/*
 * 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.vxquery.metadata;

import java.io.DataInputStream;
import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Map;
import java.util.logging.Logger;

import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
import org.apache.hyracks.api.client.NodeControllerInfo;
import org.apache.hyracks.api.comm.IFrame;
import org.apache.hyracks.api.comm.IFrameFieldAppender;
import org.apache.hyracks.api.comm.VSizeFrame;
import org.apache.hyracks.api.context.IHyracksTaskContext;
import org.apache.hyracks.api.dataflow.IOperatorNodePushable;
import org.apache.hyracks.api.dataflow.value.IRecordDescriptorProvider;
import org.apache.hyracks.api.dataflow.value.RecordDescriptor;
import org.apache.hyracks.api.exceptions.HyracksDataException;
import org.apache.hyracks.api.job.IOperatorDescriptorRegistry;
import org.apache.hyracks.data.std.api.IPointable;
import org.apache.hyracks.data.std.primitive.UTF8StringPointable;
import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
import org.apache.hyracks.dataflow.common.comm.io.FrameFixedFieldTupleAppender;
import org.apache.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
import org.apache.hyracks.dataflow.common.comm.util.ByteBufferInputStream;
import org.apache.hyracks.dataflow.common.comm.util.FrameUtils;
import org.apache.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
import org.apache.hyracks.dataflow.std.base.AbstractUnaryInputUnaryOutputOperatorNodePushable;
import org.apache.vxquery.context.DynamicContext;
import org.apache.vxquery.datamodel.accessors.TaggedValuePointable;
import org.apache.vxquery.datamodel.builders.sequence.SequenceBuilder;
import org.apache.vxquery.datamodel.values.XDMConstants;
import org.apache.vxquery.exceptions.SystemException;
import org.apache.vxquery.functions.BuiltinFunctions;
import org.apache.vxquery.runtime.functions.index.IndexConstructorUtil;
import org.apache.vxquery.runtime.functions.index.VXQueryIndexReader;
import org.apache.vxquery.runtime.functions.index.indexCentralizer.IndexCentralizerUtil;
import org.apache.vxquery.runtime.functions.index.updateIndex.IndexUpdater;
import org.apache.vxquery.xmlparser.ITreeNodeIdProvider;
import org.apache.vxquery.xmlparser.TreeNodeIdProvider;

public class VXQueryIndexingOperatorDescriptor extends AbstractSingleActivityOperatorDescriptor {
    protected static final Logger LOGGER = Logger.getLogger(VXQueryCollectionOperatorDescriptor.class.getName());
    private static final long serialVersionUID = 1L;
    private short dataSourceId;
    private short totalDataSources;
    private String[] collectionPartitions;
    private String elementPath;
    private final String functionCall;

    public VXQueryIndexingOperatorDescriptor(IOperatorDescriptorRegistry spec, VXQueryIndexingDataSource ds,
            RecordDescriptor rDesc, String hdfsConf, Map<String, NodeControllerInfo> nodeControllerInfos) {
        super(spec, 1, 1);
        this.functionCall = ds.getFunctionCall();
        collectionPartitions = ds.getCollectionPartitions();
        dataSourceId = (short) ds.getDataSourceId();
        totalDataSources = (short) ds.getTotalDataSources();
        recordDescriptors[0] = rDesc;
        this.elementPath = ds.getElementPath();
    }

    @Override
    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx,
            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
        final FrameTupleAccessor fta = new FrameTupleAccessor(
                recordDescProvider.getInputRecordDescriptor(getActivityId(), 0));
        final int fieldOutputCount = recordDescProvider.getOutputRecordDescriptor(getActivityId(), 0).getFieldCount();
        final IFrame frame = new VSizeFrame(ctx);
        final IFrameFieldAppender appender = new FrameFixedFieldTupleAppender(fieldOutputCount);
        final short partitionId = (short) ctx.getTaskAttemptId().getTaskId().getPartition();
        final ITreeNodeIdProvider nodeIdProvider = new TreeNodeIdProvider(partitionId, dataSourceId, totalDataSources);
        final String nodeId = ctx.getJobletContext().getApplicationContext().getNodeId();
        final DynamicContext dCtx = (DynamicContext) ctx.getJobletContext().getGlobalJobData();
        final String collectionName = collectionPartitions[partition % collectionPartitions.length];
        String collectionModifiedName = collectionName.replace("${nodeId}", nodeId);
        IndexCentralizerUtil indexCentralizerUtil = new IndexCentralizerUtil(
                ctx.getIOManager().getIODevices().get(0).getPath());
        indexCentralizerUtil.readIndexDirectory();

        return new AbstractUnaryInputUnaryOutputOperatorNodePushable() {
            @Override
            public void open() throws HyracksDataException {
                appender.reset(frame, true);
                writer.open();
            }

            @Override
            public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
                fta.reset(buffer);

                IPointable result = new TaggedValuePointable();

                final UTF8StringPointable stringp = (UTF8StringPointable) UTF8StringPointable.FACTORY.createPointable();
                final TaggedValuePointable nodep = (TaggedValuePointable) TaggedValuePointable.FACTORY
                        .createPointable();

                final ByteBufferInputStream bbis = new ByteBufferInputStream();
                final DataInputStream di = new DataInputStream(bbis);
                final SequenceBuilder sb = new SequenceBuilder();
                final ArrayBackedValueStorage abvs = new ArrayBackedValueStorage();
                final ArrayBackedValueStorage abvsFileNode = new ArrayBackedValueStorage();

                String indexModifiedName;
                if (collectionModifiedName.contains("hdfs://")) {
                    throw new HyracksDataException("Indexing support for HDFS not yet implemented.");
                } else {

                    if (functionCall.equals(
                            BuiltinFunctions.FN_BUILD_INDEX_ON_COLLECTION_1.getFunctionIdentifier().getName())) {
                        indexModifiedName = indexCentralizerUtil.putIndexForCollection(collectionModifiedName);
                        File collectionDirectory = new File(collectionModifiedName);

                        //check if directory is in the local file system
                        if (collectionDirectory.exists() && collectionDirectory.isDirectory()) {
                            IndexConstructorUtil indexConstructorUtil = new IndexConstructorUtil();
                            try {
                                indexConstructorUtil.evaluate(collectionModifiedName, indexModifiedName, result,
                                        stringp, bbis, di, sb, abvs, nodeIdProvider, abvsFileNode, nodep, false,
                                        nodeId);
                                XDMConstants.setTrue(result);
                                FrameUtils.appendFieldToWriter(writer, appender, result.getByteArray(),
                                        result.getStartOffset(), result.getLength());
                            } catch (SystemException e) {
                                throw new HyracksDataException("Could not create index for collection: "
                                        + collectionName + " in dir: " + indexModifiedName + " " + e.getMessage());
                            }
                        } else {
                            throw new HyracksDataException("Cannot find Collection Directory (" + nodeId + ":"
                                    + collectionDirectory.getAbsolutePath() + ")");
                        }
                    } else if (functionCall
                            .equals(BuiltinFunctions.FN_UPDATE_INDEX_1.getFunctionIdentifier().getName())) {
                        indexModifiedName = indexCentralizerUtil.getIndexForCollection(collectionModifiedName);
                        IndexUpdater updater = new IndexUpdater(indexModifiedName, result, stringp, bbis, di, sb, abvs,
                                nodeIdProvider, abvsFileNode, nodep, nodeId);
                        try {
                            updater.setup();
                            updater.updateIndex();
                            updater.updateMetadataFile();
                            updater.exit();
                            XDMConstants.setTrue(result);
                            FrameUtils.appendFieldToWriter(writer, appender, result.getByteArray(),
                                    result.getStartOffset(), result.getLength());
                        } catch (IOException | SystemException e) {
                            throw new HyracksDataException(
                                    "Could not update index in " + indexModifiedName + " " + e.getMessage());
                        }
                    } else if (functionCall
                            .equals(BuiltinFunctions.FN_DELETE_INDEX_1.getFunctionIdentifier().getName())) {
                        indexModifiedName = indexCentralizerUtil.getIndexForCollection(collectionModifiedName);
                        IndexUpdater updater = new IndexUpdater(indexModifiedName, result, stringp, bbis, di, sb, abvs,
                                nodeIdProvider, abvsFileNode, nodep, nodeId);
                        indexCentralizerUtil.deleteEntryForCollection(collectionModifiedName);
                        try {
                            updater.setup();
                            updater.deleteAllIndexes();
                            XDMConstants.setTrue(result);
                            FrameUtils.appendFieldToWriter(writer, appender, result.getByteArray(),
                                    result.getStartOffset(), result.getLength());
                        } catch (SystemException | IOException e) {
                            throw new HyracksDataException(
                                    "Could not delete index in " + indexModifiedName + " " + e.getMessage());
                        }

                    } else if (functionCall
                            .equals(BuiltinFunctions.FN_COLLECTION_FROM_INDEX_2.getFunctionIdentifier().getName())) {
                        indexModifiedName = indexCentralizerUtil.getIndexForCollection(collectionModifiedName);
                        VXQueryIndexReader indexReader = new VXQueryIndexReader(ctx, indexModifiedName, elementPath);
                        try {
                            indexReader.init();
                            while (indexReader.step(result)) {
                                FrameUtils.appendFieldToWriter(writer, appender, result.getByteArray(),
                                        result.getStartOffset(), result.getLength());
                            }
                        } catch (AlgebricksException e) {
                            throw new HyracksDataException("Could not read index.");
                        }

                    } else {
                        throw new HyracksDataException("Unsupported function call (" + functionCall + ")");
                    }
                }
            }

            @Override
            public void fail() throws HyracksDataException {
                writer.fail();
            }

            @Override
            public void close() throws HyracksDataException {
                // Check if needed?
                if (appender.getTupleCount() > 0) {
                    appender.flush(writer, true);
                }
                writer.close();
                indexCentralizerUtil.writeIndexDirectory();
            }
        };
    }
}