/**
 *    Copyright (C) 2012 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Client utilities for upgrade processes, useful operations for safe configuration upgrades.
 *
 * These are not very general purpose, however, so are not in the general cluster utilities
 * libraries.
 */

#pragma once

#include "mongo/client/dbclientinterface.h"

namespace mongo {

    /**
     * Verifies that two collections contain documents with the same _ids.
     *
     * @return OK if they do, RemoteValidationError if they do not, and an error Status if
     * anything else went wrong.
     */
    Status checkIdsTheSame(const ConnectionString& configLoc,
                           const std::string& nsA,
                           const std::string& nsB);

    /**
     * Verifies that two collections hash to the same values.
     *
     * @return OK if they do, RemoteValidationError if they do not, and an error Status if
     * anything else went wrong.
     */
    Status checkHashesTheSame(const ConnectionString& configLoc,
                              const std::string& nsA,
                              const std::string& nsB);

    /**
     * Copies a collection (which must not change during this call) to another namespace.  All
     * indexes will also be copied and constructed prior to the data being loaded.
     *
     * @return OK if copy was successful, RemoteValidationError if documents changed during the
     * copy and an error Status if anything else went wrong.
     */
    Status copyFrozenCollection(const ConnectionString& configLoc,
                                const std::string& fromNS,
                                const std::string& toNS);

    /**
     * Atomically overwrites a collection with another collection (only atomic if configLoc is a
     * single server).
     *
     * @return OK if overwrite was successful, and an error Status if anything else went wrong.
     */
    Status overwriteCollection(const ConnectionString& configLoc,
                               const std::string& fromNS,
                               const std::string& overwriteNS);

    /**
     * Creates a suffix for an upgrade's working collection
     */
    string genWorkingSuffix(const OID& lastUpgradeId);

    /**
     * Creates a suffix for an upgrade's backup collection
     */
    string genBackupSuffix(const OID& lastUpgradeId);

}