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// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

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// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

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// software distributed under the License is distributed on an

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// specific language governing permissions and limitations

// under the License.

#pragma once

#include <cstdint>

#include <memory>

#include "common/factory_creator.h"

#include "core/column/column_dictionary.h"

#include "storage/index/bloom_filter/bloom_filter.h"

#include "storage/index/inverted/inverted_index_cache.h"

#include "storage/index/inverted/inverted_index_reader.h"

#include "storage/predicate/column_predicate.h"

namespace doris {

/**

 * A wrapper predicate that delegate to nested predicate

 *  but pass (set/return true) for NULL value rows.

 *

 * At parent, it's used for topn runtime predicate.

 * Eg: original input indexs is '1,2,3,7,8,9' and value of index9 is null, we get nested predicate output index is '1,2,3', but we finally output '1,2,3,9'

*/

class AcceptNullPredicate : public ColumnPredicate {

    ENABLE_FACTORY_CREATOR(AcceptNullPredicate);

public:

    AcceptNullPredicate(const std::shared_ptr<ColumnPredicate>& nested)

            : ColumnPredicate(nested->column_id(), nested->col_name(), nested->primitive_type(),

                              nested->opposite()),

              _nested {nested} {}

    AcceptNullPredicate(const AcceptNullPredicate& other, uint32_t col_id)

            : ColumnPredicate(other, col_id),

              _nested(other._nested ? other._nested->clone(col_id) : nullptr) {}

    AcceptNullPredicate(const AcceptNullPredicate& other) = delete;

    ~AcceptNullPredicate() override = default;

    std::shared_ptr<ColumnPredicate> clone(uint32_t col_id) const override {

        return AcceptNullPredicate::create_shared(*this, col_id);

    }

    std::string debug_string() const override {

        auto n = _nested;

        fmt::memory_buffer debug_string_buffer;

        fmt::format_to(debug_string_buffer, "AcceptNullPredicate({}, nested={})",

                       ColumnPredicate::debug_string(), n ? n->debug_string() : "null");

        return fmt::to_string(debug_string_buffer);

    }

    PredicateType type() const override { return _nested->type(); }

    Status evaluate(const IndexFieldNameAndTypePair& name_with_type, IndexIterator* iterator,

                    uint32_t num_rows, roaring::Roaring* bitmap) const override {

        roaring::Roaring null_rows_in_bitmap;

        if (iterator != nullptr) {

            bool has_null = DORIS_TRY(iterator->has_null());

            if (has_null) {

                InvertedIndexQueryCacheHandle null_bitmap_cache_handle;

                RETURN_IF_ERROR(iterator->read_null_bitmap(&null_bitmap_cache_handle));

                auto null_bitmap = null_bitmap_cache_handle.get_bitmap();

                if (null_bitmap) {

                    null_rows_in_bitmap = *bitmap & *null_bitmap;

                }

            }

        }

        RETURN_IF_ERROR(_nested->evaluate(name_with_type, iterator, num_rows, bitmap));

        *bitmap |= null_rows_in_bitmap;

        return Status::OK();

    }

    void evaluate_and(const IColumn& column, const uint16_t* sel, uint16_t size,

                      bool* flags) const override {

        if (column.has_null()) {

            std::vector<uint8_t> original_flags(size);

            memcpy(original_flags.data(), flags, size);

            const auto& nullable_col = assert_cast<const ColumnNullable&>(column);

            _nested->evaluate_and(nullable_col.get_nested_column(), sel, size, flags);

            const auto& nullmap = nullable_col.get_null_map_data();

            for (uint16_t i = 0; i < size; ++i) {

                flags[i] |= (original_flags[i] && nullmap[sel[i]]);

            }

        } else {

            _nested->evaluate_and(column, sel, size, flags);

        }

    }

    void evaluate_or(const IColumn& column, const uint16_t* sel, uint16_t size,

                     bool* flags) const override {

        DCHECK(false) << "should not reach here";

    }

    bool evaluate_and(const segment_v2::ZoneMap& zone_map) const override {

        // there is null in range, accept it

        if (zone_map.has_null) {

            return true;

        }

        return _nested->evaluate_and(zone_map);

    }

    bool evaluate_and(ParquetPredicate::ColumnStat* statistic) const override {

        return _nested->evaluate_and(statistic) || statistic->has_null;

    }

    bool evaluate_and(ParquetPredicate::CachedPageIndexStat* statistic,

                      RowRanges* row_ranges) const override {

        _nested->evaluate_and(statistic, row_ranges);

        ParquetPredicate::PageIndexStat* stat = nullptr;

        if (!(statistic->get_stat_func)(&stat, column_id())) {

            return true;

        }

        for (int page_id = 0; page_id < stat->num_of_pages; page_id++) {

            if (stat->has_null[page_id]) {

                row_ranges->add(stat->ranges[page_id]);

            }

        }

        return row_ranges->count() > 0;

    }

    bool evaluate_del(const segment_v2::ZoneMap& zone_map) const override {

        return _nested->evaluate_del(zone_map);

    }

    bool evaluate_and(const BloomFilter* bf) const override { return _nested->evaluate_and(bf); }

    bool can_do_bloom_filter(bool ngram) const override {

        return _nested->can_do_bloom_filter(ngram);

    }

    void evaluate_vec(const IColumn& column, uint16_t size, bool* flags) const override {

        if (column.has_null()) {

            const auto& nullable_col = assert_cast<const ColumnNullable&>(column);

            _nested->evaluate_vec(nullable_col.get_nested_column(), size, flags);

            for (uint16_t i = 0; i < size; ++i) {

                if (!flags[i] && nullable_col.is_null_at(i)) {

                    // set true for NULL rows

                    flags[i] = true;

                }

            }

        } else {

            _nested->evaluate_vec(column, size, flags);

        }

    }

    void evaluate_and_vec(const IColumn& column, uint16_t size, bool* flags) const override {

        if (column.has_null()) {

            // copy original flags

            std::vector<uint8_t> original_flags(size);

            memcpy(original_flags.data(), flags, size);

            const auto& nullable_col = assert_cast<const ColumnNullable&>(column);

            // call evaluate_and_vec and restore true for NULL rows

            _nested->evaluate_and_vec(nullable_col.get_nested_column(), size, flags);

            for (uint16_t i = 0; i < size; ++i) {

                if (original_flags[i] && !flags[i] && nullable_col.is_null_at(i)) {

                    flags[i] = true;

                }

            }

        } else {

            _nested->evaluate_and_vec(column, size, flags);

        }

    }

    std::string get_search_str() const override { return _nested->get_search_str(); }

private:

    uint16_t _evaluate_inner(const IColumn& column, uint16_t* sel, uint16_t size) const override {

        if (column.has_null()) {

            if (size == 0) {

                return 0;

            }

            // create selected_flags

            uint16_t max_idx = sel[size - 1];

            std::vector<uint16_t> old_sel(size);

            memcpy(old_sel.data(), sel, sizeof(uint16_t) * size);

            const auto& nullable_col = assert_cast<const ColumnNullable&>(column);

            // call nested predicate evaluate

            uint16_t new_size = _nested->evaluate(nullable_col.get_nested_column(), sel, size);

            // process NULL values

            if (new_size < size) {

                std::vector<uint8_t> selected(max_idx + 1, 0);

                const auto* nullmap = nullable_col.get_null_map_data().data();

                // add rows selected by _nested->evaluate

                for (uint16_t i = 0; i < new_size; ++i) {

                    uint16_t row_idx = sel[i];

                    selected[row_idx] = true;

                }

                // reset null from original data

                for (uint16_t i = 0; i < size; ++i) {

                    uint16_t row_idx = old_sel[i];

                    selected[row_idx] |= nullmap[row_idx];

                }

                // recaculate new_size and sel array

                new_size = 0;

                for (uint16_t row_idx = 0; row_idx < max_idx + 1; ++row_idx) {

                    if (selected[row_idx]) {

                        sel[new_size++] = row_idx;

                    }

                }

            }

            return new_size;

        }

        return _nested->evaluate(column, sel, size);

    }

    std::shared_ptr<ColumnPredicate> _nested;

};

} //namespace doris