#ifndef STAN_MATH_REV_MAT_FUNCTOR_CVODES_UTILS_HPP
#define STAN_MATH_REV_MAT_FUNCTOR_CVODES_UTILS_HPP

#include <cvodes/cvodes.h>
#include <cvodes/cvodes_band.h>
#include <cvodes/cvodes_dense.h>
#include <nvector/nvector_serial.h>
#include <sstream>
#include <stdexcept>
#include <string>

namespace stan {
  namespace math {

    // no-op error handler to silence CVodes error output;  errors handled
    // directly by Stan
    extern "C"
    inline void cvodes_silent_err_handler(int error_code, const char *module,
                                   const char *function, char *msg,
                                   void *eh_data) {
    }

    inline void cvodes_check_flag(int flag, const std::string& func_name) {
      if (flag < 0) {
        std::ostringstream ss;
        ss << func_name << " failed with error flag " << flag;
        throw std::runtime_error(ss.str());
      }
    }

    inline void cvodes_set_options(void* cvodes_mem,
                                   double rel_tol, double abs_tol,
                                   // NOLINTNEXTLINE(runtime/int)
                                   long int max_num_steps) {
      // forward CVode errors to noop error handler
      CVodeSetErrHandlerFn(cvodes_mem, cvodes_silent_err_handler, 0);

      // Initialize solver parameters
      cvodes_check_flag(CVodeSStolerances(cvodes_mem, rel_tol, abs_tol),
                        "CVodeSStolerances");

      cvodes_check_flag(CVodeSetMaxNumSteps(cvodes_mem, max_num_steps),
                        "CVodeSetMaxNumSteps");

      double init_step = 0;
      cvodes_check_flag(CVodeSetInitStep(cvodes_mem, init_step),
                        "CVodeSetInitStep");

      long int max_err_test_fails = 20;  // NOLINT(runtime/int)
      cvodes_check_flag(CVodeSetMaxErrTestFails(cvodes_mem, max_err_test_fails),
                        "CVodeSetMaxErrTestFails");

      long int max_conv_fails = 50;  // NOLINT(runtime/int)
      cvodes_check_flag(CVodeSetMaxConvFails(cvodes_mem, max_conv_fails),
                        "CVodeSetMaxConvFails");
    }

  }
}
#endif
