// 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 <atomic>

#include <memory>

#include <string>

#include "common/status.h"

#include "io/fs/file_reader.h"

#include "io/fs/file_system.h"

#include "io/fs/path.h"

#include "io/fs/s3_file_system.h"

#include "util/slice.h"

namespace doris {

class RuntimeProfile;

namespace io {

struct IOContext;

class S3FileReader final : public FileReader {

public:

    static Result<FileReaderSPtr> create(std::shared_ptr<const ObjClientHolder> client,

                                         std::string bucket, std::string key, int64_t file_size,

                                         RuntimeProfile* profile);

    S3FileReader(std::shared_ptr<const ObjClientHolder> client, std::string bucket, std::string key,

                 size_t file_size, RuntimeProfile* profile);

    ~S3FileReader() override;

    Status close() override;

    const Path& path() const override { return _path; }

    size_t size() const override { return _file_size; }

    bool closed() const override { return _closed.load(std::memory_order_acquire); }

    int64_t mtime() const override { return 0; }

protected:

    Status read_at_impl(size_t offset, Slice result, size_t* bytes_read,

                        const IOContext* io_ctx) override;

    void _collect_profile_before_close() override;

private:

    struct S3Statistics {

        // The reader is shared by foreground reads and parallel background hole-fill GETs.

        std::atomic<int64_t> total_get_request_counter {0};

        std::atomic<int64_t> too_many_request_err_counter {0};

        std::atomic<int64_t> too_many_request_sleep_time_ms {0};

        std::atomic<int64_t> total_bytes_read {0};

        std::atomic<int64_t> total_get_request_time_ns {0};

    };

    Path _path;

    size_t _file_size;

    std::string _bucket;

    std::string _key;

    std::shared_ptr<const ObjClientHolder> _client;

    std::atomic<bool> _closed = false;

    RuntimeProfile* _profile = nullptr;

    S3Statistics _s3_stats;

};

} // namespace io

} // namespace doris