from datetime import date

from synthgen.periods import book_end, book_start, build_periods


def test_build_periods_simple():
    ps = build_periods("2025-Q1", 4)
    assert [p.key for p in ps] == ["2025-Q1", "2025-Q2", "2025-Q3", "2025-FY"]
    assert [p.label_1c for p in ps] == ["1 квартал 2025 г.", "1 полугодие 2025 г.", "9 месяцев 2025 г.", "2025 г."]
    assert all(p.start == date(2025, 1, 1) for p in ps)
    assert [p.end for p in ps] == [date(2025, 3, 31), date(2025, 6, 30), date(2025, 9, 30), date(2025, 12, 31)]


def test_build_periods_rollover():
    ps = build_periods("2025-Q3", 4)
    assert [p.key for p in ps] == ["2025-Q3", "2025-FY", "2026-Q1", "2026-Q2"]
    assert ps[2].start == date(2026, 1, 1) and ps[2].year == 2026 and ps[2].quarter == 1
    assert book_end(ps) == date(2026, 6, 30)


def test_book_start():
    assert book_start(build_periods("2025-Q1", 4)) == date(2024, 12, 31)
    assert book_start(build_periods("2025-Q3", 4)) == date(2024, 12, 31)