package org.eclipse.aether.internal.impl;

/*
 * 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.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

import javax.inject.Named;

import org.eclipse.aether.spi.io.FileProcessor;

A utility class helping with file-based operations.
/**
 * A utility class helping with file-based operations.
 */
@Named
public class DefaultFileProcessor
    implements FileProcessor
{

    
Thread-safe variant of File.mkdirs(). Creates the directory named by the given abstract pathname, including any necessary but nonexistent parent directories. Note that if this operation fails it may have succeeded in creating some of the necessary parent directories. 
Params:
directory – The directory to create, may be null.
Returns:
true if and only if the directory was created, along with all necessary parent directories; false otherwise/**
     * Thread-safe variant of {@link File#mkdirs()}. Creates the directory named by the given abstract pathname,
     * including any necessary but nonexistent parent directories. Note that if this operation fails it may have
     * succeeded in creating some of the necessary parent directories.
     * 
     * @param directory The directory to create, may be {@code null}.
     * @return {@code true} if and only if the directory was created, along with all necessary parent directories;
     *         {@code false} otherwise
     */
    public boolean mkdirs( File directory )
    {
        if ( directory == null )
        {
            return false;
        }

        if ( directory.exists() )
        {
            return false;
        }
        if ( directory.mkdir() )
        {
            return true;
        }

        File canonDir;
        try
        {
            canonDir = directory.getCanonicalFile();
        }
        catch ( IOException e )
        {
            return false;
        }

        File parentDir = canonDir.getParentFile();
        return ( parentDir != null && ( mkdirs( parentDir ) || parentDir.exists() ) && canonDir.mkdir() );
    }

    public void write( File target, String data )
        throws IOException
    {
        mkdirs( target.getAbsoluteFile().getParentFile() );

        OutputStream out = null;
        try
        {
            out = new FileOutputStream( target );

            if ( data != null )
            {
                out.write( data.getBytes( StandardCharsets.UTF_8 ) );
            }

            out.close();
            out = null;
        }
        finally
        {
            try
            {
                if ( out != null )
                {
                    out.close();
                }
            }
            catch ( final IOException e )
            {
                // Suppressed due to an exception already thrown in the try block.
            }
        }
    }

    public void write( File target, InputStream source )
        throws IOException
    {
        mkdirs( target.getAbsoluteFile().getParentFile() );

        OutputStream out = null;
        try
        {
            out = new FileOutputStream( target );

            copy( out, source, null );

            out.close();
            out = null;
        }
        finally
        {
            try
            {
                if ( out != null )
                {
                    out.close();
                }
            }
            catch ( final IOException e )
            {
                // Suppressed due to an exception already thrown in the try block.
            }
        }
    }

    public void copy( File source, File target )
        throws IOException
    {
        copy( source, target, null );
    }

    public long copy( File source, File target, ProgressListener listener )
        throws IOException
    {
        long total = 0L;

        InputStream in = null;
        OutputStream out = null;
        try
        {
            in = new FileInputStream( source );

            mkdirs( target.getAbsoluteFile().getParentFile() );

            out = new FileOutputStream( target );

            total = copy( out, in, listener );

            out.close();
            out = null;

            in.close();
            in = null;
        }
        finally
        {
            try
            {
                if ( out != null )
                {
                    out.close();
                }
            }
            catch ( final IOException e )
            {
                // Suppressed due to an exception already thrown in the try block.
            }
            finally
            {
                try
                {
                    if ( in != null )
                    {
                        in.close();
                    }
                }
                catch ( final IOException e )
                {
                    // Suppressed due to an exception already thrown in the try block.
                }
            }
        }

        return total;
    }

    private long copy( OutputStream os, InputStream is, ProgressListener listener )
        throws IOException
    {
        long total = 0L;

        ByteBuffer buffer = ByteBuffer.allocate( 1024 * 32 );
        byte[] array = buffer.array();

        while ( true )
        {
            int bytes = is.read( array );
            if ( bytes < 0 )
            {
                break;
            }

            os.write( array, 0, bytes );

            total += bytes;

            if ( listener != null && bytes > 0 )
            {
                try
                {
                    buffer.rewind();
                    buffer.limit( bytes );
                    listener.progressed( buffer );
                }
                catch ( Exception e )
                {
                    // too bad
                }
            }
        }

        return total;
    }

    public void move( File source, File target )
        throws IOException
    {
        if ( !source.renameTo( target ) )
        {
            copy( source, target );

            target.setLastModified( source.lastModified() );

            source.delete();
        }
    }

}