/*

 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.nio.fs;

import java.nio.file.Path;

import java.nio.file.LinkOption;

import java.nio.file.attribute.BasicFileAttributes;

import java.nio.file.spi.FileSystemProvider;

import java.io.IOException;

import java.util.Map;

/**

 * Base implementation class of FileSystemProvider

 */

public abstract class AbstractFileSystemProvider extends FileSystemProvider {

    protected AbstractFileSystemProvider() { }

    /**

     * Splits the given attribute name into the name of an attribute view and

     * the attribute. If the attribute view is not identified then it assumed

     * to be "basic".

     */

    private static String[] split(String attribute) {

        String[] s = new String[2];

        int pos = attribute.indexOf(':');

        if (pos == -1) {

            s[0] = "basic";

            s[1] = attribute;

        } else {

            s[0] = attribute.substring(0, pos++);

            s[1] = (pos == attribute.length()) ? "" : attribute.substring(pos);

        }

        return s;

    }

    /**

     * Gets a DynamicFileAttributeView by name. Returns {@code null} if the

     * view is not available.

     */

    abstract DynamicFileAttributeView getFileAttributeView(Path file,

                                                           String name,

                                                           LinkOption... options);

    @Override

    public final void setAttribute(Path file,

                                   String attribute,

                                   Object value,

                                   LinkOption... options)

        throws IOException

    {

        String[] s = split(attribute);

        if (s[0].length() == 0)

            throw new IllegalArgumentException(attribute);

        DynamicFileAttributeView view = getFileAttributeView(file, s[0], options);

        if (view == null)

            throw new UnsupportedOperationException("View '" + s[0] + "' not available");

        view.setAttribute(s[1], value);

    }

    @Override

    public final Map<String,Object> readAttributes(Path file, String attributes, LinkOption... options)

        throws IOException

    {

        String[] s = split(attributes);

        if (s[0].length() == 0)

            throw new IllegalArgumentException(attributes);

        DynamicFileAttributeView view = getFileAttributeView(file, s[0], options);

        if (view == null)

            throw new UnsupportedOperationException("View '" + s[0] + "' not available");

        return view.readAttributes(s[1].split(","));

    }

    /**

     * Deletes a file. The {@code failIfNotExists} parameters determines if an

     * {@code IOException} is thrown when the file does not exist.

     */

    abstract boolean implDelete(Path file, boolean failIfNotExists) throws IOException;

    @Override

    public final void delete(Path file) throws IOException {

        implDelete(file, true);

    }

    @Override

    public final boolean deleteIfExists(Path file) throws IOException {

        return implDelete(file, false);

    }

    /**

     * Tests whether a file is a directory.

     *

     * @return  {@code true} if the file is a directory; {@code false} if

     *          the file does not exist, is not a directory, or it cannot

     *          be determined if the file is a directory or not.

     */

    public boolean isDirectory(Path file) {

        try {

            return readAttributes(file, BasicFileAttributes.class).isDirectory();

        } catch (IOException ioe) {

            return false;

        }

    }

    /**

     * Tests whether a file is a regular file with opaque content.

     *

     * @return  {@code true} if the file is a regular file; {@code false} if

     *          the file does not exist, is not a regular file, or it

     *          cannot be determined if the file is a regular file or not.

     */

    public boolean isRegularFile(Path file) {

        try {

            return readAttributes(file, BasicFileAttributes.class).isRegularFile();

        } catch (IOException ioe) {

            return false;

        }

    }

    /**

     * Checks the existence of a file.

     *

     * @return  {@code true} if the file exists; {@code false} if the file does

     *          not exist or its existence cannot be determined.

     */

    public boolean exists(Path file) {

        try {

            checkAccess(file);

            return true;

        } catch (IOException ioe) {

            return false;

        }

    }

}