from __future__ import annotations

import json
import os
import tempfile
from pathlib import Path
from typing import Any, Dict, Optional

from .log import get_logger

LOGGER = get_logger("argus.agent.state")


def load_node_state(path: str) -> Optional[Dict[str, Any]]:
    """读取本地 node.json，容器重启后沿用之前的 ID。"""
    try:
        with open(path, "r", encoding="utf-8") as handle:
            return json.load(handle)
    except FileNotFoundError:
        return None
    except json.JSONDecodeError as exc:
        LOGGER.warning("node.json is invalid JSON; ignoring", extra={"error": str(exc)})
        return None


def save_node_state(path: str, data: Dict[str, Any]) -> None:
    """原子化写入 node.json，避免并发读取坏数据。"""
    directory = Path(path).parent
    directory.mkdir(parents=True, exist_ok=True)
    with tempfile.NamedTemporaryFile("w", dir=directory, delete=False, encoding="utf-8") as tmp:
        json.dump(data, tmp, separators=(",", ":"))
        tmp.flush()
        os.fsync(tmp.fileno())
        temp_path = tmp.name
    os.replace(temp_path, path)


def clear_node_state(path: str) -> None:
    try:
        os.remove(path)
    except FileNotFoundError:
        return
    except OSError as exc:
        LOGGER.warning("Failed to remove node state file", extra={"error": str(exc), "path": path})