import sys
from pathlib import Path
sys.path.insert(0, str(Path(__file__).parent.parent))

import persons_tree


def test_parse_year_iso_string():
    assert persons_tree._parse_year("1920-09-20") == 1920


def test_parse_year_excel_serial_birth():
    # 7568 days from 1899-12-30 = 1920-09-19 or -20 depending on leap counting
    assert persons_tree._parse_year("7568") == 1920


def test_parse_year_excel_serial_death():
    # 36222 days from 1899-12-30 ≈ 1999
    assert persons_tree._parse_year("36222") == 1999


def test_parse_year_excel_serial_small():
    # 177 days from 1899-12-30 = 1900-06-25
    assert persons_tree._parse_year("177") == 1900


def test_parse_year_german_date_string():
    assert persons_tree._parse_year("30.8.1862") == 1862


def test_parse_year_year_only():
    assert persons_tree._parse_year("1930") == 1930


def test_parse_year_free_text():
    assert persons_tree._parse_year("August 1941") == 1941


def test_parse_year_none():
    assert persons_tree._parse_year(None) is None


def test_parse_year_empty():
    assert persons_tree._parse_year("") is None


def test_parse_year_unresolvable_truncated():
    # "2.9.196" has no valid 4-digit year — returns None
    assert persons_tree._parse_year("2.9.196") is None


def test_parse_year_typo_year():
    # "4.3.1023" — year 1023 outside 1500-2100 guard — returns None
    assert persons_tree._parse_year("4.3.1023") is None