/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    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
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include <functional>
#include <map>
#include <memory>
#include <string>

#include "mongo/client/connection_string.h"
#include "mongo/client/remote_command_targeter_factory.h"
#include "mongo/s/client/shard.h"

namespace mongo {

/**
 * An object factory for creating Shard instances via calling registered builders.
 */
class ShardFactory {
    ShardFactory(const ShardFactory&) = delete;
    ShardFactory& operator=(const ShardFactory&) = delete;

public:
    using BuilderCallable =
        std::function<std::unique_ptr<Shard>(const ShardId&, const ConnectionString&)>;
    using BuildersMap = std::map<ConnectionString::ConnectionType, BuilderCallable>;

    ShardFactory(BuildersMap&&, std::unique_ptr<RemoteCommandTargeterFactory>);
    ~ShardFactory() = default;

    /**
     * Deprecated. Creates a unique_ptr with a new instance of a Shard with the provided shardId
     * and connection string. This method is currently only used for addShard.
     */
    std::unique_ptr<Shard> createUniqueShard(const ShardId& shardId,
                                             const ConnectionString& connStr);

    /**
     * Creates a shared_ptr with a new instance of a Shard with the provided shardId
     * and connection string.
     */
    std::shared_ptr<Shard> createShard(const ShardId& shardId, const ConnectionString& connStr);

private:
    // Map from ConnectionType to a function that can be used to build a Shard object for that
    // ConnectionType. This map must be set up at the initialization of the ShardFactory instance.
    BuildersMap _builders;

    // Even though ShardFactory doesn't use _targeterFactory directly, the functions contained in
    // _builders may, so ShardFactory must own _targeterFactory so that their lifetimes are tied
    // together
    std::unique_ptr<RemoteCommandTargeterFactory> _targeterFactory;
};

}  // namespace mongo