from src.codewars.kata_pagination_helper import PaginationHelper


def test_pagination():
    collection = ["a", "b", "c", "d", "e", "f"]
    helper = PaginationHelper(collection, 4)

    assert helper.page_count() == 2
    assert helper.item_count() == 6
    assert helper.page_item_count(0) == 4
    assert helper.page_item_count(1) == 2
    assert helper.page_item_count(2) == -1
    assert helper.page_index(5) == 1
    assert helper.page_index(2) == 0
    assert helper.page_index(20) == -1
    assert helper.page_index(-10) == -1

    empty = PaginationHelper([], 10)

    assert empty.item_count() == 0
    assert empty.page_count() == 0
    assert empty.page_index(0) == -1
    assert empty.page_index(1) == -1
    assert empty.page_index(-1) == -1
    assert empty.page_item_count(0) == -1
    assert empty.page_item_count(1) == -1
    assert empty.page_item_count(-1) == -1