// 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 <cstdint>

#include <string>

#include <unordered_map>

#include "common/be_mock_util.h"

#include "olap/olap_common.h"

#include "olap/rowset/segment_v2/inverted_index/query/query_info.h"

#include "runtime/runtime_state.h"

#include "vec/exprs/vexpr_fwd.h"

namespace doris {

#include "common/compile_check_begin.h"

namespace io {

class FileSystem;

using FileSystemSPtr = std::shared_ptr<FileSystem>;

} // namespace io

struct RowSetSplits;

class TabletIndex;

class TabletSchema;

using TabletSchemaSPtr = std::shared_ptr<TabletSchema>;

struct TermInfoComparer {

    bool operator()(const segment_v2::TermInfo& lhs, const segment_v2::TermInfo& rhs) const {

        return lhs.term < rhs.term;

    }

};

class CollectInfo {

public:

    std::set<segment_v2::TermInfo, TermInfoComparer> term_infos;

    const TabletIndex* index_meta = nullptr;

};

class CollectionStatistics {

public:

    CollectionStatistics() = default;

    virtual ~CollectionStatistics() = default;

    Status collect(RuntimeState* state, const std::vector<RowSetSplits>& rs_splits,

                   const TabletSchemaSPtr& tablet_schema,

                   const vectorized::VExprContextSPtrs& common_expr_ctxs_push_down);

    MOCK_FUNCTION float get_or_calculate_idf(const std::wstring& lucene_col_name,

                                             const std::wstring& term);

    MOCK_FUNCTION float get_or_calculate_avg_dl(const std::wstring& lucene_col_name);

private:

    Status extract_collect_info(RuntimeState* state,

                                const vectorized::VExprContextSPtrs& common_expr_ctxs_push_down,

                                const TabletSchemaSPtr& tablet_schema,

                                std::unordered_map<std::wstring, CollectInfo>* collect_infos);

    Status process_segment(const std::string& seg_path, const io::FileSystemSPtr& fs,

                           const TabletSchema* tablet_schema,

                           const std::unordered_map<std::wstring, CollectInfo>& collect_infos);

    uint64_t get_term_doc_freq_by_col(const std::wstring& lucene_col_name,

                                      const std::wstring& term);

    uint64_t get_total_term_cnt_by_col(const std::wstring& lucene_col_name);

    uint64_t get_doc_num() const;

    uint64_t _total_num_docs = 0;

    std::unordered_map<std::wstring, uint64_t> _total_num_tokens;

    std::unordered_map<std::wstring, std::unordered_map<std::wstring, uint64_t>> _term_doc_freqs;

    std::unordered_map<std::wstring, float> _avg_dl_by_col;

    std::unordered_map<std::wstring, std::unordered_map<std::wstring, float>> _idf_by_col_term;

    MOCK_DEFINE(friend class BM25SimilarityTest;)

    MOCK_DEFINE(friend class CollectionStatisticsTest;)

    MOCK_DEFINE(friend class BooleanQueryTest;)

};

using CollectionStatisticsPtr = std::shared_ptr<CollectionStatistics>;

#include "common/compile_check_end.h"

} // namespace doris