/*
 *  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
 *
 *      https://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.apache.tools.ant.types.selectors;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.util.PermissionUtils;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.attribute.PosixFilePermissions;

A selector that selects files based on their POSIX permissions.
Permissions are defined in terms of Files.getPosixFilePermissions, this means the selector will accept any file that exists and has given POSIX permissions.
Since:
Ant 1.10.4/**
 * A selector that selects files based on their POSIX permissions.
 *
 * <p>Permissions are defined in terms of {@link
 * java.nio.file.Files#getPosixFilePermissions}, this means the selector will accept
 * any file that exists and has given POSIX permissions.</p>
 *
 * @since Ant 1.10.4
 */
public class PosixPermissionsSelector implements FileSelector {

    private String permissions;

    private boolean followSymlinks = true;

    
Sets the permissions to look for.
Params:
permissions – the permissions string (rwxrwxrwx or octal)/**
     * Sets the permissions to look for.
     * @param permissions the permissions string (rwxrwxrwx or octal)
     */
    public void setPermissions(String permissions) {
        if (permissions.length() == 3 && permissions.matches("^[0-7]+$")) {
            this.permissions = PosixFilePermissions.toString(
                    PermissionUtils.permissionsFromMode(Integer.parseInt(permissions, 8)));
            return;
        }

        try {
            this.permissions = PosixFilePermissions.toString(PosixFilePermissions.fromString(permissions));
        } catch (IllegalArgumentException ex) {
            throw new BuildException("the permissions attribute " + permissions
                    + " is invalid", ex);
        }
    }

    
Sets the "follow symbolic links" flag.
Params:
followSymlinks – whether or not symbolic links should be followed./**
     * Sets the "follow symbolic links" flag.
     * @param followSymlinks whether or not symbolic links should be followed.
     */
    public void setFollowSymlinks(boolean followSymlinks) {
        this.followSymlinks = followSymlinks;
    }

    @Override
    public boolean isSelected(File basedir, String filename, File file) {
        if (permissions == null) {
            throw new BuildException("the permissions attribute is required");
        }
        try {
            return PosixFilePermissions.toString(followSymlinks
                    ? Files.getPosixFilePermissions(file.toPath())
                    : Files.getPosixFilePermissions(file.toPath(), LinkOption.NOFOLLOW_LINKS))
                    .equals(permissions);
        } catch (IOException e) {
            // => not the expected permissions
        }
        return false;
    }
}