ex_termbox

#include "erl_nif.h"
#include "termbox.h"
#include <stdio.h>

static ERL_NIF_TERM extb_ok(ErlNifEnv *env) {
  return enif_make_atom(env, "ok");
}

static ERL_NIF_TERM extb_error(ErlNifEnv *env, const char *reason) {
  return enif_make_tuple2(env, enif_make_atom(env, "error"),
                          enif_make_atom(env, reason));
}

static ERL_NIF_TERM extb_init(ErlNifEnv *env, int argc,
                              const ERL_NIF_TERM argv[]) {
  int code = tb_init();
  if (code == 0)
    return extb_ok(env);
  return enif_make_tuple2(env, enif_make_atom(env, "error"),
                          enif_make_int(env, code));
}

static ERL_NIF_TERM extb_shutdown(ErlNifEnv *env, int argc,
                                  const ERL_NIF_TERM argv[]) {
  tb_shutdown();
  return extb_ok(env);
}

static ERL_NIF_TERM extb_width(ErlNifEnv *env, int argc,
                               const ERL_NIF_TERM argv[]) {
  int32_t width = tb_width();
  return enif_make_int(env, width);
}

static ERL_NIF_TERM extb_height(ErlNifEnv *env, int argc,
                                const ERL_NIF_TERM argv[]) {
  int32_t height = tb_height();
  return enif_make_int(env, height);
}

static ERL_NIF_TERM extb_clear(ErlNifEnv *env, int argc,
                               const ERL_NIF_TERM argv[]) {
  tb_clear();
  return extb_ok(env);
}

static ERL_NIF_TERM extb_set_clear_attributes(ErlNifEnv *env, int argc,
                                              const ERL_NIF_TERM argv[]) {
  unsigned int fg, bg;
  enif_get_uint(env, argv[0], &fg);
  enif_get_uint(env, argv[1], &bg);

  tb_set_clear_attributes((uint32_t)fg, (uint32_t)bg);
  return extb_ok(env);
}

static ERL_NIF_TERM extb_present(ErlNifEnv *env, int argc,
                                 const ERL_NIF_TERM argv[]) {
  tb_present();
  return extb_ok(env);
}

static ERL_NIF_TERM extb_set_cursor(ErlNifEnv *env, int argc,
                                    const ERL_NIF_TERM argv[]) {
  int x, y;
  enif_get_int(env, argv[0], &x);
  enif_get_int(env, argv[1], &y);

  tb_set_cursor(x, y);
  return extb_ok(env);
}

static ERL_NIF_TERM extb_change_cell(ErlNifEnv *env, int argc,
                                     const ERL_NIF_TERM argv[]) {
  int x, y;
  unsigned int ch, fg, bg;

  enif_get_int(env, argv[0], &x);
  enif_get_int(env, argv[1], &y);
  enif_get_uint(env, argv[2], &ch);
  enif_get_uint(env, argv[3], &fg);
  enif_get_uint(env, argv[4], &bg);

  tb_change_cell(x, y, (uint32_t)ch, (uint16_t)fg, (uint16_t)bg);
  return extb_ok(env);
}

static ERL_NIF_TERM extb_select_input_mode(ErlNifEnv *env, int argc,
                                           const ERL_NIF_TERM argv[]) {
  int mode, result;
  enif_get_int(env, argv[0], &mode);
  result = tb_select_input_mode(mode);
  return enif_make_int(env, result);
}

static ERL_NIF_TERM extb_select_output_mode(ErlNifEnv *env, int argc,
                                            const ERL_NIF_TERM argv[]) {
  int mode, result;
  enif_get_int(env, argv[0], &mode);
  result = tb_select_output_mode(mode);
  return enif_make_int(env, result);
}

// Passed to the created thread's function with information on where
// to send the polling result (a local PID) and the thread's id so it
// can later be joined.
struct extb_poll_state {
  ErlNifTid thread_id;
  ErlNifPid recipient_pid;
};

void *extb_poll_event_run(void *arg) {
  struct extb_poll_state *state = (struct extb_poll_state *)arg;
  struct tb_event *event = enif_alloc(sizeof(struct tb_event));

  int event_type = tb_poll_event(event);

  ErlNifEnv *env = enif_alloc_env();
  ERL_NIF_TERM result = enif_make_tuple2(
      env, enif_make_atom(env, "event"),
      enif_make_tuple8(
          env, enif_make_uint(env, event->type),
          enif_make_uint(env, event->mod), enif_make_uint(env, event->key),
          enif_make_uint(env, event->ch), enif_make_int(env, event->w),
          enif_make_int(env, event->h), enif_make_int(env, event->x),
          enif_make_int(env, event->y)));

  int sent = enif_send(NULL, &state->recipient_pid, env, result);
  enif_free_env(env);
  enif_free(event);
  return NULL;
};

void extb_poll_thread_cleanup(ErlNifEnv *env, void *arg) {
  struct extb_poll_state *state = (struct extb_poll_state *)arg;
  void *resp;
  enif_thread_join(state->thread_id, &resp);
  enif_free(state);
}

static ERL_NIF_TERM extb_poll_event_async(ErlNifEnv *env, int argc,
                                          const ERL_NIF_TERM argv[]) {
  // Create a resource as a handle for the thread
  const char *resource_type_name = "extb-thread-handler";
  int flags = ERL_NIF_RT_CREATE | ERL_NIF_RT_TAKEOVER;
  ErlNifResourceType *res_type = enif_open_resource_type(
      env, NULL, resource_type_name, extb_poll_thread_cleanup, flags, NULL);
  struct extb_poll_state *poll_state =
      (struct extb_poll_state *)enif_alloc_resource(
          res_type, sizeof(struct extb_poll_state));

  // Set the recipient pid to the pid arg
  enif_get_local_pid(env, argv[0], &poll_state->recipient_pid);

  // Create a thread to perform the event polling
  int result = enif_thread_create("extb-event-poll", &poll_state->thread_id,
                                  extb_poll_event_run, poll_state, NULL);

  // Returns tuple with the resource for future cleanup
  return enif_make_tuple2(env, enif_make_atom(env, "ok"),
                          enif_make_resource(env, poll_state));
}

static ErlNifFunc nif_funcs[] = {
    {"init", 0, extb_init},
    {"shutdown", 0, extb_shutdown},
    {"width", 0, extb_width},
    {"height", 0, extb_height},
    {"clear", 0, extb_clear},
    {"set_clear_attributes", 2, extb_set_clear_attributes},
    {"present", 0, extb_present},
    {"set_cursor", 2, extb_set_cursor},
    {"change_cell", 5, extb_change_cell},
    {"select_input_mode", 1, extb_select_input_mode},
    {"select_output_mode", 1, extb_select_output_mode},
    {"poll_event", 1, extb_poll_event_async}
};

ERL_NIF_INIT(Elixir.ExTermbox.Bindings, nif_funcs, NULL, NULL, NULL, NULL)