// 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 <fmt/format.h>

#include <gen_cpp/Types_types.h>

#include <stddef.h>

#include <memory>

#include <string>

#include <vector>

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_numbers.h"

#include "core/block/column_with_type_and_name.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"

#include "exprs/function_context.h"

namespace doris {

class PFunctionCallRequest;

class PFunctionService_Stub;

class PValues;

} // namespace doris

namespace doris {

class RPCFnImpl {

public:

    RPCFnImpl(const TFunction& fn);

    ~RPCFnImpl() = default;

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

                    uint32_t result, size_t input_rows_count);

    bool available() { return _client != nullptr; }

private:

    Status _convert_block_to_proto(Block& block, const ColumnNumbers& arguments,

                                   size_t input_rows_count, PFunctionCallRequest* request);

    Status _convert_to_block(Block& block, const PValues& result, size_t pos);

    std::shared_ptr<PFunctionService_Stub> _client;

    std::string _function_name;

    std::string _server_addr;

    std::string _signature;

    TFunction _fn;

};

class RPCPreparedFunction : public IPreparedFunction {

public:

    ~RPCPreparedFunction() override = default;

    /// Get the main function name.

    String get_name() const override { return "RPCPreparedFunction: "; }

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

                   uint32_t result, size_t input_rows_count) const override {

        auto* fn = reinterpret_cast<RPCFnImpl*>(

                context->get_function_state(FunctionContext::FRAGMENT_LOCAL));

        return fn->vec_call(context, block, arguments, result, input_rows_count);

    }

};

class FunctionRPC : public IFunctionBase {

public:

    FunctionRPC(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<FunctionRPC>(fn, data_types, return_type);

    }

    /// Get the main function name.

    String get_name() const override {

        return fmt::format("{}: [{}/{}]", _tfn.name.function_name, _tfn.hdfs_location,

                           _tfn.scalar_fn.symbol);

    }

    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<RPCPreparedFunction>();

    }

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

    bool is_use_default_implementation_for_constants() const override { return true; }

private:

    DataTypes _argument_types;

    DataTypePtr _return_type;

    TFunction _tfn;

};

} // namespace doris