from .dates_add_days import parse_iso_date
from .dates_day_of_week import day_name
from .dates_days_between import days_between
from .todo_due_status import due_status
from .todo_item import Todo

MONTHS = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]


def due_label(todo: Todo, today: str) -> str:
    """The short English label for a todo's due date, built on due_status."""
    status = due_status(todo, today)
    if status == "done" or status == "none":
        return ""
    due = todo.due
    assert due is not None
    if status == "overdue":
        late = days_between(due, today)
        return "1 day overdue" if late == 1 else "%d days overdue" % late
    if status == "today":
        return "Due today"
    if status == "tomorrow":
        return "Due tomorrow"
    d = parse_iso_date(due)
    label = "Due %s %d %s" % (day_name(due)[0:3], d.day, MONTHS[d.month - 1])
    # The year only when it differs, so next January never reads as this one.
    return label if d.year == parse_iso_date(today).year else "%s %d" % (label, d.year)