"""Общее состояние сессий, блокировка, лимиты и TTL."""

import threading


TTL_SECONDS = 30 * 60
MAX_FILE_BYTES = 50 * 1024 * 1024
MAX_SESSION_BYTES = 500 * 1024 * 1024

_sessions: dict = {}
_lock = threading.Lock()


def _start_timer(sid: str) -> threading.Timer:
    """Запустить таймер автоочистки сессии через TTL."""

    def _clean():
        with _lock:
            _sessions.pop(sid, None)

    timer = threading.Timer(TTL_SECONDS, _clean)
    timer.daemon = True
    timer.start()
    return timer


def configure(max_file_bytes: int = None, max_session_bytes: int = None,
              ttl_seconds: int = None):
    """Переопределить лимиты и TTL из конфигурации приложения."""

    global MAX_FILE_BYTES, MAX_SESSION_BYTES, TTL_SECONDS
    if max_file_bytes is not None:
        MAX_FILE_BYTES = max_file_bytes
    if max_session_bytes is not None:
        MAX_SESSION_BYTES = max_session_bytes
    if ttl_seconds is not None:
        TTL_SECONDS = ttl_seconds