/*
 * 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
 *
 *     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.apache.hadoop.chukwa.validationframework.util;


import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.MessageDigest;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

public class MD5 {
  public static String checksum(File file) {
    try {
      InputStream fin = new FileInputStream(file);
      java.security.MessageDigest md5er = MessageDigest.getInstance("MD5");
      byte[] buffer = new byte[1024];
      int read;
      do {
        read = fin.read(buffer);
        if (read > 0)
          md5er.update(buffer, 0, read);
      } while (read != -1);
      fin.close();
      byte[] digest = md5er.digest();
      if (digest == null)
        return null;
      String strDigest = "0x";
      for (int i = 0; i < digest.length; i++) {
        strDigest += Integer.toString((digest[i] & 0xff) + 0x100, 16)
            .substring(1).toUpperCase();
      }
      return strDigest;
    } catch (Exception e) {
      return null;
    }
  }

  public static String checksum(FileSystem fs, Path file) {
    try {
      FSDataInputStream fin = fs.open(file);
      java.security.MessageDigest md5er = MessageDigest.getInstance("MD5");
      byte[] buffer = new byte[1024];
      int read;
      do {
        read = fin.read(buffer);
        if (read > 0)
          md5er.update(buffer, 0, read);
      } while (read != -1);
      fin.close();
      byte[] digest = md5er.digest();
      if (digest == null)
        return null;
      String strDigest = "0x";
      for (int i = 0; i < digest.length; i++) {
        strDigest += Integer.toString((digest[i] & 0xff) + 0x100, 16)
            .substring(1).toUpperCase();
      }
      return strDigest;
    } catch (Exception e) {
      return null;
    }
  }
}