#include "ofxhBinary.h"

using namespace OFX;

Binary::Binary(const std::string &binaryPath): _binaryPath(binaryPath), _invalid(false), _dlHandle(0), _users(0)
{
  struct stat sb;
  if (stat(binaryPath.c_str(), &sb) != 0) {
    _invalid = true;
    _time = 0;
    _size = 0;
  } 
  else {
    _time = sb.st_mtime;
    _size = sb.st_size;
  }
}


// actually open the binary.
void Binary::load() 
{
  if(_invalid)
    return;

#if defined (UNIX)
  _dlHandle = dlopen(_binaryPath.c_str(), RTLD_LAZY|RTLD_LOCAL);
#else
  _dlHandle = LoadLibrary(_binaryPath.c_str());
#endif
  if (_dlHandle == 0) {
#if defined (UNIX)
    std::cerr << "couldn't open library " << _binaryPath << " because " << dlerror() << std::endl;
#else
    LPVOID lpMsgBuf = NULL;
    DWORD err = GetLastError();

    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
      FORMAT_MESSAGE_FROM_SYSTEM |
      FORMAT_MESSAGE_IGNORE_INSERTS,
      NULL,
      err,
      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
      (LPTSTR) &lpMsgBuf,
      0, NULL);

    std::cerr << "couldn't open library " << _binaryPath << " because " << (char*)lpMsgBuf << " was returned" << std::endl;
    if (lpMsgBuf != NULL) {
      LocalFree(lpMsgBuf);
    }
#endif
    _invalid = true;
  }
}

/// close the binary
void Binary::unload() {
  if (_dlHandle != 0) {
#if defined (UNIX)
    dlclose(_dlHandle);
#elif defined (WINDOWS)
    FreeLibrary(_dlHandle);
#endif
    _dlHandle = 0;
  }
}

/// look up a symbol in the binary file and return it as a pointer.
/// returns null pointer if not found, or if the library is not loaded.
void *Binary::findSymbol(const std::string &symbol) {
  if (_dlHandle != 0) {
#if defined(UNIX)
    return dlsym(_dlHandle, symbol.c_str());
#elif defined (WINDOWS)
    return (void*)GetProcAddress(_dlHandle, symbol.c_str());
#endif
  } else {
    return 0;
  }
}


void Binary::ref()
{
  if (_users == 0) {
    load();
  }
  _users++;
}

void Binary::unref()
{
  _users--;
  if (_users == 0) {
    unload();
  }
  if (_users < 0) {
    _users = 0;
  }
}