"""Support-ticket helpers shared across user and admin routes."""

from __future__ import annotations

import hashlib
import json
import re

_SPACE_RE = re.compile(r"\s+")


def _normalize_fingerprint_part(value: str | None) -> str:
    return _SPACE_RE.sub(" ", (value or "").strip().lower())


def support_ticket_fingerprint(
    *,
    category: str,
    subject: str,
    body: str,
    source_path: str,
) -> str:
    """Return a stable hash for exact-ish duplicate support-ticket hints."""
    payload = {
        "body": _normalize_fingerprint_part(body),
        "category": _normalize_fingerprint_part(category),
        "source_path": _normalize_fingerprint_part(source_path),
        "subject": _normalize_fingerprint_part(subject),
    }
    encoded = json.dumps(payload, ensure_ascii=False, sort_keys=True, separators=(",", ":")).encode("utf-8")
    return hashlib.sha256(encoded).hexdigest()