import uuid

from app.api.scenes import _diversify_pages


def _ids(n, origin):
    return [(uuid.uuid4(), origin) for _ in range(n)]


def _mixed(flood_share=0.7, n=300, others=("b", "c", "d")):
    """Jak feed 2026-09-19: jedno zrodlo zalewa, reszta kapie, wszystko w kolejnosci czasu."""
    items, k = [], 0
    for i in range(n):
        if (i % 10) < flood_share * 10:
            items.append((uuid.uuid4(), "flood"))
        else:
            items.append((uuid.uuid4(), others[k % len(others)]))
            k += 1
    return items


def test_flood_is_capped_while_other_sources_exist():
    items = _mixed()
    pages = _diversify_pages(items, 10, 1 / 3)
    origin = dict(items)
    # 90 scen z innych zrodel wystarcza na 15 stron po 6; tyle stron trzyma limit
    for pg in pages[:15]:
        assert len(pg) == 10
        assert sum(origin[i] == "flood" for i in pg) <= 4


def test_nothing_is_lost_and_pages_are_full():
    items = _mixed()
    pages = _diversify_pages(items, 10, 1 / 3)
    assert sorted(i for pg in pages for i in pg) == sorted(i for i, _ in items)
    assert all(len(pg) == 10 for pg in pages[:-1])


def test_two_sources_still_fill_pages():
    items = _ids(40, "a") + _ids(40, "b")
    pages = _diversify_pages(items, 10, 1 / 3)
    assert all(len(pg) == 10 for pg in pages)


def test_order_within_source_is_kept():
    items = _mixed()
    flat = [i for pg in _diversify_pages(items, 10, 1 / 3) for i in pg]
    for src in ("flood", "b", "c", "d"):
        mine = [i for i, o in items if o == src]
        mine_set = set(mine)
        assert [i for i in flat if i in mine_set] == mine