/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.tools.ant.taskdefs.cvslib;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.types.FileSet;

/**
 * Change log task.
 * The task will examine the output of cvs log and group related changes together.
 * It produces an XML output representing the list of changes.
 * <PRE>
 * <FONT color=#0000ff>&lt;!-- Root element --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> changelog <FONT color=#ff00ff>(entry</FONT><FONT color=#ff00ff>+</FONT><FONT color=#ff00ff>)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- CVS Entry --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> entry <FONT color=#ff00ff>(date,author,file</FONT><FONT color=#ff00ff>+</FONT><FONT color=#ff00ff>,msg)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- Date of cvs entry --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> date <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- Author of change --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> author <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- List of files affected --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> msg <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- File changed --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> file <FONT color=#ff00ff>(name,revision,prevrevision</FONT><FONT color=#ff00ff>?</FONT><FONT color=#ff00ff>)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- Name of the file --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> name <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- Revision number --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> revision <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * <FONT color=#0000ff>&lt;!-- Previous revision number --&gt;</FONT>
 * <FONT color=#6a5acd>&lt;!ELEMENT</FONT> prevrevision <FONT color=#ff00ff>(#PCDATA)</FONT><FONT color=#6a5acd>&gt;</FONT>
 * </PRE>
 *
 * @author <a href="mailto:jeff.martin@synamic.co.uk">Jeff Martin</a>
 * @author <a href="mailto:peter@apache.org">Peter Donald</a>
 * @version $Revision$ $Date$
 * @ant.task name="changelog"
 */
public class ChangeLogTask
    extends Task
{
    /** User list */
    private File m_usersFile;

    /** User list */
    private Vector m_cvsUsers = new Vector();

    /** Input dir */
    private File m_dir;

    /** Output file */
    private File m_destfile;

    /**
     * The earliest date at which to start processing entrys.
     */
    private Date m_start;

    /**
     * The latest date at which to stop processing entrys.
     */
    private Date m_stop;

    /**
     * Filesets containting list of files against which the cvs log will be
     * performed. If empty then all files will in the working directory will
     * be checked.
     */
    private final Vector m_filesets = new Vector();

    /**
     * Set the base dir for cvs.
     */
    public void setDir( final File dir )
    {
        m_dir = dir;
    }

    /**
     * Set the output file for the log.
     */
    public void setDestfile( final File destfile )
    {
        m_destfile = destfile;
    }

    /**
     * Set a lookup list of user names & addresses
     */
    public void setUsersfile( final File usersFile )
    {
        m_usersFile = usersFile;
    }

    /**
     * Add a user to list changelog knows about.
     *
     * @param user the user
     */
    public void addUser( final CvsUser user )
    {
        m_cvsUsers.addElement( user );
    }

    /**
     * Set the date at which the changelog should start.
     *
     * @param start The date at which the changelog should start.
     */
    public void setStart( final Date start )
    {
        m_start = start;
    }

    /**
     * Set the date at which the changelog should stop.
     *
     * @param stop The date at which the changelog should stop.
     */
    public void setEnd( final Date stop )
    {
        m_stop = stop;
    }

    /**
     * Set the numbers of days worth of log entries to process.
     */
    public void setDaysinpast( final int days )
    {
        final long time = System.currentTimeMillis() - (long)days * 24 * 60 * 60 * 1000;
        setStart( new Date( time ) );
    }

    /**
     * Adds a set of files about which cvs logs will be generated.
     *
     * @param fileSet a set of files about which cvs logs will be generated.
     */
    public void addFileset( final FileSet fileSet )
    {
        m_filesets.addElement( fileSet );
    }

    /**
     * Execute task
     */
    public void execute() throws BuildException
    {
        validate();

        final Properties userList = new Properties();

        loadUserlist( userList );

        for( Enumeration e = m_cvsUsers.elements(); e.hasMoreElements(); )
        {
            final CvsUser user = (CvsUser)e.nextElement();
            user.validate();
            userList.put( user.getUserID(), user.getDisplayname() );
        }

        final Commandline command = new Commandline();
        command.setExecutable( "cvs" );
        command.createArgument().setValue( "log" );

        if( null != m_start )
        {
            final SimpleDateFormat outputDate =
                new SimpleDateFormat( "yyyy-MM-dd" );

            // We want something of the form: -d ">=YYYY-MM-dd"
            final String dateRange = "-d >=" + outputDate.format( m_start );
            command.createArgument().setValue( dateRange );
        }


        // Check if list of files to check has been specified
        if( !m_filesets.isEmpty() )
        {
            final Enumeration e = m_filesets.elements();
            while( e.hasMoreElements() )
            {
                final FileSet fileSet = (FileSet)e.nextElement();
                final DirectoryScanner scanner = fileSet.getDirectoryScanner( project );
                final String[] files = scanner.getIncludedFiles();
                for( int i = 0; i < files.length; i++ )
                {
                    command.createArgument().setValue( files[ i ] );
                }
            }
        }

        final ChangeLogParser parser = new ChangeLogParser( userList );
        final RedirectingStreamHandler handler =
            new RedirectingStreamHandler( parser );

        log( "ChangeLog command: [" + command.toString() + "]", Project.MSG_VERBOSE );

        final Execute exe = new Execute( handler );
        exe.setWorkingDirectory( m_dir );
        exe.setCommandline( command.getCommandline() );
        exe.setAntRun( getProject() );
        try
        {
            final int resultCode = exe.execute();
            if( 0 != resultCode )
            {
                throw new BuildException( "Error running cvs log" );
            }
        }
        catch( final IOException ioe )
        {
            throw new BuildException( ioe.toString() );
        }

        final String errors = handler.getErrors();
        if( null != errors )
        {
            log( errors, Project.MSG_ERR );
        }

        final CVSEntry[] entrySet = parser.getEntrySetAsArray();
        final CVSEntry[] filteredEntrySet = filterEntrySet( entrySet );
        writeChangeLog( filteredEntrySet );
    }

    /**
     * Validate the parameters specified for task.
     *
     * @throws BuildException if fails validation checks
     */
    private void validate()
        throws BuildException
    {
        if( null == m_dir )
        {
            m_dir = getProject().getBaseDir();
        }
        if( null == m_destfile )
        {
            final String message = "Destfile must be set.";
            throw new BuildException( message );
        }
        if( !m_dir.exists() )
        {
            final String message = "Cannot find base dir " + m_dir.getAbsolutePath();
            throw new BuildException( message );
        }
        if( null != m_usersFile && !m_usersFile.exists() )
        {
            final String message = "Cannot find user lookup list " + m_usersFile.getAbsolutePath();
            throw new BuildException( message );
        }
    }

    /**
     * Load the userli4st from the userList file (if specified) and
     * add to list of users.
     *
     * @throws BuildException if file can not be loaded for some reason
     */
    private void loadUserlist( final Properties userList )
        throws BuildException
    {
        if( null != m_usersFile )
        {
            try
            {
                userList.load( new FileInputStream( m_usersFile ) );
            }
            catch( final IOException ioe )
            {
                throw new BuildException( ioe.toString(), ioe );
            }
        }
    }

    /**
     * Filter the specified entrys accoridn to an appropriate
     * rule.
     *
     * @param entrySet the entry set to filter
     * @return the filtered entry set
     */
    private CVSEntry[] filterEntrySet( final CVSEntry[] entrySet )
    {
        final Vector results = new Vector();
        for( int i = 0; i < entrySet.length; i++ )
        {
            final CVSEntry cvsEntry = entrySet[ i ];
            final Date date = cvsEntry.getDate();
            if( null != m_start && m_start.after( date ) )
            {
                //Skip dates that are too early
                continue;
            }
            if( null != m_stop && m_stop.before( date ) )
            {
                //Skip dates that are too late
                continue;
            }
            results.addElement( cvsEntry );
        }

        final CVSEntry[] resultArray = new CVSEntry[ results.size() ];
        results.copyInto( resultArray );
        return resultArray;
    }

    /**
     * Print changelog to file specified in task.
     *
     * @throws BuildException if theres an error writing changelog
     */
    private void writeChangeLog( final CVSEntry[] entrySet )
        throws BuildException
    {
        FileOutputStream output = null;
        try
        {
            output = new FileOutputStream( m_destfile );
            final PrintWriter writer =
                new PrintWriter( new OutputStreamWriter( output, "UTF-8" ) );

            final ChangeLogWriter serializer = new ChangeLogWriter();
            serializer.printChangeLog( writer, entrySet );
        }
        catch( final UnsupportedEncodingException uee )
        {
            getProject().log( uee.toString(), Project.MSG_ERR );
        }
        catch( final IOException ioe )
        {
            throw new BuildException( ioe.toString(), ioe );
        }
        finally
        {
            if( null != output )
            {
                try
                {
                    output.close();
                }
                catch( final IOException ioe )
                {
                }
            }
        }
    }
}
