"""Dataset manifests, hashes and code versions (no raw data, no secrets)."""
from __future__ import annotations

import hashlib
import json
import os
import subprocess
import time
from pathlib import Path
from typing import Any, Iterable


def sha256_file(path: str | os.PathLike, chunk: int = 1 << 20) -> str:
    h = hashlib.sha256()
    with open(path, "rb") as fh:
        for block in iter(lambda: fh.read(chunk), b""):
            h.update(block)
    return h.hexdigest()


def sha256_text(text: str) -> str:
    return hashlib.sha256(text.encode()).hexdigest()


def git_sha(repo: str | os.PathLike | None = None) -> str:
    try:
        return subprocess.check_output(["git", "rev-parse", "--short=12", "HEAD"], cwd=repo, text=True,
                                       stderr=subprocess.DEVNULL).strip()
    except Exception:
        return "nogit"


def now_iso() -> str:
    return time.strftime("%Y-%m-%dT%H:%M:%S%z")


def append_jsonl(path: str | os.PathLike, record: dict[str, Any]) -> None:
    p = Path(path)
    p.parent.mkdir(parents=True, exist_ok=True)
    with open(p, "a") as fh:
        fh.write(json.dumps(record, default=str, sort_keys=True) + "\n")


def read_jsonl(path: str | os.PathLike) -> list[dict[str, Any]]:
    p = Path(path)
    if not p.exists():
        return []
    with open(p) as fh:
        return [json.loads(line) for line in fh if line.strip()]


def manifest_index(path: str | os.PathLike, keys: Iterable[str]) -> dict[tuple, dict[str, Any]]:
    keys = tuple(keys)
    return {tuple(r.get(k) for k in keys): r for r in read_jsonl(path)}


def write_json(path: str | os.PathLike, obj: Any) -> None:
    p = Path(path)
    p.parent.mkdir(parents=True, exist_ok=True)
    with open(p, "w") as fh:
        json.dump(obj, fh, indent=1, default=str, sort_keys=True)