// 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 <gen_cpp/PaloInternalService_types.h>

#include <gen_cpp/PlanNodes_types.h>

#include <stddef.h>

#include <stdint.h>

#include <memory>

#include <set>

#include <string>

#include <unordered_set>

#include <utility>

#include <vector>

#include "common/status.h"

#include "exprs/function_filter.h"

#include "gutil/strings/substitute.h"

#include "io/io_common.h"

#include "olap/delete_handler.h"

#include "olap/iterators.h"

#include "olap/olap_common.h"

#include "olap/olap_tuple.h"

#include "olap/row_cursor.h"

#include "olap/rowset/rowset.h"

#include "olap/rowset/rowset_meta.h"

#include "olap/rowset/rowset_reader.h"

#include "olap/rowset/rowset_reader_context.h"

#include "olap/tablet_fwd.h"

namespace doris {

class RuntimeState;

class BitmapFilterFuncBase;

class BloomFilterFuncBase;

class ColumnPredicate;

class DeleteBitmap;

class HybridSetBase;

class RuntimeProfile;

namespace vectorized {

class VCollectIterator;

class Block;

class VExpr;

class Arena;

class VExprContext;

} // namespace vectorized

// Used to compare row with input scan key. Scan key only contains key columns,

// row contains all key columns, which is superset of key columns.

// So we should compare the common prefix columns of lhs and rhs.

//

// NOTE: if you are not sure if you can use it, please don't use this function.

inline int compare_row_key(const RowCursor& lhs, const RowCursor& rhs) {

    auto cmp_cids = std::min(lhs.schema()->num_column_ids(), rhs.schema()->num_column_ids());

    for (uint32_t cid = 0; cid < cmp_cids; ++cid) {

        auto res = lhs.schema()->column(cid)->compare_cell(lhs.cell(cid), rhs.cell(cid));

        if (res != 0) {

            return res;

        }

    }

    return 0;

}

class TabletReader {

    struct KeysParam {

        std::string to_string() const;

        std::vector<RowCursor> start_keys;

        std::vector<RowCursor> end_keys;

        bool start_key_include = false;

        bool end_key_include = false;

    };

public:

    struct ReadSource {

        std::vector<RowSetSplits> rs_splits;

        std::vector<RowsetMetaSharedPtr> delete_predicates;

        // Fill delete predicates with `rs_splits`

        void fill_delete_predicates();

    };

    // Params for Reader,

    // mainly include tablet, data version and fetch range.

    struct ReaderParams {

        bool has_single_version() const {

            return (rs_splits.size() == 1 &&

                    rs_splits[0].rs_reader->rowset()->start_version() == 0 &&

                    !rs_splits[0].rs_reader->rowset()->rowset_meta()->is_segments_overlapping()) ||

                   (rs_splits.size() == 2 &&

                    rs_splits[0].rs_reader->rowset()->rowset_meta()->num_rows() == 0 &&

                    rs_splits[1].rs_reader->rowset()->start_version() == 2 &&

                    !rs_splits[1].rs_reader->rowset()->rowset_meta()->is_segments_overlapping());

        }

        void set_read_source(ReadSource read_source) {

            rs_splits = std::move(read_source.rs_splits);

            delete_predicates = std::move(read_source.delete_predicates);

        }

        BaseTabletSPtr tablet;

        TabletSchemaSPtr tablet_schema;

        ReaderType reader_type = ReaderType::READER_QUERY;

        bool direct_mode = false;

        bool aggregation = false;

        // for compaction, schema_change, check_sum: we don't use page cache

        // for query and config::disable_storage_page_cache is false, we use page cache

        bool use_page_cache = false;

        Version version = Version(-1, 0);

        std::vector<OlapTuple> start_key;

        std::vector<OlapTuple> end_key;

        bool start_key_include = false;

        bool end_key_include = false;

        std::vector<TCondition> conditions;

        std::vector<std::pair<string, std::shared_ptr<BloomFilterFuncBase>>> bloom_filters;

        std::vector<std::pair<string, std::shared_ptr<BitmapFilterFuncBase>>> bitmap_filters;

        std::vector<std::pair<string, std::shared_ptr<HybridSetBase>>> in_filters;

        std::vector<FunctionFilter> function_filters;

        std::vector<RowsetMetaSharedPtr> delete_predicates;

        // slots that cast may be eliminated in storage layer

        std::map<std::string, TypeDescriptor> target_cast_type_for_variants;

        std::vector<RowSetSplits> rs_splits;

        // For unique key table with merge-on-write

        DeleteBitmap* delete_bitmap = nullptr;

        // return_columns is init from query schema

        std::vector<uint32_t> return_columns;

        // output_columns only contain columns in OrderByExprs and outputExprs

        std::set<int32_t> output_columns;

        RuntimeProfile* profile = nullptr;

        RuntimeState* runtime_state = nullptr;

        // use only in vec exec engine

        std::vector<uint32_t>* origin_return_columns = nullptr;

        std::unordered_set<uint32_t>* tablet_columns_convert_to_null_set = nullptr;

        TPushAggOp::type push_down_agg_type_opt = TPushAggOp::NONE;

        vectorized::VExpr* remaining_vconjunct_root = nullptr;

        std::vector<vectorized::VExprSPtr> remaining_conjunct_roots;

        vectorized::VExprContextSPtrs common_expr_ctxs_push_down;

        // used for compaction to record row ids

        bool record_rowids = false;

        RowIdConversion* rowid_conversion;

        // flag for enable topn opt

        bool use_topn_opt = false;

        std::vector<int> topn_filter_source_node_ids;

        // used for special optimization for query : ORDER BY key LIMIT n

        bool read_orderby_key = false;

        // used for special optimization for query : ORDER BY key DESC LIMIT n

        bool read_orderby_key_reverse = false;

        // num of columns for orderby key

        size_t read_orderby_key_num_prefix_columns = 0;

        // limit of rows for read_orderby_key

        size_t read_orderby_key_limit = 0;

        // filter_block arguments

        vectorized::VExprContextSPtrs filter_block_conjuncts;

        // for vertical compaction

        bool is_key_column_group = false;

        std::vector<uint32_t> key_group_cluster_key_idxes;

        bool is_segcompaction = false;

        std::vector<RowwiseIteratorUPtr>* segment_iters_ptr = nullptr;

        void check_validation() const;

        std::string to_string() const;

        int64_t batch_size = -1;

    };

    TabletReader() = default;

    virtual ~TabletReader();

    TabletReader(const TabletReader&) = delete;

    void operator=(const TabletReader&) = delete;

    // Initialize TabletReader with tablet, data version and fetch range.

    virtual Status init(const ReaderParams& read_params);

    // Read next block with aggregation.

    // Return OK and set `*eof` to false when next block is read

    // Return OK and set `*eof` to true when no more rows can be read.

    // Return others when unexpected error happens.

    virtual Status next_block_with_aggregation(vectorized::Block* block, bool* eof) {

        return Status::Error<ErrorCode::READER_INITIALIZE_ERROR>(

                "TabletReader not support next_block_with_aggregation");

    }

    virtual uint64_t merged_rows() const { return _merged_rows; }

    uint64_t filtered_rows() const {

        return _stats.rows_del_filtered + _stats.rows_del_by_bitmap +

               _stats.rows_conditions_filtered + _stats.rows_vec_del_cond_filtered +

               _stats.rows_vec_cond_filtered + _stats.rows_short_circuit_cond_filtered;

    }

    void set_batch_size(int batch_size) { _reader_context.batch_size = batch_size; }

    int batch_size() const { return _reader_context.batch_size; }

    const OlapReaderStatistics& stats() const { return _stats; }

    OlapReaderStatistics* mutable_stats() { return &_stats; }

    virtual bool update_profile(RuntimeProfile* profile) { return false; }

    static Status init_reader_params_and_create_block(

            TabletSharedPtr tablet, ReaderType reader_type,

            const std::vector<RowsetSharedPtr>& input_rowsets,

            TabletReader::ReaderParams* reader_params, vectorized::Block* block);

protected:

    friend class vectorized::VCollectIterator;

    friend class DeleteHandler;

    Status _init_params(const ReaderParams& read_params);

    Status _capture_rs_readers(const ReaderParams& read_params);

    bool _optimize_for_single_rowset(const std::vector<RowsetReaderSharedPtr>& rs_readers);

    Status _init_keys_param(const ReaderParams& read_params);

    Status _init_orderby_keys_param(const ReaderParams& read_params);

    Status _init_conditions_param(const ReaderParams& read_params);

    ColumnPredicate* _parse_to_predicate(

            const std::pair<std::string, std::shared_ptr<BloomFilterFuncBase>>& bloom_filter);

    ColumnPredicate* _parse_to_predicate(

            const std::pair<std::string, std::shared_ptr<BitmapFilterFuncBase>>& bitmap_filter);

    ColumnPredicate* _parse_to_predicate(

            const std::pair<std::string, std::shared_ptr<HybridSetBase>>& in_filter);

    virtual ColumnPredicate* _parse_to_predicate(const FunctionFilter& function_filter);

    Status _init_delete_condition(const ReaderParams& read_params);

    Status _init_return_columns(const ReaderParams& read_params);

    const BaseTabletSPtr& tablet() { return _tablet; }

    // If original column is a variant type column, and it's predicate is normalized

    // so in order to get the real type of column predicate, we need to reset type

    // according to the related type in `target_cast_type_for_variants`.Since variant is not

    // an predicate applicable type.Otherwise return the original tablet column.

    // Eg. `where cast(v:a as bigint) > 1` will elimate cast, and materialize this variant column

    // to type bigint

    TabletColumn materialize_column(const TabletColumn& orig);

    const TabletSchema& tablet_schema() { return *_tablet_schema; }

    std::unique_ptr<vectorized::Arena> _predicate_arena;

    std::vector<uint32_t> _return_columns;

    // used for special optimization for query : ORDER BY key [ASC|DESC] LIMIT n

    // columns for orderby keys

    std::vector<uint32_t> _orderby_key_columns;

    // only use in outer join which change the column nullable which must keep same in

    // vec query engine

    std::unordered_set<uint32_t>* _tablet_columns_convert_to_null_set = nullptr;

    BaseTabletSPtr _tablet;

    RowsetReaderContext _reader_context;

    TabletSchemaSPtr _tablet_schema;

    KeysParam _keys_param;

    std::vector<bool> _is_lower_keys_included;

    std::vector<bool> _is_upper_keys_included;

    std::vector<ColumnPredicate*> _col_predicates;

    std::vector<ColumnPredicate*> _value_col_predicates;

    DeleteHandler _delete_handler;

    bool _aggregation = false;

    // for agg query, we don't need to finalize when scan agg object data

    ReaderType _reader_type = ReaderType::READER_QUERY;

    bool _next_delete_flag = false;

    bool _filter_delete = false;

    int32_t _sequence_col_idx = -1;

    bool _direct_mode = false;

    std::vector<uint32_t> _key_cids;

    std::vector<uint32_t> _value_cids;

    uint64_t _merged_rows = 0;

    OlapReaderStatistics _stats;

};

} // namespace doris