        model.getDescription ();
//        model.getUrl ();
//        model.getLicenses ();
//        model.getProperties ();
//
//        model.getOrganization ();
//        model.getMailingLists ();
//        model.getContributors ();
//        model.getDevelopers ();
//
//        model.getScm ();
//        model.getCiManagement ();
//        model.getDistributionManagement ();
//        model.getIssueManagement ();
//
//        model.getPackaging ();
////        model.getDependencies (); // done
//        model.getDependencyManagement ();
//        model.getPrerequisites ().getMaven ();
//        model.getPrerequisites ().getModelEncoding ();
//
//        model.getProfiles ();
//        model.getModules ();
//        model.getRepositories ();
//        model.getPluginRepositories ();
//
//        model.getBuild ().getDefaultGoal ();
//        model.getBuild ().getFinalName ();
//        model.getBuild ().getModelEncoding ();
//        model.getBuild ().getFilters ();
//        model.getBuild ().getDirectory ();
//        model.getBuild ().getOutputDirectory ();
//        model.getBuild ().getSourceDirectory ();
//        model.getBuild ().getResources ();
//        model.getBuild ().getScriptSourceDirectory ();
//        model.getBuild ().getTestOutputDirectory ();
//        model.getBuild ().getTestResources ();
//        model.getBuild ().getTestSourceDirectory ();
//        model.getBuild ().getPluginManagement ();
//        model.getBuild ().getExtensions ();
////        model.getBuild ().getPluginsAsMap (); // done
//
//        model.getReporting ().getModelEncoding ();
//        model.getReporting ().getOutputDirectory ();
////        model.getReporting ().getReportPluginsAsMap (); // done
//

        writePom ( model, pom );
    }

    public Model readPom ( final File pomFile )
    throws FileNotFoundException, IOException, XmlPullParserException
    { // TODO ensure correct encoding by using default one from method argument !!!

        Model model;
        Reader pomReader = null;
        try
        {
            FileCharsetDetector detector = new FileCharsetDetector ( pomFile );

            String fileEncoding = detector.isFound () ? detector.getCharset () : "UTF-8";

            pomReader = new InputStreamReader ( new FileInputStream ( pomFile ), fileEncoding );

            MavenXpp3Reader reader = new MavenXpp3Reader ();

            model = reader.read ( pomReader );

            if ( StringUtils.isEmpty ( model.getModelEncoding () ) )
            {
                model.setModelEncoding ( fileEncoding );
            }
        }
        finally
        {
            IOUtil.close ( pomReader );
        }
        return model;
    }

    public void writePom ( final Model model, final File pomFile )
    throws IOException
    {
        InputStream inputStream = null;
        Writer outputStreamWriter = null;
//        FileCharsetDetector detector = new FileCharsetDetector ( pomFile );

        String fileEncoding =
            StringUtils.isEmpty ( model.getModelEncoding () ) ? model.getModelEncoding () : "UTF-8";

        try
        {
            inputStream = new FileInputStream ( pomFile );

            SAXBuilder builder = new SAXBuilder ();
            org.jdom.Document doc = builder.build ( inputStream );
            inputStream.close ();
            inputStream = null;

            MavenJDOMWriter writer = new MavenJDOMWriter ();

            outputStreamWriter =
                new OutputStreamWriter ( new FileOutputStream ( pomFile ), fileEncoding );

            org.jdom.output.Format form =
                org.jdom.output.Format.getRawFormat ().setEncoding ( fileEncoding );
            writer.write ( model, doc, outputStreamWriter, form );
            outputStreamWriter.close ();
            outputStreamWriter = null;
        }
        catch ( JDOMException exc )
        {
            throw (IOException) new IOException ( "Cannot parse the POM by JDOM." );
        }
        catch ( FileNotFoundException e )
        {
            getLogger ().debug ( "Creating pom file " + pomFile );

            Writer pomWriter = null;

            try
            {
//                pomWriter = new FileWriter ( pomFile );
                pomWriter =
                    new OutputStreamWriter ( new FileOutputStream ( pomFile ), fileEncoding );

                MavenXpp3Writer writer = new MavenXpp3Writer ();
                writer.write ( pomWriter, model );
            }
            finally
            {
                IOUtil.close ( pomWriter );
            }
        }
        finally
        {
            IOUtil.close ( inputStream );
            IOUtil.close ( outputStreamWriter );
        }
    }

    private Map createDependencyMap ( List dependencies )
    {
        Map dependencyMap = new HashMap ();
        Iterator dependenciesIterator = dependencies.iterator ();
        while ( dependenciesIterator.hasNext () )
        {
            Dependency dependency = (Dependency) dependenciesIterator.next ();

            dependencyMap.put (
                dependency.getGroupId () + ":" + dependency.getArtifactId (),
                dependency
            );
        }

        return dependencyMap;
    }

    private void mergeBuildPlugins ( Model model, Model generatedModel )
    {
        if ( generatedModel.getBuild () != null )
        {
            if ( model.getBuild () == null )
            {
                model.setBuild ( new Build () );
            }

            Map pluginsByIds = model.getBuild ().getPluginsAsMap ();
            Map generatedPluginsByIds = generatedModel.getBuild ().getPluginsAsMap ();

            Iterator generatedPluginsIds = generatedPluginsByIds.keySet ().iterator ();
            while ( generatedPluginsIds.hasNext () )
            {
                String generatedPluginsId = (String) generatedPluginsIds.next ();

                if ( !pluginsByIds.containsKey ( generatedPluginsId ) )
                {
                    model.getBuild ().addPlugin (
                        (Plugin) generatedPluginsByIds.get ( generatedPluginsId )
                    );
                }
                else
                {
                    getLogger ().warn ( "Can not override plugin: " + generatedPluginsId );
                }
            }
        }
    }

    private void mergeDependencies ( Model model, Model generatedModel )
    {
        Map dependenciesByIds = createDependencyMap ( model.getDependencies () );
        Map generatedDependenciesByIds = createDependencyMap ( generatedModel.getDependencies () );

        Iterator generatedDependencyIds = generatedDependenciesByIds.keySet ().iterator ();
        while ( generatedDependencyIds.hasNext () )
        {
            String generatedDependencyId = (String) generatedDependencyIds.next ();

            if ( !dependenciesByIds.containsKey ( generatedDependencyId ) )
            {
                model.addDependency (
                    (Dependency) generatedDependenciesByIds.get ( generatedDependencyId )
                );
            }
            else
            {
                getLogger ().warn ( "Can not override property: " + generatedDependencyId );
            }
        }
    }

    private void mergeReportPlugins ( Model model, Model generatedModel )
    {
        if ( generatedModel.getReporting () != null )
        {
            if ( model.getReporting () == null )
            {
                model.setReporting ( new Reporting () );
            }

            Map reportPluginsByIds = model.getReporting ().getReportPluginsAsMap ();
            Map generatedReportPluginsByIds =
                generatedModel.getReporting ().getReportPluginsAsMap ();

            Iterator generatedReportPluginsIds = generatedReportPluginsByIds.keySet ().iterator ();
            while ( generatedReportPluginsIds.hasNext () )
            {
                String generatedReportPluginsId = (String) generatedReportPluginsIds.next ();

                if ( !reportPluginsByIds.containsKey ( generatedReportPluginsId ) )
                {
                    model.getReporting ().addPlugin (
                        (ReportPlugin) generatedReportPluginsByIds.get ( generatedReportPluginsId )
                    );
                }
                else
                {
                    getLogger ().warn ( "Can not override report: " + generatedReportPluginsId );
                }
            }
        }
    }
}