"""Shared logging helpers.

Per CLAUDE.md:
- Always log config + git commit ID before running anything.
- Use timestamps in folder names.
- Save more rather than less.
"""

from __future__ import annotations

import json
import os
import platform
import subprocess
import sys
from datetime import datetime, timezone
from pathlib import Path
from typing import Any


def _git_commit(repo_dir: Path) -> str:
    try:
        out = subprocess.run(
            ["git", "-C", str(repo_dir), "rev-parse", "HEAD"],
            capture_output=True,
            text=True,
            check=True,
        )
        sha = out.stdout.strip()
    except Exception as e:  # noqa: BLE001
        sha = f"<no-git: {e!s}>"
    try:
        dirty = subprocess.run(
            ["git", "-C", str(repo_dir), "status", "--porcelain"],
            capture_output=True,
            text=True,
            check=True,
        )
        if dirty.stdout.strip():
            sha = f"{sha}-dirty"
    except Exception:  # noqa: BLE001
        pass
    return sha


def make_run_dir(name: str, config: dict[str, Any], root: Path | None = None) -> Path:
    """Create logs/<ts>_<name>/ with git_commit.txt, config.json, env.json.

    Returns the directory.
    """
    repo = Path(__file__).resolve().parent.parent
    root = root or (repo / "logs")
    ts = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H%M%SZ")
    run_dir = root / f"{ts}_{name}"
    run_dir.mkdir(parents=True, exist_ok=True)
    (run_dir / "git_commit.txt").write_text(_git_commit(repo) + "\n")
    (run_dir / "config.json").write_text(json.dumps(config, indent=2, default=str))
    (run_dir / "env.json").write_text(
        json.dumps(
            {
                "python": sys.version,
                "platform": platform.platform(),
                "argv": sys.argv,
                "cwd": os.getcwd(),
                "started_utc": ts,
            },
            indent=2,
        )
    )
    return run_dir