/**
 *    Copyright (C) 2023-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.
 */

#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/cancelable_operation_context.h"
#include "mongo/db/commands.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/s/database_sharding_state.h"
#include "mongo/db/s/sharding_recovery_service.h"
#include "mongo/db/s/sharding_state.h"
#include "mongo/db/transaction/transaction_participant.h"
#include "mongo/logv2/log.h"
#include "mongo/s/catalog/sharding_catalog_client.h"
#include "mongo/s/grid.h"
#include "mongo/s/request_types/move_primary_gen.h"

#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kSharding

namespace mongo {
namespace {

class ShardsvrMovePrimaryEnterCriticalSectionCommand final
    : public TypedCommand<ShardsvrMovePrimaryEnterCriticalSectionCommand> {
public:
    using Request = ShardsvrMovePrimaryEnterCriticalSection;

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

        void typedRun(OperationContext* opCtx) {
            CommandHelpers::uassertCommandRunWithMajority(Request::kCommandName,
                                                          opCtx->getWriteConcern());

            uassert(
                ErrorCodes::InvalidOptions,
                "{} expected to be called within a retryable write "_format(Request::kCommandName),
                TransactionParticipant::get(opCtx));

            {
                // Using the original operation context, the two write operations to enter the
                // critical section (acquire and promote) would use the same txnNumber, which would
                // cause the failure of the second operation.
                auto newClient = getGlobalServiceContext()->makeClient(
                    "ShardsvrMovePrimaryEnterCriticalSection");
                AlternativeClientRegion acr(newClient);
                auto newOpCtx = CancelableOperationContext(
                    cc().makeOperationContext(),
                    opCtx->getCancellationToken(),
                    Grid::get(opCtx->getServiceContext())->getExecutorPool()->getFixedExecutor());
                newOpCtx->setAlwaysInterruptAtStepDownOrUp_UNSAFE();

                const auto& dbName = request().getCommandParameter();
                const auto& csReason = request().getReason();

                // Waiting for the critical section on the database to complete is necessary to
                // avoid the risk of invariant by attempting to enter the critical section as a
                // dropDatabase operation may have already entered it.
                waitForCriticalSectionToComplete(opCtx, dbName, csReason);

                ShardingRecoveryService::get(newOpCtx.get())
                    ->acquireRecoverableCriticalSectionBlockWrites(
                        newOpCtx.get(),
                        NamespaceString(dbName),
                        csReason,
                        ShardingCatalogClient::kLocalWriteConcern);
                ShardingRecoveryService::get(newOpCtx.get())
                    ->promoteRecoverableCriticalSectionToBlockAlsoReads(
                        newOpCtx.get(),
                        NamespaceString(dbName),
                        csReason,
                        ShardingCatalogClient::kLocalWriteConcern);
            }

            // Since no write that generated a retryable write oplog entry with this sessionId and
            // txnNumber happened, we need to make a dummy write so that the session gets durably
            // persisted on the oplog. This must be the last operation done on this command.
            DBDirectClient dbClient(opCtx);
            dbClient.update(NamespaceString::kServerConfigurationNamespace,
                            BSON("_id" << Request::kCommandName),
                            BSON("$inc" << BSON("count" << 1)),
                            true /* upsert */,
                            false /* multi */);
        }

    private:
        NamespaceString ns() const override {
            return NamespaceString(request().getDbName());
        }

        bool supportsWriteConcern() const override {
            return true;
        }

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

        void waitForCriticalSectionToComplete(OperationContext* opCtx,
                                              const DatabaseName& dbName,
                                              const BSONObj& movePrimaryReason) {
            auto criticalSectionSignal = [&]() -> boost::optional<SharedSemiFuture<void>> {
                Lock::DBLock dbLock(opCtx, dbName, MODE_IS);
                const auto scopedDss =
                    DatabaseShardingState::assertDbLockedAndAcquireShared(opCtx, dbName);

                auto optCritSectionSignalSignal =
                    scopedDss->getCriticalSectionSignal(ShardingMigrationCriticalSection::kWrite);
                if (optCritSectionSignalSignal) {
                    auto optCritSectionReason = scopedDss->getCriticalSectionReason();
                    tassert(7578800, "Found critical section without reason", optCritSectionReason);
                    if (movePrimaryReason.woCompare(*optCritSectionReason) == 0) {
                        return boost::none;
                    }
                }
                return optCritSectionSignalSignal;
            }();

            if (criticalSectionSignal) {
                criticalSectionSignal->get(opCtx);
            }
        }
    };

private:
    bool adminOnly() const override {
        return true;
    }

    bool skipApiVersionCheck() const override {
        return true;
    }

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

    std::string help() const override {
        return "Internal command. Do not call directly.";
    }

    bool supportsRetryableWrite() const {
        return true;
    }
} shardsvrMovePrimaryEnterCriticalSectionCommand;

}  // namespace
}  // namespace mongo