/*
 * 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.kylin.storage.hbase.steps;

import java.io.IOException;

import org.apache.commons.cli.Options;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FsShell;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.mapreduce.LoadIncrementalHFiles;
import org.apache.hadoop.util.ToolRunner;
import org.apache.kylin.common.util.HadoopUtil;
import org.apache.kylin.engine.mr.MRUtil;
import org.apache.kylin.engine.mr.common.AbstractHadoopJob;
import org.apache.kylin.storage.hbase.HBaseConnection;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author ysong1
 * 
 */
public class BulkLoadJob extends AbstractHadoopJob {

    protected static final Logger logger = LoggerFactory.getLogger(BulkLoadJob.class);

    @Override
    public int run(String[] args) throws Exception {
        Options options = new Options();

        options.addOption(OPTION_INPUT_PATH);
        options.addOption(OPTION_HTABLE_NAME);
        options.addOption(OPTION_CUBE_NAME);
        parseOptions(options, args);

        String tableName = getOptionValue(OPTION_HTABLE_NAME);
        // e.g
        // /tmp/kylin-3f150b00-3332-41ca-9d3d-652f67f044d7/test_kylin_cube_with_slr_ready_2_segments/hfile/
        // end with "/"
        String input = getOptionValue(OPTION_INPUT_PATH);

        Configuration conf = HBaseConnection.getCurrentHBaseConfiguration();
        FsShell shell = new FsShell(conf);

        int exitCode = -1;
        int retryCount = 10;
        while (exitCode != 0 && retryCount >= 1) {
            exitCode = shell.run(new String[] { "-chmod", "-R", "777", input });
            retryCount--;
            Thread.sleep(5000);
        }

        if (exitCode != 0) {
            logger.error("Failed to change the file permissions: " + input);
            throw new IOException("Failed to change the file permissions: " + input);
        }

        String[] newArgs = new String[2];
        newArgs[0] = input;
        newArgs[1] = tableName;

        int count = 0;
        Path inputPath = new Path(input);
        FileSystem fs = HadoopUtil.getFileSystem(inputPath);
        FileStatus[] fileStatuses = fs.listStatus(inputPath);
        for(FileStatus fileStatus: fileStatuses) {
            if(fileStatus.isDirectory()) {
                count++;
                break;
            }
        }

        int ret = 0;
        if (count > 0) {
            logger.debug("Start to run LoadIncrementalHFiles");
            ret = MRUtil.runMRJob(new LoadIncrementalHFiles(conf), newArgs);
            logger.debug("End to run LoadIncrementalHFiles");
            return ret;
        } else {
            logger.debug("Nothing to load, cube is empty");
            return ret;
        }
    }

    public static void main(String[] args) throws Exception {
        int exitCode = ToolRunner.run(new BulkLoadJob(), args);
        System.exit(exitCode);
    }
}
