/**
 * 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.crunch.io;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;

/**
 * Functions for configuring the inputs/outputs of MapReduce jobs.
 * 
 */
public class SourceTargetHelper {

  public static long getPathSize(Configuration conf, Path path) throws IOException {
    return getPathSize(path.getFileSystem(conf), path);
  }

  public static long getPathSize(FileSystem fs, Path path) throws IOException {
    FileStatus[] stati = fs.globStatus(path);
    if (stati == null || stati.length == 0) {
      return -1L;
    }
    long size = 0;
    for (FileStatus status : stati) {
      if (status.isDir()) {
        for (RemoteIterator<LocatedFileStatus> iterator = fs.listFiles(status.getPath(), true); iterator.hasNext();) {
          size += iterator.next().getLen();
        }
      } else {
        size += status.getLen();
      }
    }
    return size;
  }
  
  public static long getLastModifiedAt(FileSystem fs, Path path) throws IOException {
    FileStatus[] stati = fs.globStatus(path);
    if (stati == null || stati.length == 0) {
      return -1L;
    }
    long lastMod = -1;
    for (FileStatus status : stati) {
      if (lastMod < status.getModificationTime()) {
        lastMod = status.getModificationTime();
      }
    }
    return lastMod;
  }
}
