/* 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 <sys/types.h>
#include <list>
#include "IDBDataFile.h"
#include "IDBFactory.h"

namespace idbdatafile
{
/**
 * IDBFileSystem is a combination abstract base class and factory. The
 * purpose is to encapsulate access to various file system functions
 * across different file system types including hdfs.
 */
class IDBFileSystem
{
 public:
  /**
   * The TYPE enum defines the supported underlying filesystem types
   */
  enum Types
  {
    UNKNOWN = 0x00,
    POSIX = 0x0001,
    HDFS = 0x0002,
    CLOUD = 0x0003
  };

  /**
   * Destructor
   */
  virtual ~IDBFileSystem();

  /**
   * getFs() returns a reference to the IDBFileSystem instance for the
   * specified type
   */
  static IDBFileSystem& getFs(IDBDataFile::Types type);

  /**
   * mkdir() creates a directory specified by pathname including any
   * parent directories if needed.
   * Returns 0 on success, -1 on error
   */
  virtual int mkdir(const char* pathname) = 0;

  /**
   * remove() removes a path from the filesystem.  It will handle
   * both files and directories (including non-empty directories).  Note
   * that a call to remove of a path that does not exist will return as
   * success.
   *
   * Returns 0 on success, -1 on error
   */
  virtual int remove(const char* pathname) = 0;

  /**
   * rename() names a file, moving it between directories if required.
   * Returns 0 on success, -1 on error
   */
  virtual int rename(const char* oldpath, const char* newpath) = 0;

  /**
   * size() returns the size of the file specified by path.
   * Returns the size on success, -1 on error
   */
  virtual off64_t size(const char* path) const = 0;

  /**
   * compressedSize() returns the decompressed size of the file
   * speicified by path.
   * Returns the size on success, -1 on error
   */
  virtual off64_t compressedSize(const char* path) const = 0;

  /**
   * exists() checks for the existence of a particular path.
   * Returns true if exists, false otherwise.
   */
  virtual bool exists(const char* pathname) const = 0;

  /**
   * listDirectory() returns the contents of the directory as a
   * list of strings.  For now, no indication of whether each
   * item is a file or directory - both files and subdirectories
   * will be returned.
   * Returns 0 on success.  -1 on error (incl if directory does
   * not exist.
   */

  virtual int listDirectory(const char* pathname, std::list<std::string>& contents) const = 0;

  /**
   * isDir() returns whether or not the path is a directory
   */
  virtual bool isDir(const char* pathname) const = 0;

  /**
   * copyfile() copies the source file to the destination file
   * Returns 0 on success.  -1 on error.
   */
  virtual int copyFile(const char* srcPath, const char* destPath) const = 0;

  /**
   * isFsUp() checks if the filesystem is up
   * Returns 0 on success.  -1 on error.
   */
  virtual bool filesystemIsUp() const
  {
    return true;
  }

  virtual bool filesystemSync() const
  {
    return true;
  }

  /**
   * chown() changes the owner of the object on the FS
   * Returns 0 on success.  -1 on error.
   */
  virtual int chown(const char* objectName, const uid_t p_uid, const gid_t p_pid, int& funcErrno) const
  {
    return 0;
  }

 protected:
  explicit IDBFileSystem(Types type);

 private:
  Types m_type;
};

/**
 * getFs() returns a reference to the IDBFileSystem instance for the
 * specified type
 */
inline IDBFileSystem& IDBFileSystem::getFs(IDBDataFile::Types type)
{
  return IDBFactory::getFs(type);
}

}  // namespace idbdatafile