from __future__ import annotations

import json
import os
import time
from pathlib import Path
from typing import Any


def _runtime_dir(base_dir: str | Path | None = None) -> Path:
    root = Path(base_dir or os.environ.get("LIVE_PROJECT_ROOT") or Path(__file__).resolve().parent)
    path = root / "runtime" / "youtube_relay"
    path.mkdir(parents=True, exist_ok=True)
    return path


def heartbeat_path(pm2: str, *, base_dir: str | Path | None = None) -> Path:
    safe = "".join(ch if ch.isalnum() or ch in "._-" else "_" for ch in (pm2 or "youtube").strip()) or "youtube"
    return _runtime_dir(base_dir) / f"{safe}.json"


def write_relay_heartbeat(
    pm2: str,
    payload: dict[str, Any],
    *,
    base_dir: str | Path | None = None,
) -> None:
    data = dict(payload)
    data["updated_at"] = time.time()
    data["pm2"] = (pm2 or "").strip() or "youtube"
    path = heartbeat_path(data["pm2"], base_dir=base_dir)
    tmp = path.with_suffix(".json.tmp")
    try:
        tmp.write_text(json.dumps(data, ensure_ascii=False, separators=(",", ":")), encoding="utf-8")
        tmp.replace(path)
    except OSError:
        pass


def read_relay_heartbeat(pm2: str, *, base_dir: str | Path | None = None) -> dict[str, Any]:
    path = heartbeat_path(pm2, base_dir=base_dir)
    if not path.is_file():
        return {}
    try:
        return json.loads(path.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError):
        return {}


def clear_relay_heartbeat(pm2: str, *, base_dir: str | Path | None = None) -> None:
    path = heartbeat_path(pm2, base_dir=base_dir)
    try:
        if path.is_file():
            path.unlink()
    except OSError:
        pass