/*
 * Copyright 2002-2015 SCOOP Software GmbH
 *
 * 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.copperengine.core.util;

import java.io.File;
import java.io.FileFilter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.zip.CRC32;

public class FileUtil {

    public static long processChecksum(File directory) {
        return processChecksum(directory, null);
    }

    public static long processChecksum(List<String> directories, String fileSuffix) {
        final CRC32 crc32 = new CRC32();
        for (String dir : directories) {
            processChecksum(new File(dir), crc32, fileSuffix);
        }
        return crc32.getValue();
    }

    public static long processChecksum(File directory, String fileSuffix) {
        final CRC32 crc32 = new CRC32();
        processChecksum(directory, crc32, fileSuffix);
        return crc32.getValue();
    }

    private static void processChecksum(File dir, CRC32 crc32, String fileSuffix) {
        File[] files = dir.listFiles();
        if (files != null) {
            for (File f : files) {
                if (f.isDirectory()) {
                    processChecksum(f, crc32, fileSuffix);
                } else {
                    if (fileSuffix == null || f.getName().endsWith(fileSuffix)) {
                        crc32.update(Long.toString(f.lastModified()).getBytes());
                        crc32.update(f.getAbsolutePath().getBytes());
                    }
                }
            }
        }
    }

    public static File[] findFiles(File rootDir, String fileSuffix) {
        List<File> files = new ArrayList<File>();
        findFiles(rootDir, fileSuffix, files);
        return files.toArray(new File[files.size()]);
    }

    private static void findFiles(final File rootDir, final String fileSuffix, final List<File> files) {
        final File[] result = rootDir.listFiles(new FileFilter() {
            @Override
            public boolean accept(File pathname) {
                return pathname.getName().endsWith(fileSuffix);
            }
        });
        if (result != null) {
            files.addAll(Arrays.asList(result));
        }
        
        final File[] subdirs = rootDir.listFiles(new FileFilter() {
            @Override
            public boolean accept(File pathname) {
                return pathname.isDirectory();
            }
        });
        if (subdirs != null) {
            for (File subdir : subdirs) {
                findFiles(subdir, fileSuffix, files);
            }
        }
    }

    public static boolean deleteDirectory(File path) {
        if (path.exists()) {
            File[] files = path.listFiles();
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    if (files[i].isDirectory()) {
                        deleteDirectory(files[i]);
                    } else {
                        files[i].delete();
                    }
                }
            }
        }
        return (path.delete());
    }

}