// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#ifndef CARBON_TOOLCHAIN_SEMANTICS_NODES_FUNCTION_H_
#define CARBON_TOOLCHAIN_SEMANTICS_NODES_FUNCTION_H_

#include "common/ostream.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "toolchain/parser/parse_tree.h"
#include "toolchain/semantics/node_kind.h"
#include "toolchain/semantics/node_ref.h"

namespace Carbon::Semantics {

// Represents `fn name(params...) [-> return_expr] body`.
class Function {
 public:
  static constexpr NodeKind Kind = NodeKind::Function;

  Function(ParseTree::Node node, int32_t id,
           // llvm::SmallVector<PatternBinding, 0> params,
           // llvm::SmallVector<NodeRef, 0> return_type,
           llvm::SmallVector<NodeRef, 0> body)
      : node_(node),
        id_(id),
        // params_(std::move(params)),
        // return_expr_(return_expr),
        body_(std::move(body)) {}

  void Print(llvm::raw_ostream& out,
             std::function<void(NodeRef)> print_node_ref) const {
    out << "Function(%" << id_ << ", {";
    llvm::ListSeparator sep(", ");
    for (auto& node_ref : body_) {
      out << sep;
      print_node_ref(node_ref);
    }
    out << "})";
  }

  auto node() const -> ParseTree::Node { return node_; }
  auto id() const -> int32_t { return id_; }
  // auto params() const -> llvm::ArrayRef<PatternBinding> { return params_; }
  // auto return_expr() const -> llvm::Optional<Statement> { return
  // return_expr_; }
  auto body() const -> llvm::ArrayRef<NodeRef> { return body_; }

 private:
  // The FunctionDeclaration node.
  ParseTree::Node node_;

  // The function's ID.
  int32_t id_;

  // Regular function parameters.
  // llvm::SmallVector<PatternBinding, 0> params_;

  // The return type expression.
  llvm::SmallVector<NodeRef, 0> return_type_;

  llvm::SmallVector<NodeRef, 0> body_;
};

}  // namespace Carbon::Semantics

#endif  // CARBON_TOOLCHAIN_SEMANTICS_NODES_FUNCTION_H_