/**
  * Loads and manages the libTmsIfAdapter module
  * $Id$
  * $HeadURL$
  * $Author$
  *
  * Created by Mike Wille, ESZS, 2025-04-17
  */

#pragma once

#include "tms_if_adapter.h"

#include <stdexcept>
#include <string>

/* there's a massive problem with symbol collision between RTI DDS & Cyclone DDS (namely dds::core::Time::invalid())
 * so we need the linux specific RTLD_DEEPBIND to force the use of the Cyclone DDS symbols inside the library */
#include <dlfcn.h>


namespace UAS
{
namespace ModuleLoader
{
using dlopen_handle = void *;


dlopen_handle load(std::string libPath) noexcept(false)
{
  dlopen_handle handle = dlopen((libPath + "/libTmsIfAdapter.so").c_str(), RTLD_NOW | RTLD_LOCAL | RTLD_DEEPBIND);

  if (handle == nullptr)
  {
    throw std::runtime_error((std::string("tms_if.h => ModuleLoader::load: unable to load libTmsIfAdapter.so: ") + dlerror()).c_str());
  }

  return handle;
}


TmsIfAdapter &get(dlopen_handle handle) noexcept(false)
{
  auto get = reinterpret_cast<void *(*)()>(dlsym(handle, "get"));
  if (get == nullptr)
  {
    throw std::runtime_error((std::string("tms_if.h => ModuleLoader::get: function symbol 'get' does not exist in libTmsIfAdapter.so: ") + dlerror()).c_str());
  }

  UAS::TmsIfAdapter &adapter = *reinterpret_cast<UAS::TmsIfAdapter *>(get());
  return adapter;
}


void unload(dlopen_handle handle) noexcept(false)
{
  if (handle == nullptr)
  {
    return;
  }

  auto stop = reinterpret_cast<void *(*)()>(dlsym(handle, "stop"));
  if (stop == nullptr)
  {
    throw std::runtime_error((std::string("tms_if.h => ModuleLoader::unload: function symbol 'stop' does not exist in libTmsIfAdapter.so: ") + dlerror()).c_str());
  }

  stop();

  const int ret = dlclose(handle);

  if (ret != 0)
  {
    throw std::runtime_error((std::string("tms_if.h => ModuleLoader::unload: dlclose failed - ret != 0 (was "+std::to_string(ret)+"): ") + dlerror()).c_str());
  }
}
} // ModuleLoader
} // namespace UAS