// 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 <variant>

#include "common/status.h"

#include "storage/index/index_reader.h"

namespace doris::segment_v2 {

struct AnnTopNParam;

struct IndexQueryContext;

using IndexQueryContextPtr = std::shared_ptr<IndexQueryContext>;

class InvertedIndexQueryCacheHandle;

enum class InvertedIndexReaderType;

struct InvertedIndexParam;

using IndexParam = std::variant<InvertedIndexParam*, segment_v2::AnnTopNParam*>;

enum class AnnIndexReaderType {

    ANN = 0,

};

using IndexReaderType = std::variant<InvertedIndexReaderType, AnnIndexReaderType>;

class IndexIterator {

public:

    IndexIterator() = default;

    virtual ~IndexIterator() = default;

    virtual IndexReaderPtr get_reader(IndexReaderType reader_type) const = 0;

    virtual Status read_from_index(const IndexParam& param) = 0;

    virtual Status read_null_bitmap(InvertedIndexQueryCacheHandle* cache_handle) = 0;

    virtual Result<bool> has_null() = 0;

    void set_context(const IndexQueryContextPtr& context) { _context = context; }

    IndexQueryContextPtr get_context() const { return _context; }

protected:

    IndexQueryContextPtr _context = nullptr;

};

} // namespace doris::segment_v2