#include <ruby.h>
#include <stdbool.h>
#include <ruby/debug.h>

#include "event_store.h"
#include "trace.h"
#include "types/event.h"

static bool running = false;
static VALUE ractor;

static VALUE listen_events(VALUE data, VALUE m, int _argc, const VALUE *_argv, VALUE _) {
  running = true;
  Event event;
  int status;

  while(running) {
    get_event(&event, &status);

    if(status == 0) process_event(&event);

    rb_thread_check_ints();
  }

  return Qtrue;
}

static VALUE exit_sidecar(VALUE data, VALUE m, int _argc, const VALUE *_argv, VALUE _) {
  VALUE main_module = rb_const_get(rb_cObject, rb_intern("StackTrace"));
  VALUE sidecar_class = rb_const_get(main_module, rb_intern("Sidecar"));

  rb_funcall(sidecar_class, rb_intern("stop"), 0);

  return Qtrue;
}

static VALUE rb_run(VALUE self) {
  if(running) return Qnil;

  VALUE kernel_module = rb_const_get(rb_cObject, rb_intern("Kernel"));
  rb_block_call(kernel_module, rb_intern("at_exit"), 0, NULL, &exit_sidecar, (VALUE)NULL);

  VALUE main_module = rb_const_get(rb_cObject, rb_intern("StackTrace"));
  VALUE configuration = rb_funcall(main_module, rb_intern("configuration"), 0);
  VALUE check_proc = rb_funcall(configuration, rb_intern("check_proc"), 0);
  set_check_proc(check_proc);  // hack to share an object between main thread and ractor

  VALUE ractor_module = rb_const_get(rb_cObject, rb_intern("Ractor"));
  ractor = rb_block_call(ractor_module, rb_intern("new"), 0, NULL, &listen_events, (VALUE)NULL);

  rb_gc_register_address(&ractor); // So the GC does not try to free this object.

  return Qtrue;
}

static VALUE rb_stop(VALUE self) {
  if(!running) return Qnil;

  running = false;

  // The sidecar might be waiting for an event to arrive
  // so here we are sending a no-op event to break the loop.
  // Same could be done by using `pthread_cond_timedwait` but
  // then I have to do more changes.
  Event event = {};
  event.event = NOOP_EVENT;

  produce_event(event);

  return Qtrue;
}

static VALUE rb_is_running(VALUE self) {
  return running ? Qtrue : Qfalse;
}

void Init_sidecar() {
  VALUE main_module = rb_const_get(rb_cObject, rb_intern("StackTrace"));
  VALUE sidecar_class = rb_define_class_under(main_module, "Sidecar", rb_cObject);

  rb_define_singleton_method(sidecar_class, "run", rb_run, 0);
  rb_define_singleton_method(sidecar_class, "stop", rb_stop, 0);
  rb_define_singleton_method(sidecar_class, "running?", rb_is_running, 0);
}