// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
 * Ceph - scalable distributed file system
 *
 * Copyright (C) 2017 Red Hat Ltd
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software 
 * Foundation.  See file COPYING.
 * 
 */


#ifndef FS_COMMANDS_H_
#define FS_COMMANDS_H_

#include "Monitor.h"
#include "CommandHandler.h"

#include <iosfwd>
#include <memory>
#include <string>
#include <variant>

class Filesystem;
class FSMap;
class OSDMap;

class FileSystemCommandHandler : protected CommandHandler
{
protected:
  std::string prefix;

  using fs_or_fscid = std::variant<Filesystem*, fs_cluster_id_t>;
  enum {
    POOL_METADATA,
    POOL_DATA_DEFAULT,
    POOL_DATA_EXTRA,
  };

  /**
   * Return 0 if the pool is suitable for use with CephFS, or
   * in case of errors return a negative error code, and populate
   * the passed ostream with an explanation.
   *
   * @param metadata whether the pool will be for metadata (stricter checks)
   */
  int _check_pool(
      OSDMap &osd_map,
      const int64_t pool_id,
      int type,
      bool force,
      std::ostream *ss,
      bool allow_overlay = false) const;

  virtual std::string const &get_prefix() const {return prefix;}

  int set_val(Monitor *mon, FSMap& fsmap, MonOpRequestRef op, const cmdmap_t& cmdmap, std::ostream &ss, fs_or_fscid fs, std::string var, std::string val);

public:
  FileSystemCommandHandler(const std::string &prefix_)
    : prefix(prefix_)
  {}

  virtual ~FileSystemCommandHandler()
  {}

  int is_op_allowed(const MonOpRequestRef& op, const FSMap& fsmap,
		    const cmdmap_t& cmdmap, std::ostream &ss) const;

  int can_handle(std::string const &prefix_, MonOpRequestRef& op, FSMap& fsmap,
	         const cmdmap_t& cmdmap, std::ostream &ss) const
  {
    if (get_prefix() != prefix_) {
      return 0;
    }

    if (get_prefix() == "fs new" || get_prefix() == "fs flag set") {
      return 1;
    }

    return is_op_allowed(op, fsmap, cmdmap, ss);
  }

  static std::list<std::shared_ptr<FileSystemCommandHandler> > load(Paxos *paxos);

  virtual int handle(
    Monitor *mon,
    FSMap &fsmap,
    MonOpRequestRef op,
    const cmdmap_t& cmdmap,
    std::ostream &ss) = 0;
};


static constexpr auto errmsg_for_unhealthy_mds = \
  "MDS has one of two health warnings which could extend recovery: "
  "MDS_TRIM or MDS_CACHE_OVERSIZED. MDS failover is not recommended "
  "since it might cause unexpected file system unavailability. If "
  "you wish to proceed, pass --yes-i-really-mean-it";


#endif
