/* Copyright (C) 2014 InfiniDB, Inc.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; version 2 of
   the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

#pragma once

#include <string>
#include <vector>
#include <stdint.h>

#include <boost/thread/mutex.hpp>

#include "IDBDataFile.h"
#include "IDBFileSystem.h"
#include "IDBFactory.h"

namespace idbdatafile
{
/**
 * IDBPolicy is a static class that is used to manage the interaction
 * between the rest of infinidb and the idbdatafile subsystem.  It supports
 * mapping from a file/directory path and context (currently PrimProc or
 * WriteEngineServer) to a file and filesystem type
 */
class IDBPolicy
{
 public:
  /**
   * Define the contexts recognized by IDBPolicy.  The same file may be
   * opened as a different type depending on the context (for ex. data
   * files are buffered in WriteEngine and Unbuffered in PrimProc).
   */
  enum Contexts
  {
    PRIMPROC,
    WRITEENG
  };

  /**
   * Config the IDBPolicy based on the Columnstore.xml
   */
  static void configIDBPolicy();

  /**
   * Initialize the IDBDataFile subsystem.  This should be called once
   * by the main thread of the application prior to any other use of the
   * library.
   * bEnableLogging -- for debug only.
   * bUseRdwrMemBuffer -- If true, use Memory Buffered files (class HdfsRdwrMemBuffer) until
   * hdfsRdwrBufferMaxSize memory is used, then switch to file buffering until mem used is below
   * hdfsRdwrBufferMaxSize. hdfsRdwrScratch -- where to store file-buffered HDFS files (class
   * HdfsRdwrFileBuffer) - it should name a writable directory with sufficient space to store all needed
   * buffers (size-TBD?). hdfsRdwrBufferMaxSize -- When RdwrMemBuffers get this big, switch to file buffers .
   */
  static void init(bool bEnableLogging, bool bUseRdwrMemBuffer, const std::string& hdfsRdwrScratch,
                   int64_t hdfsRdwrBufferMaxSize);

  /**
   * Load a new filetype plugin.  Return value indicates success(true)
   * or failure (false)
   */
  static bool installPlugin(const std::string& plugin);

  /**
   * Accessor method that returns whether or not HDFS is enabled
   */
  static bool useHdfs();

  /**
   * Accessor method that returns whether or not cloud IO is enabled
   */
  static bool useCloud();

  /**
   * Checks for disk space preallocation feature status for a dbroot
   */
  static bool PreallocSpaceDisabled(uint16_t dbRoot);

  /**
   * Accessor method that returns whether to use HDFS memory buffers
   */
  static bool useRdwrMemBuffer();

  /**
   * Accessor method that returns the max amount of mem buff to use before switching to file buffering
   */
  static size_t hdfsRdwrBufferMaxSize();

  /**
   * Accessor method that returns the directory to place our temp hdfs buffer files
   */
  static const std::string& hdfsRdwrScratch();

  /**
   * getType() returns the proper IDBDataFile::Types for a file given a
   * path for the path and a context in which it will be interacted with.
   */
  static IDBDataFile::Types getType(const std::string& path, Contexts ctxt);

  /**
   * getFs() returns a reference to the proper IDBFileSystem instance that
   * is able to interact with the file/directory specified by path
   */
  static IDBFileSystem& getFs(const std::string& path);

  /**
   * These are convenience functions that simplify the syntax required to
   * make a filesystem call.  Each of the calls determines the proper
   * FileSystem to reference for the specified path and then performs the
   * actual call.  Documentation for these will not be duplicated here -
   * please see IDBFileSystem.h.
   */
  static int mkdir(const char* pathname);
  static off64_t size(const char* path);
  static off64_t compressedSize(const char* path);
  static int remove(const char* pathname);
  static int rename(const char* oldpath, const char* newpath);
  static bool exists(const char* pathname);
  static int listDirectory(const char* pathname, std::list<std::string>& contents);
  static bool isDir(const char* pathname);
  static int copyFile(const char* srcPath, const char* destPath);
  /**
   * This is used in WE shared components Unit Tests
   */
  static void enablePreallocSpace(uint16_t dbRoot);

 private:
  /**
   * don't allow this class to be constructed.  It exposes a purely
   * static interface
   */
  IDBPolicy();

  static bool isLocalFile(const std::string& path);

  static bool s_usehdfs;
  static bool s_usecloud;
  static std::vector<uint16_t> s_PreallocSpace;
  static bool s_bUseRdwrMemBuffer;
  static std::string s_hdfsRdwrScratch;
  static int64_t s_hdfsRdwrBufferMaxSize;
  static bool s_configed;
  static boost::mutex s_mutex;
};

inline const std::string& IDBPolicy::hdfsRdwrScratch()
{
  return s_hdfsRdwrScratch;
}

inline bool IDBPolicy::useHdfs()
{
  return s_usehdfs;
}

inline bool IDBPolicy::useCloud()
{
  return s_usecloud;
}

// MCOL-498 Looking for dbRoot in the List set in configIDBPolicy.
inline bool IDBPolicy::PreallocSpaceDisabled(uint16_t dbRoot)
{
  std::vector<uint16_t>::iterator dbRootIter = find(s_PreallocSpace.begin(), s_PreallocSpace.end(), dbRoot);
  return dbRootIter == s_PreallocSpace.end();
}

inline bool IDBPolicy::useRdwrMemBuffer()
{
  return s_bUseRdwrMemBuffer;
}

inline size_t IDBPolicy::hdfsRdwrBufferMaxSize()
{
  return s_hdfsRdwrBufferMaxSize;
}

inline int IDBPolicy::mkdir(const char* pathname)
{
  return IDBPolicy::getFs(pathname).mkdir(pathname);
}

inline off64_t IDBPolicy::size(const char* path)
{
  return IDBPolicy::getFs(path).size(path);
}

inline off64_t IDBPolicy::compressedSize(const char* path)
{
  return IDBPolicy::getFs(path).compressedSize(path);
}

inline int IDBPolicy::remove(const char* pathname)
{
  return IDBPolicy::getFs(pathname).remove(pathname);
}

inline int IDBPolicy::rename(const char* oldpath, const char* newpath)
{
  return IDBPolicy::getFs(oldpath).rename(oldpath, newpath);
}

inline bool IDBPolicy::exists(const char* pathname)
{
  return IDBPolicy::getFs(pathname).exists(pathname);
}

inline int IDBPolicy::listDirectory(const char* pathname, std::list<std::string>& contents)
{
  return IDBPolicy::getFs(pathname).listDirectory(pathname, contents);
}

inline bool IDBPolicy::isDir(const char* pathname)
{
  return IDBPolicy::getFs(pathname).isDir(pathname);
}

inline int IDBPolicy::copyFile(const char* srcPath, const char* destPath)
{
  return IDBPolicy::getFs(srcPath).copyFile(srcPath, destPath);
}

}  // namespace idbdatafile