package org.apache.maven.plugin.changelog;

/*
 * 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.
 */

import org.apache.maven.doxia.sink.Sink;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.scm.ChangeFile;
import org.apache.maven.scm.ChangeSet;
import org.apache.maven.scm.command.changelog.ChangeLogSet;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.ResourceBundle;

/**
 * Generate a file activity report.
 *
 * @version $Id$
 */
@Mojo(name = "file-activity")
public class FileActivityReport
    extends ChangeLogReport
{
    /**
     * {@inheritDoc}
     */
    public String getDescription( Locale locale )
    {
        return getBundle( locale ).getString( "report.file-activity.description" );
    }

    /**
     * {@inheritDoc}
     */
    public String getName( Locale locale )
    {
        return getBundle( locale ).getString( "report.file-activity.name" );
    }

    /**
     * {@inheritDoc}
     */
    public String getOutputName()
    {
        return "file-activity";
    }

    /**
     * {@inheritDoc}
     */
    protected void doGenerateEmptyReport( ResourceBundle bundle, Sink sink )
    {
        sink.head();
        sink.title();
        sink.text( bundle.getString( "report.file-activity.header" ) );
        sink.title_();
        sink.head_();

        sink.body();
        sink.section1();

        sink.sectionTitle1();
        sink.text( bundle.getString( "report.file-activity.mainTitle" ) );
        sink.sectionTitle1_();

        sink.paragraph();
        sink.text( "No sources found to create a report." );
        sink.paragraph_();

        sink.section1_();

        sink.body_();
        sink.flush();
        sink.close();
    }

    /**
     * {@inheritDoc}
     */
    protected void doGenerateReport( List<ChangeLogSet> changeLogSets, ResourceBundle bundle, Sink sink )
    {
        sink.head();
        sink.title();
        sink.text( bundle.getString( "report.file-activity.header" ) );
        sink.title_();
        sink.head_();

        sink.body();
        sink.section1();
        sink.sectionTitle1();
        sink.text( bundle.getString( "report.file-activity.mainTitle" ) );
        sink.sectionTitle1_();

        for ( ChangeLogSet set : changeLogSets )
        {
            doChangedSets( set, bundle, sink );
        }

        sink.section1_();
        sink.body_();

        sink.flush();
        sink.close();
    }

    /**
     * generates a section of the report referring to a changeset
     *
     * @param set    the current ChangeSet to generate this section of the report
     * @param bundle the resource bundle to retrieve report phrases from
     * @param sink   the report formatting tool
     */
    private void doChangedSets( ChangeLogSet set, ResourceBundle bundle, Sink sink )
    {
        sink.section2();

        doChangeSetTitle( set, bundle, sink );

        doSummary( set, bundle, sink );

        sink.table();

        sink.tableRow();
        sink.tableHeaderCell();
        sink.text( bundle.getString( "report.file-activity.filename" ) );
        sink.tableHeaderCell_();
        sink.tableHeaderCell();
        sink.text( bundle.getString( "report.file-activity.timesChanged" ) );
        sink.tableHeaderCell_();
        sink.tableRow_();

        doRows( set, sink );

        sink.table_();

        sink.section2_();
    }

    /**
     * generates the row details for the file activity report
     *
     * @param set  the changelog set to generate a report with
     * @param sink the report formatting tool
     */
    private void doRows( ChangeLogSet set, Sink sink )
    {
        List<List<ChangeFile>> list = getOrderedFileList( set.getChangeSets() );

        initReportUrls();

        for ( List<ChangeFile> revision : list )
        {
            ChangeFile file = revision.get( 0 );

            sink.tableRow();
            sink.tableCell();

            try
            {
                generateLinks( getConnection(), file.getName(), sink );
            }
            catch ( Exception e )
            {
                if ( getLog().isDebugEnabled() )
                {
                    getLog().error( e.getMessage(), e );
                }
                else
                {
                    getLog().error( e.getMessage() );
                }

                sink.text( file.getName() );
            }
            sink.tableCell_();

            sink.tableCell();
            sink.text( "" + revision.size() );

            sink.tableCell_();
            sink.tableRow_();
        }
    }

    /**
     * reads the change log entries and generates a list of files changed order by the number of times edited. This
     * used the FileActivityComparator Object to sort the list
     *
     * @param entries the changelog entries to generate the report
     * @return list of changed files within the SCM with the number of times changed in descending order
     */
    private List<List<ChangeFile>> getOrderedFileList( Collection<ChangeSet> entries )
    {
        List<List<ChangeFile>> list = new LinkedList<List<ChangeFile>>();

        Map<String, List<ChangeFile>> map = new HashMap<String, List<ChangeFile>>();

        for ( ChangeSet entry : entries )
        {
            for ( ChangeFile file : entry.getFiles() )
            {
                List<ChangeFile> revisions = map.get( file.getName() );

                if ( revisions == null )
                {
                    revisions = new LinkedList<ChangeFile>();
                    map.put( file.getName(), revisions );
                }

                revisions.add( file );
            }
        }

        list.addAll( map.values() );

        Collections.sort( list, new FileActivityComparator() );

        return list;
    }
}