#include <sstream>

#include "gui-main.h"
#include "interpreter.h"
#include "qt-interpreter.h"

#include <readline/readline.h>
#include <readline/history.h>

namespace calc
{
  static int getc (FILE *)
  {
    int tmp = gui::available_char;
    gui::available_char = 0;
    return tmp;
  }

  static void redisplay (void)
  {
    if (gui::calc_interaction_window)
      gui::calc_interaction_window->redisplay ();
  }

  static void prep_term (int)
  {
  }

  static void deprep_term (void)
  {
  }

  static void accept_line (char *line)
  {
    if (gui::calc_interaction_window)
      gui::calc_interaction_window->accept (line ? line : "");
  }

  static void display_completion_matches (char **matches, int num_matches,
                                          int /* max_length */)
  {
    if (gui::calc_interaction_window)
      {
        std::ostringstream buf;

        if (num_matches > 1)
          buf << "\n";

        for (int i = 1; i < num_matches; i++)
          buf << matches[i] << "\n";

        gui::calc_interaction_window->insert_at_end (buf.str ());

        gui::calc_interaction_window->redisplay ();
      }
  }

  static void readline_init (void)
  {
    rl_initialize ();

    rl_getc_function = getc;
    rl_redisplay_function = redisplay;
    rl_prep_term_function = prep_term;
    rl_deprep_term_function = deprep_term;
    rl_completion_display_matches_hook = display_completion_matches;

    rl_callback_handler_install (">> ", accept_line);
  }

  static void readline_fini (void)
  {
    rl_callback_handler_remove ();
  }

  qt_interpreter::qt_interpreter (void)
  {
    interpreter::init ();
  }

  qt_interpreter::~qt_interpreter (void)
  {
    interpreter::fini ();

    readline_fini ();
  }

  void qt_interpreter::execute (void)
  {
    readline_init ();
  }
}