"""Utilities shared by fail2ban-related services."""

from __future__ import annotations

import json
from datetime import UTC, datetime


def ts_to_iso(unix_ts: int) -> str:
    """Convert a Unix timestamp to an ISO 8601 UTC string."""
    return datetime.fromtimestamp(unix_ts, tz=UTC).isoformat()


def parse_data_json(raw: object) -> tuple[list[str], int]:
    """Extract matches and failure count from the fail2ban bans.data value."""
    if raw is None:
        return [], 0

    obj: dict[str, object] = {}
    if isinstance(raw, str):
        try:
            parsed = json.loads(raw)
            if isinstance(parsed, dict):
                obj = parsed
        except json.JSONDecodeError:
            return [], 0
    elif isinstance(raw, dict):
        obj = raw

    raw_matches = obj.get("matches")
    matches = [str(m) for m in raw_matches] if isinstance(raw_matches, list) else []

    raw_failures = obj.get("failures")
    failures = 0
    if isinstance(raw_failures, (int, float, str)):
        try:
            failures = int(raw_failures)
        except (ValueError, TypeError):
            failures = 0

    return matches, failures