// 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 "common/global_types.h"

#include "exprs/function/function.h"

#include "exprs/vexpr.h"

namespace doris {

class VLambdaFunctionExpr final : public VExpr {

    ENABLE_FACTORY_CREATOR(VLambdaFunctionExpr);

public:

    VLambdaFunctionExpr(const TExprNode& node) : VExpr(node) {}

    ~VLambdaFunctionExpr() override = default;

    Status prepare(RuntimeState* state, const RowDescriptor& desc, VExprContext* context) override {

        RETURN_IF_ERROR_OR_PREPARED(VExpr::prepare(state, desc, context));

        // Fix _data_type to match the lambda body's actual return type.

        // The initial _data_type was set to DataTypeString as a placeholder during

        // VExpr(TExprNode) construction; override it with the body's real type.

        data_type() = get_child(0)->data_type();

        _prepare_finished = true;

        return Status::OK();

    }

    Status open(RuntimeState* state, VExprContext* context,

                FunctionContext::FunctionStateScope scope) override {

        DCHECK(_prepare_finished);

        RETURN_IF_ERROR(VExpr::open(state, context, scope));

        _open_finished = true;

        return Status::OK();

    }

    Status execute_column(VExprContext* context, const Block* block, Selector* selector,

                          size_t count, ColumnPtr& result_column) const override {

        DCHECK(_open_finished || block == nullptr);

        return get_child(0)->execute_column(context, block, selector, count, result_column);

    }

    DataTypePtr execute_type(const Block* block) const override {

        return get_child(0)->execute_type(block);

    }

    const std::string& expr_name() const override { return _expr_name; }

    uint64_t get_digest(uint64_t seed) const override { return 0; }

private:

    const std::string _expr_name = "vlambda_function_expr";

};

} // namespace doris