"""Unit tests for schedule due-date logic (no DB)."""

from __future__ import annotations

from datetime import date, datetime, timezone

from services.schedule import (
    format_schedule_label,
    initial_due_at,
    is_due_on_date,
    next_due_after_completion,
    weekday_bit,
    weekday_mask_for_date,
)


def test_interval_daily_label():
    label = format_schedule_label({"schedule_kind": "interval", "interval_days": 1, "weekday_mask": 0})
    assert label == "Täglich"


def test_interval_seven_is_not_weekly():
    label = format_schedule_label({"schedule_kind": "interval", "interval_days": 7, "weekday_mask": 0})
    assert label == "Alle 7 Tage"


def test_weekday_label_lists_days():
    label = format_schedule_label(
        {"schedule_kind": "weekdays", "weekday_mask": weekday_bit(0) | weekday_bit(2) | weekday_bit(6)}
    )
    assert label == "Mo, Mi, So"
    assert "Wöchentlich" not in label


def test_weekday_mask_next_due_after_friday():
    schedule = {
        "schedule_kind": "weekdays",
        "weekday_mask": weekday_bit(0) | weekday_bit(2) | weekday_bit(4),
        "pause_until": None,
    }
    friday = datetime(2026, 8, 7, 12, 0, tzinfo=timezone.utc)
    nxt = next_due_after_completion(schedule=schedule, completed_at=friday)
    assert nxt.date() == date(2026, 8, 10)


def test_is_due_on_date_hides_future_weekday():
    schedule = {
        "schedule_kind": "weekdays",
        "weekday_mask": weekday_bit(1),
        "pause_until": None,
    }
    next_due = datetime(2026, 8, 18, tzinfo=timezone.utc)
    assert is_due_on_date(schedule=schedule, next_due_at=next_due, on_date=date(2026, 8, 17)) is False
    assert is_due_on_date(schedule=schedule, next_due_at=next_due, on_date=date(2026, 8, 18)) is True


def test_is_due_on_date_keeps_overdue_weekday():
    schedule = {
        "schedule_kind": "weekdays",
        "weekday_mask": weekday_bit(0),
        "pause_until": None,
    }
    missed_monday = datetime(2026, 8, 17, tzinfo=timezone.utc)
    assert (
        is_due_on_date(
            schedule=schedule, next_due_at=missed_monday, on_date=date(2026, 8, 18)
        )
        is True
    )


def test_weekday_mask_for_monday():
    assert weekday_mask_for_date(date(2026, 8, 17)) == weekday_bit(0)


def test_pause_until_pushes_initial_due():
    schedule = {
        "schedule_kind": "interval",
        "interval_days": 1,
        "weekday_mask": 0,
        "pause_until": "2026-08-10",
    }
    now = datetime(2026, 8, 4, 9, 0, tzinfo=timezone.utc)
    due = initial_due_at(schedule=schedule, now=now)
    assert due.date() == date(2026, 8, 11)