"""Трекер созданных инстансов — только те что породило приложение."""
import json
import os
import threading

_LOCK = threading.Lock()
_PATH = os.path.join(os.path.dirname(__file__), "..", "instances.json")


def _load():
    try:
        with open(_PATH) as f:
            return json.load(f)
    except (FileNotFoundError, json.JSONDecodeError):
        return {}


def _save(data):
    with open(_PATH, "w") as f:
        json.dump(data, f, indent=2)


def add(instance_uid, svc_id, display_name):
    with _LOCK:
        data = _load()
        data[instance_uid] = {
            "svcId": svc_id,
            "displayName": display_name,
            "instanceUid": instance_uid,
        }
        _save(data)


def remove(instance_uid):
    with _LOCK:
        data = _load()
        data.pop(instance_uid, None)
        _save(data)


def list_all():
    with _LOCK:
        return list(_load().values())