/**
 * 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 java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.serde2.SerDe;
import org.apache.hadoop.hive.serde2.SerDeException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.HCatMapRedUtil;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hcatalog.common.ErrorType;
import org.apache.hcatalog.common.HCatException;
import org.apache.hcatalog.common.HCatUtil;
import org.apache.hcatalog.data.HCatRecord;

/**
 * Part of the FileOutput*Container classes
 * See {@link FileOutputFormatContainer} for more information
 */
class FileRecordWriterContainer extends RecordWriterContainer {

    private final HCatStorageHandler storageHandler;
    private final SerDe serDe;
    private final ObjectInspector objectInspector;

    private boolean dynamicPartitioningUsed = false;

    private final Map<String, org.apache.hadoop.mapred.RecordWriter<? super WritableComparable<?>, ? super Writable>> baseDynamicWriters;
    private final Map<String, SerDe> baseDynamicSerDe;
    private final Map<String, org.apache.hadoop.mapred.OutputCommitter> baseDynamicCommitters;
    private final Map<String, org.apache.hadoop.mapred.TaskAttemptContext> dynamicContexts;
    private final Map<String, ObjectInspector> dynamicObjectInspectors;
    private Map<String, OutputJobInfo> dynamicOutputJobInfo;


    private final List<Integer> partColsToDel;
    private final List<Integer> dynamicPartCols;
    private int maxDynamicPartitions;

    private OutputJobInfo jobInfo;
    private TaskAttemptContext context;

    /**
     * @param baseWriter RecordWriter to contain
     * @param context current TaskAttemptContext
     * @throws IOException
     * @throws InterruptedException
     */
    public FileRecordWriterContainer(org.apache.hadoop.mapred.RecordWriter<? super WritableComparable<?>, ? super Writable> baseWriter,
                                     TaskAttemptContext context) throws IOException, InterruptedException {
        super(context,baseWriter);
        this.context = context;
        jobInfo = HCatOutputFormat.getJobInfo(context);

        storageHandler = HCatUtil.getStorageHandler(context.getConfiguration(), jobInfo.getTableInfo().getStorerInfo());
        serDe = ReflectionUtils.newInstance(storageHandler.getSerDeClass(),context.getConfiguration());
        objectInspector = InternalUtil.createStructObjectInspector(jobInfo.getOutputSchema());
        try {
            InternalUtil.initializeOutputSerDe(serDe, context.getConfiguration(), jobInfo);
        } catch (SerDeException e) {
            throw new IOException("Failed to inialize SerDe",e);
        }

        // If partition columns occur in data, we want to remove them.
        partColsToDel = jobInfo.getPosOfPartCols();
        dynamicPartitioningUsed = jobInfo.isDynamicPartitioningUsed();
        dynamicPartCols = jobInfo.getPosOfDynPartCols();
        maxDynamicPartitions = jobInfo.getMaxDynamicPartitions();

        if((partColsToDel == null) || (dynamicPartitioningUsed && (dynamicPartCols == null))){
            throw new HCatException("It seems that setSchema() is not called on " +
                    "HCatOutputFormat. Please make sure that method is called.");
        }


        if (!dynamicPartitioningUsed) {
            this.baseDynamicSerDe = null;
            this.baseDynamicWriters = null;
            this.baseDynamicCommitters = null;
            this.dynamicContexts = null;
            this.dynamicObjectInspectors = null;
            this.dynamicOutputJobInfo = null;
        }
        else {
            this.baseDynamicSerDe = new HashMap<String,SerDe>();
            this.baseDynamicWriters = new HashMap<String,org.apache.hadoop.mapred.RecordWriter<? super WritableComparable<?>, ? super Writable>>();
            this.baseDynamicCommitters = new HashMap<String, org.apache.hadoop.mapred.OutputCommitter>();
            this.dynamicContexts = new HashMap<String, org.apache.hadoop.mapred.TaskAttemptContext>();
            this.dynamicObjectInspectors = new HashMap<String, ObjectInspector>();
            this.dynamicOutputJobInfo = new HashMap<String, OutputJobInfo>();
        }
    }

    /**
     * @return the storagehandler
     */
    public HCatStorageHandler getStorageHandler() {
        return storageHandler;
    }

    @Override
    public void close(TaskAttemptContext context) throws IOException,
            InterruptedException {
        Reporter reporter = InternalUtil.createReporter(context);
        if (dynamicPartitioningUsed){
            for (org.apache.hadoop.mapred.RecordWriter<? super WritableComparable<?>, ? super Writable> bwriter : baseDynamicWriters.values()){
                //We are in RecordWriter.close() make sense that the context would be TaskInputOutput
                bwriter.close(reporter);
            }
            for(Map.Entry<String,org.apache.hadoop.mapred.OutputCommitter>entry : baseDynamicCommitters.entrySet()) {
                org.apache.hadoop.mapred.TaskAttemptContext currContext = dynamicContexts.get(entry.getKey());
                OutputCommitter baseOutputCommitter = entry.getValue();
                if (baseOutputCommitter.needsTaskCommit(currContext)){
                    baseOutputCommitter.commitTask(currContext);
                }
                org.apache.hadoop.mapred.JobContext currJobContext = HCatMapRedUtil.createJobContext(currContext);
                baseOutputCommitter.commitJob(currJobContext);
            }
        } else {
            getBaseRecordWriter().close(reporter);
        }
    }

    @Override
    public void write(WritableComparable<?> key, HCatRecord value) throws IOException,
            InterruptedException {

        org.apache.hadoop.mapred.RecordWriter localWriter;
        ObjectInspector localObjectInspector;
        SerDe localSerDe;
        OutputJobInfo localJobInfo = null;

        if (dynamicPartitioningUsed){
            // calculate which writer to use from the remaining values - this needs to be done before we delete cols
            List<String> dynamicPartValues = new ArrayList<String>();
            for (Integer colToAppend :  dynamicPartCols){
                dynamicPartValues.add(value.get(colToAppend).toString());
            }

            String dynKey = dynamicPartValues.toString();
            if (!baseDynamicWriters.containsKey(dynKey)){
                if ((maxDynamicPartitions != -1) && (baseDynamicWriters.size() > maxDynamicPartitions)){
                    throw new HCatException(ErrorType.ERROR_TOO_MANY_DYNAMIC_PTNS,
                            "Number of dynamic partitions being created "
                                    + "exceeds configured max allowable partitions["
                                    + maxDynamicPartitions
                                    + "], increase parameter ["
                                    + HiveConf.ConfVars.DYNAMICPARTITIONMAXPARTS.varname
                                    + "] if needed.");
                }

                org.apache.hadoop.mapred.TaskAttemptContext currTaskContext = HCatMapRedUtil.createTaskAttemptContext(context);
                configureDynamicStorageHandler(currTaskContext, dynamicPartValues);
                localJobInfo= HCatBaseOutputFormat.getJobInfo(currTaskContext);

                //setup serDe
                SerDe currSerDe = ReflectionUtils.newInstance(storageHandler.getSerDeClass(), currTaskContext.getJobConf());
                try {
                    InternalUtil.initializeOutputSerDe(currSerDe, currTaskContext.getConfiguration(), localJobInfo);
                } catch (SerDeException e) {
                    throw new IOException("Failed to initialize SerDe",e);
                }

                //create base OutputFormat
                org.apache.hadoop.mapred.OutputFormat baseOF =
                        ReflectionUtils.newInstance(storageHandler.getOutputFormatClass(), currTaskContext.getJobConf());
                //check outputSpecs
                baseOF.checkOutputSpecs(null,currTaskContext.getJobConf());
                //get Output Committer
                org.apache.hadoop.mapred.OutputCommitter baseOutputCommitter =  currTaskContext.getJobConf().getOutputCommitter();
                //create currJobContext the latest so it gets all the config changes
                org.apache.hadoop.mapred.JobContext currJobContext = HCatMapRedUtil.createJobContext(currTaskContext);
                //setupJob()
                baseOutputCommitter.setupJob(currJobContext);
                //recreate to refresh jobConf of currTask context
                currTaskContext =
                        HCatMapRedUtil.createTaskAttemptContext(currJobContext.getJobConf(),
                                                                                        currTaskContext.getTaskAttemptID(),
                                                                                        currTaskContext.getProgressible());
                //set temp location
                currTaskContext.getConfiguration().set("mapred.work.output.dir",
                                new FileOutputCommitter(new Path(localJobInfo.getLocation()),currTaskContext).getWorkPath().toString());
                //setupTask()
                baseOutputCommitter.setupTask(currTaskContext);

                org.apache.hadoop.mapred.RecordWriter baseRecordWriter =
                        baseOF.getRecordWriter(null,
                                                            currTaskContext.getJobConf(),
                                                            FileOutputFormat.getUniqueFile(currTaskContext, "part", ""),
                                                            InternalUtil.createReporter(currTaskContext));

                baseDynamicWriters.put(dynKey, baseRecordWriter);
                baseDynamicSerDe.put(dynKey,currSerDe);
                baseDynamicCommitters.put(dynKey,baseOutputCommitter);
                dynamicContexts.put(dynKey,currTaskContext);
                dynamicObjectInspectors.put(dynKey,InternalUtil.createStructObjectInspector(jobInfo.getOutputSchema()));
                dynamicOutputJobInfo.put(dynKey, HCatOutputFormat.getJobInfo(dynamicContexts.get(dynKey)));
            }
            
            localJobInfo = dynamicOutputJobInfo.get(dynKey);
            localWriter = baseDynamicWriters.get(dynKey);
            localSerDe = baseDynamicSerDe.get(dynKey);
            localObjectInspector = dynamicObjectInspectors.get(dynKey);
        }
        else{
            localJobInfo = jobInfo;
            localWriter = getBaseRecordWriter();
            localSerDe = serDe;
            localObjectInspector = objectInspector;
        }

        for(Integer colToDel : partColsToDel){
            value.remove(colToDel);
        }


        //The key given by user is ignored
        try {
            localWriter.write(NullWritable.get(), localSerDe.serialize(value.getAll(), localObjectInspector));
        } catch (SerDeException e) {
            throw new IOException("Failed to serialize object",e);
        }
    }

    protected void configureDynamicStorageHandler(JobContext context, List<String> dynamicPartVals) throws IOException {
        HCatOutputFormat.configureOutputStorageHandler(context, dynamicPartVals);
    }

}