"""Normalize Personendatei 2.xlsx into canonical-persons-tree.json."""
import argparse
import datetime
import json
import re
import sys
from pathlib import Path

import config
import dates
from persons import _strip_accents


def _parse_year(raw: str | None) -> int | None:
    """Extract a birth/death year from an Excel cell string.

    Handles four cases:
    1. ISO string (openpyxl date-formatted cell) → parse_date()
    2. Numeric string that is an Excel serial (1-80000) → timedelta conversion
    3. Any other string → parse_date()
    4. Unresolvable → None
    """
    if raw is None:
        return None
    s = str(raw).strip()
    if not s:
        return None

    # Try parse_date first (handles ISO, DD.MM.YYYY, year-only, month+year, etc.)
    result = dates.parse_date(s)
    if result.iso:
        year = int(result.iso[:4])
        # Reject years outside 1700-2100 (same guard as expand_year())
        if 1700 <= year <= 2100:
            return year

    # If it's a pure integer string, try Excel serial conversion.
    # parse_date() may parse large serials like "7568" as year 7568 or other edge cases.
    if re.fullmatch(r"\d+", s):
        n = int(s)
        if 1 <= n <= 80_000:
            d = datetime.date(1899, 12, 30) + datetime.timedelta(days=n)
            if 1700 <= d.year <= 2100:
                return d.year

    return None