/**
 *    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.
 */

#include "mongo/db/s/sharding_write_router.h"

namespace mongo {

ShardingWriteRouter::ShardingWriteRouter(OperationContext* opCtx,
                                         const NamespaceString& nss,
                                         CatalogCache* catalogCache) {
    if (serverGlobalParams.clusterRole.has(ClusterRole::ShardServer)) {
        _scopedCss.emplace(CollectionShardingState::assertCollectionLockedAndAcquire(opCtx, nss));
        _collDesc = (*_scopedCss)->getCollectionDescription(opCtx);

        if (!_collDesc->isSharded()) {
            invariant(!_collDesc->getReshardingKeyIfShouldForwardOps());
            return;
        }

        _reshardingKeyPattern = _collDesc->getReshardingKeyIfShouldForwardOps();
        if (_reshardingKeyPattern) {
            _ownershipFilter =
                (*_scopedCss)
                    ->getOwnershipFilter(
                        opCtx, CollectionShardingState::OrphanCleanupPolicy::kAllowOrphanCleanup);

            const auto& reshardingFields = _collDesc->getReshardingFields();
            invariant(reshardingFields);
            const auto& donorFields = reshardingFields->getDonorFields();
            invariant(donorFields);

            _reshardingChunkMgr =
                uassertStatusOK(
                    catalogCache->getCollectionRoutingInfo(
                        opCtx, donorFields->getTempReshardingNss(), true /* allowLocks */))
                    .cm;

            tassert(6862800,
                    "Routing information for the temporary resharing collection is stale",
                    _reshardingChunkMgr->isSharded());
        }
    }
}

boost::optional<ShardId> ShardingWriteRouter::getReshardingDestinedRecipient(
    const BSONObj& fullDocument) const {
    if (!_reshardingKeyPattern) {
        return boost::none;
    }

    invariant(_ownershipFilter);
    invariant(_reshardingChunkMgr);

    const auto& shardKeyPattern = _collDesc->getShardKeyPattern();
    if (!_ownershipFilter->keyBelongsToMe(shardKeyPattern.extractShardKeyFromDoc(fullDocument))) {
        return boost::none;
    }

    auto shardKey = _reshardingKeyPattern->extractShardKeyFromDocThrows(fullDocument);
    return _reshardingChunkMgr->findIntersectingChunkWithSimpleCollation(shardKey).getShardId();
}

}  // namespace mongo