/**
 * 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.hcatalog.mapreduce;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.common.FileUtils;
import org.apache.hadoop.hive.metastore.HiveMetaHook;
import org.apache.hadoop.hive.ql.io.RCFile;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.TableDesc;
import org.apache.hadoop.hive.ql.security.authorization.DefaultHiveAuthorizationProvider;
import org.apache.hadoop.hive.ql.security.authorization.HiveAuthorizationProvider;
import org.apache.hadoop.hive.serde2.SerDe;
import org.apache.hadoop.mapred.InputFormat;
import org.apache.hadoop.mapred.OutputFormat;
import org.apache.hcatalog.common.HCatConstants;
import org.apache.hcatalog.common.HCatUtil;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 *  This class is used to encapsulate the InputFormat, OutputFormat and SerDe
 *  artifacts of tables which don't define a SerDe. This StorageHandler assumes
 *  the supplied storage artifacts are for a file-based storage system.
 */
public class FosterStorageHandler extends HCatStorageHandler {

    public Configuration conf;
    /** The directory under which data is initially written for a partitioned table */
    protected static final String DYNTEMP_DIR_NAME = "_DYN";

    /** The directory under which data is initially written for a non partitioned table */
    protected static final String TEMP_DIR_NAME = "_TEMP";

    private Class<? extends InputFormat> ifClass;
    private Class<? extends OutputFormat> ofClass;
    private Class<? extends SerDe> serDeClass;

    public FosterStorageHandler(String ifName, String ofName, String serdeName) throws ClassNotFoundException {
        this((Class<? extends InputFormat>) Class.forName(ifName),
            (Class<? extends OutputFormat>) Class.forName(ofName),
            (Class<? extends SerDe>) Class.forName(serdeName));
    }

    public FosterStorageHandler(Class<? extends InputFormat> ifClass,
                                Class<? extends OutputFormat> ofClass,
                                Class<? extends SerDe> serDeClass) {
        this.ifClass = ifClass;
        this.ofClass = ofClass;
        this.serDeClass = serDeClass;
    }

    @Override
    public Class<? extends InputFormat> getInputFormatClass() {
        return ifClass;    //To change body of overridden methods use File | Settings | File Templates.
    }

    @Override
    public Class<? extends OutputFormat> getOutputFormatClass() {
        return ofClass;    //To change body of overridden methods use File | Settings | File Templates.
    }

    @Override
    public Class<? extends SerDe> getSerDeClass() {
        return serDeClass;  //To change body of implemented methods use File | Settings | File Templates.
    }

    @Override
    public HiveMetaHook getMetaHook() {
        return null;
    }

    @Override
    public void configureInputJobProperties(TableDesc tableDesc,
                                            Map<String, String> jobProperties) {

    }

    @Override
    public void configureOutputJobProperties(TableDesc tableDesc,
                                             Map<String, String> jobProperties) {
        try {
            OutputJobInfo jobInfo = (OutputJobInfo)
                HCatUtil.deserialize(tableDesc.getJobProperties().get(
                    HCatConstants.HCAT_KEY_OUTPUT_INFO));
            String parentPath = jobInfo.getTableInfo().getTableLocation();
            String dynHash = tableDesc.getJobProperties().get(
                HCatConstants.HCAT_DYNAMIC_PTN_JOBID);

            // For dynamic partitioned writes without all keyvalues specified,
            // we create a temp dir for the associated write job
            if (dynHash != null) {
                parentPath = new Path(parentPath,
                    DYNTEMP_DIR_NAME + dynHash).toString();
            }

            String outputLocation;

            // For non-partitioned tables, we send them to the temp dir
            if (dynHash == null && jobInfo.getPartitionValues().size() == 0) {
                outputLocation = TEMP_DIR_NAME;
            } else {
                List<String> cols = new ArrayList<String>();
                List<String> values = new ArrayList<String>();

                //Get the output location in the order partition keys are defined for the table.
                for (String name :
                    jobInfo.getTableInfo().
                        getPartitionColumns().getFieldNames()) {
                    String value = jobInfo.getPartitionValues().get(name);
                    cols.add(name);
                    values.add(value);
                }
                outputLocation = FileUtils.makePartName(cols, values);
            }

            jobInfo.setLocation(new Path(parentPath, outputLocation).toString());

            //only set output dir if partition is fully materialized
            if (jobInfo.getPartitionValues().size()
                == jobInfo.getTableInfo().getPartitionColumns().size()) {
                jobProperties.put("mapred.output.dir", jobInfo.getLocation());
            }

            //TODO find a better home for this, RCFile specifc
            jobProperties.put(RCFile.COLUMN_NUMBER_CONF_STR,
                Integer.toOctalString(
                    jobInfo.getOutputSchema().getFields().size()));
            jobProperties.put(HCatConstants.HCAT_KEY_OUTPUT_INFO,
                HCatUtil.serialize(jobInfo));
        } catch (IOException e) {
            throw new IllegalStateException("Failed to set output path", e);
        }

    }

    @Override
    OutputFormatContainer getOutputFormatContainer(
        org.apache.hadoop.mapred.OutputFormat outputFormat) {
        return new FileOutputFormatContainer(outputFormat);
    }

    @Override
    public Configuration getConf() {
        return conf;
    }

    @Override
    public void setConf(Configuration conf) {
        this.conf = conf;
    }

    @Override
    public HiveAuthorizationProvider getAuthorizationProvider()
        throws HiveException {
        return new DefaultHiveAuthorizationProvider();
    }

}