class ECS:
    def __init__(self):
        self.entities = {}
        self.facts = {}
        self.id_counter = 0

    def entity(self):
        self.id_counter += 1
        return self.id_counter

    def set(self, entity_id, obj):
        name = obj.__class__.__qualname__
        target = self.entities.get(name, {})
        target[entity_id] = obj
        self.entities[name] = target

    def query(self, cls):
        return self.entities[cls.__qualname__].items()


class Systems:
    def __init__(self, ecs):
        self.ecs = ecs

    def play_sounds(self):
        for eid, entity in ecs.query(Sound):
            print("TALKING: ", entity.text)

    def combat(self):
        for eid, entity in ecs.query(Combat):
            print("FIGHT: ", entity.hp)

    def movement(self):
        for eid, entity in ecs.query(Position):
            print("MOVE: ", entity.x, entity.y)

class Combat:
    def __init__(self, hp):
        self.hp = hp

class Sound:
    def __init__(self, text):
        self.text = text

class Position:
    def __init__(self, x, y):
        self.x = x
        self.y = y


ecs = ECS()
systems = Systems(ecs)

troll = ecs.entity()
ecs.set(troll, Combat(100))
ecs.set(troll, Sound("ROAR!"))
ecs.set(troll, Position(1, 2))

systems.play_sounds()
systems.combat()
systems.movement()