from __future__ import annotations

from dataclasses import asdict, is_dataclass
from datetime import datetime, timezone
import json
from pathlib import Path
import platform
import subprocess
import sys
from typing import Any


def write_run_metadata(
    output_dir: str | Path,
    *,
    run_type: str,
    args: dict[str, Any],
    config: Any,
    extra: dict[str, Any] | None = None,
) -> Path:
    output = Path(output_dir)
    output.mkdir(parents=True, exist_ok=True)
    payload = {
        "run_type": run_type,
        "created_at_utc": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
        "command": " ".join(sys.argv),
        "python": sys.executable,
        "platform": platform.platform(),
        "git_commit": _git(["rev-parse", "HEAD"]),
        "git_status_short": _git(["status", "--short"]),
        "args": _jsonable(args),
        "config": _jsonable(asdict(config) if is_dataclass(config) else config),
        "extra": _jsonable(extra or {}),
    }
    path = output / "run_metadata.json"
    path.write_text(json.dumps(payload, indent=2), encoding="utf-8")
    return path


def _git(args: list[str]) -> str | None:
    try:
        result = subprocess.run(
            ["git", *args],
            check=True,
            capture_output=True,
            text=True,
            timeout=10,
        )
    except Exception:
        return None
    return result.stdout.strip()


def _jsonable(value: Any) -> Any:
    if isinstance(value, Path):
        return str(value)
    if isinstance(value, dict):
        return {str(key): _jsonable(item) for key, item in value.items()}
    if isinstance(value, (list, tuple)):
        return [_jsonable(item) for item in value]
    return value