// 调用 ANTLR 生成的 Lexer/Parser，返回 parse tree。
#include "frontend/AntlrDriver.h"

#include <fstream>
#include <sstream>
#include <stdexcept>

#include "SysYLexer.h"
#include "SysYParser.h"
#include "antlr4-runtime.h"

AntlrResult ParseFileWithAntlr(const std::string& path) {
  std::ifstream fin(path);
  if (!fin.is_open()) {
    throw std::runtime_error("无法打开输入文件: " + path);
  }
  std::ostringstream ss;
  ss << fin.rdbuf();

  auto input = std::make_unique<antlr4::ANTLRInputStream>(ss.str());
  auto lexer = std::make_unique<SysYLexer>(input.get());
  auto tokens = std::make_unique<antlr4::CommonTokenStream>(lexer.get());
  auto parser = std::make_unique<SysYParser>(tokens.get());
  parser->removeErrorListeners();
  auto tree = parser->compUnit();

  AntlrResult result;
  result.input = std::move(input);
  result.lexer = std::move(lexer);
  result.tokens = std::move(tokens);
  result.parser = std::move(parser);
  result.tree = tree;
  return result;
}