// 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 <algorithm>

#include <cstddef>

#include "common/status.h"

#include "core/column/column_nullable.h"

#include "core/column/column_vector.h"

#include "core/data_type/data_type.h"

#include "exprs/table_function/table_function.h"

namespace doris {

class Block;

class VExplodeNumbersTableFunction : public TableFunction {

    ENABLE_FACTORY_CREATOR(VExplodeNumbersTableFunction);

public:

    VExplodeNumbersTableFunction();

    ~VExplodeNumbersTableFunction() override = default;

    Status process_init(Block* block, RuntimeState* state) override;

    void process_row(size_t row_idx) override;

    void process_close() override;

    void get_same_many_values(MutableColumnPtr& column, int length) override;

    int get_value(MutableColumnPtr& column, int max_step) override {

        max_step = std::min(max_step, (int)(_cur_size - _cur_offset));

        if (_is_const) {

            if (_is_nullable) {

                static_cast<ColumnInt32*>(

                        static_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get())

                        ->insert_range_from(*_elements_column, _cur_offset, max_step);

                static_cast<ColumnUInt8*>(

                        static_cast<ColumnNullable*>(column.get())->get_null_map_column_ptr().get())

                        ->insert_many_defaults(max_step);

            } else {

                static_cast<ColumnInt32*>(column.get())

                        ->insert_range_from(*_elements_column, _cur_offset, max_step);

            }

        } else {

            // should dispose the empty status, forward one step

            if (current_empty()) {

                column->insert_default();

                max_step = 1;

            } else {

                ColumnInt32* target = nullptr;

                if (_is_nullable) {

                    target = assert_cast<ColumnInt32*>(assert_cast<ColumnNullable*>(column.get())

                                                               ->get_nested_column_ptr()

                                                               .get());

                    assert_cast<ColumnUInt8*>(assert_cast<ColumnNullable*>(column.get())

                                                      ->get_null_map_column_ptr()

                                                      .get())

                            ->insert_many_defaults(max_step);

                } else {

                    target = assert_cast<ColumnInt32*>(column.get());

                }

                auto origin_size = target->size();

                target->resize(origin_size + max_step);

                std::iota(target->get_data().data() + origin_size,

                          target->get_data().data() + origin_size + max_step, _cur_offset);

            }

        }

        forward(max_step);

        return max_step;

    }

private:

    ColumnPtr _value_column;

    ColumnPtr _elements_column = ColumnInt32::create();

};

} // namespace doris