// Copyright 2023 PingCAP, Inc.
//
// Licensed 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 <Parsers/ASTExpressionList.h>
#include <Parsers/ASTWithAlias.h>


namespace DB
{

/** AST for function application or operator.
  */
class ASTFunction : public ASTWithAlias
{
public:
    String name;
    ASTPtr arguments;
    /// parameters - for parametric aggregate function. Example: quantile(0.9)(x) - what in first parens are 'parameters'.
    ASTPtr parameters;

public:
    /** Get text identifying the AST node. */
    String getID() const override;

    ASTPtr clone() const override;

protected:
    void formatImplWithoutAlias(const FormatSettings & settings, FormatState & state, FormatStateStacked frame)
        const override;
    String getColumnNameImpl() const override;
};


template <typename... Args>
ASTPtr makeASTFunction(const String & name, Args &&... args)
{
    const auto function = std::make_shared<ASTFunction>();

    function->name = name;
    function->arguments = std::make_shared<ASTExpressionList>();
    function->children.push_back(function->arguments);

    function->arguments->children = {std::forward<Args>(args)...};

    return function;
}

} // namespace DB