Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.rolling.helper;

import java.io.File;
import java.io.FilenameFilter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class FileFilterUtil {

    public static void sortFileArrayByName(File[] fileArray) {
        Arrays.sort(fileArray, new Comparator<File>() {
            public int compare(File o1, File o2) {
                String o1Name = o1.getName();
                String o2Name = o2.getName();
                return (o1Name.compareTo(o2Name));
            }
        });
    }

    public static void reverseSortFileArrayByName(File[] fileArray) {
        Arrays.sort(fileArray, new Comparator<File>() {
            public int compare(File o1, File o2) {
                String o1Name = o1.getName();
                String o2Name = o2.getName();
                return (o2Name.compareTo(o1Name));
            }
        });
    }

    public static String afterLastSlash(String sregex) {
        int i = sregex.lastIndexOf('/');
        if (i == -1) {
            return sregex;
        } else {
            return sregex.substring(i + 1);
        }
    }

    static public boolean isEmptyDirectory(File dir) {
        if (!dir.isDirectory()) {
            throw new IllegalArgumentException("[" + dir + "] must be a directory");
        }
        String[] filesInDir = dir.list();
        if (filesInDir == null || filesInDir.length == 0) {
            return true;
        } else {
            return false;
        }
    }

    
Return the set of files matching the stemRegex as found in 'directory'. A
stemRegex does not contain any slash characters or any folder separators.
Params:
file – 
stemRegex – 
Returns:
/**
     * Return the set of files matching the stemRegex as found in 'directory'. A
     * stemRegex does not contain any slash characters or any folder separators.
     * 
     * @param file
     * @param stemRegex
     * @return

     */
    public static File[] filesInFolderMatchingStemRegex(File file, final String stemRegex) {

        if (file == null) {
            return new File[0];
        }
        if (!file.exists() || !file.isDirectory()) {
            return new File[0];
        }
        return file.listFiles(new FilenameFilter() {
            public boolean accept(File dir, String name) {
                return name.matches(stemRegex);
            }
        });
    }

    static public int findHighestCounter(File[] matchingFileArray, final String stemRegex) {
        int max = Integer.MIN_VALUE;
        for (File aFile : matchingFileArray) {
            int aCounter = FileFilterUtil.extractCounter(aFile, stemRegex);
            if (max < aCounter)
                max = aCounter;
        }
        return max;
    }

    static public int extractCounter(File file, final String stemRegex) {
        Pattern p = Pattern.compile(stemRegex);
        String lastFileName = file.getName();

        Matcher m = p.matcher(lastFileName);
        if (!m.matches()) {
            throw new IllegalStateException("The regex [" + stemRegex + "] should match [" + lastFileName + "]");
        }
        String counterAsStr = m.group(1);
        return new Integer(counterAsStr).intValue();
    }

    public static String slashify(String in) {
        return in.replace('\\', '/');
    }

    public static void removeEmptyParentDirectories(File file, int recursivityCount) {
        // we should never go more than 3 levels higher
        if (recursivityCount >= 3) {
            return;
        }
        File parent = file.getParentFile();
        if (parent.isDirectory() && FileFilterUtil.isEmptyDirectory(parent)) {
            parent.delete();
            removeEmptyParentDirectories(parent, recursivityCount + 1);
        }
    }
}