// 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 <map>

#include <memory>

#include <string>

#include "common/status.h"

#include "core/pod_array.h"

#include "io/fs/file_handle_cache.h"

#include "io/fs/file_reader.h"

#include "io/fs/file_system.h"

#include "runtime/runtime_profile.h"

#include "service/http/http_client.h"

#include "util/slice.h"

namespace doris::io {

typedef struct OpenFileInfo {

    Path path;

    std::map<std::string, std::string> extend_info;

} OpenFileInfo;

class HttpFileReader final : public FileReader {

public:

    static Result<FileReaderSPtr> create(const std::string& url,

                                         const std::map<std::string, std::string>& props,

                                         const FileReaderOptions& opts, RuntimeProfile* profile);

    explicit HttpFileReader(const OpenFileInfo& fileInfo, std::string url, int64_t mtime);

    ~HttpFileReader() override;

    Status open(const FileReaderOptions& opts);

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

                        const IOContext* io_ctx = nullptr) override;

    Status close() override;

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

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

    size_t size() const override { return _file_size; }

    int64_t mtime() const override { return _mtime; }

private:

    // Prepare and initialize the HTTP client for a new request

    Status prepare_client(bool set_fail_on_error = true);

    // Detect if the HTTP server supports Range requests

    // Returns OK on success with _range_supported set appropriately

    Status detect_range_support();

    // Start the CDC client process

    // Called at the start of open() when enable_cdc_client=true.

    Status setup_cdc_client();

    PODArray<char> _read_buffer;

    static constexpr size_t READ_BUFFER_SIZE = 1 << 20; // 1MB

    // Default maximum file size for servers that don't support Range requests

    static constexpr size_t DEFAULT_MAX_REQUEST_SIZE = 100 << 20; // 100MB

    size_t _buffer_start = 0;

    size_t _buffer_end = 0;

    bool _size_known = false;

    bool _range_supported = true;

    std::string _etag;

    bool _initialized = false;

    std::map<std::string, std::string> _extend_kv;

    size_t _file_size = static_cast<size_t>(-1);

    Path _path;

    std::string _url;

    int64_t _last_modified = 0;

    std::atomic<bool> _closed = false;

    std::unique_ptr<HttpClient> _client;

    int64_t _mtime;

    // Configuration for non-Range request handling

    bool _enable_range_request = true;                         // Whether Range request is required

    size_t _max_request_size_bytes = DEFAULT_MAX_REQUEST_SIZE; // Max size for non-Range downloads

    // Full file cache for non-Range mode to avoid repeated downloads

    std::string _full_file_cache;   // Cache complete file content

    bool _full_file_cached = false; // Whether full file has been cached

    bool _enable_chunk_response = false; // Whether server returns chunk streaming response

};

} // namespace doris::io