// 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/status.h"

#include "exprs/lambda_function/lambda_function.h"

#include "exprs/lambda_function/lambda_function_factory.h"

#include "exprs/vexpr.h"

#include "exprs/vlambda_function_expr.h"

#include "fmt/format.h"

#include "fmt/ranges.h"

namespace doris {

class VLambdaFunctionCallExpr : public VExpr {

    ENABLE_FACTORY_CREATOR(VLambdaFunctionCallExpr);

public:

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

    ~VLambdaFunctionCallExpr() override = default;

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

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

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

        std::vector<std::string_view> child_expr_name;

        for (auto child : _children) {

            child_expr_name.emplace_back(child->expr_name());

        }

        _expr_name = fmt::format("{}({})", _fn.name.function_name, child_expr_name);

        _lambda_function = LambdaFunctionFactory::instance().get_function(_fn.name.function_name);

        if (_lambda_function == nullptr) {

            return Status::InternalError("Lambda Function {} is not implemented.",

                                         _fn.name.function_name);

        }

        RETURN_IF_ERROR(_lambda_function->prepare(state));

        _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 _lambda_function->execute(context, block, selector, count, result_column, _data_type,

                                         _children);

    }

    std::string debug_string() const override {

        std::stringstream out;

        out << "VLambdaFunctionCallExpr[";

        out << _expr_name;

        out << "]{";

        bool first = true;

        for (auto& input_expr : children()) {

            if (first) {

                first = false;

            } else {

                out << ",";

            }

            out << "\n" << input_expr->debug_string();

        }

        out << "}";

        return out.str();

    }

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

private:

    std::string _expr_name;

    LambdaFunctionPtr _lambda_function;

};

} // namespace doris