import re
import json
from dataclasses import dataclass, field, asdict
from datetime import datetime
from typing import Optional

# ── Preprocessing ────────────────────────────────────────────────────────────

_TS_RE = re.compile(r'^\[\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\]\s*')
_CHILD_RE = re.compile(r'^\[(\d+)\]\s*')


def strip_ts(line: str) -> str:
    """Remove optional `ts`-injected timestamp prefix from a log line."""
    return _TS_RE.sub('', line.strip())


def classify_line(line: str) -> tuple[str, Optional[int], str]:
    """
    Return (kind, port, content) where kind is 'router' or 'child'.
    `line` must already have the ts prefix stripped.
    """
    m = _CHILD_RE.match(line)
    if m:
        return ('child', int(m.group(1)), line[m.end():])
    return ('router', None, line)