/*
 * 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.engine.mr.steps;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.kylin.common.util.HadoopUtil;
import org.apache.kylin.cube.CubeInstance;
import org.apache.kylin.cube.CubeManager;
import org.apache.kylin.cube.CubeSegment;
import org.apache.kylin.engine.mr.CubingJob;
import org.apache.kylin.engine.mr.common.BatchConstants;
import org.apache.kylin.job.exception.ExecuteException;
import org.apache.kylin.job.execution.AbstractExecutable;
import org.apache.kylin.job.execution.ExecutableContext;
import org.apache.kylin.job.execution.ExecuteResult;
import org.apache.kylin.metadata.model.TblColRef;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 */
public class UpdateCubeInfoAfterBuildStep extends AbstractExecutable {
    private static final Logger logger = LoggerFactory.getLogger(UpdateCubeInfoAfterBuildStep.class);

    public UpdateCubeInfoAfterBuildStep() {
        super();
    }

    @Override
    protected ExecuteResult doWork(ExecutableContext context) throws ExecuteException {
        final CubeManager cubeManager = CubeManager.getInstance(context.getConfig());
        final CubeInstance cube = cubeManager.getCube(CubingExecutableUtil.getCubeName(this.getParams()));
        final CubeSegment segment = cube.getSegmentById(CubingExecutableUtil.getSegmentId(this.getParams()));

        CubingJob cubingJob = (CubingJob) getManager().getJob(CubingExecutableUtil.getCubingJobId(this.getParams()));
        long sourceCount = cubingJob.findSourceRecordCount();
        long sourceSizeBytes = cubingJob.findSourceSizeBytes();
        long cubeSizeBytes = cubingJob.findCubeSizeBytes();

        segment.setLastBuildJobID(CubingExecutableUtil.getCubingJobId(this.getParams()));
        segment.setLastBuildTime(System.currentTimeMillis());
        segment.setSizeKB(cubeSizeBytes / 1024);
        segment.setInputRecords(sourceCount);
        segment.setInputRecordsSize(sourceSizeBytes);

        try {
            if (segment.isSourceOffsetsOn()) {
                updateTimeRange(segment);
            }

            cubeManager.promoteNewlyBuiltSegments(cube, segment);
            return new ExecuteResult(ExecuteResult.State.SUCCEED, "succeed");
        } catch (IOException e) {
            logger.error("fail to update cube after build", e);
            return new ExecuteResult(ExecuteResult.State.ERROR, e.getLocalizedMessage());
        }
    }

    private void updateTimeRange(CubeSegment segment) throws IOException {
        final TblColRef partitionCol = segment.getCubeDesc().getModel().getPartitionDesc().getPartitionDateColumnRef();

        if (partitionCol == null) {
            return;
        }
        final String factColumnsInputPath = this.getParams().get(BatchConstants.CFG_OUTPUT_PATH);
        Path colDir = new Path(factColumnsInputPath, partitionCol.getIdentity());
        FileSystem fs = HadoopUtil.getWorkingFileSystem();
        Path outputFile = HadoopUtil.getFilterOnlyPath(fs, colDir, partitionCol.getName() + FactDistinctColumnsReducer.PARTITION_COL_INFO_FILE_POSTFIX);
        if (outputFile == null) {
            throw new IOException("fail to find the partition file in base dir: " + colDir);
        }

        FSDataInputStream is = null;
        BufferedReader bufferedReader = null;
        InputStreamReader isr = null;
        long minValue, maxValue;
        try {
            is = fs.open(outputFile);
            isr = new InputStreamReader(is);
            bufferedReader = new BufferedReader(isr);
            minValue = Long.parseLong(bufferedReader.readLine());
            maxValue = Long.parseLong(bufferedReader.readLine());
        } finally {
            IOUtils.closeQuietly(is);
            IOUtils.closeQuietly(isr);
            IOUtils.closeQuietly(bufferedReader);
        }
        logger.info("updateTimeRange step. minValue:" + minValue + " maxValue:" + maxValue);
        segment.setDateRangeStart(minValue);
        segment.setDateRangeEnd(maxValue);
    }
}