from types import SimpleNamespace

from enhanced_drf_jsonapi.pagination import NgxJsonApiPageNumberPagination


def make_page(*, number, pages, count, per_page, next_page=None, previous_page=None):
    return SimpleNamespace(
        number=number,
        paginator=SimpleNamespace(num_pages=pages, count=count, per_page=per_page),
        has_next=lambda: next_page is not None,
        has_previous=lambda: previous_page is not None,
        next_page_number=lambda: next_page,
        previous_page_number=lambda: previous_page,
    )


def test_pagination_response_preserves_ngx_jsonapi_contract():
    pagination = NgxJsonApiPageNumberPagination()
    pagination.page = make_page(
        number=2,
        pages=4,
        count=37,
        per_page=10,
        next_page=3,
        previous_page=1,
    )
    pagination.build_link = lambda page: None if page is None else f"/items?page={page}"

    response = pagination.get_paginated_response([{"id": "one"}])

    assert response.data == {
        "results": [{"id": "one"}],
        "meta": {
            "page": 2,
            "pages": 4,
            "total_resources": 37,
            "resources_per_page": 10,
        },
        "links": {
            "first": "/items?page=1",
            "last": "/items?page=4",
            "next": "/items?page=3",
            "prev": "/items?page=1",
        },
    }


def test_pagination_uses_null_links_at_the_boundaries():
    pagination = NgxJsonApiPageNumberPagination()
    pagination.page = make_page(number=1, pages=1, count=0, per_page=25)
    pagination.build_link = lambda page: None if page is None else f"/items?page={page}"

    response = pagination.get_paginated_response([])

    assert response.data["links"]["next"] is None
    assert response.data["links"]["prev"] is None