package org.apache.maven.plugin.assembly.utils;

/*
 * 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 java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.io.Reader;
import java.nio.channels.FileChannel;

import org.apache.maven.plugin.assembly.archive.ArchiveExpansionException;
import org.apache.maven.plugin.assembly.format.AssemblyFormattingException;
import org.codehaus.plexus.archiver.ArchiverException;
import org.codehaus.plexus.archiver.UnArchiver;
import org.codehaus.plexus.archiver.manager.ArchiverManager;
import org.codehaus.plexus.archiver.manager.NoSuchArchiverException;
import org.codehaus.plexus.logging.Logger;
import org.codehaus.plexus.util.IOUtil;

/**
 * @version $Id$
 */
public final class AssemblyFileUtils
{

    public static final String LINE_ENDING_KEEP = "keep";
    public static final String LINE_ENDING_DOS = "dos";
    public static final String LINE_ENDING_WINDOWS = "windows";
    public static final String LINE_ENDING_UNIX = "unix";
    public static final String LINE_ENDING_CRLF = "crlf";
    public static final String LINE_ENDING_LF = "lf";

    private AssemblyFileUtils()
    {
    }
    
    public static String makePathRelativeTo( String path, final File basedir )
    {
        if ( basedir == null )
        {
            return path;
        }

        if ( path == null )
        {
            return null;
        }

        path = path.trim();

        String base = basedir.getAbsolutePath();
        if ( path.startsWith( base ) )
        {
            path = path.substring( base.length() );
            if ( path.length() > 0 )
            {
                if ( path.startsWith( "/" ) || path.startsWith( "\\" ) )
                {
                    path = path.substring( 1 );
                }
            }
            
            if ( path.length() == 0 )
            {
                path = ".";
            }
        }

        if ( !new File( path ).isAbsolute() )
        {
            path = path.replace( '\\', '/' );
        }

        return path;
    }

    public static void verifyTempDirectoryAvailability( final File tempDir, final Logger logger )
    {
        if (!tempDir.exists())
        {
            tempDir.mkdirs();
        }
    }

    /**
     * Unpacks the archive file.
     *
     * @param source
     *            File to be unpacked.
     * @param destDir
     *            Location where to put the unpacked files.
     */
    public static void unpack( File source, File destDir, ArchiverManager archiverManager )
        throws ArchiveExpansionException, NoSuchArchiverException
    {
        try
        {
            UnArchiver unArchiver = archiverManager.getUnArchiver( source );

            unArchiver.setSourceFile( source );

            unArchiver.setDestDirectory( destDir );

            unArchiver.extract();
        }
        catch ( ArchiverException e )
        {
            throw new ArchiveExpansionException( "Error unpacking file: " + source + "to: " + destDir, e );
        }
    }

    /**
     * NOTE: It is the responsibility of the caller to close the source Reader instance.
     * The file content is written using platform encoding.
     * @param lineEndings This is the result of the getLineEndingChars(..) method in this utility class; the actual
     *   line-ending characters.
     */
    public static void convertLineEndings( Reader source, File dest, String lineEndings )
        throws IOException
    {
        BufferedWriter out = null;
        BufferedReader bufferedSource = null;
        try
        {
            if ( source instanceof BufferedReader )
            {
                bufferedSource = (BufferedReader) source;
            }
            else
            {
                bufferedSource = new BufferedReader( source );
            }

            out = new BufferedWriter( new FileWriter( dest ) ); // platform encoding

            String line;

            do
            {
                line = bufferedSource.readLine();
                if ( line != null )
                {
                    out.write( line );
                    out.write( lineEndings );
                }
            } while ( line != null );

            out.flush();
        }
        finally
        {
            IOUtil.close( out );
        }
    }

    public static String getLineEndingCharacters( String lineEnding )
        throws AssemblyFormattingException
    {
        String value = lineEnding;
        if ( lineEnding != null )
        {
            if ( LINE_ENDING_KEEP.equals( lineEnding ) )
            {
                value = null;
            }
            else if ( LINE_ENDING_DOS.equals( lineEnding ) || LINE_ENDING_WINDOWS.equals( lineEnding ) || LINE_ENDING_CRLF.equals( lineEnding ) )
            {
                value = "\r\n";
            }
            else if ( LINE_ENDING_UNIX.equals( lineEnding ) || LINE_ENDING_LF.equals( lineEnding ) )
            {
                value = "\n";
            }
            else
            {
                throw new AssemblyFormattingException( "Illegal lineEnding specified: '" + lineEnding + "'" );
            }
        }

        return value;
    }

    public static void copyFile( File src, File dst ) throws IOException
    {
        FileChannel c1 = new RandomAccessFile( src, "r" ).getChannel();
        FileChannel c2 = new RandomAccessFile( dst, "rw" ).getChannel();

        long tCount = 0, size = c1.size();
        while ( ( tCount += c2.transferFrom( c1, 0, size - tCount ) ) < size )
            ;

        c1.close();
        c2.force( true );
        c2.close();
    }

    public static String normalizePath( String path )
    {
        return path.replace( '\\', '/' );
    }

}