// 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 <memory>

#include <vector>

#include "common/status.h"

#include "io/fs/file_reader_writer_fwd.h"

#include "olap/merger.h"

#include "olap/simple_rowid_conversion.h"

#include "olap/tablet.h"

#include "segment_v2/segment.h"

namespace doris {

class Schema;

namespace segment_v2 {

class SegmentWriter;

} // namespace segment_v2

namespace vectorized {

class RowSourcesBuffer;

class VerticalBlockReader;

} // namespace vectorized

struct OlapReaderStatistics;

using SegCompactionCandidates = std::vector<segment_v2::SegmentSharedPtr>;

using SegCompactionCandidatesSharedPtr = std::shared_ptr<SegCompactionCandidates>;

class BetaRowsetWriter;

class SegcompactionWorker {

    friend class BetaRowsetWriter;

public:

    explicit SegcompactionWorker(BetaRowsetWriter* writer);

    ~SegcompactionWorker() {

        DCHECK(_seg_compact_mem_tracker != nullptr);

        SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(_seg_compact_mem_tracker);

        if (_rowid_conversion) {

            _rowid_conversion.reset();

        }

    }

    void compact_segments(SegCompactionCandidatesSharedPtr segments);

    bool need_convert_delete_bitmap();

    void convert_segment_delete_bitmap(DeleteBitmapPtr src_delete_bitmap, uint32_t src_seg_id,

                                       uint32_t dest_seg_id);

    void convert_segment_delete_bitmap(DeleteBitmapPtr src_delete_bitmap, uint32_t src_begin,

                                       uint32_t src_end, uint32_t dest_seg_id);

    DeleteBitmapPtr get_converted_delete_bitmap() { return _converted_delete_bitmap; }

    io::FileWriterPtr& get_file_writer() { return _file_writer; }

    // set the cancel flag, tasks already started will not be cancelled.

    bool cancel();

    void init_mem_tracker(int64_t txn_id);

private:

    Status _create_segment_writer_for_segcompaction(

            std::unique_ptr<segment_v2::SegmentWriter>* writer, uint32_t begin, uint32_t end);

    Status _get_segcompaction_reader(SegCompactionCandidatesSharedPtr segments,

                                     TabletSharedPtr tablet, std::shared_ptr<Schema> schema,

                                     OlapReaderStatistics* stat,

                                     vectorized::RowSourcesBuffer& row_sources_buf, bool is_key,

                                     std::vector<uint32_t>& return_columns,

                                     std::unique_ptr<vectorized::VerticalBlockReader>* reader);

    std::unique_ptr<segment_v2::SegmentWriter> _create_segcompaction_writer(uint32_t begin,

                                                                            uint32_t end);

    Status _delete_original_segments(uint32_t begin, uint32_t end);

    Status _check_correctness(OlapReaderStatistics& reader_stat, Merger::Statistics& merger_stat,

                              uint32_t begin, uint32_t end);

    Status _do_compact_segments(SegCompactionCandidatesSharedPtr segments);

private:

    //TODO(zhengyu): current impl depends heavily on the access to feilds of BetaRowsetWriter

    // Currently cloud storage engine doesn't need segcompaction

    BetaRowsetWriter* _writer = nullptr;

    io::FileWriterPtr _file_writer;

    // for unique key mow table

    std::unique_ptr<SimpleRowIdConversion> _rowid_conversion = nullptr;

    DeleteBitmapPtr _converted_delete_bitmap;

    std::shared_ptr<MemTrackerLimiter> _seg_compact_mem_tracker = nullptr;

    // the state is not mutable when 1)actual compaction operation started or 2) cancelled

    std::atomic<bool> _is_compacting_state_mutable = true;

};

} // namespace doris