#include <stdio.h>
#include <stdlib.h>

enum entitytype_enum {
	SPRITE = 1,
	BACKGROUND,
	ROOM,
	OBJECT,
	INSTANCE
};

typedef struct Entity {
	int type;
	/*
    SDL_Surface *image;
	SDL_Rect *rects;
    */
    int cols, rows; /* These variables are for sprite sheets */
	int x, y;
	struct Entity *sprite;
	struct Entity *instances;
	struct Entity *next;
} Entity;

Entity *startEntity = NULL;

Entity *newEntity(int type) {
	Entity *entity = (Entity*)malloc(sizeof(Entity));
	entity->type = type;
	/*
    entity->image = NULL;
    entity->rects = NULL;
    */
	entity->cols = 0;
	entity->rows = 0;
	entity->sprite = NULL;
	entity->instances = NULL;
	entity->next = NULL;
	if (startEntity == NULL) {
		startEntity = entity;
	} else {
		Entity *tmp = startEntity;
		while (tmp->next != NULL) tmp = tmp->next;
		tmp->next = entity;
	}
	return entity;
}

void freeEntities() {
	Entity *current = startEntity;
	while (current != NULL) {
		Entity *tmp = current->next;
		/*
		if (current->image != NULL) {
			SDL_FreeSurface(current->image);
		}
		*/
		free(current);
		current = tmp;
	}
}

Entity *getEntity(int type, int index) {
	Entity *current = startEntity;
	int i = 0;
	while (current != NULL) {
		if (current->type == type) {
			if (i == index) break;
			++i;
		}
		current = current->next;
	}
	return current;
}

int main(int argc, char *argv[]) {
	newEntity(SPRITE);
	newEntity(BACKGROUND);
	newEntity(ROOM);
	newEntity(OBJECT);
    newEntity(ROOM);
	if (getEntity(ROOM, 0)->type == ROOM) printf("ROOM 0 = ROOM");
	freeEntities();
	return 0;
}