// 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 "core/column/column_array.h"

#include "core/column/column_map.h"

#include "core/data_type/data_type_array.h"

#include "core/data_type/data_type_number.h"

#include "exprs/function/array/function_array_utils.h"

#include "exprs/function/function.h"

#include "exprs/function/function_helpers.h"

#include "exprs/function/simple_function_factory.h"

namespace doris {

// size function for size with map and array

class FunctionSize : public IFunction {

public:

    static constexpr auto name = "size";

    static FunctionPtr create() { return std::make_shared<FunctionSize>(); }

    String get_name() const override { return name; }

    bool is_variadic() const override { return true; }

    size_t get_number_of_arguments() const override { return 0; }

    bool use_default_implementation_for_constants() const override { return false; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

        DataTypePtr datatype = arguments[0];

        DCHECK(datatype->get_primitive_type() == TYPE_MAP ||

               datatype->get_primitive_type() == TYPE_ARRAY)

                << "first argument for function: " << name

                << " should be DataTypeMap or DataTypeArray";

        return std::make_shared<DataTypeInt64>();

    }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,

                        uint32_t result, size_t input_rows_count) const override {

        const auto& [left_column, left_const] =

                unpack_if_const(block.get_by_position(arguments[0]).column);

        const auto type = block.get_by_position(arguments[0]).type;

        const ColumnArray* array_column = nullptr;

        const ColumnMap* map_column = nullptr;

        if (type->get_primitive_type() == TYPE_ARRAY) {

            array_column = check_and_get_column<ColumnArray>(*left_column.get());

        } else if (type->get_primitive_type() == TYPE_MAP) {

            map_column = check_and_get_column<ColumnMap>(*left_column.get());

        }

        auto dst_column = ColumnInt64::create(input_rows_count);

        auto& dst_data = dst_column->get_data();

        if (left_const && map_column) {

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

                dst_data[i] = map_column->size_at(0);

            }

        } else if (left_const && array_column) {

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

                dst_data[i] = array_column->size_at(0);

            }

        } else if (map_column) {

            for (size_t i = 0; i < map_column->size(); i++) {

                dst_data[i] = map_column->size_at(i);

            }

        } else if (array_column) {

            for (size_t i = 0; i < array_column->size(); i++) {

                dst_data[i] = array_column->size_at(i);

            }

        } else {

            return Status::RuntimeError("unsupported types for function {}({})", get_name(),

                                        block.get_by_position(arguments[0]).type->get_name());

        }

        block.replace_by_position(result, std::move(dst_column));

        return Status::OK();

    }

};

void register_function_size(SimpleFunctionFactory& factory) {

    factory.register_function<FunctionSize>();

    factory.register_alias(FunctionSize::name, "map_size");

    factory.register_alias(FunctionSize::name, "cardinality");

    factory.register_alias(FunctionSize::name, "array_size");

}

} // namespace doris