/*-
 * Copyright (c) 2014-2019 Red Hat, Inc.
 *
 * Licensed 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.fedoraproject.xmvn.tools.install.impl;

import static java.nio.file.FileVisitResult.CONTINUE;

import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.List;

/**
 * A file visitor which collects basic information about each file it visits.
 * 
 * @author Mikolaj Izdebski
 */
class FileSystemWalker
    implements FileVisitor<Path>
{
    private final Path root;

    private final List<String> lines;

    public FileSystemWalker( Path root, List<String> lines )
    {
        this.root = root;
        this.lines = lines;
    }

    @Override
    public FileVisitResult preVisitDirectory( Path path, BasicFileAttributes attribs )
        throws IOException
    {
        if ( !path.equals( root ) )
            lines.add( "D /" + root.relativize( path ) );

        return CONTINUE;
    }

    @Override
    public FileVisitResult postVisitDirectory( Path path, IOException e )
        throws IOException
    {
        return CONTINUE;
    }

    @Override
    public FileVisitResult visitFile( Path path, BasicFileAttributes attribs )
    {
        if ( attribs.isRegularFile() )
        {
            lines.add( "F /" + root.relativize( path ) );
        }
        else if ( attribs.isSymbolicLink() )
        {
            lines.add( "L /" + root.relativize( path ) );
        }
        else
        {
            lines.add( "? /" + root.relativize( path ) );
        }

        return CONTINUE;
    }

    @Override
    public FileVisitResult visitFileFailed( Path path, IOException e )
        throws IOException
    {
        throw e;
    }
}
