#!/usr/bin/env python3
"""Shared deterministic helpers for the parley-bidding skill."""

from __future__ import annotations

import hashlib
import json
import os
import tempfile
from datetime import datetime, timezone
from pathlib import Path
from typing import Any


def now_utc() -> str:
    return datetime.now(timezone.utc).replace(microsecond=0).isoformat()


def load_json(path: Path | str) -> dict[str, Any]:
    target = Path(path)
    with target.open("r", encoding="utf-8") as handle:
        value = json.load(handle)
    if not isinstance(value, dict):
        raise ValueError(f"{target}: expected a JSON object")
    return value


def write_json_atomic(path: Path | str, value: Any) -> None:
    target = Path(path)
    target.parent.mkdir(parents=True, exist_ok=True)
    payload = json.dumps(value, ensure_ascii=False, indent=2, sort_keys=True) + "\n"
    descriptor, temporary_name = tempfile.mkstemp(
        prefix=f".{target.name}.", suffix=".tmp", dir=target.parent
    )
    try:
        with os.fdopen(descriptor, "w", encoding="utf-8") as handle:
            handle.write(payload)
            handle.flush()
            os.fsync(handle.fileno())
        os.replace(temporary_name, target)
    except Exception:
        try:
            os.unlink(temporary_name)
        except FileNotFoundError:
            pass
        raise


def sha256_file(path: Path | str) -> str:
    digest = hashlib.sha256()
    with Path(path).open("rb") as handle:
        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
            digest.update(chunk)
    return digest.hexdigest()


def canonical_sha256(value: Any) -> str:
    payload = json.dumps(
        value, ensure_ascii=False, sort_keys=True, separators=(",", ":")
    ).encode("utf-8")
    return hashlib.sha256(payload).hexdigest()


def relative_posix(path: Path, root: Path) -> str:
    return path.relative_to(root).as_posix()