#include <deal.II-cdr/parameters.h>

#include <fstream>
#include <string>

namespace CDR
{
  void Parameters::configure_parameter_handler(ParameterHandler &parameter_handler)
  {
    parameter_handler.enter_subsection("Geometry");
    {
      parameter_handler.declare_entry
      ("inner_radius", "1.0", Patterns::Double(0.0), "Inner radius.");
      parameter_handler.declare_entry
      ("outer_radius", "2.0", Patterns::Double(0.0), "Outer radius.");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Physical Parameters");
    {
      parameter_handler.declare_entry
      ("diffusion_coefficient", "1.0", Patterns::Double(0.0), "Diffusion coefficient.");
      parameter_handler.declare_entry
      ("reaction_coefficient", "1.0", Patterns::Double(0.0), "Reaction coefficient.");
      parameter_handler.declare_entry
      ("time_dependent_forcing", "true", Patterns::Bool(), "Whether or not "
       "the forcing function depends on time.");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Finite Element");
    {
      parameter_handler.declare_entry
      ("initial_refinement_level", "1", Patterns::Integer(1),
       "Initial number of levels in the mesh.");
      parameter_handler.declare_entry
      ("max_refinement_level", "1", Patterns::Integer(1),
       "Maximum number of levels in the mesh.");
      parameter_handler.declare_entry
      ("fe_order", "1", Patterns::Integer(1), "Finite element order.");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Time Step");
    {
      parameter_handler.declare_entry
      ("start_time", "0.0", Patterns::Double(0.0), "Start time.");
      parameter_handler.declare_entry
      ("stop_time", "1.0", Patterns::Double(1.0), "Stop time.");
      parameter_handler.declare_entry
      ("n_time_steps", "1", Patterns::Integer(1), "Number of time steps.");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Output");
    {
      parameter_handler.declare_entry
      ("save_interval", "10", Patterns::Integer(1), "Save interval.");
      parameter_handler.declare_entry
      ("patch_level", "2", Patterns::Integer(0), "Patch level.");
    }
    parameter_handler.leave_subsection();
  }

  void Parameters::read_parameter_file(const std::string &file_name)
  {
    ParameterHandler parameter_handler;
    {
      std::ifstream file(file_name);
      configure_parameter_handler(parameter_handler);
      parameter_handler.parse_input(file);
    }

    parameter_handler.enter_subsection("Geometry");
    {
      inner_radius = parameter_handler.get_double("inner_radius");
      outer_radius = parameter_handler.get_double("outer_radius");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Physical Parameters");
    {
      diffusion_coefficient = parameter_handler.get_double("diffusion_coefficient");
      reaction_coefficient = parameter_handler.get_double("reaction_coefficient");
      time_dependent_forcing = parameter_handler.get_bool("time_dependent_forcing");
    }
    parameter_handler.leave_subsection();


    parameter_handler.enter_subsection("Finite Element");
    {
      initial_refinement_level = parameter_handler.get_integer("initial_refinement_level");
      max_refinement_level = parameter_handler.get_integer("max_refinement_level");
      fe_order = parameter_handler.get_integer("fe_order");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Time Step");
    {
      start_time = parameter_handler.get_double("start_time");
      stop_time = parameter_handler.get_double("stop_time");
      n_time_steps = parameter_handler.get_integer("n_time_steps");
    }
    parameter_handler.leave_subsection();

    parameter_handler.enter_subsection("Output");
    {
      save_interval = parameter_handler.get_integer("save_interval");
      patch_level = parameter_handler.get_integer("patch_level");
    }
    parameter_handler.leave_subsection();
  }
}