/*
 * $Header: /cvsroot/mvnforum/myvietnam/src/net/myvietnam/mvncore/util/FileUtil.java,v 1.39 2006/04/15 02:59:20 minhnn Exp $
 * $Author: minhnn $
 * $Revision: 1.39 $
 * $Date: 2006/04/15 02:59:20 $
 *
 * ====================================================================
 *
 * Copyright (C) 2002-2006 by MyVietnam.net
 *
 * All copyright notices regarding MyVietnam and MyVietnam CoreLib
 * MUST remain intact in the scripts and source code.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Correspondence and Marketing Questions can be sent to:
 * info at MyVietnam net
 *
 * @author: Minh Nguyen  
 * @author: Mai  Nguyen  
 */
package net.myvietnam.mvncore.util;

import java.io.*;
import java.net.URL;
import java.text.DecimalFormat;

import net.myvietnam.mvncore.exception.BadInputException;
import net.myvietnam.mvncore.filter.DisableHtmlTagFilter;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public final class FileUtil {

    private static Log log = LogFactory.getLog(FileUtil.class);

    private static FileUtil instance = new FileUtil();

    private static String servletClassesPath = null;

    private FileUtil() { // prevent instantiation
    }

    public static void checkGoodFilePath(String str) throws BadInputException {
        byte[] s = str.getBytes();
        int length = s.length;
        byte b = 0;

        for (int i = 0; i < length; i++) {
            b = s[i];
            if ((b == '*') ||
                (b == '?') ||
                (b == '<') ||
                (b == '>') ||
                (b == '"') ||
                (b == '|') ||
                (b == '\0')) {//null char : is it correct ????
                // not good char, throw an BadInputException
                //@todo : localize me
                throw new BadInputException("The string '" + DisableHtmlTagFilter.filter(str) + "' is not a good file path. Reason: character '" + (char)(b) + "' is not allowed.");
            }
        }// for
    }

    public static void checkGoodFileName(String str) throws BadInputException {
        // must be a good file path first
        checkGoodFilePath(str);
        byte[] s = str.getBytes();
        int length = s.length;
        byte b = 0;

        for (int i = 0; i < length; i++) {
            b = s[i];
            if ((b == '/') ||
                (b == '\\') ||
                (b == ':')) {
                // not good char, throw an BadInputException
                //@todo : localize me
                throw new BadInputException("The string '" + DisableHtmlTagFilter.filter(str) + "' is not a good file name. Reason: character '" + (char)(b) + "' is not allowed.");
            }
        }// for
    }

    public static void createDir(String dir, boolean ignoreIfExitst) throws IOException {
        File file = new File(dir);

        if (ignoreIfExitst && file.exists()) {
            return;
        }

        if ( file.mkdir() == false) {
            throw new IOException("Cannot create the directory = " + dir);
        }
    }

    public static void createDirs(String dir, boolean ignoreIfExitst) throws IOException {
        File file = new File(dir);

        if (ignoreIfExitst && file.exists()) {
            return;
        }

        if ( file.mkdirs() == false) {
            throw new IOException("Cannot create directories = " + dir);
        }
    }

    public static void deleteFile(String filename) throws IOException {
        File file = new File(filename);
        log.trace("Delete file = " + filename);
        if (file.isDirectory()) {
            throw new IOException("IOException -> BadInputException: not a file.");
        }
        if (file.exists() == false) {
            throw new IOException("IOException -> BadInputException: file is not exist.");
        }
        if (file.delete() == false) {
            throw new IOException("Cannot delete file. filename = " + filename);
        }
    }

    public static void deleteDir(File dir) throws IOException {
        if (dir.isFile()) throw new IOException("IOException -> BadInputException: not a directory.");
        File[] files = dir.listFiles();
        if (files != null) {
            for (int i = 0; i < files.length; i++) {
                File file = files[i];
                if (file.isFile()) {
                    file.delete();
                } else {
                    deleteDir(file);
                }
            }
        }//if
        dir.delete();
    }

    public static long getDirLength(File dir) throws IOException {
        if (dir.isFile()) throw new IOException("BadInputException: not a directory.");
        long size = 0;
        File[] files = dir.listFiles();
        if (files != null) {
            for (int i = 0; i < files.length; i++) {
                File file = files[i];
                long length = 0;
                if (file.isFile()) {
                    length = file.length();
                } else {
                    length = getDirLength(file);
                }
                size += length;
            }//for
        }//if
        return size;
    }

    public static long getDirLength_onDisk(File dir) throws IOException {
        if (dir.isFile()) throw new IOException("BadInputException: not a directory.");
        long size = 0;
        File[] files = dir.listFiles();
        if (files != null) {
            for (int i = 0; i < files.length; i++) {
                File file = files[i];
                long length = 0;
                if (file.isFile()) {
                    length = file.length();
                } else {
                    length = getDirLength_onDisk(file);
                }
                double mod = Math.ceil(((double)length)/512);
                if (mod == 0) mod = 1;
                length = ((long)mod) * 512;
                size += length;
            }
        }//if
        return size;
    }

    public static void emptyFile(String srcFilename) throws IOException {
        File srcFile = new File(srcFilename);
        if (!srcFile.exists()) {
            throw new FileNotFoundException("Cannot find the file: " + srcFile.getAbsolutePath());
        }
        if (!srcFile.canWrite()) {
            throw new IOException("Cannot write the file: " + srcFile.getAbsolutePath());
        }

        FileOutputStream outputStream = new FileOutputStream(srcFilename);
        outputStream.close();
    }

    public static void copyFile(String srcFilename, String destFilename, boolean overwrite) throws IOException {

        File srcFile = new File(srcFilename);
        if (!srcFile.exists()) {
            throw new FileNotFoundException("Cannot find the source file: " + srcFile.getAbsolutePath());
        }
        if (!srcFile.canRead()) {
            throw new IOException("Cannot read the source file: " + srcFile.getAbsolutePath());
        }

        File destFile = new File(destFilename);
        if (overwrite == false) {
            if (destFile.exists()) return;
        } else {
            if (destFile.exists()) {
                if (!destFile.canWrite()) {
                    throw new IOException("Cannot write the destination file: " + destFile.getAbsolutePath());
                }
            } else {
                if (!destFile.createNewFile()) {
                    throw new IOException("Cannot write the destination file: " + destFile.getAbsolutePath());
                }
            }
        }

        BufferedInputStream inputStream = null;
        BufferedOutputStream outputStream = null;
        byte[] block = new byte[1024];
        try {
            inputStream = new BufferedInputStream(new FileInputStream(srcFile));
            outputStream = new BufferedOutputStream(new FileOutputStream(destFile));
            while (true) {
                int readLength = inputStream.read(block);
                if (readLength == -1) break;// end of file
                outputStream.write(block, 0, readLength);
            }
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException ex) {
                    // just ignore
                }
            }
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException ex) {
                    // just ignore
                }
            }
        }
    }

    //@todo: why this method does not close the inputStream ???
    public static byte[] getBytes(InputStream inputStream) throws IOException {
        BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1024);
        byte[] block = new byte[4096];
        while (true) {
            int readLength = bufferedInputStream.read(block);
            if (readLength == -1) break;// end of file
            byteArrayOutputStream.write(block, 0, readLength);
        }
        byte[] retValue = byteArrayOutputStream.toByteArray();
        byteArrayOutputStream.close();
        return retValue;
    }

    public static String getFileName(String fullFilePath) {
        if (fullFilePath == null) {
            return "";
        }
        int index1 = fullFilePath.lastIndexOf('/');
        int index2 = fullFilePath.lastIndexOf('\\');

        //index is the maximum value of index1 and index2
        int index = (index1 > index2) ? index1 : index2;
        if (index == -1) {
            // not found the path separator
            return fullFilePath;
        }
        String fileName = fullFilePath.substring(index + 1);
        return fileName;
    }