#include <cstdlib>
#include <fstream>
#include <iostream>
#include <unistd.h>
using namespace std;
#include "SysYLexer.h"
#include "SysYParser.h"
using namespace antlr4;
#include "ASTPrinter.h"
#include "Backend.h"
#include "SysYIRGenerator.h"
#include "LLVMIRGenerator.h"
using namespace sysy;

static string argStopAfter;
static string argInputFile;
static bool argFormat = false;

void usage(int code = EXIT_FAILURE) {
  const char *msg = "Usage: sysyc [options] inputfile\n\n"
                    "Supported options:\n"
                    "  -h \tprint help message and exit\n";
  "  -f \tpretty-format the input file\n";
  "  -s {ast,ir,asm,llvmir}\tstop after generating AST/IR/Assembly\n";
  cerr << msg;
  exit(code);
}

void parseArgs(int argc, char **argv) {
  const char *optstr = "hfs:";
  int opt = 0;
  while ((opt = getopt(argc, argv, optstr)) != -1) {
    switch (opt) {
    case 'h':
      usage(EXIT_SUCCESS);
      break;
    case 'f':
      argFormat = true;
      break;
    case 's':
      argStopAfter = optarg;
      break;
    default: /* '?' */
      usage();
    }
  }
  if (optind >= argc)
    usage();
  argInputFile = argv[optind];
}

int main(int argc, char **argv) {
  parseArgs(argc, argv);

  // open the input file
  ifstream fin(argInputFile);
  if (not fin) {
    cerr << "Failed to open file " << argv[1];
    return EXIT_FAILURE;
  }

  // parse sysy source to AST
  ANTLRInputStream input(fin);
  SysYLexer lexer(&input);
  CommonTokenStream tokens(&lexer);
  SysYParser parser(&tokens);
  auto moduleAST = parser.compUnit();
  if (argStopAfter == "ast") {
    cout << moduleAST->toStringTree(true) << '\n';
    return EXIT_SUCCESS;
  }


  // visit AST to generate IR

  if (argStopAfter == "ir") {
    SysYIRGenerator generator;
    generator.visitCompUnit(moduleAST);
    auto moduleIR = generator.get();
    moduleIR->print(cout);
    return EXIT_SUCCESS;
  } else if (argStopAfter == "llvmir") {
    LLVMIRGenerator llvmirGenerator;
    llvmirGenerator.generateIR(moduleAST); // 使用公共接口生成 IR
    cout << llvmirGenerator.getIR();
    return EXIT_SUCCESS;
  }

  // // generate assembly
  // CodeGen codegen(moduleIR);
  // string asmCode = codegen.code_gen();
  // cout << asmCode << endl;
  // if (argStopAfter == "asm")
  //   return EXIT_SUCCESS;

  return EXIT_SUCCESS;
}