// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#pragma once

#include <mutex>

#include "storage/olap_common.h"

#include "storage/partial_update_info.h"

#include "storage/rowset/rowset.h"

#include "storage/tablet/tablet_meta.h"

#include "storage/txn/txn_manager.h"

#include "util/countdown_latch.h"

#include "util/lru_cache.h"

namespace doris {

// Record transaction related delete bitmaps using a lru cache.

class CloudTxnDeleteBitmapCache : public LRUCachePolicy {

public:

    CloudTxnDeleteBitmapCache(size_t size_in_bytes);

    ~CloudTxnDeleteBitmapCache() override;

    Status init();

    Status get_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,

                               RowsetSharedPtr* rowset, DeleteBitmapPtr* delete_bitmap,

                               RowsetIdUnorderedSet* rowset_ids, int64_t* txn_expiration,

                               std::shared_ptr<PartialUpdateInfo>* partial_update_info,

                               std::shared_ptr<PublishStatus>* publish_status,

                               TxnPublishInfo* previous_publish_info);

    void set_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,

                             DeleteBitmapPtr delete_bitmap, const RowsetIdUnorderedSet& rowset_ids,

                             RowsetSharedPtr rowset, int64_t txn_expirationm,

                             std::shared_ptr<PartialUpdateInfo> partial_update_info);

    Status update_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,

                                  DeleteBitmapPtr delete_bitmap,

                                  const RowsetIdUnorderedSet& rowset_ids,

                                  PublishStatus publish_status, TxnPublishInfo publish_info = {});

    void remove_expired_tablet_txn_info();

    void remove_unused_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id);

    // Mark a rowset as empty/skipped (lightweight marker, no rowset stored)

    // Used for empty rowsets when skip_writing_empty_rowset_metadata is enabled

    void mark_empty_rowset(TTransactionId txn_id, int64_t tablet_id, int64_t txn_expiration);

    // Check if this is a known empty/skipped rowset

    // Returns true if was marked as empty rowset

    // Note: Does not remove the marker, as CalcDeleteBitmapTask may retry.

    // Cleanup is handled by expiration-based removal in remove_expired_tablet_txn_info()

    bool is_empty_rowset(TTransactionId txn_id, int64_t tablet_id);

    // !!!ATTENTION!!!: the delete bitmap stored in CloudTxnDeleteBitmapCache contains sentinel marks,

    // and the version in BitmapKey is DeleteBitmap::TEMP_VERSION_COMMON.

    // when using delete bitmap from this cache, the caller should manually remove these marks if don't need it

    // and should replace versions in BitmapKey by the correct version

    Status get_delete_bitmap(TTransactionId transaction_id, int64_t tablet_id,

                             DeleteBitmapPtr* delete_bitmap, RowsetIdUnorderedSet* rowset_ids,

                             std::shared_ptr<PublishStatus>* publish_status);

private:

    void _clean_thread_callback();

    class DeleteBitmapCacheValue : public LRUCacheValueBase {

    public:

        DeleteBitmapPtr delete_bitmap;

        // records rowsets calc in commit txn

        RowsetIdUnorderedSet rowset_ids;

        DeleteBitmapCacheValue(DeleteBitmapPtr delete_bitmap_, const RowsetIdUnorderedSet& ids_)

                : delete_bitmap(std::move(delete_bitmap_)), rowset_ids(ids_) {}

    };

    struct TxnKey {

        TTransactionId txn_id;

        int64_t tablet_id;

        TxnKey(TTransactionId txn_id_, int64_t tablet_id_)

                : txn_id(txn_id_), tablet_id(tablet_id_) {}

        auto operator<=>(const TxnKey&) const = default;

    };

    struct TxnVal {

        RowsetSharedPtr rowset;

        int64_t txn_expiration;

        std::shared_ptr<PartialUpdateInfo> partial_update_info;

        std::shared_ptr<PublishStatus> publish_status = nullptr;

        // used to determine if the retry needs to re-calculate the delete bitmap

        TxnPublishInfo publish_info;

        TxnVal() : txn_expiration(0) {};

        TxnVal(RowsetSharedPtr rowset_, int64_t txn_expiration_,

               std::shared_ptr<PartialUpdateInfo> partial_update_info_,

               std::shared_ptr<PublishStatus> publish_status_)

                : rowset(std::move(rowset_)),

                  txn_expiration(txn_expiration_),

                  partial_update_info(std::move(partial_update_info_)),

                  publish_status(std::move(publish_status_)) {}

    };

    std::map<TxnKey, TxnVal> _txn_map;

    std::multimap<int64_t, TxnKey> _expiration_txn;

    // Lightweight markers for empty/skipped rowsets (only stores TxnKey, ~16 bytes per entry)

    // Used to track empty rowsets that were not committed to meta-service

    std::set<TxnKey> _empty_rowset_markers;

    std::shared_mutex _rwlock;

    std::shared_ptr<Thread> _clean_thread;

    CountDownLatch _stop_latch;

};

} // namespace doris