/**
 * Copyright (c) 2022 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "event.h"

void eventManagerInit(eventmanager_t *manager) {
  uint8_t i;

  ASSERT_NOT_NULL(manager);

  for(i = 0; i < EVENT_LISTENER_COUNT_MAX; i++) {
    manager->listeners[i].callback = NULL;
  }
}

bool _eventManagerFindFree(int32_t i, void *item) {
  return ((eventlistener_t *) item)->callback == NULL;
}

eventlistener_t * eventManagerSubscribe(
  eventmanager_t *man, event_t event, void *user, eventcallback_t *callback
) {
  int32_t first;
  eventlistener_t *listener;

  ASSERT_NOT_NULL(man);
  ASSERT_NOT_NULL(callback);

  // Find the first available space.
  first = arrayFindCallback(
    sizeof(eventmanager_t), man->listeners,
    EVENT_LISTENER_COUNT_MAX, _eventManagerFindFree
  );

  ASSERT_LESS_THAN(first, EVENT_LISTENER_COUNT_MAX);
  ASSERT_GREATER_THAN_EQUAL_TO(first, 0);

  // Insert
  listener = man->listeners + first;
  listener->callback = callback;
  listener->user = user;
  listener->event = event;

  return listener;
}

void eventManagerUnsubscribe(eventmanager_t *man, eventlistener_t *listener) {
  ASSERT_NOT_NULL(man);
  ASSERT_NOT_NULL(listener);

  listener->callback = NULL;
}

bool eventManagerTrigger(
  eventmanager_t *manager, event_t event, void *args[], int32_t argc
) {
  uint8_t i;
  eventlistener_t *listener;
  bool result;
  
  ASSERT_GREATER_THAN_EQUAL_TO(argc, 0);
  ASSERT_IF(
    argc > 0,
    ASSERT_NOT_NULL(args)
  );

  for(i = 0; i < EVENT_LISTENER_COUNT_MAX; i++) {
    listener = manager->listeners + i;
    if(listener->callback == NULL) continue;
    if(listener->event != event) continue;

    result = listener->callback(listener->user, event, args, argc);
    if(!result) return false;
  }

  return true;
}