#include <stdio.h>
#include "redraw_man.h"
#include "observer.h"
#include "tools.h"

subject_t *subject_new(ob_factory_t *factory, void *obj, int obj_type) {
    subject_t *subject;

    subject = factory->subject_alloc(factory);
    if(subject == NULL)
	return NULL;

    subject->obj = obj;
    subject->obj_type = obj_type;
    subject->flags = 0;
    STAILQ_INIT(subject->observers);

    return subject;
}

void subject_free(ob_factory_t *factory, subject_t *subject) {
    observer_t *observer;

    while((observer = STAILQ_HEAD(subject->observers))) {
	STAILQ_REMOVE(subject->observers, observer_t, next, observer);
	factory->observer_free(factory, observer);
    }
    factory->subject_free(factory, subject);
}


void subject_notify(ob_factory_t *factory, subject_t *subject, event_t *evt) {
    observer_t *observer;

    while(subject) {
	for(observer = STAILQ_HEAD(subject->observers);
	    observer != NULL;
	    observer = STAILQ_NEXT(observer_t, next, observer)) {
	    observer->hdr(evt, observer->arg);
	}

	if(subject->flags & SUBF_STOP_PROPAGATE)
	    break;

	subject = factory->get_parent_subject(factory, subject);
    }
}

observer_t *subject_add_observer(ob_factory_t *factory,
				 subject_t *subject,
				 evt_handler hdr, void *arg) {
    observer_t *observer;

    observer = factory->observer_alloc(factory);
    if(observer == NULL)
	return NULL;
    observer->hdr = hdr;
    observer->arg = arg;

    STAILQ_INS_TAIL(subject->observers, observer_t, next, observer);

    return observer;
}

void subject_remove_observer(ob_factory_t *factory,
			     subject_t *subject,
			     observer_t *observer) {
    STAILQ_REMOVE(subject->observers, observer_t, next, observer);
    factory->observer_free(factory, observer);
}

#ifdef UNITTEST

#include <CUnit/Basic.h>
#include <stdlib.h>

static subject_t *test_subject_alloc(ob_factory_t *factory) {
    subject_t *subject;

    subject = (subject_t *)malloc(sizeof(subject_t));
    return subject;
}

static void test_subject_free(ob_factory_t *factory, subject_t *subject) {
    free(subject);
}

static observer_t *test_observer_alloc(ob_factory_t *factory) {
    observer_t *observer;

    observer = (observer_t *)malloc(sizeof(observer_t));
    return observer;
}

static void test_observer_free(ob_factory_t *factory, observer_t *observer) {
    free(observer);
}

static subject_t *test_get_parent_subject(ob_factory_t *factory,
					  subject_t *subject) {
    return NULL;
}

static ob_factory_t test_factory = {
    test_subject_alloc,
    test_subject_free,
    test_observer_alloc,
    test_observer_free,
    test_get_parent_subject
};

static void handler(event_t *evt, void *arg) {
    int *cnt = (int *)arg;

    CU_ASSERT(evt->type == EVT_MOUSE_OVER);
    (*cnt)++;
}

void test_observer(void) {
    subject_t *subject;
    observer_t *observer;
    event_t evt;
    int cnt = 0;

    subject = subject_new(&test_factory, NULL, 0);
    subject->flags |= SUBF_STOP_PROPAGATE;
    observer = subject_add_observer(&test_factory, subject,
				    handler, &cnt);

    evt.type = EVT_MOUSE_OVER;
    evt.tgt = NULL;
    evt.cur_tgt = NULL;
    subject_notify(&test_factory, subject, &evt);
    CU_ASSERT(cnt == 1);

    subject_remove_observer(&test_factory, subject, observer);
    subject_free(&test_factory, subject);
}

CU_pSuite get_observer_suite(void) {
    CU_pSuite suite;

    suite = CU_add_suite("Suite_observer", NULL, NULL);
    CU_ADD_TEST(suite, test_observer);

    return suite;
}

#endif /* UNITTEST */