/**
 * @file MergeContent.h
 * MergeContent class declaration
 *
 * 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 __MERGE_CONTENT_H__
#define __MERGE_CONTENT_H__

#include "ArchiveCommon.h"
#include "BinFiles.h"
#include "archive_entry.h"
#include "archive.h"
#include "core/logging/LoggerConfiguration.h"

namespace org {
namespace apache {
namespace nifi {
namespace minifi {
namespace processors {

namespace merge_content_options {

constexpr const char *MERGE_STRATEGY_BIN_PACK = "Bin-Packing Algorithm";
constexpr const char *MERGE_STRATEGY_DEFRAGMENT = "Defragment";
constexpr const char *MERGE_FORMAT_TAR_VALUE = "TAR";
constexpr const char *MERGE_FORMAT_ZIP_VALUE = "ZIP";
constexpr const char *MERGE_FORMAT_FLOWFILE_STREAM_V3_VALUE = "FlowFile Stream, v3";
constexpr const char *MERGE_FORMAT_FLOWFILE_STREAM_V2_VALUE = "FlowFile Stream, v2";
constexpr const char *MERGE_FORMAT_FLOWFILE_TAR_V1_VALUE = "FlowFile Tar, v1";
constexpr const char *MERGE_FORMAT_CONCAT_VALUE = "Binary Concatenation";
constexpr const char *MERGE_FORMAT_AVRO_VALUE = "Avro";
constexpr const char *DELIMITER_STRATEGY_FILENAME = "Filename";
constexpr const char *DELIMITER_STRATEGY_TEXT = "Text";
constexpr const char *ATTRIBUTE_STRATEGY_KEEP_COMMON = "Keep Only Common Attributes";
constexpr const char *ATTRIBUTE_STRATEGY_KEEP_ALL_UNIQUE = "Keep All Unique Attributes";

} /* namespace merge_content_options */

// MergeBin Class
class MergeBin {
public:

  virtual ~MergeBin() = default;
  virtual std::string getMergedContentType() = 0;
  // merge the flows in the bin
  virtual void merge(core::ProcessContext *context, core::ProcessSession *session,
      std::deque<std::shared_ptr<core::FlowFile>> &flows, std::string &header, std::string &footer, std::string &demarcator,
      const std::shared_ptr<core::FlowFile> &flowFile) = 0;
};

// BinaryConcatenationMerge Class
class BinaryConcatenationMerge : public MergeBin {
public:
  static const char *mimeType;
  std::string getMergedContentType() override {
    return mimeType;
  }
  void merge(
    core::ProcessContext *context, core::ProcessSession *session, std::deque<std::shared_ptr<core::FlowFile>> &flows,
    std::string &header, std::string &footer, std::string &demarcator, const std::shared_ptr<core::FlowFile> &flowFile) override;
  // Nest Callback Class for read stream
  class ReadCallback : public InputStreamCallback {
   public:
    ReadCallback(uint64_t size, std::shared_ptr<io::BaseStream> stream)
        : buffer_size_(size), stream_(stream) {
    }
    ~ReadCallback() = default;
    int64_t process(std::shared_ptr<io::BaseStream> stream) {
      uint8_t buffer[4096U];
      int64_t ret = 0;
      uint64_t read_size = 0;
      while (read_size < buffer_size_) {
        int readRet = stream->read(buffer, sizeof(buffer));
        if (readRet > 0) {
          ret += stream_->write(buffer, readRet);
          read_size += readRet;
        } else {
          break;
        }
      }
      return ret;
    }
    uint64_t buffer_size_;
    std::shared_ptr<io::BaseStream> stream_;
  };
  // Nest Callback Class for write stream
  class WriteCallback: public OutputStreamCallback {
  public:
    WriteCallback(std::string &header, std::string &footer, std::string &demarcator, std::deque<std::shared_ptr<core::FlowFile>> &flows, core::ProcessSession *session) :
      header_(header), footer_(footer), demarcator_(demarcator), flows_(flows), session_(session) {
    }
    std::string &header_;
    std::string &footer_;
    std::string &demarcator_;
    std::deque<std::shared_ptr<core::FlowFile>> &flows_;
    core::ProcessSession *session_;
    int64_t process(std::shared_ptr<io::BaseStream> stream) {
      int64_t ret = 0;
      if (!header_.empty()) {
        int64_t len = stream->write(reinterpret_cast<uint8_t*>(const_cast<char*>(header_.data())), header_.size());
        if (len < 0)
          return len;
        ret += len;
      }
      bool isFirst = true;
      for (auto flow : flows_) {
        if (!isFirst && !demarcator_.empty()) {
          int64_t len = stream->write(reinterpret_cast<uint8_t*>(const_cast<char*>(demarcator_.data())), demarcator_.size());
          if (len < 0)
            return len;
          ret += len;
        }
        ReadCallback readCb(flow->getSize(), stream);
        session_->read(flow, &readCb);
        ret += flow->getSize();
        isFirst = false;
      }
      if (!footer_.empty()) {
        int64_t len = stream->write(reinterpret_cast<uint8_t*>(const_cast<char*>(footer_.data())), footer_.size());
        if (len < 0)
          return len;
        ret += len;
      }
      return ret;
    }
  };
};


// Archive Class
class ArchiveMerge {
public:
  // Nest Callback Class for read stream
  class ReadCallback: public InputStreamCallback {
  public:
    ReadCallback(uint64_t size, struct archive *arch, struct archive_entry *entry) :
        buffer_size_(size), arch_(arch), entry_(entry) {
    }
    ~ReadCallback() = default;
    int64_t process(std::shared_ptr<io::BaseStream> stream) {
      uint8_t buffer[4096U];
      int64_t ret = 0;
      uint64_t read_size = 0;
      ret = archive_write_header(arch_, entry_);
      while (read_size < buffer_size_) {
        int readRet = stream->read(buffer, sizeof(buffer));
        if (readRet > 0) {
          ret += archive_write_data(arch_, buffer, readRet);
          read_size += readRet;
        }
        else {
          break;
        }
      }
      return ret;
    }
    uint64_t buffer_size_;
    struct archive *arch_;
    struct archive_entry *entry_;
  };
  // Nest Callback Class for write stream
  class WriteCallback: public OutputStreamCallback {
  public:
    WriteCallback(std::string merge_type, std::deque<std::shared_ptr<core::FlowFile>> &flows, core::ProcessSession *session) :
        merge_type_(merge_type), flows_(flows), session_(session),
        logger_(logging::LoggerFactory<ArchiveMerge>::getLogger()) {
      size_ = 0;
      stream_ = nullptr;
    }
    ~WriteCallback() = default;

    std::string merge_type_;
    std::deque<std::shared_ptr<core::FlowFile>> &flows_;
    core::ProcessSession *session_;
    std::shared_ptr<io::BaseStream> stream_;
    int64_t size_;
    std::shared_ptr<logging::Logger> logger_;

    static la_ssize_t archive_write(struct archive *arch, void *context, const void *buff, size_t size) {
      WriteCallback *callback = (WriteCallback *) context;
      la_ssize_t ret = callback->stream_->write(reinterpret_cast<uint8_t*>(const_cast<void*>(buff)), size);
      if (ret > 0)
        callback->size_ += (int64_t) ret;
      return ret;
    }

    int64_t process(std::shared_ptr<io::BaseStream> stream) {
      struct archive *arch;

      arch = archive_write_new();
      if (merge_type_ == merge_content_options::MERGE_FORMAT_TAR_VALUE) {
        archive_write_set_format_pax_restricted(arch);  // tar format
      }
      if (merge_type_ == merge_content_options::MERGE_FORMAT_ZIP_VALUE) {
        archive_write_set_format_zip(arch);  // zip format
      }
      archive_write_set_bytes_per_block(arch, 0);
      archive_write_add_filter_none(arch);
      stream_ = stream;
      archive_write_open(arch, this, NULL, archive_write, NULL);

      for (auto flow : flows_) {
        struct archive_entry *entry = archive_entry_new();
        std::string fileName;
        flow->getAttribute(core::SpecialFlowAttribute::FILENAME, fileName);
        archive_entry_set_pathname(entry, fileName.c_str());
        archive_entry_set_size(entry, flow->getSize());
        archive_entry_set_mode(entry, S_IFREG | 0755);
        if (merge_type_ == merge_content_options::MERGE_FORMAT_TAR_VALUE) {
          std::string perm;
          int permInt;
          if (flow->getAttribute(BinFiles::TAR_PERMISSIONS_ATTRIBUTE, perm)) {
            try {
              permInt = std::stoi(perm);
              logger_->log_debug("Merge Tar File %s permission %s", fileName, perm);
              archive_entry_set_perm(entry, (mode_t) permInt);
            } catch (...) {
            }
          }
        }
        ReadCallback readCb(flow->getSize(), arch, entry);
        session_->read(flow, &readCb);
        archive_entry_free(entry);
      }

      archive_write_close(arch);
      archive_write_free(arch);
      return size_;
    }
  };
};

// TarMerge Class
class TarMerge: public ArchiveMerge, public MergeBin {
public:
  static const char *mimeType;
  void merge(core::ProcessContext *context, core::ProcessSession *session, std::deque<std::shared_ptr<core::FlowFile>> &flows, std::string &header, std::string &footer,
    std::string &demarcator, const std::shared_ptr<core::FlowFile> &flowFile) override;
  std::string getMergedContentType() override {
    return mimeType;
  }
};

// ZipMerge Class
class ZipMerge: public ArchiveMerge, public MergeBin {
public:
  static const char *mimeType;
  void merge(core::ProcessContext *context, core::ProcessSession *session, std::deque<std::shared_ptr<core::FlowFile>> &flows, std::string &header, std::string &footer,
    std::string &demarcator, const std::shared_ptr<core::FlowFile> &flowFile) override;
  std::string getMergedContentType() override {
    return mimeType;
  }
};

class AttributeMerger {
public:
  explicit AttributeMerger(std::deque<std::shared_ptr<org::apache::nifi::minifi::core::FlowFile>> &flows)
    : flows_(flows) {}
  void mergeAttributes(core::ProcessSession *session, const std::shared_ptr<core::FlowFile> &merge_flow);
  virtual ~AttributeMerger() = default;
protected:
  std::map<std::string, std::string> getMergedAttributes();
  virtual void processFlowFile(const std::shared_ptr<core::FlowFile> &flow_file, std::map<std::string, std::string> &merged_attributes) = 0;

  const std::deque<std::shared_ptr<core::FlowFile>> &flows_;
};

class KeepOnlyCommonAttributesMerger: public AttributeMerger {
public:
  explicit KeepOnlyCommonAttributesMerger(std::deque<std::shared_ptr<org::apache::nifi::minifi::core::FlowFile>> &flows)
    : AttributeMerger(flows) {}
protected:
  void processFlowFile(const std::shared_ptr<core::FlowFile> &flow_file, std::map<std::string, std::string> &merged_attributes) override;
};

class KeepAllUniqueAttributesMerger: public AttributeMerger {
public:
  explicit KeepAllUniqueAttributesMerger(std::deque<std::shared_ptr<org::apache::nifi::minifi::core::FlowFile>> &flows)
    : AttributeMerger(flows) {}
protected:
  void processFlowFile(const std::shared_ptr<core::FlowFile> &flow_file, std::map<std::string, std::string> &merged_attributes) override;

private:
  std::vector<std::string> removed_attributes_;
};

// MergeContent Class
class MergeContent : public processors::BinFiles {
public:
  // Constructor
  /*!
   * Create a new processor
   */
  explicit MergeContent(std::string name, utils::Identifier uuid = utils::Identifier())
      : processors::BinFiles(name, uuid),
        logger_(logging::LoggerFactory<MergeContent>::getLogger()) {
    mergeStrategy_ = merge_content_options::MERGE_STRATEGY_DEFRAGMENT;
    mergeFormat_ = merge_content_options::MERGE_FORMAT_CONCAT_VALUE;
    delimiterStrategy_ = merge_content_options::DELIMITER_STRATEGY_FILENAME;
    keepPath_ = false;
    attributeStrategy_ = merge_content_options::ATTRIBUTE_STRATEGY_KEEP_COMMON;
  }
  // Destructor
  virtual ~MergeContent() = default;
  // Processor Name
  static constexpr char const* ProcessorName = "MergeContent";
  // Supported Properties
  static core::Property MergeStrategy;
  static core::Property MergeFormat;
  static core::Property CorrelationAttributeName;
  static core::Property DelimiterStrategy;
  static core::Property KeepPath;
  static core::Property Header;
  static core::Property Footer;
  static core::Property Demarcator;
  static core::Property AttributeStrategy;

  // Supported Relationships
  static core::Relationship Merge;

 public:
  /**
   * Function that's executed when the processor is scheduled.
   * @param context process context.
   * @param sessionFactory process session factory that is used when creating
   * ProcessSession objects.
   */
  void onSchedule(core::ProcessContext *context, core::ProcessSessionFactory *sessionFactory);
  // OnTrigger method, implemented by NiFi MergeContent
  virtual void onTrigger(core::ProcessContext *context, core::ProcessSession *session);
  // Initialize, over write by NiFi MergeContent
  virtual void initialize(void);
  virtual bool processBin(core::ProcessContext *context, core::ProcessSession *session, std::unique_ptr<Bin> &bin);

 protected:
  // Returns a group ID representing a bin. This allows flow files to be binned into like groups
  virtual std::string getGroupId(core::ProcessContext *context, std::shared_ptr<core::FlowFile> flow);
  // check whether the defragment bin is validate
  bool checkDefragment(std::unique_ptr<Bin> &bin);

 private:
  void validatePropertyOptions();

  std::shared_ptr<logging::Logger> logger_;
  std::string mergeStrategy_;
  std::string mergeFormat_;
  std::string correlationAttributeName_;
  bool keepPath_;
  std::string delimiterStrategy_;
  std::string header_;
  std::string footer_;
  std::string demarcator_;
  std::string headerContent_;
  std::string footerContent_;
  std::string demarcatorContent_;
  std::string attributeStrategy_;
  // readContent
  std::string readContent(std::string path);
};

REGISTER_RESOURCE(MergeContent, "Merges a Group of FlowFiles together based on a user-defined strategy and packages them into a single FlowFile. "
    "MergeContent should be configured with only one incoming connection as it won't create grouped Flow Files."
    "This processor updates the mime.type attribute as appropriate.");

} /* namespace processors */
} /* namespace minifi */
} /* namespace nifi */
} /* namespace apache */
} /* namespace org */

#endif