// 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/Types_types.h>

#include <functional>

#include <memory>

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_numbers.h"

#include "core/block/columns_with_type_and_name.h"

#include "core/data_type/data_type.h"

#include "core/types.h"

#include "exprs/function/function.h"

namespace doris {

class PythonUDFPreparedFunction : public PreparedFunctionImpl {

public:

    using execute_call_back = std::function<Status(FunctionContext* context, Block& block,

                                                   const ColumnNumbers& arguments, uint32_t result,

                                                   size_t input_rows_count)>;

    explicit PythonUDFPreparedFunction(const execute_call_back& func, const std::string& name)

            : callback_function(func), name(name) {}

    String get_name() const override { return name; }

protected:

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

                        uint32_t result, size_t input_rows_count) const override {

        return callback_function(context, block, arguments, result, input_rows_count);

    }

    bool use_default_implementation_for_nulls() const override { return false; }

private:

    execute_call_back callback_function;

    std::string name;

};

class PythonFunctionCall : public IFunctionBase {

public:

    PythonFunctionCall(const TFunction& fn, const DataTypes& argument_types,

                       const DataTypePtr& return_type);

    static FunctionBasePtr create(const TFunction& fn, const ColumnsWithTypeAndName& argument_types,

                                  const DataTypePtr& return_type) {

        DataTypes data_types(argument_types.size());

        for (size_t i = 0; i < argument_types.size(); ++i) {

            data_types[i] = argument_types[i].type;

        }

        return std::make_shared<PythonFunctionCall>(fn, data_types, return_type);

    }

    /// Get the main function name.

    String get_name() const override { return _fn.name.function_name; }

    const DataTypes& get_argument_types() const override { return _argument_types; }

    const DataTypePtr& get_return_type() const override { return _return_type; }

    PreparedFunctionPtr prepare(FunctionContext* context, const Block& sample_block,

                                const ColumnNumbers& arguments, uint32_t result) const override {

        return std::make_shared<PythonUDFPreparedFunction>(

                [this](auto&& PH1, auto&& PH2, auto&& PH3, auto&& PH4, auto&& PH5) {

                    return PythonFunctionCall::execute_impl(

                            std::forward<decltype(PH1)>(PH1), std::forward<decltype(PH2)>(PH2),

                            std::forward<decltype(PH3)>(PH3), std::forward<decltype(PH4)>(PH4),

                            std::forward<decltype(PH5)>(PH5));

                },

                _fn.name.function_name);

    }

    Status open(FunctionContext* context, FunctionContext::FunctionStateScope scope) override;

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

                        uint32_t result, size_t input_rows_count) const;

    Status close(FunctionContext* context, FunctionContext::FunctionStateScope scope) override;

    bool is_use_default_implementation_for_constants() const override { return true; }

    bool is_udf_function() const override { return true; }

private:

    const TFunction& _fn;

    const DataTypes _argument_types;

    const DataTypePtr _return_type {nullptr};

};

} // namespace doris