"""Tests for `_paginate` and `_page_nav`."""
from handlers import _paginate, _page_nav, PER_PAGE


def test_paginate_default_is_one():
    assert _paginate({}) == 1


def test_paginate_reads_query_string():
    assert _paginate({"p": ["3"]}) == 3


def test_paginate_clamps_to_one():
    assert _paginate({"p": ["0"]}) == 1
    assert _paginate({"p": ["-5"]}) == 1


def test_paginate_handles_bad_input():
    assert _paginate({"p": ["not-a-number"]}) == 1
    assert _paginate({"p": []}) == 1


def test_paginate_custom_key():
    assert _paginate({"batch": ["7"]}, key="batch") == 7


def test_page_nav_empty_when_single_page():
    assert _page_nav(1, PER_PAGE, "/?q=foo") == ""
    assert _page_nav(1, 0, "/?q=foo") == ""


def test_page_nav_shows_next_on_first_page():
    out = _page_nav(1, PER_PAGE * 3, "/?q=foo")
    assert "next" in out
    assert "prev" not in out
    assert "page 1 of 3" in out


def test_page_nav_shows_both_in_middle():
    out = _page_nav(2, PER_PAGE * 3, "/?q=foo")
    assert "next" in out
    assert "prev" in out


def test_page_nav_shows_prev_on_last_page():
    out = _page_nav(3, PER_PAGE * 3, "/?q=foo")
    assert "next" not in out
    assert "prev" in out
    assert "page 3 of 3" in out


def test_page_nav_handles_query_string_separator():
    # when base_url already has ?, pagination links must use &
    out = _page_nav(1, PER_PAGE * 2, "/?q=foo")
    assert "&p=2" in out
    # when base_url has no ?, pagination links use ?
    out = _page_nav(1, PER_PAGE * 2, "/pages")
    assert "?p=2" in out