/* Copyright (c) 2018, 2024, Oracle and/or its affiliates.

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 designed to work with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have either included with
the program or referenced in the documentation.

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 St, Fifth Floor, Boston, MA  02110-1301  USA */

#include <sql/handler.h>
#include <sql/sql_class.h>
#include "mysql_page_track_imp.h"
#include "string_with_len.h"

/** Check if thd has backup privilege.
@param[in]	thd	thread context
@return 0 if thd has backup privilege, else 1 */
bool check_backup_privilege(MYSQL_THD thd) {
  auto sctx = thd->security_context();

  if (!(sctx->has_global_grant(STRING_WITH_LEN("BACKUP_ADMIN")).first)) {
    my_error(ER_SPECIFIC_ACCESS_DENIED_ERROR, MYF(0), "BACKUP_ADMIN");
    return (true);
  }
  return (false);
}

DEFINE_METHOD(int, Page_track_implementation::start,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type,
               uint64_t *start_id)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  enum legacy_db_type db_type;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  return (ddse->page_track.start(start_id));
}

DEFINE_METHOD(int, Page_track_implementation::stop,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type,
               uint64_t *stop_id)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  enum legacy_db_type db_type = DB_TYPE_UNKNOWN;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  return (ddse->page_track.stop(stop_id));
}

DEFINE_METHOD(int, Page_track_implementation::purge,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type,
               uint64_t *purge_id)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  enum legacy_db_type db_type = DB_TYPE_UNKNOWN;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  return (ddse->page_track.purge(purge_id));
}

DEFINE_METHOD(int, Page_track_implementation::get_page_ids,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type, uint64_t *start_id,
               uint64_t *stop_id, unsigned char *buffer, size_t buffer_len,
               Page_Track_Callback cbk_func, void *cbk_ctx)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  enum legacy_db_type db_type = DB_TYPE_UNKNOWN;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  return (ddse->page_track.get_page_ids(cbk_func, cbk_ctx, start_id, stop_id,
                                        buffer, buffer_len));
}

DEFINE_METHOD(int, Page_track_implementation::get_num_page_ids,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type, uint64_t *start_id,
               uint64_t *stop_id, uint64_t *num_pages)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  enum legacy_db_type db_type = DB_TYPE_UNKNOWN;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  return (ddse->page_track.get_num_page_ids(start_id, stop_id, num_pages));
}

DEFINE_METHOD(int, Page_track_implementation::get_status,
              (MYSQL_THD opaque_thd, Page_Track_SE se_type,
               uint64_t *initial_start_id, uint64_t *last_start_id)) {
  if (check_backup_privilege(opaque_thd)) {
    return (ER_SPECIFIC_ACCESS_DENIED_ERROR);
  }

  assert(se_type == PAGE_TRACK_SE_INNODB);

  *initial_start_id = 0;
  *last_start_id = 0;

  enum legacy_db_type db_type = DB_TYPE_UNKNOWN;

  switch (se_type) {
    case PAGE_TRACK_SE_INNODB:
      db_type = DB_TYPE_INNODB;
      break;
  }

  handlerton *ddse = ha_resolve_by_legacy_type(opaque_thd, db_type);

  /** Vector of a pair of (ID, bool) where ID is the start/stop point and bool
  is true if the ID is a start point else false */
  static std::vector<std::pair<uint64_t, bool>> status;
  status.clear();

  ddse->page_track.get_status(status);

  if (status.size() == 0) {
    return (false);
  }

  bool is_active = (status.back().second == true);

  if (is_active) {
    *last_start_id = status.back().first;

    for (auto rit = status.rbegin(); rit != status.rend(); ++rit) {
      if (rit->second == false) {
        break;
      }
      *initial_start_id = rit->first;
    }
  }

  return (is_active);
}