/*
 * Copyright 2007-2010 the original author or authors.
 *
 * 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 net.paoding.rose.load.vfs;

import java.io.IOException;

/**
 * 
 * @author 王志亮 [qieqie.wang@gmail.com]
 *
 */
public class FileNameImpl implements FileName {

    private final FileObject fileObject;

    private final String baseName;

    public FileNameImpl(FileObject fileObject, String baseName) {
        this.fileObject = fileObject;
        this.baseName = baseName;
    }

    @Override
    public String getBaseName() {
        return baseName;
    }

    @Override
    public FileObject getFileObject() {
        return fileObject;
    }

    @Override
    public String getRelativeName(FileName subFileName) throws IOException {
        String basePath = fileObject.getURL().getPath();
        String subPath = subFileName.getFileObject().getURL().getPath();
        if (!subPath.startsWith(basePath)) {
            throw new IllegalArgumentException("basePath='" + basePath + "'; subPath='" + subPath
                    + "'");
        }
        return subPath.substring(basePath.length());
    }
}