/*
 * Copyright © 2008-2023 Dynare Team
 *
 * This file is part of Dynare.
 *
 * Dynare is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Dynare is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Dynare.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef _DYNAMIC_DLL_HH
#define _DYNAMIC_DLL_HH

#if defined(_WIN32) || defined(__CYGWIN32__)
# ifndef NOMINMAX
#  define NOMINMAX // Do not define "min" and "max" macros
# endif
# include <windows.h>
#else
# include <dlfcn.h> // unix/linux DLL (.so) handling routines
#endif

#include <string>
#include <utility>
#include <vector>

#include "dynare_exception.hh"

#include "dynamic_abstract_class.hh"

using dynamic_tt_fct
    = void (*)(const double* y, const double* x, int nb_row_x, const double* params,
               const double* steady_state, int it_, double* T);
using dynamic_resid_or_g1_fct
    = void (*)(const double* y, const double* x, int nb_row_x, const double* params,
               const double* steady_state, int it_, const double* T, double* resid_or_g1);
using dynamic_higher_deriv_fct = void (*)(const double* y, const double* x, int nb_row_x,
                                          const double* params, const double* steady_state, int it_,
                                          const double* T, double* g_i, double* g_j, double* g_v);

/**
 * creates pointer to Dynamic function inside <model>_dynamic.dll
 * and handles calls to it.
 **/
class DynamicModelDLL : public DynamicModelAC
{
private:
  std::vector<dynamic_tt_fct> dynamic_tt;
  dynamic_resid_or_g1_fct dynamic_resid, dynamic_g1;
  std::vector<dynamic_higher_deriv_fct> dynamic_higher_deriv; // Index 0 is g2
#if defined(_WIN32) || defined(__CYGWIN32__)
  HINSTANCE dynamicHinstance; // DLL instance pointer in Windows
#else
  void* dynamicHinstance; // and in Linux or Mac
#endif
  std::vector<double> tt; // Vector of temporary terms

  template<typename T>
  std::pair<T, dynamic_tt_fct>
  getSymbolsFromDLL(const std::string& funcname, const std::string& fName)
  {
    dynamic_tt_fct tt;
    T deriv;
#if defined(__CYGWIN32__) || defined(_WIN32)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-function-type"
    deriv = reinterpret_cast<T>(GetProcAddress(dynamicHinstance, funcname.c_str()));
    tt = reinterpret_cast<dynamic_tt_fct>(
        GetProcAddress(dynamicHinstance, (funcname + "_tt").c_str()));
# pragma GCC diagnostic pop
#else
    deriv = reinterpret_cast<T>(dlsym(dynamicHinstance, funcname.c_str()));
    tt = reinterpret_cast<dynamic_tt_fct>(dlsym(dynamicHinstance, (funcname + "_tt").c_str()));
#endif
    if (!deriv || !tt)
      {
#if defined(__CYGWIN32__) || defined(_WIN32)
        FreeLibrary(dynamicHinstance);
#else
        dlclose(dynamicHinstance);
#endif
        throw DynareException(__FILE__, __LINE__,
                              "Error when loading symbols from " + fName
#if !defined(__CYGWIN32__) && !defined(_WIN32)
                                  + ": " + dlerror()
#endif
        );
      }
    return {deriv, tt};
  }

public:
  // construct and load Dynamic model DLL
  explicit DynamicModelDLL(const std::string& fname, int ntt_arg, int order);
  ~DynamicModelDLL() override;

  void eval(const Vector& y, const Vector& x, const Vector& params, const Vector& ySteady,
            Vector& residual, std::vector<TwoDMatrix>& md) override;
};
#endif