import datetime
import json
import os
import threading
from pathlib import Path
from zoneinfo import ZoneInfo


_MOSCOW = ZoneInfo("Europe/Moscow")
_LOG_PATH = Path("schedule_requests.json")
_LOCK = threading.RLock()


def append_schedule_request(request: str) -> None:
    """Append a user-entered schedule search to the persistent JSON history."""
    value = request.strip()
    if not value:
        return

    with _LOCK:
        try:
            with _LOG_PATH.open("r", encoding="utf-8") as file:
                history = json.load(file)
        except FileNotFoundError:
            history = []

        if not isinstance(history, list):
            raise ValueError(f"{_LOG_PATH} must contain a JSON list")

        history.append(
            {
                "time": datetime.datetime.now(_MOSCOW).isoformat(timespec="seconds"),
                "request": value,
            }
        )

        temporary_path = _LOG_PATH.with_suffix(".json.tmp")
        with temporary_path.open("w", encoding="utf-8") as file:
            json.dump(history, file, ensure_ascii=False, indent=2)
            file.write("\n")
        os.replace(temporary_path, _LOG_PATH)