/**
 *    Copyright (C) 2021-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.
 */

#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kResharding

#include "mongo/platform/basic.h"

#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/privilege.h"
#include "mongo/db/catalog_raii.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/op_observer.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/s/shard_filtering_metadata_refresh.h"
#include "mongo/db/s/sharding_state.h"
#include "mongo/logv2/log.h"
#include "mongo/s/catalog_cache_loader.h"
#include "mongo/s/grid.h"
#include "mongo/s/request_types/flush_resharding_state_change_gen.h"

namespace mongo {
namespace {

void doNoopWrite(OperationContext* opCtx, const NamespaceString& nss) {
    writeConflictRetry(
        opCtx, "_flushReshardingStateChange no-op", NamespaceString::kRsOplogNamespace.ns(), [&] {
            AutoGetOplog oplogWrite(opCtx, OplogAccessMode::kWrite);

            const std::string msg = str::stream()
                << "no-op for _flushReshardingStateChange on " << nss;
            WriteUnitOfWork wuow(opCtx);
            opCtx->getClient()->getServiceContext()->getOpObserver()->onInternalOpMessage(
                opCtx,
                {},
                boost::none,
                BSON("msg" << msg),
                boost::none,
                boost::none,
                boost::none,
                boost::none,
                boost::none);
            wuow.commit();
        });
}

class FlushReshardingStateChangeCmd final : public TypedCommand<FlushReshardingStateChangeCmd> {
public:
    using Request = _flushReshardingStateChange;

    bool skipApiVersionCheck() const override {
        // Internal command (server to server).
        return true;
    }

    std::string help() const override {
        return "Internal command used by the resharding coordinator to flush state changes to the "
               "participant shards while the critical section is active.";
    }

    bool adminOnly() const override {
        return true;
    }

    Command::AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
        return Command::AllowedOnSecondary::kNever;
    }

    class Invocation final : public InvocationBase {
    public:
        using InvocationBase::InvocationBase;

        bool supportsWriteConcern() const override {
            return true;
        }

        NamespaceString ns() const override {
            return request().getCommandParameter();
        }

        UUID reshardingUUID() const {
            return request().getReshardingUUID();
        }

        void doCheckAuthorization(OperationContext* opCtx) const override {
            uassert(ErrorCodes::Unauthorized,
                    "Unauthorized",
                    AuthorizationSession::get(opCtx->getClient())
                        ->isAuthorizedForActionsOnResource(ResourcePattern::forClusterResource(),
                                                           ActionType::internal));
        }

        void typedRun(OperationContext* opCtx) {
            auto const shardingState = ShardingState::get(opCtx);
            uassertStatusOK(shardingState->canAcceptShardedCommands());

            uassert(ErrorCodes::IllegalOperation,
                    "Can't issue _flushReshardingStateChange from 'eval'",
                    !opCtx->getClient()->isInDirectClient());

            uassert(ErrorCodes::IllegalOperation,
                    "Can't call _flushReshardingStateChange if in read-only mode",
                    !storageGlobalParams.readOnly);

            ExecutorFuture<void>(Grid::get(opCtx)->getExecutorPool()->getArbitraryExecutor())
                .then([svcCtx = opCtx->getServiceContext(), nss = ns()] {
                    ThreadClient tc("FlushReshardingStateChange", svcCtx);
                    {
                        stdx::lock_guard<Client> lk(*tc.get());
                        tc->setSystemOperationKillableByStepdown(lk);
                    }

                    auto opCtx = tc->makeOperationContext();
                    onShardVersionMismatch(
                        opCtx.get(), nss, boost::none /* shardVersionReceived */);
                })
                .onError([](const Status& status) {
                    LOGV2_WARNING(5808100,
                                  "Error on deferred _flushReshardingStateChange execution",
                                  "error"_attr = redact(status));
                })
                .getAsync([](auto) {});

            // Ensure the command isn't run on a stale primary.
            doNoopWrite(opCtx, ns());
        }
    };
} _flushReshardingStateChange;

}  // namespace
}  // namespace mongo
