// Licensed to the LF AI & Data foundation 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 <string>
#include <optional>
#include <memory>

#include "knowhere/file_manager.h"

namespace milvus::storage {

class FileManagerImpl : public knowhere::FileManager {
 public:
    /**
     * @brief Load a file to the local disk, so we can use stl lib to operate it.
     *
     * @param filename
     * @return false if any error, or return true.
     */
    virtual bool
    LoadFile(const std::string& filename) noexcept = 0;

    /**
     * @brief Add file to FileManager to manipulate it.
     *
     * @param filename
     * @return false if any error, or return true.
     */
    virtual bool
    AddFile(const std::string& filename) noexcept = 0;

    /**
     * @brief Check if a file exists.
     *
     * @param filename
     * @return std::nullopt if any error, or return if the file exists.
     */
    virtual std::optional<bool>
    IsExisted(const std::string& filename) noexcept = 0;

    /**
     * @brief Delete a file from FileManager.
     *
     * @param filename
     * @return false if any error, or return true.
     */
    virtual bool
    RemoveFile(const std::string& filename) noexcept = 0;
};

using FileManagerImplPtr = std::shared_ptr<FileManagerImpl>;

}  // namespace milvus::storage
