// 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 <CLucene.h> // IWYU pragma: keep

#include <CLucene/store/IndexInput.h>

#include <gen_cpp/olap_common.pb.h>

#include <gen_cpp/olap_file.pb.h>

#include <string>

#include <utility>

#include "common/be_mock_util.h"

#include "io/fs/file_system.h"

#include "io/fs/file_writer.h"

#include "io/fs/local_file_system.h"

#include "storage/index/index_storage_format.h"

#include "storage/index/inverted/inverted_index_common.h"

#include "storage/index/inverted/inverted_index_compound_reader.h"

#include "storage/index/inverted/inverted_index_searcher.h"

namespace doris {

class TabletIndex;

namespace segment_v2 {

class DorisFSDirectory;

using InvertedIndexDirectoryMap =

        std::map<std::pair<int64_t, std::string>, std::shared_ptr<lucene::store::Directory>>;

class IndexFileWriter;

using IndexFileWriterPtr = std::unique_ptr<IndexFileWriter>;

class IndexFileWriter {

public:

    IndexFileWriter(io::FileSystemSPtr fs, std::string index_path_prefix, std::string rowset_id,

                    int64_t seg_id, InvertedIndexStorageFormatPB storage_format,

                    io::FileWriterPtr file_writer = nullptr, bool can_use_ram_dir = true);

    virtual ~IndexFileWriter() = default;

    MOCK_FUNCTION Result<std::shared_ptr<DorisFSDirectory>> open(const TabletIndex* index_meta);

    Status delete_index(const TabletIndex* index_meta);

    Status initialize(InvertedIndexDirectoryMap& indices_dirs);

    Status add_into_searcher_cache();

    // Begin the close process. This mainly triggers the asynchronous close operation of

    // _idx_v2_writer by calling close(true), which starts the close process but returns

    // immediately without waiting for completion.

    Status begin_close();

    // Finish the close process. This waits for the close operation to complete by calling

    // _idx_v2_writer->close(false), which blocks until the close is fully done.

    Status finish_close();

    const InvertedIndexFileInfo* get_index_file_info() const {

        DCHECK(_closed) << debug_string();

        return &_file_info;

    }

    int64_t get_index_file_total_size() const {

        DCHECK(_closed) << debug_string();

        return _total_file_size;

    }

    const io::FileSystemSPtr& get_fs() const { return _fs; }

    InvertedIndexStorageFormatPB get_storage_format() const { return _storage_format; }

    void set_file_writer_opts(const io::FileWriterOptions& opts) { _opts = opts; }

    std::vector<std::string> get_index_file_names() const;

    std::string debug_string() const;

    // Get internal file writer (for merge file index collection)

    io::FileWriter* get_file_writer() const { return _idx_v2_writer.get(); }

private:

    Status _insert_directory_into_map(int64_t index_id, const std::string& index_suffix,

                                      std::shared_ptr<DorisFSDirectory> dir);

    virtual Result<std::unique_ptr<IndexSearcherBuilder>> _construct_index_searcher_builder(

            const DorisCompoundReader* dir);

    // Member variables...

    InvertedIndexDirectoryMap _indices_dirs;

    const io::FileSystemSPtr _fs;

    std::string _index_path_prefix;

    std::string _rowset_id;

    int64_t _seg_id;

    InvertedIndexStorageFormatPB _storage_format;

    std::string _tmp_dir;

    const std::shared_ptr<io::LocalFileSystem>& _local_fs;

    // write to disk or stream

    io::FileWriterPtr _idx_v2_writer = nullptr;

    io::FileWriterOptions _opts;

    // v1: all file size

    // v2: file size

    int64_t _total_file_size = 0;

    InvertedIndexFileInfo _file_info;

    // only once

    bool _closed = false;

    bool _can_use_ram_dir = true;

    IndexStorageFormatPtr _index_storage_format;

    friend class IndexStorageFormatV1;

    friend class IndexStorageFormatV2;

    friend class IndexFileWriterTest;

};

} // namespace segment_v2

} // namespace doris