"""Slot computation (§8.1): working hours − busy, quantization, notice, horizon."""

from datetime import date, datetime
from zoneinfo import ZoneInfo

from gogo.scheduling.slots import compute_slots, subtract_busy

TZ = ZoneInfo("Europe/Sarajevo")


def dt(day: int, h: int, m: int = 0) -> datetime:
    return datetime(2026, 7, day, h, m, tzinfo=TZ)


WH = {
    "mon": [["09:00", "13:00"], ["14:00", "18:00"]],  # lunch break
    "tue": [["09:00", "18:00"]],
    "wed": [["09:00", "18:00"]],
    "thu": [["09:00", "18:00"]],
    "fri": [["09:00", "18:00"]],
    "sat": [["09:00", "14:00"]],
    "sun": [],
}

# Mon 2026-07-13 .. Sun 2026-07-19
NOW = dt(13, 8, 0)  # Monday 08:00


def test_subtract_busy_splits_interval():
    free = subtract_busy((dt(13, 9), dt(13, 13)), [(dt(13, 10), dt(13, 11))])
    assert free == [(dt(13, 9), dt(13, 10)), (dt(13, 11), dt(13, 13))]


def test_subtract_busy_no_overlap():
    free = subtract_busy((dt(13, 9), dt(13, 13)), [(dt(13, 14), dt(13, 15))])
    assert free == [(dt(13, 9), dt(13, 13))]


def test_slots_respect_break_and_duration():
    slots = compute_slots(
        working_hours=WH, busy=[], duration_min=60, date_from=date(2026, 7, 13),
        date_to=date(2026, 7, 13), tz=TZ, now=NOW, min_notice_hours=0, max_slots=50,
    )
    starts = [s.start for s in slots]
    # no slot may span the 13:00-14:00 break
    assert dt(13, 13) not in starts
    for s in slots:
        assert not (s.start < dt(13, 14) and s.end > dt(13, 13))
    assert slots[0].start == dt(13, 9)
    assert all((s.end - s.start).total_seconds() == 3600 for s in slots)


def test_min_notice_pushes_first_slot():
    slots = compute_slots(
        working_hours=WH, busy=[], duration_min=30, date_from=date(2026, 7, 13),
        date_to=date(2026, 7, 13), tz=TZ, now=dt(13, 9, 5), min_notice_hours=2,
    )
    assert slots[0].start >= dt(13, 11, 5)


def test_busy_blocks_remove_slots():
    slots = compute_slots(
        working_hours=WH, busy=[(dt(14, 9), dt(14, 12))], duration_min=60,
        date_from=date(2026, 7, 14), date_to=date(2026, 7, 14), tz=TZ, now=NOW,
        min_notice_hours=0,
    )
    assert slots[0].start == dt(14, 12)


def test_sunday_closed():
    slots = compute_slots(
        working_hours=WH, busy=[], duration_min=30, date_from=date(2026, 7, 19),
        date_to=date(2026, 7, 19), tz=TZ, now=NOW, min_notice_hours=0,
    )
    assert slots == []


def test_max_days_ahead_horizon():
    slots = compute_slots(
        working_hours=WH, busy=[], duration_min=30, date_from=date(2026, 7, 13),
        date_to=date(2026, 8, 30), tz=TZ, now=NOW, min_notice_hours=0,
        max_days_ahead=2, max_slots=1000,
    )
    assert max(s.start for s in slots).date() <= date(2026, 7, 15)


def test_buffer_extends_step():
    slots = compute_slots(
        working_hours=WH, busy=[], duration_min=45, buffer_min=15,
        date_from=date(2026, 7, 14), date_to=date(2026, 7, 14), tz=TZ, now=NOW,
        min_notice_hours=0,
    )
    # steps of 60 (45+15), but slot end = start + 45
    assert slots[0].start == dt(14, 9)
    assert slots[0].end == dt(14, 9, 45)
    assert slots[1].start == dt(14, 10)