/**
 * 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.
 */

#ifndef ORC_READER_IMPL_HH
#define ORC_READER_IMPL_HH

#include "orc/Int128.hh"
#include "orc/OrcFile.hh"
#include "orc/Reader.hh"

#include "ColumnReader.hh"
#include "orc/Exceptions.hh"
#include "RLE.hh"
#include "TypeImpl.hh"

namespace orc {

  static const uint64_t DIRECTORY_SIZE_GUESS = 16 * 1024;

  /**
  * WriterVersion Implementation
  */
  class WriterVersionImpl {
  private:
    WriterVersion version;
  public:
    // Known Versions with issues resolved
    // The static method below is to fix global constructors Clang warning
    static const WriterVersionImpl& VERSION_HIVE_8732();

    WriterVersionImpl(WriterVersion ver) : version(ver) {}

    bool compareGT(const WriterVersion other) const {
      return version > other;
    }
  };

  /**
  * State shared between Reader and Row Reader
  */
  struct FileContents {
    std::unique_ptr<InputStream> stream;
    std::unique_ptr<proto::PostScript> postscript;
    std::unique_ptr<proto::Footer> footer;
    std::unique_ptr<Type> schema;
    uint64_t blockSize;
    CompressionKind compression;
    MemoryPool *pool;
    std::ostream *errorStream;
  };

  proto::StripeFooter getStripeFooter(const proto::StripeInformation& info,
                                      const FileContents& contents);

  class ReaderImpl;

  class ColumnSelector {
   private:
    std::map<std::string, uint64_t> nameIdMap;
    std::map<uint64_t, const Type*> idTypeMap;
    const FileContents* contents;
    std::vector<std::string> columns;

    // build map from type name and id, id to Type
    void buildTypeNameIdMap(const Type* type);
    std::string toDotColumnPath();

   public:
    // Select a field by name
    void updateSelectedByName(std::vector<bool>& selectedColumns, const std::string& name);
    // Select a field by id
    void updateSelectedByFieldId(std::vector<bool>& selectedColumns, uint64_t fieldId);
    // Select a type by id
    void updateSelectedByTypeId(std::vector<bool>& selectedColumns, uint64_t typeId);

    // Select all of the recursive children of the given type.
    void selectChildren(std::vector<bool>& selectedColumns, const Type& type);

    // For each child of type, select it if one of its children
    // is selected.
    bool selectParents(std::vector<bool>& selectedColumns, const Type& type);
   /**
    * Constructor that selects columns.
    * @param contents of the file
    */
    ColumnSelector(const FileContents* contents);

    // Select the columns from the RowReaderoptions object
    void updateSelected(std::vector<bool>& selectedColumns, const RowReaderOptions& options);

    // Select the columns from the Readeroptions object
    void updateSelected(std::vector<bool>& selectedColumns, const ReaderOptions& options);
  };


  class RowReaderImpl : public RowReader {
  private:
    const Timezone& localTimezone;

    // contents
    std::shared_ptr<FileContents> contents;
    const bool throwOnHive11DecimalOverflow;
    const int32_t forcedScaleOnHive11Decimal;

    // inputs
    std::vector<bool> selectedColumns;

    // footer
    proto::Footer* footer;
    DataBuffer<uint64_t> firstRowOfStripe;
    mutable std::unique_ptr<Type> selectedSchema;

    // reading state
    uint64_t previousRow;
    uint64_t firstStripe;
    uint64_t currentStripe;
    uint64_t lastStripe; // the stripe AFTER the last one
    uint64_t currentRowInStripe;
    uint64_t rowsInCurrentStripe;
    proto::StripeInformation currentStripeInfo;
    proto::StripeFooter currentStripeFooter;
    std::unique_ptr<ColumnReader> reader;

    // internal methods
    void startNextStripe();

  public:
   /**
    * Constructor that lets the user specify additional options.
    * @param contents of the file
    * @param options options for reading
    */
    RowReaderImpl(std::shared_ptr<FileContents> contents,
                  const RowReaderOptions& options);

    // Select the columns from the options object
    void updateSelected();
    const std::vector<bool> getSelectedColumns() const override;

    const Type& getSelectedType() const override;

    std::unique_ptr<ColumnVectorBatch> createRowBatch(uint64_t size
                                                      ) const override;

    bool next(ColumnVectorBatch& data) override;

    CompressionKind getCompression() const;

    uint64_t getCompressionSize() const;

    uint64_t getRowNumber() const override;

    void seekToRow(uint64_t rowNumber) override;

    const FileContents& getFileContents() const;
    bool getThrowOnHive11DecimalOverflow() const;
    int32_t getForcedScaleOnHive11Decimal() const;
  };

  class ReaderImpl : public Reader {
   private:
    // FileContents
    std::shared_ptr<FileContents> contents;

    // inputs
    const ReaderOptions options;
    const uint64_t fileLength;
    const uint64_t postscriptLength;

    // footer
    proto::Footer* footer;
    uint64_t numberOfStripes;
    uint64_t getMemoryUse(int stripeIx, std::vector<bool>& selectedColumns);

    // internal methods
    void readMetadata() const;
    void checkOrcVersion();
    void getRowIndexStatistics(uint64_t stripeOffset,
                               const proto::StripeFooter& currentStripeFooter,
                               std::vector<std::vector<proto::ColumnStatistics> >* indexStats) const;

    // metadata
    mutable std::unique_ptr<proto::Metadata> metadata;
    mutable bool isMetadataLoaded;
   public:
    /**
     * Constructor that lets the user specify additional options.
     * @param contents of the file
     * @param options options for reading
     * @param fileLength the length of the file in bytes
     * @param postscriptLength the length of the postscript in bytes
     */
    ReaderImpl(std::shared_ptr<FileContents> contents,
               const ReaderOptions& options,
               uint64_t fileLength,
               uint64_t postscriptLength);

    const ReaderOptions& getReaderOptions() const;

    CompressionKind getCompression() const override;

    FileVersion getFormatVersion() const override;

    WriterId getWriterId() const override;

    uint32_t getWriterIdValue() const override;

    WriterVersion getWriterVersion() const override;

    uint64_t getNumberOfRows() const override;

    uint64_t getRowIndexStride() const override;

    std::list<std::string> getMetadataKeys() const override;

    std::string getMetadataValue(const std::string& key) const override;

    bool hasMetadataValue(const std::string& key) const override;

    uint64_t getCompressionSize() const override;

    uint64_t getNumberOfStripes() const override;

    std::unique_ptr<StripeInformation> getStripe(uint64_t
                                                 ) const override;

    uint64_t getNumberOfStripeStatistics() const override;

    const std::string& getStreamName() const override;

    std::unique_ptr<StripeStatistics>
    getStripeStatistics(uint64_t stripeIndex) const override;

    std::unique_ptr<RowReader> createRowReader() const override;

    std::unique_ptr<RowReader> createRowReader(const RowReaderOptions& options
                                               ) const override;

    uint64_t getContentLength() const override;
    uint64_t getStripeStatisticsLength() const override;
    uint64_t getFileFooterLength() const override;
    uint64_t getFilePostscriptLength() const override;
    uint64_t getFileLength() const override;

    std::unique_ptr<Statistics> getStatistics() const override;

    std::unique_ptr<ColumnStatistics> getColumnStatistics(uint32_t columnId
                                                          ) const override;

    std::string getSerializedFileTail() const override;

    const Type& getType() const override;

    bool hasCorrectStatistics() const override;

    const proto::PostScript* getPostscript() const {return contents->postscript.get();}

    uint64_t getBlockSize() const {return contents->blockSize;}

    const proto::Footer* getFooter() const {return contents->footer.get();}

    const Type* getSchema() const {return contents->schema.get();}

    InputStream* getStream() const {return contents->stream.get();}

    uint64_t getMemoryUse(int stripeIx = -1) override;

    uint64_t getMemoryUseByFieldId(const std::list<uint64_t>& include, int stripeIx=-1) override;

    uint64_t getMemoryUseByName(const std::list<std::string>& names, int stripeIx=-1) override;

    uint64_t getMemoryUseByTypeId(const std::list<uint64_t>& include, int stripeIx=-1) override;
  };

}// namespace

#endif