// 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.

#include "format/table/equality_delete.h"

#include "core/column/column_const.h"

#include "core/column/column_nullable.h"

#include "exprs/create_predicate_function.h"

#include "util/hash_util.hpp"

namespace doris {

namespace {

// Iceberg BINARY / FIXED keys are read as VARBINARY and string keys as STRING, and the delete file and

// the data file may carry the same key in different ones of these classes (a delete block holding

// STRING bytes for a VARBINARY data column, say). Keys of these types therefore match by their bytes.

bool is_equality_delete_byte_type(const DataTypePtr& type) {

    const auto primitive_type = remove_nullable(type)->get_primitive_type();

    return is_string_type(primitive_type) || is_varbinary(primitive_type);

}

// The rows of a byte-key column. A const column repeats its single value, which can be NULL: when the FE does

// not send Iceberg scan semantics v2, a key column that the data file lacks is filled from

// Const(Nullable(String) NULL), and its rows must match a NULL delete key rather than an empty string.

class ByteKeyColumn {

public:

    explicit ByteKeyColumn(const IColumn& column) : _values(&column) {

        if (const auto* const_column = check_and_get_column<ColumnConst>(_values)) {

            _values = &const_column->get_data_column();

            _is_const = true;

        }

        if (const auto* nullable = check_and_get_column<ColumnNullable>(_values)) {

            _null_map = &nullable->get_null_map_data();

            _values = &nullable->get_nested_column();

        }

    }

    bool is_null(size_t row) const {

        return _null_map != nullptr && (*_null_map)[_is_const ? 0 : row] != 0;

    }

    StringRef value(size_t row) const { return _values->get_data_at(_is_const ? 0 : row); }

private:

    const IColumn* _values;

    const NullMap* _null_map = nullptr;

    bool _is_const = false;

};

void insert_byte_values(const IColumn& column, HybridSetBase* byte_set) {

    const ByteKeyColumn keys(column);

    for (size_t row = 0; row < column.size(); ++row) {

        if (keys.is_null(row)) {

            byte_set->insert(static_cast<const void*>(nullptr));

            continue;

        }

        const StringRef value = keys.value(row);

        byte_set->insert(&value);

    }

}

void find_byte_values(const IColumn& column, const HybridSetBase& byte_set,

                      IColumn::Filter* matches) {

    const ByteKeyColumn keys(column);

    for (size_t row = 0; row < column.size(); ++row) {

        if (keys.is_null(row)) {

            (*matches)[row] = byte_set.contain_null();

            continue;

        }

        const StringRef value = keys.value(row);

        (*matches)[row] = byte_set.find(&value);

    }

}

void update_equality_delete_hashes(const ColumnWithTypeAndName& column_and_type,

                                   std::vector<uint64_t>* hashes) {

    if (!is_equality_delete_byte_type(column_and_type.type)) {

        column_and_type.column->update_hashes_with_value(hashes->data(), nullptr);

        return;

    }

    // Hash the bytes rather than call update_hashes_with_value: VARBINARY does not implement it, and a

    // STRING delete key must land on the same hash as the equal VARBINARY data key.

    const ByteKeyColumn keys(*column_and_type.column);

    for (size_t row = 0; row < column_and_type.column->size(); ++row) {

        if (keys.is_null(row)) {

            (*hashes)[row] = HashUtil::xxHash64NullWithSeed((*hashes)[row]);

            continue;

        }

        const StringRef value = keys.value(row);

        (*hashes)[row] = HashUtil::xxHash64WithSeed(value.data, value.size, (*hashes)[row]);

    }

}

bool equality_delete_values_equal(const ColumnWithTypeAndName& data_column, size_t data_row,

                                  const ColumnWithTypeAndName& delete_column, size_t delete_row) {

    if (!is_equality_delete_byte_type(data_column.type) ||

        !is_equality_delete_byte_type(delete_column.type)) {

        return data_column.column->compare_at(data_row, delete_row, *delete_column.column, -1) == 0;

    }

    const ByteKeyColumn data_keys(*data_column.column);

    const ByteKeyColumn delete_keys(*delete_column.column);

    if (data_keys.is_null(data_row) || delete_keys.is_null(delete_row)) {

        return data_keys.is_null(data_row) && delete_keys.is_null(delete_row);

    }

    return data_keys.value(data_row) == delete_keys.value(delete_row);

}

} // namespace

std::unique_ptr<EqualityDeleteBase> EqualityDeleteBase::get_delete_impl(

        const Block* delete_block, const std::vector<int>& delete_col_ids) {

    DCHECK_EQ(delete_block->columns(), delete_col_ids.size());

    if (delete_block->columns() == 1) {

        return std::make_unique<SimpleEqualityDelete>(delete_block, delete_col_ids);

    } else {

        return std::make_unique<MultiEqualityDelete>(delete_block, delete_col_ids);

    }

}

Status SimpleEqualityDelete::_build_set() {

    COUNTER_UPDATE(num_delete_rows, _delete_block->rows());

    if (_delete_block->columns() != 1) [[unlikely]] {

        return Status::InternalError("Simple equality delete can be only applied with one column");

    }

    const auto& column_and_type = _delete_block->get_by_position(0);

    auto delete_column_type = remove_nullable(column_and_type.type)->get_primitive_type();

    size_t non_null_rows = _delete_block->rows();

    if (const auto* nullable = check_and_get_column<ColumnNullable>(column_and_type.column.get());

        nullable != nullptr) {

        non_null_rows = std::ranges::count(nullable->get_null_map_data(), UInt8(0));

    }

    if (is_equality_delete_byte_type(column_and_type.type)) {

        // create_set has no VARBINARY set (it throws NOT_IMPLEMENTED), so every byte key goes into a

        // STRING set as bytes, whichever of STRING and VARBINARY the delete file was read as.

        _hybrid_set.reset(create_set(TYPE_STRING, non_null_rows, true));

        insert_byte_values(*column_and_type.column, _hybrid_set.get());

    } else {

        _hybrid_set.reset(create_set(delete_column_type, non_null_rows, true));

        _hybrid_set->insert_fixed_len(column_and_type.column, 0);

    }

    return Status::OK();

}

Status SimpleEqualityDelete::filter_data_block(

        Block* data_block, const std::unordered_map<std::string, uint32_t>* col_name_to_block_idx,

        const std::unordered_map<int, std::string>& id_to_block_column_name,

        IColumn::Filter& filter) {

    SCOPED_TIMER(equality_delete_time);

    DCHECK(_delete_col_ids.size() == 1);

    auto column_field_id = _delete_col_ids[0];

    const auto& block_col_name = id_to_block_column_name.at(column_field_id);

    auto block_idx = col_name_to_block_idx->at(block_col_name);

    auto column_and_type = data_block->get_by_position(block_idx);

    const bool delete_is_byte =

            is_equality_delete_byte_type(_delete_block->get_by_position(0).type);

    const bool byte_compatible =

            delete_is_byte && is_equality_delete_byte_type(column_and_type.type);

    // The byte set can only be probed with bytes: an INT data column would be read as StringRef values.

    if (delete_is_byte && !byte_compatible) [[unlikely]] {

        return Status::InternalError(

                "Not support type change in column '{}', src type: {}, target type: {}",

                column_and_type.name, _delete_block->get_by_position(0).type->get_name(),

                column_and_type.type->get_name());

    }

    size_t rows = data_block->rows();

    //     _filter: 1 => in _hybrid_set; 0 => not in _hybrid_set

    if (_single_filter == nullptr) {

        _single_filter = std::make_unique<IColumn::Filter>(rows, 0);

    } else {

        // reset the array capacity and fill all elements using the 0

        _single_filter->assign(rows, UInt8(0));

    }

    auto column = column_and_type.column->convert_to_full_column_if_const();

    if (byte_compatible) {

        find_byte_values(*column, *_hybrid_set, _single_filter.get());

    } else if (const auto* nullable = check_and_get_column<ColumnNullable>(column.get())) {

        const NullMap& null_map = nullable->get_null_map_data();

        _hybrid_set->find_batch_nullable(*remove_nullable(column), rows, null_map, *_single_filter);

        if (_hybrid_set->contain_null()) {

            auto* filter_data = _single_filter->data();

            for (size_t i = 0; i < rows; ++i) {

                filter_data[i] = filter_data[i] || null_map[i];

            }

        }

    } else {

        _hybrid_set->find_batch(*column, rows, *_single_filter);

    }

    // should reverse _filter

    auto* filter_data = filter.data();

    for (size_t i = 0; i < rows; ++i) {

        filter_data[i] &= !_single_filter->data()[i];

    }

    return Status::OK();

}

Status MultiEqualityDelete::_build_set() {

    COUNTER_UPDATE(num_delete_rows, _delete_block->rows());

    size_t rows = _delete_block->rows();

    _delete_hashes.clear();

    _delete_hashes.resize(rows, 0);

    for (const auto& column : _delete_block->get_columns_with_type_and_name()) {

        update_equality_delete_hashes(column, &_delete_hashes);

    }

    for (size_t i = 0; i < rows; ++i) {

        _delete_hash_map.insert({_delete_hashes[i], i});

    }

    _data_column_index.resize(_delete_block->columns());

    return Status::OK();

}

Status MultiEqualityDelete::filter_data_block(

        Block* data_block, const std::unordered_map<std::string, uint32_t>* col_name_to_block_idx,

        const std::unordered_map<int, std::string>& id_to_block_column_name,

        IColumn::Filter& filter) {

    SCOPED_TIMER(equality_delete_time);

    DCHECK_EQ(_delete_block->get_columns_with_type_and_name().size(), _delete_col_ids.size());

    size_t column_index = 0;

    for (size_t idx = 0; idx < _delete_block->get_columns_with_type_and_name().size(); ++idx) {

        auto delete_col = _delete_block->get_columns_with_type_and_name()[idx];

        auto delete_col_id = _delete_col_ids[idx];

        DCHECK(id_to_block_column_name.contains(delete_col_id));

        const auto& block_column_name = id_to_block_column_name.at(delete_col_id);

        if (!col_name_to_block_idx->contains(block_column_name)) [[unlikely]] {

            return Status::InternalError("Column '{}' not found in data block: {}",

                                         block_column_name, data_block->dump_structure());

        }

        auto column_and_type =

                data_block->safe_get_by_position(col_name_to_block_idx->at(block_column_name));

        // A STRING delete key may meet a VARBINARY data column for the same Iceberg BINARY field: both are

        // hashed and compared as bytes, so only a change to or from a non-byte type is rejected.

        const bool byte_compatible = is_equality_delete_byte_type(delete_col.type) &&

                                     is_equality_delete_byte_type(column_and_type.type);

        if (!delete_col.type->equals(*column_and_type.type) && !byte_compatible) [[unlikely]] {

            return Status::InternalError(

                    "Not support type change in column '{}', src type: {}, target type: {}",

                    block_column_name, delete_col.type->get_name(),

                    column_and_type.type->get_name());

        }

        _data_column_index[column_index++] = col_name_to_block_idx->at(block_column_name);

    }

    size_t rows = data_block->rows();

    _data_hashes.clear();

    _data_hashes.resize(rows, 0);

    for (size_t index : _data_column_index) {

        update_equality_delete_hashes(data_block->get_by_position(index), &_data_hashes);

    }

    auto* filter_data = filter.data();

    for (size_t i = 0; i < rows; ++i) {

        for (auto beg = _delete_hash_map.lower_bound(_data_hashes[i]),

                  end = _delete_hash_map.upper_bound(_data_hashes[i]);

             beg != end; ++beg) {

            if (filter[i] && _equal(data_block, i, beg->second)) {

                filter_data[i] = 0;

                break;

            }

        }

    }

    return Status::OK();

}

bool MultiEqualityDelete::_equal(Block* data_block, size_t data_row_index,

                                 size_t delete_row_index) {

    for (size_t i = 0; i < _delete_block->columns(); ++i) {

        if (!equality_delete_values_equal(data_block->get_by_position(_data_column_index[i]),

                                          data_row_index, _delete_block->get_by_position(i),

                                          delete_row_index)) {

            return false;

        }

    }

    return true;

}

} // namespace doris