from __future__ import annotations

from leanbench.document import Document, Page, PageWindow, normalise_page_text


def test_pages_are_numbered_from_one(two_page_book: Document) -> None:
    assert len(two_page_book) == 2
    assert [p.number for p in two_page_book.pages] == [1, 2]
    assert two_page_book.page(1).text.startswith("Chapter 1")


def test_window_locate_maps_back_to_the_right_page() -> None:
    window = PageWindow([Page(7, "abcdef"), Page(8, "ghij")])
    assert window.text == "abcdef\nghij"
    assert window.locate(0) == (7, 0)
    assert window.locate(5) == (7, 5)
    assert window.locate(6) == (7, 6)      # end of page 7
    assert window.locate(7) == (8, 0)      # first char of page 8
    assert window.locate(10) == (8, 3)
    assert window.locate(999) == (8, 4)    # clamped


def test_window_globalise_is_the_inverse() -> None:
    window = PageWindow([Page(1, "hello"), Page(2, "world")])
    for page, offset in [(1, 0), (1, 4), (2, 0), (2, 4)]:
        assert window.locate(window.globalise(page, offset)) == (page, offset)


def test_document_slice_reconstructs_a_cross_page_span(two_page_book: Document) -> None:
    page_one = two_page_book.page(1).text
    start = page_one.index("Theorem 1.6.3")
    end = two_page_book.page(2).text.index("has a greatest")
    text = two_page_book.slice(1, start, 2, end)
    assert text.startswith("Theorem 1.6.3")
    assert text.rstrip().endswith("divisors of a and b")


def test_normalisation_is_stable_and_gentle() -> None:
    text = "first line   \nsecond"
    assert normalise_page_text(text) == "first line\nsecond"
    assert normalise_page_text(normalise_page_text(text)) == normalise_page_text(text)


def test_page_checksum_changes_with_content() -> None:
    assert Page(1, "a").checksum != Page(1, "b").checksum
    assert Page(1, "a").checksum == Page(9, "a").checksum