#define NOMINMAX
#define UNICODE
#define _UNICODE

#include <fstream>
#include <string>
#include <string_view>
#include <iostream>
#include <io.h>
#include <fcntl.h>
#include <Windows.h>

using namespace std::literals;


int ShowUsage(const wchar_t* program) {
  std::wcerr << L"dmpres v0.1.0"sv << std::endl;
  std::wcerr << L"Copyright (c) 2019 SegaraRai"sv << std::endl;
  std::wcerr << std::endl;
  std::wcerr << L"usage: infile resource_name outfile"sv << std::endl;
  std::wcerr << std::endl;
  std::wcerr << L"set outfile to \"-\" to output to stdout"sv << std::endl;
  std::wcerr << std::endl;
  return 2;
}


int wmain(int argc, wchar_t* argv[]) {
  if (argc != 4) {
    return ShowUsage(argv[0]);
  }

  const std::wstring inFile(argv[1]);
  const std::wstring resourceName(argv[2]);
  const std::wstring outFile(argv[3]);

  const bool useStdout = outFile == L"-"sv;


  bool success = false;

  std::ofstream ofs;

  HMODULE hModule = NULL;
  HRSRC hResource = NULL;
  HGLOBAL hGlobal = NULL;

  hModule = LoadLibraryW(inFile.c_str());
  if (!hModule) {
    std::wcerr << L"cannot load module "sv << inFile << std::endl;
    goto end;
  }

  hResource = FindResourceW(hModule, resourceName.c_str(), RT_RCDATA);
  if (!hResource) {
    std::wcerr << L"resource "sv << resourceName << L" not found"sv << std::endl;
    goto end;
  }

  hGlobal = LoadResource(hModule, hResource);
  if (!hGlobal) {
    std::wcerr << L"cannot load resource"sv << std::endl;
    goto end;
  }

  const auto size = SizeofResource(hModule, hResource);
  // skip error check

  const auto data = LockResource(hGlobal);
  if (!data) {
    std::wcerr << L"cannot load resource data"sv << std::endl;
    goto end;
  }

  if (useStdout) {
    if (_setmode(_fileno(stdout), _O_BINARY) == -1) {
      std::wcerr << L"_setmode failed"sv << std::endl;
      goto end;
    }
  }

  if (!useStdout) {
    ofs.open(outFile, std::ios::binary);
    if (ofs.fail() || ofs.bad()) {
      std::wcerr << L"failed to open outuput file"sv << std::endl;
      goto end;
    }
  }

  std::ostream* os = useStdout ? &std::cout : &ofs;

  os->write(static_cast<const char*>(data), static_cast<std::streamsize>(size));
  os->flush();

  success = true;

end:
  // close file
  if (ofs.is_open()) {
    ofs.close();
  }

  // no need to free hGlobal
  hGlobal = NULL;

  // no need to free hResource
  hResource = NULL;

  // free hModule
  if (hModule) {
    FreeLibrary(hModule);
    hModule = NULL;
  }

  return success ? 0 : 1;
}